1 /*
  2     Copyright 2008-2021
  3         Matthias Ehmann,
  4         Michael Gerhaeuser,
  5         Carsten Miller,
  6         Bianca Valentin,
  7         Alfred Wassermann,
  8         Peter Wilfahrt
  9 
 10     This file is part of JSXGraph.
 11 
 12     JSXGraph is free software dual licensed under the GNU LGPL or MIT License.
 13 
 14     You can redistribute it and/or modify it under the terms of the
 15 
 16       * GNU Lesser General Public License as published by
 17         the Free Software Foundation, either version 3 of the License, or
 18         (at your option) any later version
 19       OR
 20       * MIT License: https://github.com/jsxgraph/jsxgraph/blob/master/LICENSE.MIT
 21 
 22     JSXGraph is distributed in the hope that it will be useful,
 23     but WITHOUT ANY WARRANTY; without even the implied warranty of
 24     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 25     GNU Lesser General Public License for more details.
 26 
 27     You should have received a copy of the GNU Lesser General Public License and
 28     the MIT License along with JSXGraph. If not, see <http://www.gnu.org/licenses/>
 29     and <http://opensource.org/licenses/MIT/>.
 30  */
 31 
 32 
 33 /*global JXG:true, define: true*/
 34 /*jslint nomen: true, plusplus: true*/
 35 
 36 /* depends:
 37  jxg
 38  base/constants
 39  math/math
 40  utils/color
 41  utils/type
 42  */
 43 
 44 define([
 45     'jxg', 'base/constants', 'math/math', 'utils/color', 'utils/type'
 46 ], function (JXG, Const, Mat, Color, Type) {
 47 
 48     "use strict";
 49 
 50     /**
 51      * Options Namespace
 52      * @description These are the default options of the board and of all geometry elements.
 53      * @namespace
 54      * @name JXG.Options
 55      */
 56     JXG.Options = {
 57         jc: {
 58             enabled: true,
 59             compile: true
 60         },
 61 
 62         /*
 63          * Options that are used directly within the board class
 64          */
 65         board: {
 66             /**#@+
 67              * @visprop
 68              */
 69 
 70             //updateType: 'hierarchical', // 'all'
 71 
 72             /**
 73              * Bounding box of the visible area in user coordinates.
 74              * It is an array consisting of four values:
 75              * [x<sub>1</sub>, y<sub>1</sub>, x<sub>2</sub>, y<sub>2</sub>]
 76              *
 77              * The canvas will be spanned from the upper left corner (<sub>1</sub>, y<sub>1</sub>)
 78              * to the lower right corner (x<sub>2</sub>, y<sub>2</sub>).
 79              *
 80              * @name JXG.Board#boundingbox
 81              * @type Array
 82              * @default [-5, 5, 5, -5]
 83              * @example
 84              * var board = JXG.JSXGraph.initBoard('jxgbox', {
 85              *         boundingbox: [-5, 5, 5, -5],
 86              *         axis: true
 87              *     });
 88              */
 89             boundingBox: [-5, 5, 5, -5],
 90 
 91             /**
 92              * Maximal bounding box of the visible area in user coordinates.
 93              * It is an array consisting of four values:
 94              * [x<sub>1</sub>, y<sub>1</sub>, x<sub>2</sub>, y<sub>2</sub>]
 95              *
 96              * The bounding box of the canvas must be inside of this maximal
 97              * boundings box.
 98              * @name JXG.Board#maxboundingbox
 99              * @type Array
100              * @see JXG.Board#boundingbox
101              * @default [-Infinity, Infinity, Infinity, -Infinity]
102              *
103              * @example
104              * var board = JXG.JSXGraph.initBoard('jxgbox', {
105              *         boundingbox: [-5, 5, 5, -5],
106              *         maxboundingbox: [-8, 8, 8, -8],
107              *         pan: {enabled: true},
108              *         axis: true
109              *     });
110              *
111              * </pre><div id="JXG065e2750-217c-48ed-a52b-7d7df6de7055" class="jxgbox" style="width: 300px; height: 300px;"></div>
112              * <script type="text/javascript">
113              *     (function() {
114              *         var board = JXG.JSXGraph.initBoard('JXG065e2750-217c-48ed-a52b-7d7df6de7055', {
115              *             showcopyright: false, shownavigation: false,
116              *             boundingbox: [-5,5,5,-5],
117              *             maxboundingbox: [-8,8,8,-8],
118              *             pan: {enabled: true},
119              *             axis:true
120              *         });
121              *
122              *     })();
123              *
124              * </script><pre>
125              *
126              */
127             maxBoundingBox: [-Infinity, Infinity, Infinity, -Infinity],
128 
129             /**
130              * Additional zoom factor multiplied to {@link JXG.Board#zoomX} and {@link JXG.Board#zoomY}.
131              *
132              * @name JXG.Board#zoomFactor
133              * @type Number
134              * @default 1.0
135              */
136             zoomFactor: 1,
137 
138             /**
139              * Zoom factor in horizontal direction.
140              *
141              * @name JXG.Board#zoomX
142              * @see JXG.Board#zoomY
143              * @type Number
144              * @default 1.0
145              */
146             zoomX: 1,
147 
148             /**
149              * Zoom factor in vertical direction.
150              *
151              * @name JXG.Board#zoomY
152              * @see JXG.Board#zoomX
153              * @type Number
154              * @default 1.0
155              */
156             zoomY: 1,
157 
158             /**
159              * Title string for the board.
160              * Primarily used in an invisible text element which is adressed by
161              * the attribute 'aria-labelledby' from the JSXGraph container.
162              * JSXGraph creates a new div-element with id "{containerid}_ARIAlabel"
163              * containing this string.
164              *
165              * @name JXG.Board#title
166              * @see JXG.Board#description
167              * @type String
168              * @default ''
169              *
170              */
171             title: '',
172 
173             /**
174              * Description string for the board.
175              * Primarily used in an invisible text element which is adressed by
176              * the attribute 'aria-describedby' from the JSXGraph container.
177              * JSXGraph creates a new div-element with id "{containerid}_ARIAdescription"
178              * containing this string.
179              *
180              * @name JXG.Board#description
181              * @see JXG.Board#title
182              * @type String
183              * @default ''
184              *
185              */
186             description: '',
187 
188             /**
189              * Show copyright string in canvas.
190              *
191              * @name JXG.Board#showCopyright
192              * @type Boolean
193              * @default true
194              */
195             showCopyright: true,
196 
197             /**
198              * Show default axis.
199              * If shown, the horizontal axis can be accessed via JXG.Board.defaultAxes.x, the
200              * vertical axis can be accessed via JXG.Board.defaultAxes.y.
201              * Both axes have a sub-element "defaultTicks".
202              *
203              * Value can be Boolean or an object containing axis attributes.
204              *
205              * @name JXG.Board#axis
206              * @type Boolean
207              * @default false
208              */
209             axis: false,
210 
211             /**
212              * Attributes for the default axes in case of the attribute
213              * axis:true in {@link JXG.JSXGraph#initBoard}.
214              *
215              * @name JXG.Board#defaultAxes
216              * @type Object
217              * @default {x: {name:'x'}, y: {name: 'y'}}
218              *
219              */
220             defaultAxes: {
221                 x: {
222                     name: 'x',
223                     ticks: {
224                         label: {
225                             visible: 'inherit',
226                             anchorX: 'middle',
227                             anchorY: 'top',
228                             fontSize: 12,
229                             offset: [0, -3]
230                         },
231                         drawZero: false,
232                         visible: 'inherit'
233                     }
234                 },
235                 y: {
236                     name: 'y',
237                     ticks: {
238                         label: {
239                             visible: 'inherit',
240                             anchorX: 'right',
241                             anchorY: 'middle',
242                             fontSize: 12,
243                             offset: [-6, 0]
244                         },
245                         tickEndings: [1, 0],
246                         drawZero: false,
247                         visible: 'inherit'
248                     }
249                 }
250             },
251 
252             /**
253              * Display of navigation arrows and zoom buttons in the navigation bar.
254              *
255              * @name JXG.Board#showNavigation
256              * @type Boolean
257              * @default true
258              */
259             showNavigation: true,
260 
261             /**
262              * Display of zoom buttons in the navigation bar. To show zoom buttons, additionally
263              * showNavigation has to be set to true.
264              *
265              * @name JXG.Board#showZoom
266              * @type Boolean
267              * @default true
268              */
269             showZoom: true,
270 
271             /**
272              * Show a button in the navigation bar to force reload of a construction.
273              * Works only with the JessieCode tag.
274              *
275              * @name JXG.Board#showReload
276              * @type Boolean
277              * @default false
278              */
279             showReload: false,
280 
281             /**
282              * Show a button in the navigation bar to enable screenshots.
283              *
284              * @name JXG.Board#showScreenshot
285              * @type Boolean
286              * @default false
287              */
288             showScreenshot: false,
289 
290             /**
291              * Attributes to control the screenshot function.
292              * The following attributes can be set:
293              * <ul>
294              *  <li>scale: scaling factor (default=1.0)
295              *  <li>type: format of the screenshot image. Default: png
296              *  <li>symbol: Unicode symbol which is shown in the navigation bar. Default: '\u2318'
297              *  <li>css: CSS rules to format the div element containing the screen shot image
298              *  <li>cssButton: CSS rules to format the close button of the div element containing the screen shot image
299              * </ul>
300              *
301              * @name JXG.Board#screenshot
302              * @type Object
303              */
304             screenshot: {
305                 scale: 1.0,
306                 type: 'png',
307                 symbol: '\u2318', //'\u22b9', //'\u26f6',
308                 css: 'background-color:#eeeeee; opacity:1.0; border:2px solid black; border-radius:10px; text-align:center',
309                 cssButton:  'padding: 4px 10px; border: solid #356AA0 1px; border-radius: 5px; position: absolute; right: 2ex; top: 2ex; background-color: rgba(255, 255, 255, 0.3);'
310             },
311 
312             /**
313              * Show a button in the navigation bar to start fullscreen mode.
314              *
315              * @name JXG.Board#showFullscreen
316              * @type Boolean
317              * @see JXG.Board#fullscreen
318              * @default false
319              */
320             showFullscreen: false,
321 
322             /**
323              * Attribute(s) to control the fullscreen icon. The attribute "showFullscreen"
324              * controls if the icon is shown.
325              * The following attribute(s) can be set:
326              * <ul>
327              *  <li>symbol (String): Unicode symbol which is shown in the navigation bar. Default: '\u25a1'
328              *  <li>id (String): Id of the HTML element which is brought to full screen or null if the JSXgraph div is taken.
329              * It may be an outer div element, e.g. if the old aspect ratio trick is used. Default: null, i.e. use the JSXGraph div.
330              * </ul>
331              *
332              * @example
333              * var board = JXG.JSXGraph.initBoard('35bec5a2-fd4d-11e8-ab14-901b0e1b8723',
334              *             {boundingbox: [-8, 8, 8,-8], axis: true,
335              *             showcopyright: false,
336              *             showFullscreen: true,
337              *             fullscreen: {
338              *                  symbol: '\u22c7'
339              *              }
340              *             });
341              * var pol = board.create('polygon', [[0, 1], [3,4], [1,-4]], {fillColor: 'yellow'});
342              *
343              * </pre><div id="JXGa35bec5a2-fd4d-11e8-ab14-901b0e1b8723" class="jxgbox" style="width: 300px; height: 300px;"></div>
344              * <script type="text/javascript">
345              *     (function() {
346              *         var board = JXG.JSXGraph.initBoard('JXGa35bec5a2-fd4d-11e8-ab14-901b0e1b8723',
347              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false,
348              *              showFullscreen: true,
349              *              fullscreen: {
350              *                  symbol: '\u22c7'
351              *                  }
352              *             });
353              *     var pol = board.create('polygon', [[0, 1], [3,4], [1,-4]], {fillColor: 'yellow'});
354              *     })();
355              *
356              * </script><pre>
357              *
358              * @name JXG.Board#fullscreen
359              * @see JXG.Board#showFullscreen
360              * @type Object
361              */
362             fullscreen: {
363                 symbol: '\u26f6', // '\u25a1'
364                 id: null
365             },
366 
367             /**
368              * Show a button which allows to clear all traces of a board.
369              *
370              * @name JXG.Board#showClearTraces
371              * @type Boolean
372              * @default false
373              */
374             showClearTraces: false,
375 
376             /**
377              * If set to true the bounding box might be changed such that
378              * the ratio of width and height of the hosting HTML div is equal
379              * to the ratio of width and height of the bounding box.
380              *
381              * This is necessary if circles should look like circles and not
382              * like ellipses. It is recommended to set keepAspectRatio = true
383              * for geometric applets. For function plotting keepAspectRatio = false
384              * might be the better choice.
385              *
386              * @name JXG.Board#keepAspectRatio
387              * @see JXG.Board#boundingbox
388              * @see JXG.Board#setBoundingBox
389              * @type Boolean
390              * @default false
391              */
392             keepAspectRatio: false,
393 
394             /**
395              * If set true and
396              * hasPoint() is true for both an element and it's label,
397              * the element (and not the label) is taken as drag element.
398              *
399              * If set false and hasPoint() is true for both an element and it's label,
400              * the label is taken (if it is on a higher layer than the element)
401              *
402              * @name JXG.Board#ignoreLabels
403              * @type Booelan
404              * @default true
405              */
406             ignoreLabels: true,
407 
408             /**
409              * Maximum number of digits in automatic label generation.
410              * For example, if set to 1 automatic point labels end at "Z".
411              * If set to 2, point labels end at "ZZ".
412              *
413              * @name JXG.Board#maxNameLength
414              * @see JXG.Board#generateName
415              * @type Number
416              * @default 1
417              */
418             maxNameLength: 1,
419 
420             /**
421              * Supply the document object. Defaults to window.document
422              *
423              * @name JXG.Board#document
424              * @type DOM object
425              * @default false (meaning window.document)
426              */
427             document: false,
428 
429             /**
430              * If true the first element of the set JXG.board.objects having hasPoint==true is taken as drag element.
431              *
432              * @name JXG.Board#takeFirst
433              * @type Boolean
434              * @default false
435              */
436             takeFirst: false,
437 
438             /**
439             * If true, when read from a file or string - the size of the div can be changed by the construction text.
440             *
441             * @name JXG.Board#takeSizeFromFile
442             * @type Boolean
443             * @default false
444             */
445             takeSizeFromFile: false,
446 
447             /**
448              * Default rendering engine. Possible values are 'svg', 'canvas', 'vml', 'no', or 'auto'.
449              * If the rendering engine is not available JSXGraph tries to detect a different engine.
450              *
451              * <p>
452              * In case of 'canvas' it is advisable to call 'board.update()' after all elements have been
453              * constructed. This ensures that all elements are drawn with their intended visual appearance.
454              *
455              * @name JXG.Board#renderer
456              * @type String
457              * @default 'auto'
458              */
459             renderer: 'auto',
460 
461             /**
462              * Time (in msec) between two animation steps. Used in
463              * {@link JXG.CoordsElement#moveAlong}, {@link JXG.CoordsElement#moveTo} and
464              * {@link JXG.CoordsElement#visit}.
465              *
466              * @name JXG.Board#animationDelay
467              * @type Number
468              * @default 35
469              * @see JXG.CoordsElement#moveAlong
470              * @see JXG.CoordsElement#moveTo
471              * @see JXG.CoordsElement#visit
472              */
473             animationDelay: 35,
474 
475             /**
476              * Maximum frame rate of the board, i.e. maximum number of updates per second
477              * triggered by move events.
478              *
479              * @name JXG.Board#maxFrameRate
480              * @type Number
481              * @default 40
482              */
483             maxFrameRate: 40,
484 
485             /**
486              * Allow user interaction by registering mouse, pointer and touch events.
487              *
488              * @name JXG.Board#registerEvents
489              * @type Boolean
490              * @default true
491              */
492             registerEvents: true,
493 
494             /**
495              * Change redraw strategy in SVG rendering engine.
496              * <p>
497              * This optimization seems to be <b>obsolete</b> in newer browsers (from 2021 on, at least)
498              * and even slow down the constructions. Therefore, the default is set to 'none' since v1.2.4.
499              * <p>
500              * If set to 'svg', before every redrawing of the JSXGraph construction
501              * the SVG sub-tree of the DOM tree is taken out of the DOM.
502              *
503              * If set to 'all', before every redrawing of the JSXGraph construction the
504              * complete DOM tree is taken out of the DOM.
505              * If set to 'none' the redrawing is done in-place.
506              *
507              * Using 'svg' or 'all' speeds up the update process considerably. The risk
508              * is that if there is an exception, only a white div or window is left.
509              *
510              *
511              * @name JXG.Board#minimizeReflow
512              * @type String
513              * @default 'none'
514              */
515             minimizeReflow: 'none',
516 
517             /**
518              * A number that will be added to the absolute position of the board used in mouse coordinate
519              * calculations in {@link JXG.Board#getCoordsTopLeftCorner}.
520              *
521              * @name JXG.Board#offsetX
522              * @see JXG.Board#offsetY
523              * @type Number
524              * @default 0
525              */
526             offsetX: 0,
527 
528             /**
529              * A number that will be added to the absolute position of the board used in mouse coordinate
530              * calculations in {@link JXG.Board#getCoordsTopLeftCorner}.
531              *
532              * @name JXG.Board#offsetY
533              * @see JXG.Board#offsetX
534              * @type Number
535              * @default 0
536              */
537             offsetY: 0,
538 
539             /**
540              * Control the possibilities for zoom interaction.
541              *
542              * Possible sub-attributes with default values are:
543              * <pre>
544              * zoom: {
545              *   factorX: 1.25,  // horizontal zoom factor (multiplied to {@link JXG.Board#zoomX})
546              *   factorY: 1.25,  // vertical zoom factor (multiplied to {@link JXG.Board#zoomY})
547              *   wheel: true,     // allow zooming by mouse wheel or
548              *   				   // by pinch-to-toom gesture on touch devices
549              *   needShift: true, // mouse wheel zooming needs pressing of the shift key
550              *   min: 0.001        // minimal values of {@link JXG.Board#zoomX} and {@link JXG.Board#zoomY}, limits zoomOut
551              *   max: 1000.0       // maximal values of {@link JXG.Board#zoomX} and {@link JXG.Board#zoomY}, limits zoomIn
552              *
553              *   pinchHorizontal: true // Allow pinch-to-zoom to zoom only horizontal axis
554              *   pinchVertical: true   // Allow pinch-to-zoom to zoom only vertical axis
555              *   pinchSensitivity: 7   // Sensitivity (in degrees) for recognizing horizontal or vertical pinch-to-zoom gestures.
556              * }
557              * </pre>
558              *
559              * Deprecated: zoom.eps which is superseded by zoom.min
560              *
561              * @name JXG.Board#zoom
562              * @type Object
563              * @default
564              */
565             zoom: {
566                 enabled: true,
567                 factorX: 1.25,
568                 factorY: 1.25,
569                 wheel: true,
570                 needShift: true,
571                 min: 0.0001,
572                 max: 10000.0,
573                 pinchHorizontal: true,
574                 pinchVertical: true,
575                 pinchSensitivity: 7
576             },
577 
578             /**
579              * Control the possibilities for panning interaction (i.e. moving the origin).
580              *
581              * Possible sub-attributes with default values are:
582              * <pre>
583              * pan: {
584              *   enabled: true   // Allow panning
585              *   needTwoFingers: false, // panning is done with two fingers on touch devices
586              *   needShift: true, // mouse panning needs pressing of the shift key
587              * }
588              * </pre>
589              *
590              * @name JXG.Board#pan
591              * @type Object
592              */
593             pan: {
594                 needShift: true,
595                 needTwoFingers: false,
596                 enabled: true
597             },
598 
599             /**
600              * Control the possibilities for dragging objects.
601              *
602              * Possible sub-attributes with default values are:
603              * <pre>
604              * drag: {
605              *   enabled: true   // Allow dragging
606              * }
607              * </pre>
608              *
609              * @name JXG.Board#drag
610              * @type Object
611              * @default {enabled: true}
612              */
613             drag: {
614                 enabled: true
615             },
616 
617             /**
618              * Control using the keyboard to change the construction.
619              * <ul>
620              * <li> enabled: true / false
621              * <li> dx: horizontal shift amount per key press
622              * <li> dy: vertical shift amount per key press
623              * <li> panShift: zoom if shift key is pressed
624              * <li> panCtrl: zoom if ctrl key is pressed
625              * </ul>
626              *
627              * @example
628              * var board = JXG.JSXGraph.initBoard("jxgbox", {boundingbox: [-5,5,5,-5],
629              *     axis: true,
630              *     showCopyright:true,
631              *     showNavigation:true,
632              *     keyboard: {
633              *         enabled: true,
634              *         dy: 30,
635              *         panShift: true,
636              *         panCtrl: false
637              *     }
638              * });
639              *
640              * </pre><div id="JXGb1d3aab6-ced2-4fe9-8fa5-b0accc8c7266" class="jxgbox" style="width: 300px; height: 300px;"></div>
641              * <script type="text/javascript">
642              *     (function() {
643              *         var board = JXG.JSXGraph.initBoard('JXGb1d3aab6-ced2-4fe9-8fa5-b0accc8c7266',
644              *             {boundingbox: [-5,5,5,-5],
645              *         axis: true,
646              *         showCopyright:true,
647              *         showNavigation:true,
648              *         keyboard: {
649              *             enabled: true,
650              *             dy: 30,
651              *             panShift: true,
652              *             panCtrl: false
653              *         }
654              *     });
655              * 
656              *     })();
657              * 
658              * </script><pre>
659              * 
660              *
661              * @see JXG.Board#keyDownListener
662              * @see JXG.Board#keyFocusInListener
663              * @see JXG.Board#keyFocusOutListener
664              *
665              * @name JXG.Board#keyboard
666              * @type Object
667              * @default {enabled: true, dx: 10, dy:10, panShift: true, panCtrl: false}
668              */
669             keyboard: {
670                 enabled: true,
671                 dx: 10,
672                 dy: 10,
673                 panShift: true,
674                 panCtrl: false
675             },
676 
677             /**
678              * Control if JSXGraph reacts to resizing of the JSXGraph container element
679              * by the user / browser.
680              * The attribute "throttle" determines the minimal time in msec between to
681              * resize calls.
682              *
683              * @see JXG.Board#startResizeObserver
684              * @see JXG.Board#resizeListener
685              *
686              * @name JXG.Board#resize
687              * @type Object
688              * @default {enabled: true, throttle: 10}
689              *
690              * @example
691              *     var board = JXG.JSXGraph.initBoard('jxgbox', {
692              *         boundingbox: [-5,5,5,-5],
693              *         keepAspectRatio: true,
694              *         axis: true,
695              *         resize: {enabled: true, throttle: 200}
696              *     });
697              *
698              * </pre><div id="JXGb55d4608-5d71-4bc3-b332-18c15fbda8c3" class="jxgbox" style="width: 300px; height: 300px;"></div>
699              * <script type="text/javascript">
700              *     (function() {
701              *         var board = JXG.JSXGraph.initBoard('JXGb55d4608-5d71-4bc3-b332-18c15fbda8c3', {
702              *             boundingbox: [-5,5,5,-5],
703              *             keepAspectRatio: true,
704              *             axis: true,
705              *             resize: {enabled: true, throttle: 200}
706              *         });
707              * 
708              *     })();
709              * 
710              * </script><pre>
711              * 
712              *
713              */
714             resize: {
715                 enabled: true,
716                 throttle: 10
717             },
718 
719             /**
720              * Element which listens to move events of the pointing device.
721              * This allows to drag elements of a JSXGraph construction outside of the board.
722              * Especially, on mobile devices this enhances the user experience.
723              * However, it is recommended to allow dragging outside of the JSXGraph board only
724              * in certain constructions where users may not "loose" points outside of the board.
725              * Then points may become unreachable.
726              * <p>
727              * A situation where dragging outside of the board is uncritical is for example if
728              * only sliders are used to interact with the construction.
729              * <p>
730              * Possible values for this attributes are:
731              * <ul>
732              * <li> an element specified by document.getElementById('some id');
733              * <li> null: to use the JSXgraph container div element
734              * <li> document
735              * </ul>
736              *
737              * @name JXG.Board#moveTarget
738              * @type HTML node or document
739              * @default null
740              *
741              * @example
742              *     var board = JXG.JSXGraph.initBoard('jxgbox', {
743              *         boundingbox: [-5,5,5,-5],
744              *         axis: true,
745              *         moveTarget: document
746              *     });
747              *
748              * </pre><div id="JXG973457e5-c63f-4516-8570-743f2cc560e1" class="jxgbox" style="width: 300px; height: 300px;"></div>
749              * <script type="text/javascript">
750              *     (function() {
751              *         var board = JXG.JSXGraph.initBoard('JXG973457e5-c63f-4516-8570-743f2cc560e1',
752              *             {boundingbox: [-5,5,5,-5],
753              *             axis: true,
754              *             moveTarget: document
755              *         });
756              * 
757              *     })();
758              * 
759              * </script><pre>
760              * 
761              *
762              */
763             moveTarget: null,
764 
765             /**
766              * Control the possibilities for a selection rectangle.
767              * Starting a selection event triggers the "startselecting" event.
768              * When the mouse pointer is released, the "stopselecting" event is fired.
769              * The "stopselecting" event must be supplied by the user.
770              * <p>
771              * Possible sub-attributes with default values are:
772              * <pre>
773              * selection: {
774              *   enabled: false,
775              *   name: 'selectionPolygon',
776              *   needShift: false,  // mouse selection needs pressing of the shift key
777              *   needCtrl: true,    // mouse selection needs pressing of the shift key
778              *   withLines: false,  // Selection polygon has border lines
779              *   vertices: {
780              *       visible: false
781              *   },
782              *   fillColor: '#ffff00',
783              *   visible: false      // Initial visibility. Should be set to false always
784              * }
785              * </pre>
786              *
787              * @example
788              * board.on('stopselecting', function(){
789              *     var box = board.stopSelectionMode(),
790              *     // bbox has the coordinates of the selectionr rectangle.
791              *     // Attention: box[i].usrCoords have the form [1, x, y], i.e.
792              *     // are homogeneous coordinates.
793              *     bbox = box[0].usrCoords.slice(1).concat(box[1].usrCoords.slice(1));
794              *     // Set a new bounding box
795              *     board.setBoundingBox(bbox, false);
796              * });
797              *
798              * @name JXG.Board#selection
799              * @see JXG.Board#startselecting
800              * @see JXG.Board#stopselecting
801              * @see JXG.Board#mousestartselecting
802              * @see JXG.Board#pointerstartselecting
803              * @see JXG.Board#touchstartselecting
804              * @see JXG.Board#mousestopselecting
805              * @see JXG.Board#pointerstopselecting
806              * @see JXG.Board#touchstopselecting
807              * @type Object
808              * @default
809              */
810             selection: {
811                 enabled: false,
812                 name: 'selectionPolygon',
813                 needShift: false,
814                 needCtrl: true,
815                 withLines: false,
816                 vertices: {
817                     visible: false
818                 },
819                 fillColor: '#ffff00',
820                 visible: false
821             },
822 
823             /**
824              * If true, the infobox is shown on mouse/pen over for all points
825              * which have set their attribute showInfobox to 'inherit'.
826              * If a point has set its attribute showInfobox to false or true,
827              * that value will have priority over this value.
828              *
829              * @name JXG.Board#showInfobox
830              * @see Point#showInfobox
831              * @type Boolean
832              * @default true
833              */
834             showInfobox: true
835 
836             /**#@-*/
837         },
838 
839         /**
840          * Options that are used by the navigation bar.
841          *
842          * Default values are
843          * <pre>
844          * JXG.Option.navbar: {
845          *   strokeColor: '#333333',
846          *   fillColor: 'transparent',
847          *   highlightFillColor: '#aaaaaa',
848          *   padding: '2px',
849          *   position: 'absolute',
850          *   fontSize: '14px',
851          *   cursor: 'pointer',
852          *   zIndex: '100',
853          *   right: '5px',
854          *   bottom: '5px'
855          * },
856          * </pre>
857          * These settings are overruled by the CSS class 'JXG_navigation'.
858          * @deprecated
859          * @type Object
860          * @name JXG.Options#navbar
861          *
862          */
863         navbar: {
864             strokeColor: '#333333', //'#aaaaaa',
865             fillColor: 'transparent', //#f5f5f5',
866             highlightFillColor: '#aaaaaa',
867             padding: '2px',
868             position: 'absolute',
869             fontSize: '14px',
870             cursor: 'pointer',
871             zIndex: '100',
872             right: '5px',
873             bottom: '5px'
874             //border: 'none 1px black',
875             //borderRadius: '4px'
876         },
877 
878          /*
879           *  Generic options used by {@link JXG.GeometryElement}
880           */
881         elements: {
882             // the following tag is a meta tag: http://code.google.com/p/jsdoc-toolkit/wiki/MetaTags
883 
884             /**#@+
885              * @visprop
886              */
887 
888             /**
889              * The stroke color of the given geometry element.
890              * @type String
891              * @name JXG.GeometryElement#strokeColor
892              * @see JXG.GeometryElement#highlightStrokeColor
893              * @see JXG.GeometryElement#strokeWidth
894              * @see JXG.GeometryElement#strokeOpacity
895              * @see JXG.GeometryElement#highlightStrokeOpacity
896              * @default {@link JXG.Options.elements.color#strokeColor}
897              */
898             strokeColor: Color.palette.blue,
899 
900             /**
901              * The stroke color of the given geometry element when the user moves the mouse over it.
902              * @type String
903              * @name JXG.GeometryElement#highlightStrokeColor
904              * @see JXG.GeometryElement#strokeColor
905              * @see JXG.GeometryElement#strokeWidth
906              * @see JXG.GeometryElement#strokeOpacity
907              * @see JXG.GeometryElement#highlightStrokeOpacity
908              * @default {@link JXG.Options.elements.color#highlightStrokeColor}
909              */
910             highlightStrokeColor: '#c3d9ff',
911 
912             /**
913              * The fill color of this geometry element.
914              * @type String
915              * @name JXG.GeometryElement#fillColor
916              * @see JXG.GeometryElement#highlightFillColor
917              * @see JXG.GeometryElement#fillOpacity
918              * @see JXG.GeometryElement#highlightFillOpacity
919              * @default {@link JXG.Options.elements.color#fillColor}
920              */
921             fillColor: Color.palette.red,
922 
923             /**
924              * The fill color of the given geometry element when the mouse is pointed over it.
925              * @type String
926              * @name JXG.GeometryElement#highlightFillColor
927              * @see JXG.GeometryElement#fillColor
928              * @see JXG.GeometryElement#fillOpacity
929              * @see JXG.GeometryElement#highlightFillOpacity
930              * @default {@link JXG.Options.elements.color#highlightFillColor}
931              */
932             highlightFillColor: 'none',
933 
934             /**
935              * Opacity for element's stroke color.
936              * @type Number
937              * @name JXG.GeometryElement#strokeOpacity
938              * @see JXG.GeometryElement#strokeColor
939              * @see JXG.GeometryElement#highlightStrokeColor
940              * @see JXG.GeometryElement#strokeWidth
941              * @see JXG.GeometryElement#highlightStrokeOpacity
942              * @default {@link JXG.Options.elements#strokeOpacity}
943              */
944             strokeOpacity: 1,
945 
946             /**
947              * Opacity for stroke color when the object is highlighted.
948              * @type Number
949              * @name JXG.GeometryElement#highlightStrokeOpacity
950              * @see JXG.GeometryElement#strokeColor
951              * @see JXG.GeometryElement#highlightStrokeColor
952              * @see JXG.GeometryElement#strokeWidth
953              * @see JXG.GeometryElement#strokeOpacity
954              * @default {@link JXG.Options.elements#highlightStrokeOpacity}
955              */
956             highlightStrokeOpacity: 1,
957 
958             /**
959              * Opacity for fill color.
960              * @type Number
961              * @name JXG.GeometryElement#fillOpacity
962              * @see JXG.GeometryElement#fillColor
963              * @see JXG.GeometryElement#highlightFillColor
964              * @see JXG.GeometryElement#highlightFillOpacity
965              * @default {@link JXG.Options.elements.color#fillOpacity}
966              */
967             fillOpacity: 1,
968 
969             /**
970              * Opacity for fill color when the object is highlighted.
971              * @type Number
972              * @name JXG.GeometryElement#highlightFillOpacity
973              * @see JXG.GeometryElement#fillColor
974              * @see JXG.GeometryElement#highlightFillColor
975              * @see JXG.GeometryElement#fillOpacity
976              * @default {@link JXG.Options.elements.color#highlightFillOpacity}
977              */
978             highlightFillOpacity: 1,
979 
980             /**
981              * Gradient type. Possible values are 'linear'. 'radial' or null.
982              *
983              * @example
984              *     var a = board.create('slider', [[0, -0.2], [3.5, -0.2], [0, 0, 2 * Math.PI]], {name: 'angle'});
985              *     var b = board.create('slider', [[0, -0.4], [3.5, -0.4], [0, 0, 1]], {name: 'offset1'});
986              *     var c = board.create('slider', [[0, -0.6], [3.5, -0.6], [0, 1, 1]], {name: 'offset2'});
987              *
988              *     var pol = board.create('polygon', [[0, 0], [4, 0], [4,4], [0,4]], {
989              *                 fillOpacity: 1,
990              *                 fillColor: 'yellow',
991              *                 gradient: 'linear',
992              *                 gradientSecondColor: 'blue',
993              *                 gradientAngle: function() { return a.Value(); },
994              *                 gradientStartOffset: function() { return b.Value(); },
995              *                 gradientEndOffset: function() { return c.Value(); },
996              *                 hasInnerPoints: true
997              *         });
998              *
999              * </pre><div id="JXG3d04b5fd-0cd4-4f49-8c05-4e9686cd7ff0" class="jxgbox" style="width: 300px; height: 300px;"></div>
1000              * <script type="text/javascript">
1001              *     (function() {
1002              *         var board = JXG.JSXGraph.initBoard('JXG3d04b5fd-0cd4-4f49-8c05-4e9686cd7ff0',
1003              *             {boundingbox: [-1.5, 4.5, 5, -1.5], axis: true, showcopyright: false, shownavigation: false});
1004              *         var a = board.create('slider', [[0, -0.2], [3.5, -0.2], [0, 0, 2 * Math.PI]], {name: 'angle'});
1005              *         var b = board.create('slider', [[0, -0.4], [3.5, -0.4], [0, 0, 1]], {name: 'offset1'});
1006              *         var c = board.create('slider', [[0, -0.6], [3.5, -0.6], [0, 1, 1]], {name: 'offset2'});
1007              *
1008              *         var pol = board.create('polygon', [[0, 0], [4, 0], [4,4], [0,4]], {
1009              *                     fillOpacity: 1,
1010              *                     fillColor: 'yellow',
1011              *                     gradient: 'linear',
1012              *                     gradientSecondColor: 'blue',
1013              *                     gradientAngle: function() { return a.Value(); },
1014              *                     gradientStartOffset: function() { return b.Value(); },
1015              *                     gradientEndOffset: function() { return c.Value(); },
1016              *                     hasInnerPoints: true
1017              *             });
1018              *
1019              *     })();
1020              *
1021              * </script><pre>
1022              *
1023              * @example
1024              *     var cx = board.create('slider', [[0, -.2], [3.5, -.2], [0, 0.5, 1]], {name: 'cx, cy'});
1025              *     var fx = board.create('slider', [[0, -.4], [3.5, -.4], [0, 0.5, 1]], {name: 'fx, fy'});
1026              *     var o1 = board.create('slider', [[0, -.6], [3.5, -.6], [0, 0.0, 1]], {name: 'offset1'});
1027              *     var o2 = board.create('slider', [[0, -.8], [3.5, -.8], [0, 1, 1]], {name: 'offset2'});
1028              *     var r = board.create('slider', [[0, -1], [3.5, -1], [0, 0.5, 1]], {name: 'r'});
1029              *     var fr = board.create('slider', [[0, -1.2], [3.5, -1.2], [0, 0, 1]], {name: 'fr'});
1030              *
1031              *     var pol = board.create('polygon', [[0, 0], [4, 0], [4,4], [0,4]], {
1032              *                 fillOpacity: 1,
1033              *                 fillColor: 'yellow',
1034              *                 gradient: 'radial',
1035              *                 gradientSecondColor: 'blue',
1036              *                 gradientCX: function() { return cx.Value(); },
1037              *                 gradientCY: function() { return cx.Value(); },
1038              *                 gradientR: function() { return r.Value(); },
1039              *                 gradientFX: function() { return fx.Value(); },
1040              *                 gradientFY: function() { return fx.Value(); },
1041              *                 gradientFR: function() { return fr.Value(); },
1042              *                 gradientStartOffset: function() { return o1.Value(); },
1043              *                 gradientEndOffset: function() { return o2.Value(); },
1044              *                 hasInnerPoints: true
1045              *     });
1046              *
1047              * </pre><div id="JXG6081ca7f-0d09-4525-87ac-325a02fe2225" class="jxgbox" style="width: 300px; height: 300px;"></div>
1048              * <script type="text/javascript">
1049              *     (function() {
1050              *         var board = JXG.JSXGraph.initBoard('JXG6081ca7f-0d09-4525-87ac-325a02fe2225',
1051              *             {boundingbox: [-1.5, 4.5, 5, -1.5], axis: true, showcopyright: false, shownavigation: false});
1052              *         var cx = board.create('slider', [[0, -.2], [3.5, -.2], [0, 0.5, 1]], {name: 'cx, cy'});
1053              *         var fx = board.create('slider', [[0, -.4], [3.5, -.4], [0, 0.5, 1]], {name: 'fx, fy'});
1054              *         var o1 = board.create('slider', [[0, -.6], [3.5, -.6], [0, 0.0, 1]], {name: 'offset1'});
1055              *         var o2 = board.create('slider', [[0, -.8], [3.5, -.8], [0, 1, 1]], {name: 'offset2'});
1056              *         var r = board.create('slider', [[0, -1], [3.5, -1], [0, 0.5, 1]], {name: 'r'});
1057              *         var fr = board.create('slider', [[0, -1.2], [3.5, -1.2], [0, 0, 1]], {name: 'fr'});
1058              *
1059              *         var pol = board.create('polygon', [[0, 0], [4, 0], [4,4], [0,4]], {
1060              *                     fillOpacity: 1,
1061              *                     fillColor: 'yellow',
1062              *                     gradient: 'radial',
1063              *                     gradientSecondColor: 'blue',
1064              *                     gradientCX: function() { return cx.Value(); },
1065              *                     gradientCY: function() { return cx.Value(); },
1066              *                     gradientR: function() { return r.Value(); },
1067              *                     gradientFX: function() { return fx.Value(); },
1068              *                     gradientFY: function() { return fx.Value(); },
1069              *                     gradientFR: function() { return fr.Value(); },
1070              *                     gradientStartOffset: function() { return o1.Value(); },
1071              *                     gradientEndOffset: function() { return o2.Value(); },
1072              *                     hasInnerPoints: true
1073              *         });
1074              *
1075              *     })();
1076              *
1077              * </script><pre>
1078              *
1079              *
1080              * @type String
1081              * @name JXG.GeometryElement#gradient
1082              * @see JXG.GeometryElement#gradientSecondColor
1083              * @see JXG.GeometryElement#gradientSecondOpacity
1084              * @default null
1085              */
1086             gradient: null,
1087 
1088             /**
1089              * Second color for gradient.
1090              * @type String
1091              * @name JXG.GeometryElement#gradientSecondColor
1092              * @see JXG.GeometryElement#gradient
1093              * @see JXG.GeometryElement#gradientSecondOpacity
1094              * @default '#ffffff'
1095              */
1096             gradientSecondColor: '#ffffff',
1097 
1098             /**
1099              * Opacity of second gradient color. Takes a value between 0 and 1.
1100              * @type Number
1101              * @name JXG.GeometryElement#gradientSecondOpacity
1102              * @see JXG.GeometryElement#gradient
1103              * @see JXG.GeometryElement#gradientSecondColor
1104              * @default 1
1105              */
1106             gradientSecondOpacity: 1,
1107 
1108             /**
1109              * The gradientStartOffset attribute is a number (ranging from 0 to 1) which indicates where the first gradient stop is placed,
1110              * see the SVG specification for more information.
1111              * For linear gradients, this attribute represents a location along the gradient vector.
1112              * For radial gradients, it represents a percentage distance from (fx,fy) to the edge of the outermost/largest circle.
1113              * @type Number
1114              * @name JXG.GeometryElement#gradientStartOffset
1115              * @see JXG.GeometryElement#gradient
1116              * @see JXG.GeometryElement#gradientEndOffset
1117              * @default 0.0
1118              */
1119             gradientStartOffset: 0.0,
1120 
1121             /**
1122              * The gradientEndOffset attribute is a number (ranging from 0 to 1) which indicates where the second gradient stop is placed,
1123              * see the SVG specification for more information.
1124              * For linear gradients, this attribute represents a location along the gradient vector.
1125              * For radial gradients, it represents a percentage distance from (fx,fy) to the edge of the outermost/largest circle.
1126              * @type Number
1127              * @name JXG.GeometryElement#gradientEndOffset
1128              * @see JXG.GeometryElement#gradient
1129              * @see JXG.GeometryElement#gradientStartOffset
1130              * @default 1.0
1131              */
1132             gradientEndOffset: 1.0,
1133 
1134 
1135             /**
1136              * Angle (in radians) of the gradiant in case the gradient is of type 'linear'.
1137              * If the angle is 0, the first color is on the left and the second color is on the right.
1138              * If the angle is pi/4 the first color is on top and the second color at the
1139              * bottom.
1140              * @type Number
1141              * @name JXG.GeometryElement#gradientAngle
1142              * @see JXG.GeometryElement#gradient
1143              * @default 0
1144              */
1145             gradientAngle: 0,
1146 
1147             /**
1148              * From the SVG specification: ‘cx’, ‘cy’ and ‘r’ define the largest (i.e., outermost) circle for the radial gradient.
1149              * The gradient will be drawn such that the 100% gradient stop is mapped to the perimeter of this largest (i.e., outermost) circle.
1150              * For radial gradients in canvas this is the value 'x1'.
1151              * Takes a value between 0 and 1.
1152              * @type Number
1153              * @name JXG.GeometryElement#gradientCX
1154              * @see JXG.GeometryElement#gradient
1155              * @see JXG.GeometryElement#gradientCY
1156              * @see JXG.GeometryElement#gradientR
1157              * @default 0.5
1158              */
1159             gradientCX: 0.5,
1160 
1161             /**
1162              * From the SVG specification: ‘cx’, ‘cy’ and ‘r’ define the largest (i.e., outermost) circle for the radial gradient.
1163              * The gradient will be drawn such that the 100% gradient stop is mapped to the perimeter of this largest (i.e., outermost) circle.
1164              * For radial gradients in canvas this is the value 'y1'.
1165              * Takes a value between 0 and 1.
1166              * @type Number
1167              * @name JXG.GeometryElement#gradientCY
1168              * @see JXG.GeometryElement#gradient
1169              * @see JXG.GeometryElement#gradientCX
1170              * @see JXG.GeometryElement#gradientR
1171              * @default 0.5
1172              */
1173             gradientCY: 0.5,
1174 
1175             /**
1176              * From the SVG specification: ‘cx’, ‘cy’ and ‘r’ define the largest (i.e., outermost) circle for the radial gradient.
1177              * The gradient will be drawn such that the 100% gradient stop is mapped to the perimeter of this largest (i.e., outermost) circle.
1178              * For radial gradients in canvas this is the value 'r1'.
1179              * Takes a value between 0 and 1.
1180              * @type Number
1181              * @name JXG.GeometryElement#gradientR
1182              * @see JXG.GeometryElement#gradient
1183              * @see JXG.GeometryElement#gradientCX
1184              * @see JXG.GeometryElement#gradientCY
1185              * @default 0.5
1186              */
1187             gradientR: 0.5,
1188 
1189             /**
1190              * ‘fx’ and ‘fy’ define the focal point for the radial gradient.
1191              * The gradient will be drawn such that the 0% gradient stop is mapped to (fx, fy).
1192              * For radial gradients in canvas this is the value 'x0'.
1193              * Takes a value between 0 and 1.
1194              * @type Number
1195              * @name JXG.GeometryElement#gradientFX
1196              * @see JXG.GeometryElement#gradient
1197              * @see JXG.GeometryElement#gradientFY
1198              * @see JXG.GeometryElement#gradientFR
1199              * @default 0.5
1200              */
1201             gradientFX: 0.5,
1202 
1203             /**
1204              * y-coordinate of the circle center for the second color in case of gradient 'radial'. (The attribute fy in SVG)
1205              * For radial gradients in canvas this is the value 'y0'.
1206              * Takes a value between 0 and 1.
1207              * @type Number
1208              * @name JXG.GeometryElement#gradientFY
1209              * @see JXG.GeometryElement#gradient
1210              * @see JXG.GeometryElement#gradientFX
1211              * @see JXG.GeometryElement#gradientFR
1212              * @default 0.5
1213              */
1214             gradientFY: 0.5,
1215 
1216             /**
1217              * This attribute defines the radius of the start circle of the radial gradient.
1218              * The gradient will be drawn such that the 0% <stop> is mapped to the perimeter of the start circle.
1219              * For radial gradients in canvas this is the value 'r0'.
1220              * Takes a value between 0 and 1.
1221              * @type Number
1222              * @name JXG.GeometryElement#gradientFR
1223              * @see JXG.GeometryElement#gradient
1224              * @see JXG.GeometryElement#gradientFX
1225              * @see JXG.GeometryElement#gradientFY
1226              * @default 0.0
1227              */
1228             gradientFR: 0.0,
1229 
1230             /**
1231              * Transition duration (in milliseconds) for color and opacity
1232              * changes. Works in SVG renderer, only.
1233              * @type Number
1234              * @name JXG.GeometryElement#transitionDuration
1235              * @see JXG.GeometryElement#strokeColor
1236              * @see JXG.GeometryElement#highlightStrokeColor
1237              * @see JXG.GeometryElement#strokeOpacity
1238              * @see JXG.GeometryElement#highlightStrokeOpacity
1239              * @see JXG.GeometryElement#fillColor
1240              * @see JXG.GeometryElement#highlightFillColor
1241              * @see JXG.GeometryElement#fillOpacity
1242              * @see JXG.GeometryElement#highlightFillOpacity
1243              * @default {@link JXG.Options.elements#transitionDuration}
1244              */
1245             transitionDuration: 100,
1246 
1247             /**
1248              * Width of the element's stroke.
1249              * @type Number
1250              * @name JXG.GeometryElement#strokeWidth
1251              * @see JXG.GeometryElement#strokeColor
1252              * @see JXG.GeometryElement#highlightStrokeColor
1253              * @see JXG.GeometryElement#strokeOpacity
1254              * @see JXG.GeometryElement#highlightStrokeOpacity
1255              * @default {@link JXG.Options.elements#strokeWidth}
1256              */
1257             strokeWidth: 2,
1258 
1259             /**
1260              * Width of the element's stroke when the mouse is pointed over it.
1261              * @type Number
1262              * @name JXG.GeometryElement#highlightStrokeWidth
1263              * @see JXG.GeometryElement#strokeColor
1264              * @see JXG.GeometryElement#highlightStrokeColor
1265              * @see JXG.GeometryElement#strokeOpacity
1266              * @see JXG.GeometryElement#highlightStrokeOpacity
1267              * @see JXG.GeometryElement#highlightFillColor
1268              * @default {@link JXG.Options.elements#strokeWidth}
1269              */
1270             highlightStrokeWidth: 2,
1271 
1272             /**
1273              * If true the element is fixed and can not be dragged around. The element
1274              * will be repositioned on zoom and moveOrigin events.
1275              * @type Boolean
1276              * @default false
1277              * @name JXG.GeometryElement#fixed
1278              */
1279             fixed: false,
1280 
1281             /**
1282              * If true the element is fixed and can not be dragged around. The element
1283              * will even stay at its position on zoom and moveOrigin events.
1284              * Only free elements like points, texts, curves can be frozen.
1285              * @type Boolean
1286              * @default false
1287              * @name JXG.GeometryElement#frozen
1288              */
1289             frozen: false,
1290 
1291             /**
1292              * If true a label will display the element's name.
1293              * @type Boolean
1294              * @default false
1295              * @name JXG.GeometryElement#withLabel
1296              */
1297             withLabel: false,
1298 
1299             /**
1300              * If false the element won't be visible on the board, otherwise it is shown.
1301              * @type Boolean
1302              * @name JXG.GeometryElement#visible
1303              * @see JXG.GeometryElement#hideElement
1304              * @see JXG.GeometryElement#showElement
1305              * @default true
1306              */
1307             visible: true,
1308 
1309             /**
1310              * A private element will be inaccessible in certain environments, e.g. a graphical user interface.
1311              * @default false
1312              */
1313             priv: false,
1314 
1315             /**
1316              * Display layer which will contain the element.
1317              * @see JXG.Options#layer
1318              * @default See {@link JXG.Options#layer}
1319              */
1320             layer: 0,
1321 
1322             /**
1323              * Determines the elements border-style.
1324              * Possible values are:
1325              * <ul><li>0 for a solid line</li>
1326              * <li>1 for a dotted line</li>
1327              * <li>2 for a line with small dashes</li>
1328 
1329 
1330              * <li>3 for a line with medium dashes</li>
1331              * <li>4 for a line with big dashes</li>
1332              * <li>5 for a line with alternating medium and big dashes and large gaps</li>
1333              * <li>6 for a line with alternating medium and big dashes and small gaps</li></ul>
1334              * @type Number
1335              * @name JXG.GeometryElement#dash
1336              * @default 0
1337              */
1338             dash: 0,
1339 
1340             /**
1341              * If true the element will get a shadow.
1342              * @type Boolean
1343              * @name JXG.GeometryElement#shadow
1344              * @default false
1345              */
1346             shadow: false,
1347 
1348             /**
1349              * If true the element will be traced, i.e. on every movement the element will be copied
1350              * to the background. Use {@link JXG.GeometryElement#clearTrace} to delete the trace elements.
1351              *
1352              * The calling of element.setAttribute({trace:false}) additionally
1353              * deletes all traces of this element. By calling
1354              * element.setAttribute({trace:'pause'})
1355              * the removal of already existing traces can be prevented.
1356              * @see JXG.GeometryElement#clearTrace
1357              * @see JXG.GeometryElement#traces
1358              * @see JXG.GeometryElement#numTraces
1359              * @type Boolean|String
1360              * @default false
1361              * @name JXG.GeometryElement#trace
1362              */
1363             trace: false,
1364 
1365             /**
1366              * Extra visual properties for traces of an element
1367              * @type Object
1368              * @see JXG.GeometryElement#trace
1369              * @name JXG.GeometryElement#traceAttributes
1370              */
1371             traceAttributes: {},
1372 
1373             /**
1374              *
1375              * @type Boolean
1376              * @default true
1377              * @name JXG.GeometryElement#highlight
1378              */
1379             highlight: true,
1380 
1381             /**
1382              * If this is set to true, the element is updated in every update
1383              * call of the board. If set to false, the element is updated only after
1384              * zoom events or more generally, when the bounding box has been changed.
1385              * Examples for the latter behaviour should be axes.
1386              * @type Boolean
1387              * @default true
1388              * @see JXG.GeometryElement#needsRegularUpdate
1389              * @name JXG.GeometryElement#needsRegularUpdate
1390              */
1391             needsRegularUpdate: true,
1392 
1393             /**
1394              * Snaps the element or its parents to the grid. Currently only relevant for points, circles,
1395              * and lines. Points are snapped to grid directly, on circles and lines it's only the parent
1396              * points that are snapped
1397              * @type Boolean
1398              * @default false
1399              * @name JXG.GeometryElement#snapToGrid
1400              */
1401             snapToGrid: false,
1402 
1403             /**
1404              * Determines whether two-finger manipulation of this object may change its size.
1405              * If set to false, the object is only rotated and translated.
1406              * <p>
1407              * In case the element is a horizontal or vertical line having ticks, "scalable:true"
1408              * enables zooming of the board by dragging ticks lines. This feature is enabled,
1409              * for the ticks element of the line element the attribute "fixed" has to be false
1410              * and the line element's scalable attribute has to be true.
1411              * <p>
1412              * In case the element is a polygon or line and it has the attribute "scalable:false",
1413              * moving the element with two fingers results in a rotation or translation.
1414              *
1415              * @type Boolean
1416              * @default true
1417              * @name JXG.GeometryElement#scalable
1418              * @see JXG.Ticks#fixed
1419              */
1420             scalable: true,
1421 
1422             /**
1423              * If the element is dragged it will be moved on mousedown or touchstart to the
1424              * top of its layer. Works only for SVG renderer and for simple elements
1425              * consisting of one SVG node.
1426              * @example
1427              * var li1 = board.create('line', [1, 1, 1], {strokeWidth: 20, dragToTopOfLayer: true});
1428              * var li2 = board.create('line', [1, -1, 1], {strokeWidth: 20, strokeColor: 'red'});
1429              *
1430              * </pre><div id="JXG38449fee-1ab4-44de-b7d1-43caa1f50f86" class="jxgbox" style="width: 300px; height: 300px;"></div>
1431              * <script type="text/javascript">
1432              *     (function() {
1433              *         var board = JXG.JSXGraph.initBoard('JXG38449fee-1ab4-44de-b7d1-43caa1f50f86',
1434              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
1435              *     var li1 = board.create('line', [1, 1, 1], {strokeWidth: 20, dragToTopOfLayer: true});
1436              *     var li2 = board.create('line', [1, -1, 1], {strokeWidth: 20, strokeColor: 'red'});
1437              *
1438              *     })();
1439              *
1440              * </script><pre>
1441              *
1442              * @type Boolean
1443              * @default false
1444              * @name JXG.GeometryElement#dragToTopOfLayer
1445              */
1446             dragToTopOfLayer: false,
1447 
1448             /**
1449              * Precision options for JSXGraph elements.
1450              * This attributes takes either the value 'inherit' or an object of the form:
1451              * <pre>
1452              * precision: {
1453              *      touch: 30,
1454              *      mouse: 4,
1455              *      pen: 4
1456              * }
1457              * </pre>
1458              *
1459              * In the first case, the global, JSXGraph-wide values of JXGraph.Options.precision
1460              * are taken.
1461              *
1462              * @type {String|Object}
1463              * @name JXG.GeometryElement#precision
1464              * @see JXG.Options#precision
1465              * @default 'inherit'
1466              */
1467             precision: 'inherit',
1468 
1469             /*draft options */
1470             draft: {
1471                 /**
1472                  * If true the element will be drawn in grey scale colors to visualize that it's only a draft.
1473                  * @type Boolean
1474                  * @name JXG.GeometryElement#draft
1475                  * @default {@link JXG.Options.elements.draft#draft}
1476                  */
1477                 draft: false,
1478                 strokeColor: '#565656',
1479                 fillColor: '#565656',
1480                 strokeOpacity: 0.8,
1481                 fillOpacity: 0.8,
1482                 strokeWidth: 1
1483             },
1484 
1485             /**
1486              * @private
1487              * By default, an element is not a label. Do not change this.
1488              */
1489             isLabel: false,
1490 
1491 
1492             tabindex: 0
1493 
1494             // close the meta tag
1495             /**#@-*/
1496         },
1497 
1498          /*
1499           *  Generic options used by {@link JXG.Ticks}
1500           */
1501         ticks: {
1502             /**#@+
1503              * @visprop
1504              */
1505 
1506             /**
1507              * A function that expects two {@link JXG.Coords}, the first one representing the coordinates of the
1508              * tick that is to be labeled, the second one the coordinates of the center (the tick with position 0).
1509              *
1510              * @type function
1511              * @name Ticks#generateLabelText
1512              */
1513             generateLabelText: null,
1514 
1515             /**
1516              * A function that expects two {@link JXG.Coords}, the first one representing the coordinates of the
1517              * tick that is to be labeled, the second one the coordinates of the center (the tick with position 0).
1518              *
1519              * @deprecated Use {@link JGX.Options@generateLabelValue}
1520              * @type function
1521              * @name Ticks#generateLabelValue
1522              */
1523             generateLabelValue: null,
1524 
1525             /**
1526              * Draw labels yes/no
1527              *
1528              * @type Boolean
1529              * @name Ticks#drawLabels
1530              * @default false
1531              */
1532             drawLabels: false,
1533 
1534             /**
1535              * Attributes for the ticks labels
1536              *
1537              * @name Ticks#label
1538              * @type Object
1539              * @default {}
1540              *
1541              */
1542             label: {
1543             },
1544 
1545             /**
1546             * Format tick labels that were going to have scientific notation
1547             * like 5.00e+6 to look like 5•10⁶.
1548             *
1549             * @example
1550             * var board = JXG.JSXGraph.initBoard("jxgbox", {
1551             *     boundingbox: [-500000, 500000, 500000, -500000],
1552             *     axis: true,
1553             *     defaultAxes: {
1554             *         x: {
1555             *             scalable: true,
1556             *             ticks: {
1557             *                 beautifulScientificTickLabels: true
1558             *           },
1559             *         },
1560             *         y: {
1561             *             scalable: true,
1562             *             ticks: {
1563             *                 beautifulScientificTickLabels: true
1564             *           },
1565             *         }
1566             *     },
1567             * });
1568             *
1569             * </pre><div id="JXGc1e46cd1-e025-4002-80aa-b450869fdaa2" class="jxgbox" style="width: 300px; height: 300px;"></div>
1570             * <script type="text/javascript">
1571             *     (function() {
1572             *     var board = JXG.JSXGraph.initBoard('JXGc1e46cd1-e025-4002-80aa-b450869fdaa2', {
1573             *         boundingbox: [-500000, 500000, 500000, -500000],
1574             *         showcopyright: false, shownavigation: false,
1575             *         axis: true,
1576             *         defaultAxes: {
1577             *             x: {
1578             *                 scalable: true,
1579             *                 ticks: {
1580             *                     beautifulScientificTickLabels: true
1581             *               },
1582             *             },
1583             *             y: {
1584             *                 scalable: true,
1585             *                 ticks: {
1586             *                     beautifulScientificTickLabels: true
1587             *               },
1588             *             }
1589             *         },
1590             *     });
1591             * 
1592             *     })();
1593             * 
1594             * </script><pre>
1595             *
1596             * @name Ticks#beautifulScientificTickLabels
1597             * @type Boolean
1598             * @default false
1599             */
1600             beautifulScientificTickLabels: false,
1601 
1602             /**
1603              * Use the unicode character 0x2212, i.e. the HTML entity &minus; as minus sign.
1604              * That is −1 instead of -1.
1605              *
1606              * @type Boolean
1607              * @name Ticks#useUnicodeMinus
1608              * @default true
1609              */
1610             useUnicodeMinus: true,
1611 
1612             /**
1613              * Determine the position of the tick with value 0. 'left' means point1 of the line, 'right' means point2,
1614              * and 'middle' is equivalent to the midpoint of the defining points. This attribute is ignored if the parent
1615              * line is of type axis.
1616              *
1617              * @type String
1618              * @name Ticks#anchor
1619              * @default 'left'
1620              */
1621             anchor: 'left',
1622 
1623             /**
1624              * Draw the zero tick, that lies at line.point1?
1625              *
1626              * @type Boolean
1627              * @name Ticks#drawZero
1628              * @default false
1629              */
1630             drawZero: false,
1631 
1632             /**
1633              * If the distance between two ticks is too big we could insert new ticks. If insertTicks
1634              * is <tt>true</tt>, we'll do so, otherwise we leave the distance as is.
1635              * This option is ignored if equidistant is false. In the example below the distance between
1636              * two ticks is given as <tt>1</tt> but because insertTicks is set to true many ticks will
1637              * be omitted in the rendering process to keep the display clear.
1638              *
1639              * @type Boolean
1640              * @name Ticks#insertTicks
1641              * @see Ticks#minTicksDistance
1642              * @default false
1643              * @example
1644              * // Create an axis providing two coord pairs.
1645              *   var p1 = board.create('point', [0, 0]);
1646              *   var p2 = board.create('point', [50, 25]);
1647              *   var l1 = board.create('line', [p1, p2]);
1648              *   var t = board.create('ticks', [l1, 1], {
1649              *      insertTicks: true,
1650              *      majorHeight: -1,
1651              *      label: {
1652              *          offset: [4, -9]
1653              *      },
1654              *      drawLabels: true
1655              *  });
1656              * </pre><div class="jxgbox" id="JXG2f6fb842-40bd-4223-aa28-3e9369d2097f" style="width: 300px; height: 300px;"></div>
1657              * <script type="text/javascript">
1658              * (function () {
1659              *   var board = JXG.JSXGraph.initBoard('JXG2f6fb842-40bd-4223-aa28-3e9369d2097f', {boundingbox: [-100, 70, 70, -100], showcopyright: false, shownavigation: false});
1660              *   var p1 = board.create('point', [0, 0]);
1661              *   var p2 = board.create('point', [50, 25]);
1662              *   var l1 = board.create('line', [p1, p2]);
1663              *   var t = board.create('ticks', [l1, 1], {insertTicks: true, majorHeight: -1, label: {offset: [4, -9]}, drawLabels: true});
1664              * })();
1665              * </script><pre>
1666              */
1667             insertTicks: false,
1668 
1669             /**
1670              * Minimum distance in pixel of equidistant ticks in case insertTicks==true.
1671              * @name Ticks#minTicksDistance
1672              * @type: Number
1673              * @default: 10
1674              * @see Ticks#insertTicks
1675              */
1676             minTicksDistance: 10,
1677 
1678             /**
1679              * Total height of a minor tick. If negative the full height of the board is taken.
1680              *
1681              * @type Number
1682              * @name Ticks#minorHeight
1683              * @default 4
1684              */
1685             minorHeight: 4,
1686 
1687             /**
1688              * Total height of a major tick. If negative the full height of the board is taken.
1689              *
1690              * @type Number
1691              * @name Ticks#majorHeight
1692              * @default 10
1693              */
1694             majorHeight: 10,
1695 
1696             /**
1697              * Decides in which direction finite ticks are visible. Possible values are either the constants
1698              * 0=false or 1=true or a function returning 0 or 1.
1699              *
1700              * In case of [0,1] the tick is only visible to the right of the line. In case of
1701              * [1,0] the tick is only visible to the left of the line.
1702              *
1703              * @type Array
1704              * @name Ticks#tickEndings
1705              * @default [1, 1]
1706              */
1707             tickEndings: [1, 1],
1708 
1709             /**
1710              * The number of minor ticks between two major ticks.
1711              * @type Number
1712              * @name Ticks#minorTicks
1713              * @default 4
1714              */
1715             minorTicks: 4,
1716 
1717             /**
1718              * Scale the ticks but not the tick labels.
1719              * @type Number
1720              * @default 1
1721              * @name Ticks#scale
1722              * @see Ticks#scaleSymbol
1723              */
1724             scale: 1,
1725 
1726             /**
1727              * A string that is appended to every tick, used to represent the scale
1728              * factor given in {@link Ticks#scaleSymbol}.
1729              *
1730              * @type String
1731              * @default ''
1732              * @name Ticks#scaleSymbol
1733              * @see Ticks#scale
1734              */
1735             scaleSymbol: '',
1736 
1737             /**
1738              * User defined labels for special ticks. Instead of the i-th tick's position, the i-th string stored in this array
1739              * is shown. If the number of strings in this array is less than the number of special ticks, the tick's position is
1740              * shown as a fallback.
1741              *
1742              * @type Array
1743              * @name Ticks#labels
1744              * @default []
1745              */
1746             labels: [],
1747 
1748             /**
1749              * The maximum number of characters a tick label can use.
1750              *
1751              * @type Number
1752              * @name Ticks#maxLabelLength
1753              * @see Ticks#precision
1754              * @default 5
1755              */
1756             maxLabelLength: 5,
1757 
1758             /**
1759              * If a label exceeds {@link Ticks#maxLabelLength} this determines the precision used to shorten the tick label.
1760              *
1761              * @type Number
1762              * @name Ticks#precision
1763              * @see Ticks#maxLabelLength
1764              * @default 3
1765              */
1766             precision: 3,
1767 
1768             /**
1769              * The default distance between two ticks. Please be aware that this value does not have
1770              * to be used if {@link Ticks#insertTicks} is set to true.
1771              *
1772              * @type Number
1773              * @name Ticks#ticksDistance
1774              * @see Ticks#insertTicks
1775              * @default 1
1776              */
1777             ticksDistance: 1,
1778 
1779             /**
1780              * Tick face for ticks of finite length.  By default (face: '|') this is a straight line.
1781              * Possible other values are '<' and '>'. These faces are used in
1782              * {@link JXG.Hatch} for hatch marking parallel lines.
1783              * @type String
1784              * @name{Ticks#face}
1785              * @see hatch
1786              * @default '|'
1787              * @example
1788              *   var p1 = board.create('point', [0, 3]);
1789              *   var p2 = board.create('point', [1, 3]);
1790              *   var l1 = board.create('line', [p1, p2]);
1791              *   var t = board.create('ticks', [l1], {ticksDistance: 2, face: '>'});
1792              *
1793              * </pre><div id="JXG950a568a-1264-4e3a-b61d-b6881feecf4b" class="jxgbox" style="width: 300px; height: 300px;"></div>
1794              * <script type="text/javascript">
1795              *     (function() {
1796              *         var board = JXG.JSXGraph.initBoard('JXG950a568a-1264-4e3a-b61d-b6881feecf4b',
1797              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
1798              *       var p1 = board.create('point', [0, 3]);
1799              *       var p2 = board.create('point', [1, 3]);
1800              *       var l1 = board.create('line', [p1, p2]);
1801              *       var t = board.create('ticks', [l1], {ticksDistance: 2, face: '>'});
1802              *
1803              *     })();
1804              *
1805              * </script><pre>
1806              *
1807              */
1808             face: '|',
1809 
1810             strokeOpacity: 1,
1811             strokeWidth: 1,
1812             strokeColor: '#000000',
1813             highlightStrokeColor: '#888888',
1814             fillColor: 'none',
1815             highlightFillColor: 'none',
1816             visible: 'inherit',
1817 
1818             /**
1819              * Whether line boundaries should be counted or not in the lower and upper bounds when
1820              * creating ticks.
1821              *
1822              * @type Boolean
1823              * @name Ticks#includeBoundaries
1824              * @default false
1825              */
1826             includeBoundaries: false,
1827 
1828             /**
1829              * Set the ticks type.
1830              * Possible values are 'linear' or 'polar'.
1831              *
1832              * @type String
1833              * @name Ticks#type
1834              * @default 'linear'
1835              */
1836             type: 'linear'
1837 
1838             // close the meta tag
1839             /**#@-*/
1840         },
1841 
1842          /*
1843           *  Generic options used by {@link JXG.Hatch}
1844           */
1845         hatch: {
1846             drawLabels: false,
1847             drawZero: true,
1848             majorHeight: 20,
1849             anchor: 'middle',
1850             face: '|',
1851             strokeWidth: 2,
1852             strokeColor: Color.palette.blue,
1853             ticksDistance: 0.2
1854         },
1855 
1856         /**
1857          * Precision options, defining how close a pointer device (mouse, finger, pen) has to be
1858          * to an object such that the object is highlighted or can be dragged.
1859          * These values are board-wide and can be overwritten for individual elements by
1860          * changing their precision attribute.
1861          *
1862          * The default values are
1863          * <pre>
1864          * JXG.Options.precision: {
1865          *   touch: 30,
1866          *   touchMax: 100,
1867          *   mouse: 4,
1868          *   pen: 4,
1869          *   epsilon: 0.0001,
1870          *   hasPoint: 4
1871          * }
1872          * </pre>
1873          *
1874          * @type Object
1875          * @name JXG.Options#precision
1876          * @see JXG.GeometryElement#precision
1877          */
1878         precision: {
1879             touch: 30,
1880             touchMax: 100,
1881             mouse: 4,
1882             pen: 4,
1883             epsilon: 0.0001, // Unused
1884             hasPoint: 4
1885         },
1886 
1887         /**
1888          * Default ordering of the layers.
1889          * The numbering starts from 0 and the highest layer number is numlayers-1.
1890          *
1891          * The default values are
1892          * <pre>
1893          * JXG.Options.layer: {
1894          *   numlayers: 20, // only important in SVG
1895          *   text: 9,
1896          *   point: 9,
1897          *   glider: 9,
1898          *   arc: 8,
1899          *   line: 7,
1900          *   circle: 6,
1901          *   curve: 5,
1902          *   turtle: 5,
1903          *   polygon: 3,
1904          *   sector: 3,
1905          *   angle: 3,
1906          *   integral: 3,
1907          *   axis: 2,
1908          *   ticks: 2,
1909          *   grid: 1,
1910          *   image: 0,
1911          *   trace: 0
1912          * }
1913          * </pre>
1914          * @type Object
1915          * @name JXG.Options#layer
1916          */
1917         layer: {
1918             numlayers: 20, // only important in SVG
1919             unused9: 19,
1920             unused8: 18,
1921             unused7: 17,
1922             unused6: 16,
1923             unused5: 15,
1924             unused4: 14,
1925             unused3: 13,
1926             unused2: 12,
1927             unused1: 11,
1928             unused0: 10,
1929             text: 9,
1930             point: 9,
1931             glider: 9,
1932             arc: 8,
1933             line: 7,
1934             circle: 6,
1935             curve: 5,
1936             turtle: 5,
1937             polygon: 3,
1938             sector: 3,
1939             angle: 3,
1940             integral: 3,
1941             axis: 2,
1942             ticks: 2,
1943             grid: 1,
1944             image: 0,
1945             trace: 0
1946         },
1947 
1948         /* special angle options */
1949         angle: {
1950             /**#@+
1951              * @visprop
1952              */
1953 
1954             withLabel: true,
1955 
1956             /**
1957              * Radius of the sector, displaying the angle.
1958              * The radius can be given as number (in user coordinates)
1959              * or as string 'auto'. In the latter case, the angle
1960              * is set to an value between 20 and 50 px.
1961              *
1962              * @type {Number|String}
1963              * @name Angle#radius
1964              * @default 'auto'
1965              * @visprop
1966              */
1967             radius: 'auto',
1968 
1969             /**
1970              * Display type of the angle field. Possible values are
1971              * 'sector' or 'sectordot' or 'square' or 'none'.
1972              *
1973              * @type String
1974              * @default 'sector'
1975              * @name Angle#type
1976              * @visprop
1977              */
1978             type: 'sector',
1979 
1980             /**
1981              * Display type of the angle field in case of a right angle. Possible values are
1982              * 'sector' or 'sectordot' or 'square' or 'none'.
1983              *
1984              * @type String
1985              * @default square
1986              * @name Angle#orthoType
1987              * @see Angle#orthoSensitivity
1988              * @visprop
1989              */
1990             orthoType: 'square',
1991 
1992             /**
1993              * Sensitivity (in degrees) to declare an angle as right angle.
1994              * If the angle measure is inside this distance from a rigth angle, the orthoType
1995              * of the angle is used for display.
1996              *
1997              * @type Number
1998              * @default 1.0
1999              * @name Angle#orthoSensitivity
2000              * @see Angle#orthoType
2001              * @visprop
2002              */
2003             orthoSensitivity: 1.0,
2004 
2005             fillColor: Color.palette.orange,
2006             highlightFillColor: Color.palette.orange,
2007             strokeColor: Color.palette.orange,
2008             // fillColor: '#ff7f00',
2009             // highlightFillColor: '#ff7f00',
2010             // strokeColor: '#ff7f00',
2011 
2012             fillOpacity: 0.3,
2013             highlightFillOpacity: 0.3,
2014 
2015             /**
2016              * @deprecated
2017              */
2018             radiuspoint: {
2019                 withLabel: false,
2020                 visible: false,
2021                 name: ''
2022             },
2023 
2024             /**
2025              * @deprecated
2026              */
2027             pointsquare: {
2028                 withLabel: false,
2029                 visible: false,
2030                 name: ''
2031             },
2032 
2033             dot: {
2034                 visible: false,
2035                 strokeColor: 'none',
2036                 fillColor: '#000000',
2037                 size: 2,
2038                 face: 'o',
2039                 withLabel: false,
2040                 name: ''
2041             },
2042 
2043             label: {
2044                 position: 'top',
2045                 offset: [0, 0],
2046                 strokeColor: Color.palette.blue
2047             },
2048 
2049             /**
2050              * Attributes for sub-element arc. In general, the arc will run through the first point and
2051              * thus will not have the same radius as the angle sector.
2052              *
2053              * @type Arc
2054              * @name Angle#arc
2055              * @default '{visible:false}'
2056              */
2057             arc: {
2058                 visible: false,
2059                 fillColor: 'none'
2060             },
2061 
2062             /**#@-*/
2063         },
2064 
2065         /* special arc options */
2066         arc: {
2067             /**#@+
2068              * @visprop
2069              */
2070 
2071             /**
2072              * Type of arc. Possible values are 'minor', 'major', and 'auto'.
2073              *
2074              * @type String
2075              * @name Arc#selection
2076              * @default 'auto'
2077              */
2078             selection: 'auto',
2079 
2080             /**
2081              * If <tt>true</tt>, moving the mouse over inner points triggers hasPoint.
2082              *
2083              * @see JXG.GeometryElement#hasPoint
2084              * @name Arc#hasInnerPoints
2085              * @type Boolean
2086              * @default false
2087              */
2088             hasInnerPoints: false,
2089 
2090             label: {
2091                 anchorX: 'auto',
2092                 anchorY: 'auto'
2093             },
2094             firstArrow: false,
2095             lastArrow: false,
2096             fillColor: 'none',
2097             highlightFillColor: 'none',
2098             strokeColor: Color.palette.blue,
2099             highlightStrokeColor: '#c3d9ff',
2100             useDirection: false,
2101 
2102             /**
2103              * Attributes for center point.
2104              *
2105              * @type Point
2106              * @name Arc#center
2107              */
2108             center: {
2109             },
2110 
2111             /**
2112              * Attributes for radius point.
2113              *
2114              * @type Point
2115              * @name Arc#radiusPoint
2116              */
2117             radiusPoint: {
2118             },
2119 
2120             /**
2121              * Attributes for angle point.
2122              *
2123              * @type Point
2124              * @name Arc#anglePoint
2125              */
2126             anglePoint: {
2127             }
2128 
2129             /**#@-*/
2130         },
2131 
2132         /* special arrow options */
2133         arrow: {
2134             /**#@+
2135              * @visprop
2136              */
2137 
2138             firstArrow: false,
2139 
2140             lastArrow: {
2141                 type: 1,
2142                 highlightSize: 6,
2143                 size: 6
2144             }
2145 
2146             /**#@-*/
2147         },
2148 
2149         /* special axis options */
2150         axis: {
2151             /**#@+
2152              * @visprop
2153              */
2154 
2155             name: '',                            // By default, do not generate names for axes.
2156             needsRegularUpdate: false,           // Axes only updated after zooming and moving of the origin.
2157             strokeWidth: 1,
2158             lastArrow: {
2159                 type: 1,
2160                 highlightSize: 8,
2161                 size: 8
2162             },
2163             strokeColor: '#666666',
2164             highlightStrokeWidth: 1,
2165             highlightStrokeColor: '#888888',
2166 
2167 
2168             /**
2169              * Show / hide ticks.
2170              *
2171              * Deprecated. Suggested alternative is "ticks: {visible: false}"
2172              *
2173              * @type Boolean
2174              * @name Axis#withTicks
2175              * @default true
2176              * @deprecated
2177              */
2178             withTicks: true,
2179             straightFirst: true,
2180             straightLast: true,
2181             margin: -4,
2182             withLabel: false,
2183             scalable: false,
2184 
2185             /**
2186              * Attributes for ticks of the axis.
2187              *
2188              * @type Ticks
2189              * @name Axis#ticks
2190              */
2191             ticks: {
2192                 label: {
2193                     offset: [4, -12 + 3],     // This seems to be a good offset for 12 point fonts
2194                     parse: false,
2195                     needsRegularUpdate: false,
2196                     display: 'internal',
2197                     visible: 'inherit',
2198                     layer: 9
2199                 },
2200                 visible: 'inherit',
2201                 needsRegularUpdate: false,
2202                 strokeWidth: 1,
2203                 strokeColor: '#666666',
2204                 highlightStrokeColor: '#888888',
2205                 drawLabels: true,
2206                 drawZero: false,
2207                 insertTicks: true,
2208                 minTicksDistance: 5,
2209                 minorHeight: 10,          // if <0: full width and height
2210                 majorHeight: -1,          // if <0: full width and height
2211                 tickEndings: [0, 1],
2212                 minorTicks: 4,
2213                 ticksDistance: 1,         // TODO doc
2214                 strokeOpacity: 0.25
2215             },
2216 
2217             /**
2218              * Attributes for first point the axis.
2219              *
2220              * @type Point
2221              * @name Axis#point1
2222              */
2223             point1: {                  // Default values for point1 if created by line
2224                 needsRegularUpdate: false,
2225                 visible: false
2226             },
2227 
2228             /**
2229              * Attributes for second point the axis.
2230              *
2231              * @type Point
2232              * @name Axis#point2
2233              */
2234             point2: {                  // Default values for point2 if created by line
2235                 needsRegularUpdate: false,
2236                 visible: false
2237             },
2238 
2239             tabindex: -1,
2240 
2241             /**
2242              * Attributes for the axis label.
2243              *
2244              * @type Label
2245              * @name Axis#label
2246              */
2247             label: {
2248                 position: 'lft',
2249                 offset: [10, 10]
2250             }
2251             /**#@-*/
2252         },
2253 
2254         /* special options for angle bisector of 3 points */
2255         bisector: {
2256             /**#@+
2257              * @visprop
2258              */
2259 
2260             strokeColor: '#000000', // Bisector line
2261 
2262             /**
2263              * Attributes for the helper point of the bisector.
2264              *
2265              * @type Point
2266              * @name Bisector#point
2267              */
2268             point: {               // Bisector point
2269                 visible: false,
2270                 fixed: false,
2271                 withLabel: false,
2272                 name: ''
2273             }
2274 
2275             /**#@-*/
2276         },
2277 
2278         /* special options for the 2 bisectors of 2 lines */
2279         bisectorlines: {
2280             /**#@+
2281              * @visprop
2282              */
2283 
2284             /**
2285              * Attributes for first line.
2286              *
2287              * @type Line
2288              * @name Bisectorlines#line1
2289              */
2290             line1: {               //
2291                 strokeColor: '#000000'
2292             },
2293 
2294             /**
2295              * Attributes for second line.
2296              *
2297              * @type Line
2298              * @name Bisectorlines#line2
2299              */
2300             line2: {               //
2301                 strokeColor: '#000000'
2302             }
2303 
2304             /**#@-*/
2305         },
2306 
2307         /* special options for boxplot curves */
2308         boxplot: {
2309             /**#@+
2310              * @visprop
2311              */
2312 
2313             /**
2314              *  Direction of the box plot: 'vertical' or 'horizontal'
2315              *
2316              * @type String
2317              * @name Boxplot#dir
2318              * @default: 'vertical'
2319              */
2320             dir: 'vertical',
2321 
2322             /**
2323              * Relative width of the maximum and minimum quantile
2324              *
2325              * @type Number
2326              * @name Boxplot#smallWidth
2327              * @default: 0.5
2328              */
2329             smallWidth: 0.5,
2330 
2331             strokeWidth: 2,
2332             strokeColor: Color.palette.blue,
2333             fillColor: Color.palette.blue,
2334             fillOpacity: 0.2,
2335             highlightStrokeWidth: 2,
2336             highlightStrokeColor: Color.palette.blue,
2337             highlightFillColor: Color.palette.blue,
2338             highlightFillOpacity: 0.1
2339 
2340             /**#@-*/
2341         },
2342 
2343         /* special button options */
2344         button: {
2345             /**#@+
2346              * @visprop
2347              */
2348 
2349             /**
2350              * Control the attribute "disabled" of the HTML button.
2351              *
2352              * @name disabled
2353              * @memberOf Button.prototype
2354              *
2355              * @type Boolean
2356              * @default false
2357              */
2358             disabled: false,
2359 
2360             display: 'html'
2361 
2362             /**#@-*/
2363         },
2364 
2365         /* special cardinal spline options */
2366         cardinalspline: {
2367             /**#@+
2368              * @visprop
2369              */
2370 
2371              /**
2372               * Controls if the data points of the cardinal spline when given as
2373               * arrays should be converted into {@link JXG.Points}.
2374               *
2375               * @name createPoints
2376               * @memberOf Cardinalspline.prototype
2377               *
2378               * @see Cardinalspline#points
2379               *
2380               * @type Boolean
2381               * @default true
2382               */
2383             createPoints: true,
2384 
2385             /**
2386              * If set to true, the supplied coordinates are interpreted as
2387              * [[x_0, y_0], [x_1, y_1], p, ...].
2388              * Otherwise, if the data consists of two arrays of equal length,
2389              * it is interpreted as
2390              * [[x_o x_1, ..., x_n], [y_0, y_1, ..., y_n]]
2391              *
2392              * @name isArrayOfCoordinates
2393              * @memberOf Cardinalspline.prototype
2394              * @type Boolean
2395              * @default false
2396              */
2397             isArrayOfCoordinates: false,
2398 
2399             /**
2400              * Attributes for the points generated by Cardinalspline in cases
2401              * {@link createPoints} is set to true
2402              *
2403              * @name points
2404              * @memberOf Cardinalspline.prototype
2405              *
2406              * @see Cardinalspline#createPoints
2407              * @type Object
2408              */
2409             points: {
2410                 strokeOpacity: 0.05,
2411                 fillOpacity: 0.05,
2412                 highlightStrokeOpacity: 1.0,
2413                 highlightFillOpacity: 1.0,
2414                 withLabel: false,
2415                 name: '',
2416                 fixed: false
2417             }
2418 
2419             /**#@-*/
2420         },
2421 
2422         /* special chart options */
2423         chart: {
2424             /**#@+
2425              * @visprop
2426              */
2427 
2428             chartStyle: 'line',
2429             colors: ['#B02B2C', '#3F4C6B', '#C79810', '#D15600', '#FFFF88', '#c3d9ff', '#4096EE', '#008C00'],
2430             highlightcolors: null,
2431             fillcolor: null,
2432             highlightonsector: false,
2433             highlightbysize: false,
2434 
2435             fillOpacity: 0.6,
2436             withLines:  false,
2437 
2438             label: {
2439             }
2440             /**#@-*/
2441         },
2442 
2443         /* special html slider options */
2444         checkbox: {
2445             /**#@+
2446              * @visprop
2447              */
2448 
2449             /**
2450              * Control the attribute "disabled" of the HTML checkbox.
2451              *
2452              * @name disabled
2453              * @memberOf Checkbox.prototype
2454              *
2455              * @type Boolean
2456              * @default false
2457              */
2458             disabled: false,
2459 
2460             /**
2461              * Control the attribute "checked" of the HTML checkbox.
2462              *
2463              * @name checked
2464              * @memberOf Checkbox.prototype
2465              *
2466              * @type Boolean
2467              * @default false
2468              */
2469             checked: false,
2470 
2471             display: 'html'
2472 
2473             /**#@-*/
2474         },
2475 
2476         /*special circle options */
2477         circle: {
2478             /**#@+
2479              * @visprop
2480              */
2481 
2482             /**
2483              * If <tt>true</tt>, moving the mouse over inner points triggers hasPoint.
2484              *
2485              * @see JXG.GeometryElement#hasPoint
2486              * @name Circle#hasInnerPoints
2487              * @type Boolean
2488              * @default false
2489              */
2490             hasInnerPoints: false,
2491 
2492             fillColor: 'none',
2493             highlightFillColor: 'none',
2494             strokeColor: Color.palette.blue,
2495             highlightStrokeColor: '#c3d9ff',
2496 
2497             /**
2498              * Attributes for center point.
2499              *
2500              * @type Point
2501              * @name Circle#center
2502              */
2503             center: {
2504                 visible: false,
2505                 withLabel: false,
2506                 fixed: false,
2507 
2508                 fillColor: Color.palette.red,
2509                 strokeColor: Color.palette.red,
2510                 highlightFillColor: '#c3d9ff',
2511                 highlightStrokeColor: '#c3d9ff',
2512     
2513                 name: ''
2514             },
2515 
2516             /**
2517              * Attributes for center point.
2518              *
2519              * @type Point
2520              * @name Circle#center
2521              */
2522             point2: {
2523                 visible: false,
2524                 withLabel: false,
2525                 fixed: false,
2526                 name: ''
2527             },
2528 
2529             /**
2530              * Attributes for circle label.
2531              *
2532              * @type Label
2533              * @name Circle#label
2534              */
2535             label: {
2536                 position: 'urt'
2537             }
2538             /**#@-*/
2539         },
2540 
2541         /* special options for circumcircle of 3 points */
2542         circumcircle: {
2543             /**#@+
2544              * @visprop
2545              */
2546 
2547             fillColor: 'none',
2548             highlightFillColor: 'none',
2549             strokeColor: Color.palette.blue,
2550             highlightStrokeColor: '#c3d9ff',
2551 
2552             /**
2553              * Attributes for center point.
2554              *
2555              * @type Point
2556              * @name Circumcircle#center
2557              */
2558             center: {               // center point
2559                 visible: false,
2560                 fixed: false,
2561                 withLabel: false,
2562                 fillColor: Color.palette.red,
2563                 strokeColor: Color.palette.red,
2564                 highlightFillColor: '#c3d9ff',
2565                 highlightStrokeColor: '#c3d9ff',
2566                 name: ''
2567             }
2568             /**#@-*/
2569         },
2570 
2571         circumcirclearc: {
2572             /**#@+
2573              * @visprop
2574              */
2575 
2576             fillColor: 'none',
2577             highlightFillColor: 'none',
2578             strokeColor: Color.palette.blue,
2579             highlightStrokeColor: '#c3d9ff',
2580 
2581             /**
2582              * Attributes for center point.
2583              *
2584              * @type Point
2585              * @name CircumcircleArc#center
2586              */
2587             center: {
2588                 visible: false,
2589                 withLabel: false,
2590                 fixed: false,
2591                 name: ''
2592             }
2593             /**#@-*/
2594         },
2595 
2596         /* special options for circumcircle sector of 3 points */
2597         circumcirclesector: {
2598             /**#@+
2599              * @visprop
2600              */
2601 
2602             useDirection: true,
2603             fillColor: Color.palette.yellow,
2604             highlightFillColor: Color.palette.yellow,
2605             fillOpacity: 0.3,
2606             highlightFillOpacity: 0.3,
2607             strokeColor: Color.palette.blue,
2608             highlightStrokeColor: '#c3d9ff',
2609 
2610             /**
2611              * Attributes for center point.
2612              *
2613              * @type Point
2614              * @name Circle#point
2615              */
2616             point: {
2617                 visible: false,
2618                 fixed: false,
2619                 withLabel: false,
2620                 name: ''
2621             }
2622             /**#@-*/
2623         },
2624 
2625         /* special conic options */
2626         conic: {
2627             /**#@+
2628              * @visprop
2629              */
2630 
2631             fillColor: 'none',
2632             highlightFillColor: 'none',
2633             strokeColor: Color.palette.blue,
2634             highlightStrokeColor: '#c3d9ff',
2635 
2636             /**
2637              * Attributes for foci points.
2638              *
2639              * @type Point
2640              * @name Conic#foci
2641              */
2642             foci: {
2643                 // points
2644                 fixed: false,
2645                 visible: false,
2646                 withLabel: false,
2647                 name: ''
2648             },
2649 
2650             /**
2651              * Attributes for center point.
2652              *
2653              * @type Point
2654              * @name Conic#center
2655              */
2656             center: {
2657                 visible: false,
2658                 withLabel: false,
2659                 name: ''
2660             },
2661 
2662             /**
2663              * Attributes for five points defining the conic, if some of them are given as coordinates.
2664              *
2665              * @type Point
2666              * @name Conic#point
2667              */
2668             point: {
2669                 withLabel: false,
2670                 name: ''
2671             },
2672 
2673             /**
2674              * Attributes for parabola line in case the line is given by two
2675              * points or coordinate pairs.
2676              *
2677              * @type Line
2678              * @name Conic#line
2679              */
2680             line: {
2681                 visible: false
2682             }
2683 
2684             /**#@-*/
2685         },
2686 
2687         /* special curve options */
2688         curve: {
2689             strokeWidth: 1,
2690             strokeColor: Color.palette.blue,
2691             fillColor: 'none',
2692             fixed: true,
2693 
2694             useQDT: false,
2695 
2696             /**#@+
2697              * @visprop
2698              */
2699 
2700             /**
2701              * The data points of the curve are not connected with straight lines but with bezier curves.
2702              * @name Curve#handDrawing
2703              * @type Boolean
2704              * @default false
2705              */
2706             handDrawing: false,
2707 
2708             /**
2709              * The curveType is set in {@link JXG.Curve#generateTerm} and used in {@link JXG.Curve#updateCurve}.
2710              * Possible values are <ul>
2711              * <li>'none'</li>
2712              * <li>'plot': Data plot</li>
2713              * <li>'parameter': we can not distinguish function graphs and parameter curves</li>
2714              * <li>'functiongraph': function graph</li>
2715              * <li>'polar'</li>
2716              * <li>'implicit' (not yet)</li></ul>
2717              * Only parameter and plot are set directly. Polar is set with {@link JXG.GeometryElement#setAttribute} only.
2718              * @name Curve#curveType
2719              * @type String
2720              * @default null
2721              */
2722             curveType: null,
2723 
2724             /**
2725              * Apply Ramer-Douglas-Peuker smoothing.
2726              *
2727              * @type Boolean
2728              * @name Curve#RDPsmoothing
2729              * @default false
2730              */
2731             RDPsmoothing: false,     // Apply the Ramer-Douglas-Peuker algorithm
2732 
2733             /**
2734              * Number of points used for plotting triggered by up events
2735              * (i.e. high quality plotting) in case
2736              * {@link Curve#doAdvancedPlot} is false.
2737              *
2738              * @name Curve#numberPointsHigh
2739              * @see Curve#doAdvancedPlot
2740              * @type Number
2741              * @default 1600
2742              */
2743             numberPointsHigh: 1600,  // Number of points on curves after mouseUp
2744 
2745             /**
2746              * Number of points used for plotting triggered by move events
2747              * (i.e. lower quality plotting but fast) in case
2748              * {@link Curve#doAdvancedPlot} is false.
2749              *
2750              * @name Curve#numberPointsLow
2751              * @see Curve#doAdvancedPlot
2752              * @type Number
2753              * @default 400
2754              */
2755             numberPointsLow: 400,    // Number of points on curves after mousemove
2756 
2757             /**
2758              * If true use a recursive bisection algorithm.
2759              * It is slower, but usually the result is better. It tries to detect jumps
2760              * and singularities.
2761              *
2762              * @name Curve#doAdvancedPlot
2763              * @type Boolean
2764              * @default true
2765              */
2766             doAdvancedPlot: true,
2767 
2768             /**
2769              *
2770              * Recursion depth used for plotting triggered by up events
2771              * (i.e. high quality plotting) in case
2772              * {@link Curve#doAdvancedPlot} is true.
2773              *
2774              * @name Curve#recursionDepthHigh
2775              * @see Curve#doAdvancedPlot
2776              * @type Number
2777              * @default 17
2778              */
2779              recursionDepthHigh: 17,
2780 
2781             /**
2782              * Number of points used for plotting triggered by move events in case
2783              * (i.e. lower quality plotting but fast)
2784              * {@link Curve#doAdvancedPlot} is true.
2785              *
2786              * @name Curve#recursionDepthLow
2787              * @see Curve#doAdvancedPlot
2788              * @type Number
2789              * @default 13
2790              */
2791              recursionDepthLow: 15,
2792 
2793             /**
2794              * If true use the algorithm by Gillam and Hohenwarter, which was default until version 0.98.
2795              *
2796              * @name Curve#doAdvancedPlotOld
2797              * @see Curve#doAdvancedPlot
2798              * @type Boolean
2799              * @default false
2800              * @deprecated
2801              */
2802             doAdvancedPlotOld: false,   // v1
2803 
2804             /**
2805              * Select the version of the plot algorithm.
2806              * <ul>
2807              * <li> Version 1 is very outdated
2808              * <li> Version 2 is the default version in JSXGraph v0.99.*, v1.0, and v1.1, v1.2.0
2809              * <li> Version 3 is an internal version that was never published in  a stable version.
2810              * <li> Version 4 is available since JSXGraph v1.2.0
2811              * </ul>
2812              * Version 4 plots correctly logarithms if the function term is supplied as string (i.e. as JessieCode)
2813              *
2814              * @example
2815              *   var c = board.create('functiongraph', ["log(x)"]);
2816              *
2817              * @name Curve#plotVersion
2818              * @type Number
2819              * @default 2
2820              */
2821             plotVersion: 2,
2822 
2823             /**
2824              * Attributes for circle label.
2825              *
2826              * @type Label
2827              * @name Circle#label
2828              */
2829             label: {
2830                 position: 'lft'
2831             },
2832 
2833             /**
2834              * Configure arrow head at the start position for curve.
2835              * Recommended arrow head type is 7.
2836              *
2837              * @name Curve#firstArrow
2838              * @type Boolean / Object
2839              * @default false
2840              * @see Line#firstArrow for options
2841              */
2842             firstArrow: false,
2843 
2844             /**
2845              * Configure arrow head at the end position for curve.
2846              * Recommended arrow head type is 7.
2847              *
2848              * @name Curve#lastArrow
2849              * @see Line#lastArrow for options
2850              * @type Boolean / Object
2851              * @default false
2852              */
2853             lastArrow: false
2854 
2855             /**#@-*/
2856         },
2857 
2858         /* special foreignObject options */
2859         foreignobject: {
2860 
2861             /**#@+
2862              * @visprop
2863              */
2864             attractors: [],
2865             fixed: true,
2866             visible: true
2867 
2868             /**#@-*/
2869         },
2870 
2871         glider: {
2872             /**#@+
2873              * @visprop
2874              */
2875 
2876             label: {}
2877             /**#@-*/
2878         },
2879 
2880         /* special grid options */
2881         grid: {
2882             /**#@+
2883              * @visprop
2884              */
2885 
2886             /* grid styles */
2887             needsRegularUpdate: false,
2888             hasGrid: false,
2889             gridX: 1,
2890             gridY: 1,
2891             //strokeColor: '#c0c0c0',
2892             strokeColor: '#c0c0c0',
2893             strokeOpacity: 0.5,
2894             strokeWidth: 1,
2895             dash: 0,    // dashed grids slow down the iPad considerably
2896             /* snap to grid options */
2897 
2898             /**
2899              * @deprecated
2900              */
2901             snapToGrid: false,
2902             /**
2903              * @deprecated
2904              */
2905             snapSizeX: 10,
2906             /**
2907              * @deprecated
2908              */
2909             snapSizeY: 10
2910 
2911             /**#@-*/
2912         },
2913 
2914         group: {
2915             needsRegularUpdate: true
2916         },
2917 
2918         /* special html slider options */
2919         htmlslider: {
2920             /**#@+
2921              * @visprop
2922              */
2923 
2924             /**
2925              *
2926              * These affect the DOM element input type="range".
2927              * The other attributes affect the DOM element div containing the range element.
2928              */
2929             widthRange: 100,
2930             widthOut: 34,
2931             step: 0.01,
2932 
2933             frozen: true,
2934             isLabel: false,
2935             strokeColor: '#000000',
2936             display: 'html',
2937             anchorX: 'left',
2938             anchorY: 'middle',
2939             withLabel: false
2940 
2941             /**#@-*/
2942         },
2943 
2944         /* special image options */
2945         image: {
2946             /**#@+
2947              * @visprop
2948              */
2949 
2950             imageString: null,
2951             fillOpacity: 1.0,
2952             highlightFillOpacity: 0.6,
2953 
2954 
2955             /**
2956              * Defines the CSS class used by the image. CSS attributes defined in
2957              * this class will overwrite the corresponding JSXGraph attributes, e.g.
2958              * opacity.
2959              * The default CSS class is defined in jsxgraph.css.
2960              *
2961              * @name Image#cssClass
2962              *
2963              * @see Image#highlightCssClass
2964              * @type String
2965              * @default 'JXGimage'
2966              */
2967             cssClass: 'JXGimage',
2968 
2969             /**
2970              * Defines the CSS class used by the image when highlighted.
2971              * CSS attributes defined in this class will overwrite the
2972              * corresponding JSXGraph attributes, e.g. highlightFillOpacity.
2973              * The default CSS class is defined in jsxgraph.css.
2974              *
2975              * @name Image#highlightCssClass
2976              *
2977              * @see Image#cssClass
2978              * @type String
2979              * @default 'JXGimageHighlight'
2980              */
2981             highlightCssClass: 'JXGimageHighlight',
2982 
2983             /**
2984              * Image rotation in degrees.
2985              *
2986              * @name Image#rotate
2987              * @type Number
2988              * @default 0
2989              */
2990             rotate: 0,
2991 
2992             /**
2993              * Defines together with {@link Image#snapSizeY} the grid the image snaps on to.
2994              * The image will only snap on user coordinates which are
2995              * integer multiples to snapSizeX in x and snapSizeY in y direction.
2996              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
2997              * of the default ticks of the default x axes of the board.
2998              *
2999              * @name Image#snapSizeX
3000              *
3001              * @see Point#snapToGrid
3002              * @see Image#snapSizeY
3003              * @see JXG.Board#defaultAxes
3004              * @type Number
3005              * @default 1
3006              */
3007             snapSizeX: 1,
3008 
3009             /**
3010              * Defines together with {@link Image#snapSizeX} the grid the image snaps on to.
3011              * The image will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
3012              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
3013              * of the default ticks of the default y axes of the board.
3014              *
3015              * @name Image#snapSizeY
3016              *
3017              * @see Point#snapToGrid
3018              * @see Image#snapSizeX
3019              * @see JXG.Board#defaultAxes
3020              * @type Number
3021              * @default 1
3022              */
3023             snapSizeY: 1,
3024 
3025             /**
3026              * List of attractor elements. If the distance of the image is less than
3027              * attractorDistance the image is made to glider of this element.
3028              *
3029              * @name Image#attractors
3030              *
3031              * @type Array
3032              * @default empty
3033              */
3034             attractors: []
3035 
3036             /**#@-*/
3037         },
3038 
3039         /* special options for incircle of 3 points */
3040         incircle: {
3041             /**#@+
3042              * @visprop
3043              */
3044 
3045             fillColor: 'none',
3046             highlightFillColor: 'none',
3047             strokeColor: Color.palette.blue,
3048             highlightStrokeColor: '#c3d9ff',
3049 
3050             /**
3051              * Attributes of circle center.
3052              *
3053              * @type Point
3054              * @name Incircle#center
3055              */
3056             center: {               // center point
3057                 visible: false,
3058                 fixed: false,
3059                 withLabel: false,
3060                 fillColor: Color.palette.red,
3061                 strokeColor: Color.palette.red,
3062                 highlightFillColor: '#c3d9ff',
3063                 highlightStrokeColor: '#c3d9ff',
3064                 name: ''
3065             }
3066             /**#@-*/
3067         },
3068 
3069         inequality: {
3070             /**#@+
3071              * @visprop
3072              */
3073 
3074             fillColor: Color.palette.red,
3075             fillOpacity: 0.2,
3076             strokeColor: 'none',
3077 
3078             /**
3079              * By default an inequality is less (or equal) than. Set inverse to <tt>true</tt> will consider the inequality
3080              * greater (or equal) than.
3081              *
3082              * @type Boolean
3083              * @default false
3084              * @name Inequality#inverse
3085              * @visprop
3086              */
3087             inverse: false
3088             /**#@-*/
3089         },
3090 
3091         infobox: {
3092             /**#@+
3093              * @visprop
3094              */
3095 
3096             fontSize: 12,
3097             isLabel: false,
3098             strokeColor: '#bbbbbb',
3099             display: 'html',             // 'html' or 'internal'
3100             anchorX: 'left',             //  'left', 'middle', or 'right': horizontal alignment
3101                                          //  of the text.
3102             anchorY: 'middle',           //  'top', 'middle', or 'bottom': vertical alignment
3103                                          //  of the text.
3104             cssClass: 'JXGinfobox',
3105             rotate: 0,                   // works for non-zero values only in combination
3106                                          // with display=='internal'
3107             visible: true,
3108             parse: false,
3109             transitionDuration: 0,
3110             needsRegularUpdate: false
3111 
3112             /**#@-*/
3113         },
3114 
3115         /* special options for integral */
3116         integral: {
3117             /**#@+
3118              * @visprop
3119              */
3120 
3121             axis: 'x',        // 'x' or 'y'
3122             withLabel: true,    // Show integral value as text
3123             fixed: true,
3124             strokeWidth: 0,
3125             strokeOpacity: 0,
3126             fillColor: Color.palette.red,
3127             fillOpacity: 0.3,
3128             highlightFillColor: Color.palette.red,
3129             highlightFillOpacity: 0.2,
3130 
3131             /**
3132              * Attributes of the (left) starting point of the integral.
3133              *
3134              * @type Point
3135              * @name Integral#curveLeft
3136              * @see Integral#baseLeft
3137              */
3138             curveLeft: {    // Start point
3139                 visible: true,
3140                 withLabel: false,
3141                 color: Color.palette.red,
3142                 fillOpacity: 0.8,
3143                 layer: 9
3144             },
3145 
3146             /**
3147              * Attributes of the (left) base point of the integral.
3148              *
3149              * @type Point
3150              * @name Integral#baseLeft
3151              * @see Integral#curveLeft
3152              */
3153             baseLeft: {    // Start point
3154                 visible: false,
3155                 fixed: false,
3156                 withLabel: false,
3157                 name: ''
3158             },
3159 
3160             /**
3161              * Attributes of the (right) end point of the integral.
3162              *
3163              * @type Point
3164              * @name Integral#curveRight
3165              * @see Integral#baseRight
3166              */
3167             curveRight: {      // End point
3168                 visible: true,
3169                 withLabel: false,
3170                 color: Color.palette.red,
3171                 fillOpacity: 0.8,
3172                 layer: 9
3173             },
3174 
3175             /**
3176              * Attributes of the (right) base point of the integral.
3177              *
3178              * @type Point
3179              * @name Integral#baseRight
3180              * @see Integral#curveRight
3181              */
3182             baseRight: {      // End point
3183                 visible: false,
3184                 fixed: false,
3185                 withLabel: false,
3186                 name: ''
3187             },
3188 
3189             /**
3190              * Attributes for integral label.
3191              *
3192              * @type Label
3193              * @name Integral#label
3194              */
3195             label: {
3196                 fontSize: 20
3197             }
3198             /**#@-*/
3199         },
3200 
3201         /* special input options */
3202         input: {
3203             /**#@+
3204              * @visprop
3205              */
3206 
3207             /**
3208              * Control the attribute "disabled" of the HTML input field.
3209              *
3210              * @name disabled
3211              * @memberOf Input.prototype
3212              *
3213              * @type Boolean
3214              * @default false
3215              */
3216             disabled: false,
3217 
3218             /**
3219              * Control the attribute "maxlength" of the HTML input field.
3220              *
3221              * @name maxlength
3222              * @memberOf Input.prototype
3223              *
3224              * @type Number
3225              * @default 524288 (as in HTML)
3226              */
3227             maxlength: 524288,
3228 
3229             display: 'html'
3230 
3231             /**#@-*/
3232         },
3233 
3234         /* special intersection point options */
3235         intersection: {
3236             /**#@+
3237              * @visprop
3238              */
3239 
3240             /**
3241              * Used in {@link JXG.Intersection}.
3242              * This flag sets the behaviour of intersection points of e.g.
3243              * two segments. If true, the intersection is treated as intersection of lines. If false
3244              * the intersection point exists if the segments intersect setwise.
3245              *
3246              * @name Intersection.alwaysIntersect
3247              * @type Boolean
3248              * @default true
3249              */
3250             alwaysIntersect: true
3251 
3252             /**#@-*/
3253         },
3254 
3255         /* special label options */
3256         label: {
3257             /**#@+
3258              * @visprop
3259              */
3260 
3261             visible: 'inherit',
3262             strokeColor: '#000000',
3263             strokeOpacity: 1,
3264             highlightStrokeOpacity: 0.666666,
3265             highlightStrokeColor: '#000000',
3266 
3267             fixed: true,
3268 
3269             /**
3270              * Possible string values for the position of a label for
3271              * label anchor points are:
3272              * <ul>
3273              * <li> 'lft'
3274              * <li> 'rt'
3275              * <li> 'top'
3276              * <li> 'bot'
3277              * <li> 'ulft'
3278              * <li> 'urt'
3279              * <li> 'llft'
3280              * <li> 'lrt'
3281              * </ul>
3282              * This is relevant for non-points: line, circle, curve.
3283              *
3284              * The names have been borrowed from <a href="https://www.tug.org/metapost.html">MetaPost</a>.
3285              *
3286              * @name Label#position
3287              * @see Label#offset
3288              * @type String
3289              * @default 'urt'
3290              */
3291             position: 'urt',
3292 
3293             /**
3294              *  Label offset from label anchor.
3295              *  The label anchor is determined by {@link Label#position}
3296              *
3297              * @name Label#offset
3298              * @see Label#position
3299              * @type Array
3300              * @default [10,10]
3301              */
3302             offset: [10, 10],
3303 
3304             /**
3305              * Automatic position of label text. When called first, the positioning algorithm
3306              * starts at the position defined by offset.
3307              * The algorithm tries to find a position with the least number of
3308              * overlappings with other elements, while retaining the distance
3309              * to the anchor element.
3310              *
3311              * @name Label#autoPosition
3312              * @see Label#offset
3313              * @type Boolean
3314              * @default false
3315              *
3316              * @example
3317              * 	var p1 = board.create('point', [-2, 1], {id: 'A'});
3318              * 	var p2 = board.create('point', [-0.85, 1], {
3319              *      name: 'B', id: 'B', label:{autoPosition: true, offset:[10, 10]}
3320              *  });
3321              * 	var p3 = board.create('point', [-1, 1.2], {
3322              *      name: 'C', id: 'C', label:{autoPosition: true, offset:[10, 10]}
3323              *  });
3324              *  var c = board.create('circle', [p1, p2]);
3325              * 	var l = board.create('line', [p1, p2]);
3326              *
3327              * </pre><div id="JXG7d4dafe7-1a07-4d3f-95cb-bfed9d96dea2" class="jxgbox" style="width: 300px; height: 300px;"></div>
3328              * <script type="text/javascript">
3329              *     (function() {
3330              *         var board = JXG.JSXGraph.initBoard('JXG7d4dafe7-1a07-4d3f-95cb-bfed9d96dea2',
3331              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
3332              *     	var p1 = board.create('point', [-2, 1], {id: 'A'});
3333              *     	var p2 = board.create('point', [-0.85, 1], {name: 'B', id: 'B', label:{autoPosition: true, offset:[10, 10]}});
3334              *     	var p3 = board.create('point', [-1, 1.2], {name: 'C', id: 'C', label:{autoPosition: true, offset:[10, 10]}});
3335              *      var c = board.create('circle', [p1, p2]);
3336              *     	var l = board.create('line', [p1, p2]);
3337              *
3338              *     })();
3339              *
3340              * </script><pre>
3341              *
3342              *
3343              */
3344             autoPosition: false
3345 
3346             /**#@-*/
3347         },
3348 
3349         /* special legend options */
3350         legend: {
3351             /**
3352              * @visprop
3353              */
3354 
3355              /**
3356               * Default style of a legend element. The only possible value is 'vertical'.
3357               * @name: Legend#style
3358               * @type String
3359               * @default 'vertical'
3360               */
3361             style: 'vertical',
3362 
3363             /**
3364              * Label names of a legend element.
3365              * @name: Legend#labels
3366              * @type Array
3367              * @default "['1', '2', '3', '4', '5', '6', '7', '8']"
3368              */
3369             labels: ['1', '2', '3', '4', '5', '6', '7', '8'],
3370 
3371             /**
3372              * (Circular) array of label colors.
3373              * @name: Legend#colors
3374              * @type Array
3375              * @default "['#B02B2C', '#3F4C6B', '#C79810', '#D15600', '#FFFF88', '#c3d9ff', '#4096EE', '#008C00']"
3376              */
3377             colors: ['#B02B2C', '#3F4C6B', '#C79810', '#D15600', '#FFFF88', '#c3d9ff', '#4096EE', '#008C00'],
3378 
3379             /**
3380              * Height (in px) of one legend entry
3381              * @name: Legend#rowHeight
3382              * @type Number
3383              * @default 20
3384              *
3385              */
3386             rowHeight: 20,
3387 
3388             strokeWidth: 5
3389 
3390             /**#@-*/
3391         },
3392 
3393         /* special line options */
3394         line: {
3395             /**#@+
3396              * @visprop
3397              */
3398 
3399             /**
3400              * Configure the arrow head at the position of its first point or the corresponding
3401              * intersection with the canvas border
3402              *
3403              * In case firstArrow is an object it has the sub-attributes:
3404              * <pre>
3405              * {
3406              *      type: 1, // possible values are 1, 2, ..., 7. Default value is 1.
3407              *      size: 6, // size of the arrow head. Default value is 6.
3408              *               // This value is multiplied with the strokeWidth of the line
3409              *               // Exception: for type=7 size is ignored
3410              *      highlightSize: 6, // size of the arrow head in case the element is highlighted. Default value
3411              * }
3412              * </pre>
3413              * type=7 is the default for curves if firstArrow: true
3414              *
3415              * @name Line#firstArrow
3416              * @see Line#lastArrow
3417              * @see Line#touchFirstPoint
3418              * @type Boolean / Object
3419              * @default false
3420              */
3421             firstArrow: false,
3422 
3423             /**
3424              * Configute the arrow head at the position of its second point or the corresponding
3425              * intersection with the canvas border.
3426              *
3427              * In case lastArrow is an object it has the sub-attributes:
3428              * <pre>
3429              * {
3430              *      type: 1, // possible values are 1, 2, ..., 7. Default value is 1.
3431              *      size: 6, // size of the arrow head. Default value is 6.
3432              *               // This value is multiplied with the strokeWidth of the line.
3433              *               // Exception: for type=7 size is ignored
3434              *      highlightSize: 6, // size of the arrow head in case the element is highlighted. Default value is 6.
3435              * }
3436              * </pre>
3437              * type=7 is the default for curves if lastArrow: true
3438              *
3439              * @example
3440              *     var p1 = board.create('point', [-5, 2], {size:1});
3441              *     var p2 = board.create('point', [5, 2], {size:10});
3442              *     var li = board.create('segment', ['A','B'],
3443              *         {name:'seg',
3444              *          strokeColor:'#000000',
3445              *          strokeWidth:1,
3446              *          highlightStrokeWidth: 5,
3447              *          lastArrow: {type: 2, size: 8, highlightSize: 6},
3448              *          touchLastPoint: true,
3449              *          firstArrow: {type: 3, size: 8}
3450              *         });
3451              *
3452              * </pre><div id="JXG184e915c-c2ef-11e8-bece-04d3b0c2aad3" class="jxgbox" style="width: 300px; height: 300px;"></div>
3453              * <script type="text/javascript">
3454              *     (function() {
3455              *         var board = JXG.JSXGraph.initBoard('JXG184e915c-c2ef-11e8-bece-04d3b0c2aad3',
3456              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
3457              *         var p1 = board.create('point', [-5, 2], {size:1});
3458              *         var p2 = board.create('point', [5, 2], {size:10});
3459              *         var li = board.create('segment', ['A','B'],
3460              *             {name:'seg',
3461              *              strokeColor:'#000000',
3462              *              strokeWidth:1,
3463              *              highlightStrokeWidth: 5,
3464              *              lastArrow: {type: 2, size: 8, highlightSize: 6},
3465              *              touchLastPoint: true,
3466              *              firstArrow: {type: 3, size: 8}
3467              *             });
3468              *
3469              *     })();
3470              *
3471              * </script>
3472              *
3473              * @name Line#lastArrow
3474              * @see Line#firstArrow
3475              * @see Line#touchLastPoint
3476              * @type Boolean / Object
3477              * @default false
3478              */
3479             lastArrow: false,
3480 
3481 
3482             /**
3483              * This number (pixel value) controls where infinite lines end at the canvas border. If zero, the line
3484              * ends exactly at the border, if negative there is a margin to the inside, if positive the line
3485              * ends outside of the canvas (which is invisible).
3486              *
3487              * @name: Line#margin
3488              * @type Number
3489              * @default 0
3490              */
3491             margin: 0,
3492 
3493             /**
3494              * If true, line stretches infinitely in direction of its first point.
3495              * Otherwise it ends at point1.
3496              *
3497              * @name Line#straightFirst
3498              * @see Line#straightLast
3499              * @type Boolean
3500              * @default true
3501              */
3502             straightFirst: true,
3503 
3504             /**
3505              * If true, line stretches infinitely in direction of its second point.
3506              * Otherwise it ends at point2.
3507              *
3508              * @name Line#straightLast
3509              * @see Line#straightFirst
3510              * @type Boolean
3511              * @default true
3512              */
3513             straightLast: true,
3514 
3515             fillColor: 'none',               // Important for VML on IE
3516             highlightFillColor: 'none',  // Important for VML on IE
3517             strokeColor: Color.palette.blue,
3518             highlightStrokeColor: '#c3d9ff',
3519             withTicks: false,
3520 
3521             /**
3522              * Attributes for first defining point of the line.
3523              *
3524              * @type Point
3525              * @name Line#point1
3526              */
3527             point1: {                  // Default values for point1 if created by line
3528                 visible: false,
3529                 withLabel: false,
3530                 fixed: false,
3531                 name: ''
3532             },
3533 
3534             /**
3535              * Attributes for second defining point of the line.
3536              *
3537              * @type Point
3538              * @name Line#point2
3539              */
3540             point2: {                  // Default values for point2 if created by line
3541                 visible: false,
3542                 withLabel: false,
3543                 fixed: false,
3544                 name: ''
3545             },
3546 
3547             /**
3548              * Attributes for ticks of the line.
3549              *
3550              * @type Ticks
3551              * @name Line#ticks
3552              */
3553             ticks: {
3554                 drawLabels: true,
3555                 label: {
3556                     offset: [4, -12 + 3] // This seems to be a good offset for 12 point fonts
3557                 },
3558                 drawZero: false,
3559                 insertTicks: false,
3560                 minTicksDistance: 50,
3561                 minorHeight: 4,          // if <0: full width and height
3562                 majorHeight: -1,         // if <0: full width and height
3563                 minorTicks: 4,
3564                 defaultDistance: 1,
3565                 strokeOpacity: 0.3,
3566                 visible: 'inherit'
3567             },
3568 
3569             /**
3570              * Attributes for the line label.
3571              *
3572              * @type Label
3573              * @name Line#label
3574              */
3575             label: {
3576                 position: 'llft'
3577             },
3578 
3579             /**
3580              * If set to true, the point will snap to a grid defined by
3581              * {@link Point#snapSizeX} and {@link Point#snapSizeY}.
3582              *
3583              * @see Point#snapSizeX
3584              * @see Point#snapSizeY
3585              * @type Boolean
3586              * @name Line#snapToGrid
3587              * @default false
3588              */
3589             snapToGrid: false,
3590 
3591             /**
3592              * Defines together with {@link Point#snapSizeY} the grid the point snaps on to.
3593              * The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
3594              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
3595              * of the default ticks of the default x axes of the board.
3596              *
3597              * @see Point#snapToGrid
3598              * @see Point#snapSizeY
3599              * @see JXG.Board#defaultAxes
3600              * @type Number
3601              * @name Line#snapSizeX
3602              * @default 1
3603              */
3604             snapSizeX: 1,
3605 
3606             /**
3607              * Defines together with {@link Point#snapSizeX} the grid the point snaps on to.
3608              * The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
3609              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
3610              * of the default ticks of the default y axes of the board.
3611              *
3612              * @see Point#snapToGrid
3613              * @see Point#snapSizeX
3614              * @see JXG.Board#defaultAxes
3615              * @type Number
3616              * @name Line#snapSizeY
3617              * @default 1
3618              */
3619             snapSizeY: 1,
3620 
3621             /**
3622              * If set to true and {@link Line#firstArrow} is set to true, the arrow head will just touch
3623              * the circle line of the start point of the line.
3624              *
3625              * @see Line#firstArrow
3626              * @type Boolean
3627              * @name Line#touchFirstPoint
3628              * @default false
3629              */
3630             touchFirstPoint: false,
3631 
3632             /**
3633              * If set to true and {@link Line#lastArrow} is set to true, the arrow head will just touch
3634              * the circle line of the start point of the line.
3635              * @see Line#firstArrow
3636              * @type Boolean
3637              * @name Line#touchLastPoint
3638              * @default false
3639              */
3640             touchLastPoint: false,
3641 
3642             /**
3643              * Line endings (linecap) of a straight line.
3644              * Possible values are:
3645              * <ul>
3646              * <li> 'butt',
3647              * <li> 'round',
3648              * <li> 'square'.
3649              * </ul>
3650              * Not available for VML renderer.
3651              * [lineCap description]
3652              * @name Line#lineCap
3653              * @type String
3654              * @default 'butt'
3655              */
3656             lineCap: 'butt'
3657 
3658 
3659             /**#@-*/
3660         },
3661 
3662         /* special options for locus curves */
3663         locus: {
3664             /**#@+
3665              * @visprop
3666              */
3667 
3668             translateToOrigin: false,
3669             translateTo10: false,
3670             stretch: false,
3671             toOrigin: null,
3672             to10: null
3673             /**#@-*/
3674         },
3675 
3676         /* special cardinal spline options */
3677         metapostspline: {
3678             /**#@+
3679              * @visprop
3680              */
3681 
3682              /**
3683               * Controls if the data points of the cardinal spline when given as
3684               * arrays should be converted into {@link JXG.Points}.
3685               *
3686               * @name createPoints
3687               * @memberOf Metapostspline.prototype
3688               *
3689               * @see Metapostspline#points
3690               *
3691               * @type Boolean
3692               * @default true
3693               */
3694             createPoints: true,
3695 
3696             /**
3697              * If set to true, the supplied coordinates are interpreted as
3698              * [[x_0, y_0], [x_1, y_1], p, ...].
3699              * Otherwise, if the data consists of two arrays of equal length,
3700              * it is interpreted as
3701              * [[x_o x_1, ..., x_n], [y_0, y_1, ..., y_n]]
3702              *
3703              * @name isArrayOfCoordinates
3704              * @memberOf Metapostspline.prototype
3705              * @type Boolean
3706              * @default false
3707              */
3708             isArrayOfCoordinates: false,
3709 
3710             /**
3711              * Attributes for the points generated by Metapostspline in cases
3712              * {@link createPoints} is set to true
3713              *
3714              * @name points
3715              * @memberOf Metapostspline.prototype
3716              *
3717              * @see Metapostspline#createPoints
3718              * @type Object
3719              */
3720             points: {
3721                 strokeOpacity: 0.05,
3722                 fillOpacity: 0.05,
3723                 highlightStrokeOpacity: 1.0,
3724                 highlightFillOpacity: 1.0,
3725                 withLabel: false,
3726                 name: '',
3727                 fixed: false
3728             }
3729 
3730             /**#@-*/
3731         },
3732 
3733         /* special mirrorelement options */
3734         mirrorelement: {
3735             /**#@+
3736              * @visprop
3737              */
3738 
3739             fixed: true,
3740 
3741             /**
3742              * Attributes of mirror point, i.e. the point along which the element is mirrored.
3743              *
3744              * @type Point
3745              * @name mirrorelement#point
3746              */
3747             point: {},
3748 
3749             /**
3750              * Attributes of circle center, i.e. the center of the circle,
3751              * if a circle is the mirror element and the transformation type is 'Euclidean'
3752              *
3753              * @type Point
3754              * @name mirrorelement#center
3755              */
3756             center: {},
3757 
3758             /**
3759              * Type of transformation. Possible values are 'Euclidean', 'projective'.
3760              *
3761              * If the value is 'Euclidean', the mirror element of a circle is again a circle,
3762              * otherwise it is a conic section.
3763              *
3764              * @type String
3765              * @name mirrorelement#type
3766              * @default 'Euclidean'
3767              */
3768             type: 'Euclidean'
3769 
3770             /**#@-*/
3771         },
3772 
3773         // /* special options for Msector of 3 points */
3774         // msector: {
3775         //     strokeColor: '#000000', // Msector line
3776         //     point: {               // Msector point
3777         //         visible: false,
3778         //         fixed: false,
3779         //         withLabel: false,
3780         //         name: ''
3781         //     }
3782         // },
3783 
3784         /* special options for normal lines */
3785         normal: {
3786             /**#@+
3787              * @visprop
3788              */
3789 
3790             strokeColor: '#000000', //  normal line
3791 
3792             /**
3793              * Attributes of helper point of normal.
3794              *
3795              * @type Point
3796              * @name Normal#point
3797              */
3798             point: {
3799                 visible: false,
3800                 fixed: false,
3801                 withLabel: false,
3802                 name: ''
3803             }
3804             /**#@-*/
3805         },
3806 
3807         /* special options for orthogonal projection points */
3808         orthogonalprojection: {
3809             /**#@+
3810              * @visprop
3811              */
3812 
3813 
3814             /**#@-*/
3815         },
3816 
3817         /* special options for parallel lines */
3818         parallel: {
3819             /**#@+
3820              * @visprop
3821              */
3822 
3823             strokeColor: '#000000', // Parallel line
3824 
3825             /**
3826              * Attributes of helper point of normal.
3827              *
3828              * @type Point
3829              * @name Parallel#point
3830              */
3831             point: {
3832                 visible: false,
3833                 fixed: false,
3834                 withLabel: false,
3835                 name: ''
3836             },
3837 
3838             label: {
3839                 position: 'llft'
3840             }
3841             /**#@-*/
3842         },
3843 
3844         /* special perpendicular options */
3845         perpendicular: {
3846             /**#@+
3847              * @visprop
3848              */
3849 
3850             strokeColor: '#000000', // Perpendicular line
3851             straightFirst: true,
3852             straightLast: true
3853             /**#@-*/
3854         },
3855 
3856         /* special perpendicular options */
3857         perpendicularsegment: {
3858             /**#@+
3859              * @visprop
3860              */
3861 
3862             strokeColor: '#000000', // Perpendicular segment
3863             straightFirst: false,
3864             straightLast: false,
3865             point: {               // Perpendicular point
3866                 visible: false,
3867                 fixed: true,
3868                 withLabel: false,
3869                 name: ''
3870             }
3871             /**#@-*/
3872         },
3873 
3874         /* special point options */
3875         point: {
3876             /**#@+
3877              * @visprop
3878              */
3879 
3880             withLabel: true,
3881             label: {},
3882 
3883             /**
3884              * This attribute was used to determined the point layout. It was derived from GEONExT and was
3885              * replaced by {@link Point#face} and {@link Point#size}.
3886              *
3887              * @name Point#style
3888              *
3889              * @see Point#face
3890              * @see Point#size
3891              * @type Number
3892              * @default 5
3893              * @deprecated
3894              */
3895             style: 5,
3896 
3897             /**
3898              * There are different point styles which differ in appearance.
3899              * Posssible values are
3900              * <table><tr><th>Value</th></tr>
3901              * <tr><td>cross</td></tr>
3902              * <tr><td>circle</td></tr>
3903              * <tr><td>square</td></tr>
3904              * <tr><td>plus</td></tr>
3905              * <tr><td>diamond</td></tr>
3906              * <tr><td>triangleUp</td></tr>
3907              * <tr><td>triangleDown</td></tr>
3908              * <tr><td>triangleLeft</td></tr>
3909              * <tr><td>triangleRight</td></tr>
3910              * </table>
3911              *
3912              * @name Point#face
3913              *
3914              * @type String
3915              * @see JXG.Point#setStyle
3916              * @default circle
3917              */
3918             face: 'o',
3919 
3920             /**
3921              * Size of a point, either in pixel or user coordinates.
3922              * Means radius resp. half the width of a point (depending on the face).
3923              *
3924              * @name Point#size
3925              *
3926              * @see Point#face
3927              * @see JXG.Point#setStyle
3928              * @see Point#sizeUnit
3929              * @type Number
3930              * @default 3
3931              */
3932             size: 3,
3933 
3934             /**
3935              * Unit for size.
3936              * Possible values are 'screen' and 'user.
3937              *
3938              * @name Point#sizeUnit
3939              *
3940              * @see Point#size
3941              * @type String
3942              * @default 'screen'
3943              */
3944             sizeUnit: 'screen',
3945 
3946             strokeWidth: 2,
3947 
3948             fillColor: Color.palette.red,
3949             strokeColor: Color.palette.red,
3950             highlightFillColor:'#c3d9ff',
3951             highlightStrokeColor: '#c3d9ff',
3952             // strokeOpacity: 1.0,
3953             // fillOpacity: 1.0,
3954             // highlightFillOpacity: 0.5,
3955             // highlightStrokeOpacity: 0.5,
3956 
3957             // fillColor: '#ff0000',
3958             // highlightFillColor: '#eeeeee',
3959             // strokeWidth: 2,
3960             // strokeColor: '#ff0000',
3961             // highlightStrokeColor: '#c3d9ff',
3962 
3963             /**
3964              * If true, the point size changes on zoom events.
3965              *
3966              * @type Boolean
3967              * @name Point#zoom
3968              * @default false
3969              *
3970              */
3971             zoom: false,             // Change the point size on zoom
3972 
3973             /**
3974              * If true, the infobox is shown on mouse/pen over, if false not.
3975              * If the value is 'inherit', the value of
3976              * {@link JXG.Board#showInfobox} is taken.
3977              *
3978              * @name Point#showInfobox
3979              * @see JXG.Board#showInfobox
3980              * @type {Boolean|String} true | false | 'inherit'
3981              * @default true
3982              */
3983             showInfobox: 'inherit',
3984 
3985             /**
3986              * Truncating rule for the digits in the infobox.
3987              * <ul>
3988              * <li>'auto': done automatically by JXG.autoDigits()
3989              * <li>'none': no truncation
3990              * <li>number: truncate after "number digits" with JXG.toFixed()
3991              * </ul>
3992              *
3993              * @name Point#infoboxDigits
3994              *
3995              * @type String, Number
3996              * @default 'auto'
3997              * @see JXG#autoDigits
3998              * @see JXG#toFixed
3999              */
4000             infoboxDigits: 'auto',
4001 
4002             draft: false,
4003 
4004             /**
4005              * List of attractor elements. If the distance of the point is less than
4006              * attractorDistance the point is made to glider of this element.
4007              *
4008              * @name Point#attractors
4009              *
4010              * @type Array
4011              * @default empty
4012              */
4013             attractors: [],
4014 
4015             /**
4016              * Unit for attractorDistance and snatchDistance, used for magnetized points and for snapToPoints.
4017              * Possible values are 'screen' and 'user'.
4018              *
4019              * @name Point#attractorUnit
4020              *
4021              * @see Point#attractorDistance
4022              * @see Point#snatchDistance
4023              * @see Point#snapToPoints
4024              * @see Point#attractors
4025              * @type String
4026              * @default 'user'
4027              */
4028             attractorUnit: 'user',    // 'screen', 'user'
4029 
4030             /**
4031              * If the distance of the point to one of its attractors is less
4032              * than this number the point will be a glider on this
4033              * attracting element.
4034              * If set to zero nothing happens.
4035              *
4036              * @name Point#attractorDistance
4037              *
4038              * @type Number
4039              * @default 0.0
4040              */
4041             attractorDistance: 0.0,
4042 
4043             /**
4044              * If the distance of the point to one of its attractors is at least
4045              * this number the point will be released from being a glider on the
4046              * attracting element.
4047              * If set to zero nothing happens.
4048              *
4049              * @name Point#snatchDistance
4050              *
4051              * @type Number
4052              * @default 0.0
4053              */
4054             snatchDistance: 0.0,
4055 
4056             /**
4057              * If set to true, the point will snap to a grid of integer multiples of 
4058              * {@link Point#snapSizeX} and {@link Point#snapSizeY} (in user coordinates).
4059              * <p>
4060              * The coordinates of the grid points are either integer multiples of snapSizeX and snapSizeY
4061              * (given in user coordinates, not pixels) or are the intersection points
4062              * of the major ticks of the boards default axes in case that snapSizeX, snapSizeY are negative.
4063              *
4064              * @name Point#snapToGrid
4065              *
4066              * @see Point#snapSizeX
4067              * @see Point#snapSizeY
4068              * @type Boolean
4069              * @default false
4070              */
4071             snapToGrid: false,
4072 
4073             /**
4074              * If set to true, the point will only snap to (possibly invisibly) grid points
4075              * when within {@link Point#attractorDistance} of such a grid point.
4076              * <p>
4077              * The coordinates of the grid points are either integer multiples of snapSizeX and snapSizeY
4078              * (given in user coordinates, not pixels) or are the intersection points
4079              * of the major ticks of the boards default axes in case that snapSizeX, snapSizeY are negative.
4080              *
4081              * @name Point#attractToGrid
4082              *
4083              * @see Point#attractorDistance
4084              * @see Point#attractorUnit
4085              * @see Point#snapToGrid
4086              * @see Point#snapSizeX
4087              * @see Point#snapSizeY
4088              * @type Boolean
4089              * @default false
4090              *
4091              * @example
4092              * board.create('point', [3, 3], { attractToGrid: true, attractorDistance: 10, attractorunit: 'screen' });
4093              *
4094              * </pre><div id="JXG397ab787-cd40-449c-a7e7-a3f7bab1d4f6" class="jxgbox" style="width: 300px; height: 300px;"></div>
4095              * <script type="text/javascript">
4096              *     (function() {
4097              *         var board = JXG.JSXGraph.initBoard('JXG397ab787-cd40-449c-a7e7-a3f7bab1d4f6',
4098              *             {boundingbox: [-1, 4, 7,-4], axis: true, showcopyright: false, shownavigation: false});
4099              *     board.create('point', [3, 3], { attractToGrid: true, attractorDistance: 10, attractorunit: 'screen' });
4100              *
4101              *     })();
4102              *
4103              * </script><pre>
4104              *
4105              */
4106             attractToGrid: false,
4107 
4108             /**
4109              * Defines together with {@link Point#snapSizeY} the grid the point snaps on to.
4110              * It is given in user coordinates, not in pixels.
4111              * The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
4112              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
4113              * of the default ticks of the default x axes of the board.
4114              *
4115              * @name Point#snapSizeX
4116              *
4117              * @see Point#snapToGrid
4118              * @see Point#snapSizeY
4119              * @see JXG.Board#defaultAxes
4120              * @type Number
4121              * @default 1
4122              */
4123             snapSizeX: 1,
4124 
4125             /**
4126              * Defines together with {@link Point#snapSizeX} the grid the point snaps on to.
4127              * It is given in user coordinates, not in pixels.
4128              * The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
4129              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
4130              * of the default ticks of the default y axes of the board.
4131              *
4132              * @name Point#snapSizeY
4133              *
4134              * @see Point#snapToGrid
4135              * @see Point#snapSizeX
4136              * @see JXG.Board#defaultAxes
4137              * @type Number
4138              * @default 1
4139              */
4140             snapSizeY: 1,
4141 
4142             /**
4143              * If set to true, the point will snap to the nearest point in distance of
4144              * {@link Point#attractorDistance}.
4145              *
4146              * @name Point#snapToPoints
4147              *
4148              * @see Point#attractorDistance
4149              * @type Boolean
4150              * @default false
4151              */
4152             snapToPoints: false,
4153 
4154             /**
4155              * List of elements which are ignored by snapToPoints.
4156              * @name Point#ignoredSnapToPoints
4157              *
4158              * @type Array
4159              * @default empty
4160              */
4161             ignoredSnapToPoints: []
4162 
4163             /**#@-*/
4164         },
4165 
4166         /* special polygon options */
4167         polygon: {
4168             /**#@+
4169              * @visprop
4170              */
4171 
4172             /**
4173              * If <tt>true</tt>, moving the mouse over inner points triggers hasPoint.
4174              *
4175              * @see JXG.GeometryElement#hasPoint
4176              * @name Polygon#hasInnerPoints
4177              * @type Boolean
4178              * @default false
4179              */
4180             hasInnerPoints: false,
4181 
4182             fillColor: Color.palette.yellow,
4183             highlightFillColor: Color.palette.yellow,
4184             // fillColor: '#00ff00',
4185             // highlightFillColor: '#00ff00',
4186             fillOpacity: 0.3,
4187             highlightFillOpacity: 0.2,
4188 
4189             /**
4190              * Is the polygon bordered by lines?
4191              *
4192              * @type Boolean
4193              * @name Polygon#withLines
4194              * @default true
4195              */
4196             withLines: true,
4197 
4198             /**
4199              * Attributes for the polygon border lines.
4200              *
4201              * @type Line
4202              * @name Polygon#borders
4203              */
4204             borders: {
4205                 withLabel: false,
4206                 strokeWidth: 1,
4207                 highlightStrokeWidth: 1,
4208                 // Polygon layer + 1
4209                 layer: 5,
4210                 label: {
4211                     position: 'top'
4212                 },
4213                 visible: 'inherit'
4214             },
4215 
4216             /**
4217              * Attributes for the polygon vertices.
4218              *
4219              * @type Point
4220              * @name Polygon#vertices
4221              */
4222             vertices: {
4223                 layer: 9,
4224                 withLabel: false,
4225                 name: '',
4226                 strokeColor: Color.palette.red,
4227                 fillColor: Color.palette.red,
4228                 fixed: false,
4229                 visible: 'inherit'
4230             },
4231 
4232             /**
4233              * Attributes for the polygon label.
4234              *
4235              * @type Label
4236              * @name Polygon#label
4237              */
4238             label: {
4239                 offset: [0, 0]
4240             }
4241 
4242             /**#@-*/
4243         },
4244 
4245         /* special polygonal chain options
4246         */
4247         polygonalchain: {
4248             /**#@+
4249              * @visprop
4250              */
4251 
4252             fillColor: 'none',
4253             highlightFillColor: 'none'
4254 
4255             /**#@-*/
4256         },
4257 
4258         /* special prescribed angle options
4259         * Not yet implemented. But angle.setAngle(val) is implemented.
4260         */
4261         prescribedangle: {
4262             /**#@+
4263              * @visprop
4264              */
4265 
4266             /**
4267              * Attributes for the helper point of the prescribed angle.
4268              *
4269              * @type Point
4270              * @name PrescribedAngle#anglePoint
4271              */
4272             anglePoint: {
4273                 size: 2,
4274                 visible: false,
4275                 withLabel: false
4276             }
4277 
4278             /**#@-*/
4279         },
4280 
4281         /* special reflection options */
4282         reflection: {
4283             /**#@+
4284              * @visprop
4285              */
4286 
4287             fixed: true,
4288 
4289             /**
4290              * Attributes of circle center, i.e. the center of the circle,
4291              * if a circle is the mirror element and the transformation type is 'Euclidean'
4292              *
4293              * @type Point
4294              * @name mirrorelement#center
4295              */
4296             center: {},
4297 
4298             /**
4299              * Type of transformation. Possible values are 'Euclidean', 'projective'.
4300              *
4301              * If the value is 'Euclidean', the reflected element of a circle is again a circle,
4302              * otherwise it is a conic section.
4303              *
4304              * @type String
4305              * @name reflection#type
4306              * @default 'Euclidean'
4307              */
4308             type: 'Euclidean'
4309 
4310             /**#@-*/
4311         },
4312 
4313         /* special regular polygon options */
4314         regularpolygon: {
4315             /**#@+
4316              * @visprop
4317              */
4318 
4319             /**
4320              * If <tt>true</tt>, moving the mouse over inner points triggers hasPoint.
4321              * @see JXG.GeometryElement#hasPoint
4322              *
4323              * @name RegularPolygon#hasInnerPoints
4324              * @type Boolean
4325              * @default false
4326              */
4327             hasInnerPoints: false,
4328             fillColor: Color.palette.yellow,
4329             highlightFillColor: Color.palette.yellow,
4330             fillOpacity: 0.3,
4331             highlightFillOpacity: 0.2,
4332 
4333             /**
4334              * Is the polygon bordered by lines?
4335              *
4336              * @type Boolean
4337              * @name RegularPolygon#withLines
4338              * @default true
4339              */
4340             withLines: true,
4341 
4342             /**
4343              * Attributes for the polygon border lines.
4344              *
4345              * @type Line
4346              * @name RegularPolygon#borders
4347              */
4348             borders: {
4349                 withLabel: false,
4350                 strokeWidth: 1,
4351                 highlightStrokeWidth: 1,
4352                 // Polygon layer + 1
4353                 layer: 5,
4354                 label: {
4355                     position: 'top'
4356                 }
4357             },
4358 
4359             /**
4360              * Attributes for the polygon vertices.
4361              *
4362              * @type Point
4363              * @name RegularPolygon#vertices
4364              */
4365             vertices: {
4366                 layer: 9,
4367                 withLabel: true,
4368                 strokeColor: Color.palette.red,
4369                 fillColor: Color.palette.red,
4370                 fixed: false
4371             },
4372 
4373             /**
4374              * Attributes for the polygon label.
4375              *
4376              * @type Label
4377              * @name Polygon#label
4378              */
4379             label: {
4380                 offset: [0, 0]
4381             }
4382 
4383             /**#@-*/
4384         },
4385 
4386         /* special options for riemann sums */
4387         riemannsum: {
4388             /**#@+
4389              * @visprop
4390              */
4391 
4392             withLabel: false,
4393             fillOpacity: 0.3,
4394             fillColor: Color.palette.yellow
4395 
4396             /**#@-*/
4397         },
4398 
4399         /* special sector options */
4400         sector: {
4401             /**#@+
4402              * @visprop
4403              */
4404 
4405             fillColor: Color.palette.yellow,
4406             highlightFillColor: Color.palette.yellow,
4407             // fillColor: '#00ff00',
4408             // highlightFillColor: '#00ff00',
4409 
4410             fillOpacity: 0.3,
4411             highlightFillOpacity: 0.3,
4412             highlightOnSector: false,
4413             highlightStrokeWidth: 0,
4414 
4415             /**
4416              * Type of sector. Possible values are 'minor', 'major', and 'auto'.
4417              *
4418              * @type String
4419              * @name Sector#selection
4420              * @default 'auto'
4421              */
4422             selection: 'auto',
4423 
4424             /**
4425              * Attributes for sub-element arc. It is only available, if the sector is defined by three points.
4426              *
4427              * @type Arc
4428              * @name Sector#arc
4429              * @default '{visible:false}'
4430              */
4431             arc: {
4432                 visible: false,
4433                 fillColor: 'none'
4434             },
4435 
4436             /**
4437              * Attributes for helper point radiuspoint in case it is provided by coordinates.
4438              *
4439              * @type Point
4440              * @name Sector#radiusPoint
4441              */
4442             radiusPoint: {
4443                 visible: false,
4444                 withLabel: false
4445             },
4446 
4447             /**
4448              * Attributes for helper point center in case it is provided by coordinates.
4449              *
4450              * @type Point
4451              * @name Sector#center
4452              */
4453             center: {
4454                 visible: false,
4455                 withLabel: false
4456             },
4457 
4458             /**
4459              * Attributes for helper point anglepoint in case it is provided by coordinates.
4460              *
4461              * @type Point
4462              * @name Sector#anglePoint
4463              */
4464             anglePoint: {
4465                 visible: false,
4466                 withLabel: false
4467             },
4468 
4469             /**
4470              * Attributes for the sector label.
4471              *
4472              * @type Label
4473              * @name Sector#label
4474              */
4475             label: {
4476                 offset: [0, 0],
4477                 anchorX: 'auto',
4478                 anchorY: 'auto'
4479             }
4480 
4481             /**#@-*/
4482         },
4483 
4484         /* special segment options */
4485         segment: {
4486             /**#@+
4487              * @visprop
4488              */
4489 
4490             label: {
4491                 position: 'top'
4492             }
4493             /**#@-*/
4494         },
4495 
4496         semicircle: {
4497             /**#@+
4498              * @visprop
4499              */
4500 
4501             /**
4502              * Attributes for center point of the semicircle.
4503              *
4504              * @type Point
4505              * @name Semicircle#center
4506              */
4507             center: {
4508                 visible: false,
4509                 withLabel: false,
4510                 fixed: false,
4511                 fillColor: Color.palette.red,
4512                 strokeColor: Color.palette.red,
4513                 highlightFillColor:'#eeeeee',
4514                 highlightStrokeColor: Color.palette.red,
4515                 name: ''
4516             }
4517 
4518             /**#@-*/
4519         },
4520 
4521         /* special slider options */
4522         slider: {
4523             /**#@+
4524              * @visprop
4525              */
4526 
4527             /**
4528              * The slider only returns integer multiples of this value, e.g. for discrete values set this property to <tt>1</tt>. For
4529              * continuous results set this to <tt>-1</tt>.
4530              *
4531              * @memberOf Slider.prototype
4532              * @name snapWidth
4533              * @type Number
4534              */
4535             snapWidth: -1,      // -1 = deactivated
4536 
4537             /**
4538              * The precision of the slider value displayed in the optional text.
4539              * @memberOf Slider.prototype
4540              * @name precision
4541              * @type Number
4542              * @default 2
4543              */
4544             precision: 2,
4545 
4546             firstArrow: false,
4547             lastArrow: false,
4548 
4549             /**
4550              * Show slider ticks.
4551              *
4552              * @type Boolean
4553              * @name Slider#withTicks
4554              * @default true
4555              */
4556             withTicks: true,
4557 
4558             /**
4559              * Show slider label.
4560              *
4561              * @type Boolean
4562              * @name Slider#withLabel
4563              * @default true
4564              */
4565             withLabel: true,
4566 
4567             /**
4568              * If not null, this replaces the part "name = " in the slider label.
4569              * Possible types: string, number or function.
4570              * @type String
4571              * @name suffixLabel
4572              * @memberOf Slider.prototype
4573              * @default null
4574              * @see JXG.Slider#unitLabel
4575              * @see JXG.Slider#postLabel
4576              */
4577             suffixLabel: null,
4578 
4579             /**
4580              * If not null, this is appended to the value in the slider label.
4581              * Possible types: string, number or function.
4582              * @type String
4583              * @name unitLabel
4584              * @memberOf Slider.prototype
4585              * @default null
4586              * @see JXG.Slider#suffixLabel
4587              * @see JXG.Slider#postLabel
4588              */
4589             unitLabel: null,
4590 
4591             /**
4592              * If not null, this is appended to the value and to unitLabel in the slider label.
4593              * Possible types: string, number or function.
4594              * @type String
4595              * @name postLabel
4596              * @memberOf Slider.prototype
4597              * @default null
4598              * @see JXG.Slider#suffixLabel
4599              * @see JXG.Slider#unitLabel
4600              */
4601             postLabel: null,
4602 
4603             layer: 9,
4604             showInfobox: false,
4605             name: '',
4606             visible: true,
4607             strokeColor: '#000000',
4608             highlightStrokeColor: '#888888',
4609             fillColor: '#ffffff',
4610             highlightFillColor: 'none',
4611 
4612             /**
4613              * Size of slider point.
4614              *
4615              * @type Number
4616              * @name Slider#size
4617              * @default 6
4618              * @see Point#size
4619              */
4620             size: 6,
4621 
4622             /**
4623              * Attributes for first (left) helper point defining the slider position.
4624              *
4625              * @type Point
4626              * @name Slider#point1
4627              */
4628             point1: {
4629                 needsRegularUpdate: false,
4630                 showInfobox: false,
4631                 withLabel: false,
4632                 visible: false,
4633                 fixed: true,
4634                 name: ''
4635             },
4636 
4637             /**
4638              * Attributes for second (right) helper point defining the slider position.
4639              *
4640              * @type Point
4641              * @name Slider#point2
4642              */
4643             point2: {
4644                 needsRegularUpdate: false,
4645                 showInfobox: false,
4646                 withLabel: false,
4647                 visible: false,
4648                 fixed: true,
4649                 name: ''
4650             },
4651 
4652             /**
4653              * Attributes for the base line of the slider.
4654              *
4655              * @type Line
4656              * @name Slider#baseline
4657              */
4658             baseline: {
4659                 needsRegularUpdate: false,
4660                 visible: 'inherit',
4661                 fixed: true,
4662                 scalable: false,
4663                 name: '',
4664                 strokeWidth: 1,
4665                 strokeColor: '#000000',
4666                 highlightStrokeColor: '#888888'
4667             },
4668 
4669             /**
4670              * Attributes for the ticks of the base line of the slider.
4671              *
4672              * @type Ticks
4673              * @name Slider#ticks
4674              */
4675             ticks: {
4676                 needsRegularUpdate: false,
4677                 fixed: true,
4678 
4679                 // Label drawing
4680                 drawLabels: false,
4681                 precision: 2,
4682                 includeBoundaries: 1,
4683                 drawZero: true,
4684                 label: {
4685                     offset: [-4, -14],
4686                     display: 'internal'
4687                 },
4688 
4689                 minTicksDistance: 30,
4690                 insertTicks: true,
4691                 minorHeight: 4,         // if <0: full width and height
4692                 majorHeight: 5,        // if <0: full width and height
4693                 minorTicks: 0,
4694                 defaultDistance: 1,
4695                 strokeOpacity: 1,
4696                 strokeWidth: 1,
4697                 tickEndings: [0, 1],
4698                 strokeColor: '#000000',
4699                 visible: 'inherit'
4700             },
4701 
4702             /**
4703              * Attributes for the highlighting line of the slider.
4704              *
4705              * @type Line
4706              * @name Slider#highline
4707              */
4708             highline: {
4709                 strokeWidth: 3,
4710                 visible: 'inherit',
4711                 fixed: true,
4712                 name: '',
4713                 strokeColor: '#000000',
4714                 highlightStrokeColor: '#888888'
4715             },
4716 
4717             /**
4718              * Attributes for the slider label.
4719              *
4720              * @type Label
4721              * @name Slider#label
4722              */
4723             label: {
4724                 visible: 'inherit',
4725                 strokeColor: '#000000'
4726             },
4727 
4728             /**
4729              * If true, 'up' events on the baseline will trigger slider moves.
4730              *
4731              * @type: Boolean
4732              * @name Slider#moveOnUp
4733              * @default: true
4734              */
4735             moveOnUp: true
4736 
4737             /**#@-*/
4738         },
4739 
4740         /* special options for comb */
4741         comb: {
4742             /**#@+
4743              * @visprop
4744              */
4745 
4746             /**
4747              * Frequency of comb elements.
4748              *
4749              * @type Number
4750              * @name Comb#frequency
4751              * @default 0.2
4752              */
4753             frequency: 0.2,
4754 
4755             /**
4756              * Width of the comb.
4757              *
4758              * @type Number
4759              * @name Comb#width
4760              * @default 0.4
4761              */
4762             width: 0.4,
4763 
4764             /**
4765              * Angle under which comb elements are positioned.
4766              *
4767              * @type Number
4768              * @name Comb#angle
4769              * @default 60 degrees
4770              */
4771             angle: Math.PI / 3,
4772 
4773             /**
4774              * Should the comb go right to left instead of left to right.
4775              *
4776              * @type Boolean
4777              * @name Comb#reverse
4778              * @default false
4779              */
4780             reverse: false,
4781 
4782             /**
4783              * Attributes for first defining point of the comb.
4784              *
4785              * @type Point
4786              * @name Comb#point1
4787              */
4788             point1: {
4789                 visible: false,
4790                 withLabel: false,
4791                 fixed: false,
4792                 name: ''
4793             },
4794 
4795             /**
4796              * Attributes for second defining point of the comb.
4797              *
4798              * @type Point
4799              * @name Comb#point2
4800              */
4801             point2: {
4802                 visible: false,
4803                 withLabel: false,
4804                 fixed: false,
4805                 name: ''
4806             },
4807 
4808             /**
4809              * Attributes for the curve displaying the comb.
4810              *
4811              * @type Curve
4812              * @name Comb#curve
4813              */
4814             curve: {
4815                 strokeWidth: 1,
4816                 strokeColor: '#000000',
4817                 fillColor: 'none'
4818             }
4819         },
4820 
4821         /* special options for slope triangle */
4822         slopetriangle: {
4823             /**#@+
4824              * @visprop
4825              */
4826 
4827             fillColor: Color.palette.red,
4828             fillOpacity: 0.4,
4829             highlightFillColor: Color.palette.red,
4830             highlightFillOpacity: 0.3,
4831 
4832             borders: {
4833                 lastArrow: {
4834                     type: 1,
4835                     size: 6
4836                 }
4837             },
4838 
4839             /**
4840              * Attributes for the gliding helper point.
4841              *
4842              * @type Point
4843              * @name Slopetriangle#glider
4844              */
4845             glider: {
4846                 fixed: true,
4847                 visible: false,
4848                 withLabel: false
4849             },
4850 
4851             /**
4852              * Attributes for the base line.
4853              *
4854              * @type Line
4855              * @name Slopetriangle#baseline
4856              */
4857             baseline: {
4858                 visible: false,
4859                 withLabel: false,
4860                 name: ''
4861             },
4862 
4863             /**
4864              * Attributes for the base point.
4865              *
4866              * @type Point
4867              * @name Slopetriangle#basepoint
4868              */
4869             basepoint: {
4870                 visible: false,
4871                 withLabel: false,
4872                 name: ''
4873             },
4874 
4875             /**
4876              * Attributes for the tangent.
4877              * The tangent is constructed by slop triangle if the construction
4878              * is based on a glider, solely.
4879              *
4880              * @type Line
4881              * @name Slopetriangle#tangent
4882              */
4883             tangent: {
4884                 visible: false,
4885                 withLabel: false,
4886                 name: ''
4887             },
4888 
4889             /**
4890              * Attributes for the top point.
4891              *
4892              * @type Point
4893              * @name Slopetriangle#toppoint
4894              */
4895             toppoint: {
4896                 visible: false,
4897                 withLabel: false,
4898                 name: ''
4899             },
4900 
4901             /**
4902              * Attributes for the slope triangle label.
4903              *
4904              * @type Label
4905              * @name Slopetriangle#label
4906              */
4907             label: {
4908                 visible: true
4909             }
4910             /**#@-*/
4911         },
4912 
4913         /* special options for step functions */
4914         stepfunction: {
4915             /**#@+
4916              * @visprop
4917              */
4918 
4919             /**#@-*/
4920         },
4921 
4922         /* special tape measure options */
4923         tapemeasure: {
4924             /**#@+
4925              * @visprop
4926              */
4927 
4928             strokeColor: '#000000',
4929             strokeWidth: 2,
4930             highlightStrokeColor: '#000000',
4931 
4932             /**
4933              * Show tape measure ticks.
4934              *
4935              * @type Boolean
4936              * @name Tapemeasure#withTicks
4937              * @default true
4938              */
4939             withTicks: true,
4940 
4941             /**
4942              * Show tape measure label.
4943              *
4944              * @type Boolean
4945              * @name Tapemeasure#withLabel
4946              * @default true
4947              */
4948             withLabel: true,
4949 
4950             /**
4951              * The precision of the tape measure value displayed in the optional text.
4952              * @memberOf Tapemeasure.prototype
4953              * @name precision
4954              * @type Number
4955              * @default 2
4956              */
4957             precision: 2,
4958 
4959             /**
4960              * Attributes for first helper point defining the tape measure position.
4961              *
4962              * @type Point
4963              * @name Tapemeasure#point1
4964              */
4965             point1: {
4966                 visible: 'inherit',
4967                 strokeColor: '#000000',
4968                 fillColor: '#ffffff',
4969                 fillOpacity: 0.0,
4970                 highlightFillOpacity: 0.1,
4971                 size: 6,
4972                 snapToPoints: true,
4973                 attractorUnit: 'screen',
4974                 attractorDistance: 20,
4975                 showInfobox: false,
4976                 withLabel: false,
4977                 name: ''
4978             },
4979 
4980             /**
4981              * Attributes for second helper point defining the tape measure position.
4982              *
4983              * @type Point
4984              * @name Tapemeasure#point2
4985              */
4986             point2: {
4987                 visible: 'inherit',
4988                 strokeColor: '#000000',
4989                 fillColor: '#ffffff',
4990                 fillOpacity: 0.0,
4991                 highlightFillOpacity: 0.1,
4992                 size: 6,
4993                 snapToPoints: true,
4994                 attractorUnit: 'screen',
4995                 attractorDistance: 20,
4996                 showInfobox: false,
4997                 withLabel: false,
4998                 name: ''
4999             },
5000 
5001             /**
5002              * Attributes for the ticks of the tape measure.
5003              *
5004              * @type Ticks
5005              * @name Tapemeasure#ticks
5006              */
5007             ticks: {
5008                 drawLabels: false,
5009                 drawZero: true,
5010                 insertTicks: true,
5011                 minorHeight: 8,
5012                 majorHeight: 16,
5013                 minorTicks: 4,
5014                 tickEndings: [0, 1],
5015                 defaultDistance: 0.1,
5016                 strokeOpacity: 1,
5017                 strokeWidth: 1,
5018                 strokeColor: '#000000',
5019                 visible: 'inherit'
5020             },
5021 
5022             /**
5023              * Attributes for the tape measure label.
5024              *
5025              * @type Label
5026              * @name Tapemeasure#label
5027              */
5028             label: {
5029                 position: 'top'
5030             }
5031             /**#@-*/
5032         },
5033 
5034         /* special text options */
5035         text: {
5036             /**#@+
5037              * @visprop
5038              */
5039 
5040             /**
5041              * The font size in pixels.
5042              *
5043              * @name fontSize
5044              * @memberOf Text.prototype
5045              * @default 12
5046              * @type Number
5047              * @see Text#fontUnit
5048              */
5049             fontSize: 12,
5050 
5051             /**
5052              * CSS unit for the font size of a text element. Usually, this will be the default value 'px' but
5053              * for responsive application, also 'vw', 'vh', vmax', 'vmin' or 'rem' might be useful.
5054              *
5055              * @name fontUnit
5056              * @memberOf Text.prototype
5057              * @default 'px'
5058              * @type String
5059              * @see Text#fontSize
5060              *
5061              * @example
5062              * var txt = board.create('text', [2, 2, "hello"], {fontSize: 8, fontUnit: 'vmin'});
5063              *
5064              * </pre><div id="JXG2da7e972-ac62-416b-a94b-32559c9ec9f9" class="jxgbox" style="width: 300px; height: 300px;"></div>
5065              * <script type="text/javascript">
5066              *     (function() {
5067              *         var board = JXG.JSXGraph.initBoard('JXG2da7e972-ac62-416b-a94b-32559c9ec9f9',
5068              *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
5069              *     var txt = board.create('text', [2, 2, "hello"], {fontSize: 8, fontUnit: 'vmin'});
5070              * 
5071              *     })();
5072              * 
5073              * </script><pre>
5074              * 
5075              */
5076             fontUnit: 'px',
5077 
5078             /**
5079              * Used to round texts given by a number.
5080              *
5081              * @name digits
5082              * @memberOf Text.prototype
5083              * @default 2
5084              * @type Number
5085              */
5086             digits: 2,
5087 
5088             /**
5089              * If set to true, the text is parsed and evaluated.
5090              * For labels parse==true results in converting names of the form k_a to subscripts.
5091              * If the text is given by string and parse==true, the string is parsed as
5092              * JessieCode expression.
5093              *
5094              * @name parse
5095              * @memberOf Text.prototype
5096              * @default true
5097              * @type Boolean
5098              */
5099             parse: true,
5100 
5101             /**
5102              * If set to true and caja's sanitizeHTML function can be found it
5103              * will be used to sanitize text output.
5104              *
5105              * @name useCaja
5106              * @memberOf Text.prototype
5107              * @default false
5108              * @type Boolean
5109              */
5110             useCaja: false,
5111 
5112             /**
5113              * If enabled, the text will be handled as label. Intended for internal use.
5114              *
5115              * @name isLabel
5116              * @memberOf Text.prototype
5117              * @default false
5118              * @type Boolean
5119              */
5120             isLabel: false,
5121 
5122             strokeColor: '#000000',
5123             highlightStrokeColor: '#000000',
5124             highlightStrokeOpacity: 0.666666,
5125 
5126             /**
5127              * Default CSS properties of the HTML text element.
5128              * <p>
5129              * The CSS properties which are set here, are handed over to the style property
5130              * of the HTML text element. That means, they have higher property than any
5131              * CSS class.
5132              * <p>
5133              * If a property which is set here should be overruled by a CSS class
5134              * then this property should be removed here.
5135              * <p>
5136              * The reason, why this attribute should be kept to its default value at all,
5137              * is that screen dumps of SVG boards with <tt>board.renderer.dumpToCanvas()</tt>
5138              * will ignore the font-family if it is set in a CSS class.
5139              * It has to be set explicitly as style attribute.
5140              * <p>
5141              * In summary, the order of priorities from high to low is
5142              * <ol>
5143              *  <li> JXG.Options.text.cssStyle
5144              *  <li> JXG.Options.text.cssDefaultStyle
5145              *  <li> JXG.Options.text.cssClass
5146              * </ol>
5147              * @example
5148              * If all texts should get its font-family from the default CSS class
5149              * before initializing the board
5150              * <pre>
5151              *   JXG.Options.text.cssDefaultStyle = '';
5152              *   JXG.Options.text.highlightCssDefaultStyle = '';
5153              * </pre>
5154              * should be called.
5155              *
5156              * @name cssDefaultStyle
5157              * @memberOf Text.prototype
5158              * @default  'font-family: Arial, Helvetica, Geneva, sans-serif;'
5159              * @type String
5160              * @see Text#highlightCssDefaultStyle
5161              * @see Text#cssStyle
5162              * @see Text#highlightCssStyle
5163              */
5164             cssDefaultStyle: 'font-family: Arial, Helvetica, Geneva, sans-serif;',
5165 
5166             /**
5167              * Default CSS properties of the HTML text element in case of highlighting.
5168              * <p>
5169              * The CSS properties which are set here, are handed over to the style property
5170              * of the HTML text element. That means, they have higher property than any
5171              * CSS class.
5172              * @example
5173              * If all texts should get its font-family from the default CSS class
5174              * before initializing the board
5175              * <pre>
5176              *   JXG.Options.text.cssDefaultStyle = '';
5177              *   JXG.Options.text.highlightCssDefaultStyle = '';
5178              * </pre>
5179              * should be called.
5180              *
5181              * @name highlightCssDefaultStyle
5182              * @memberOf Text.prototype
5183              * @default  'font-family: Arial, Helvetica, Geneva, sans-serif;'
5184              * @type String
5185              * @see Text#cssDefaultStyle
5186              * @see Text#cssStyle
5187              * @see Text#highlightCssStyle
5188             */
5189             highlightCssDefaultStyle: 'font-family: Arial, Helvetica, Geneva, sans-serif;',
5190 
5191             /**
5192              * CSS properties of the HTML text element.
5193              * <p>
5194              * The CSS properties which are set here, are handed over to the style property
5195              * of the HTML text element. That means, they have higher property than any
5196              * CSS class.
5197              *
5198              * @name cssStyle
5199              * @memberOf Text.prototype
5200              * @default  ''
5201              * @type String
5202              * @see Text#cssDefaultStyle
5203              * @see Text#highlightCssDefaultStyle
5204              * @see Text#highlightCssStyle
5205             */
5206             cssStyle: '',
5207 
5208             /**
5209              * CSS properties of the HTML text element in case of highlighting.
5210              * <p>
5211              * The CSS properties which are set here, are handed over to the style property
5212              * of the HTML text element. That means, they have higher property than any
5213              * CSS class.
5214              *
5215              * @name highlightCssStyle
5216              * @memberOf Text.prototype
5217              * @default  ''
5218              * @type String
5219              * @see Text#cssDefaultStyle
5220              * @see Text#highlightCssDefaultStyle
5221              * @see Text#cssStyle
5222             */
5223             highlightCssStyle: '',
5224 
5225             /**
5226              * If true, the input will be given to ASCIIMathML before rendering.
5227              *
5228              * @name useASCIIMathML
5229              * @memberOf Text.prototype
5230              * @default false
5231              * @type Boolean
5232              */
5233             useASCIIMathML: false,
5234 
5235             /**
5236              * If true, MathJax will be used to render the input string.
5237              * Supports MathJax 2 as well as Mathjax 3.
5238              * It is recommended to use this option together with the option
5239              * "parse: false". Otherwise, 4 backslashes (e.g. \\\\alpha) are needed
5240              * instead of two (e.g. \\alpha).
5241              *
5242              * @name useMathJax
5243              * @memberOf Text.prototype
5244              * @default false
5245              * @type Boolean
5246              * @see Text#parse
5247              *
5248              * @example
5249              *  // Before loading MathJax, it has to be configured something like this:
5250              * window.MathJax = {
5251              *   tex: {
5252              *     inlineMath: [ ['$','$'], ["\\(","\\)"] ],
5253              *     displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
5254              *     packages: ['base', 'ams']
5255              *   },
5256              *   options: {
5257              *     ignoreHtmlClass: 'tex2jax_ignore',
5258              *     processHtmlClass: 'tex2jax_process'
5259              *   }
5260              * };
5261              *
5262              * // Display style
5263              * board.create('text',[ 2,2,  function(){return '$$X=\\frac{2}{x}$$'}], {
5264              *     fontSize: 15, color:'green', useMathJax: true});
5265              *
5266              * // Inline style
5267              * board.create('text',[-2,2,  function(){return '$X_A=\\frac{2}{x}$'}], {
5268              *     fontSize: 15, color:'green', useMathJax: true});
5269              *
5270              * var A = board.create('point', [-2, 0]);
5271              * var B = board.create('point', [1, 0]);
5272              * var C = board.create('point', [0, 1]);
5273              *
5274              * var graph = board.create('ellipse', [A, B, C], {
5275              *         fixed: true,
5276              *         withLabel: true,
5277              *         strokeColor: 'black',
5278              *         strokeWidth: 2,
5279              *         fillColor: '#cccccc',
5280              *         fillOpacity: 0.3,
5281              *         highlightStrokeColor: 'red',
5282              *         highlightStrokeWidth: 3,
5283              *         name: '$1=\\frac{(x-h)^2}{a^2}+\\frac{(y-k)^2}{b^2}$',
5284              *         label: {useMathJax: true}
5285              *     });
5286              *
5287              * var nvect1 = board.create('text', [-4, -3, '\\[\\overrightarrow{V}\\]'],
5288              * {
5289              *   fontSize: 24, parse: false
5290              * });
5291              * var nvect1 = board.create('text', [-2, -4, function() {return '$\\overrightarrow{G}$';}],
5292              * {
5293              *   fontSize: 24, useMathJax: true
5294              * });
5295              *
5296              * </pre>
5297              * <script>
5298              * window.MathJax = {
5299              *   tex: {
5300              *     inlineMath: [ ['$','$'], ["\\(","\\)"] ],
5301              *     displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
5302              *     packages: ['base', 'ams']
5303              *   },
5304              *   options: {
5305              *     ignoreHtmlClass: 'tex2jax_ignore',
5306              *     processHtmlClass: 'tex2jax_process'
5307              *   }
5308              * };
5309              * </script>
5310              * <script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js" id="MathJax-script"></script>
5311              * <div id="JXGe2a04876-5813-4db0-b7e8-e48bf4e220b9" class="jxgbox" style="width: 400px; height: 400px;"></div>
5312              * <script type="text/javascript">
5313              *     (function() {
5314              *         var board = JXG.JSXGraph.initBoard('JXGe2a04876-5813-4db0-b7e8-e48bf4e220b9',
5315              *             {boundingbox: [-5, 5, 5, -5], axis: true, showcopyright: false, shownavigation: false});
5316              *     // Display style
5317              *     board.create('text',[ 2,2,  function(){return '$$X=\\frac{2}{x}$$'}], {
5318              *         fontSize: 15, color:'green', useMathJax: true});
5319              *
5320              *     // Inline style
5321              *     board.create('text',[-2,2,  function(){return '$X_A=\\frac{2}{x}$'}], {
5322              *         fontSize: 15, color:'green', useMathJax: true});
5323              *
5324              *     var A = board.create('point', [-2, 0]);
5325              *     var B = board.create('point', [1, 0]);
5326              *     var C = board.create('point', [0, 1]);
5327              *
5328              *     var graph = board.create('ellipse', [A, B, C], {
5329              *             fixed: true,
5330              *             withLabel: true,
5331              *             strokeColor: 'black',
5332              *             strokeWidth: 2,
5333              *             fillColor: '#cccccc',
5334              *             fillOpacity: 0.3,
5335              *             highlightStrokeColor: 'red',
5336              *             highlightStrokeWidth: 3,
5337              *             name: '$1=\\frac{(x-h)^2}{a^2}+\\frac{(y-k)^2}{b^2}$',
5338              *             label: {useMathJax: true}
5339              *         });
5340              *
5341              *     var nvect1 = board.create('text', [-4, -3, '\\[\\overrightarrow{V}\\]'],
5342              *     {
5343              *       fontSize: 24, parse: false
5344              *     });
5345              *     var nvect1 = board.create('text', [-2, -4, function() {return '$\\overrightarrow{G}$';}],
5346              *     {
5347              *       fontSize: 24, useMathJax: true
5348              *     });
5349              *     })();
5350              *
5351              * </script><pre>
5352              *
5353              *
5354              * @example
5355              * // Load MathJax:
5356              * // <script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"<</script>
5357              *
5358              * // function and its derivative
5359              * var f1 = function(x) { return x * x * x; },
5360              * graph1 = board.create('functiongraph', [f1, -0.1, 1.1]),
5361              *
5362              * A = board.create('glider', [0.5, f1(0.5), graph1], {
5363              *             name: 'f(x)',
5364              *             color: 'black',
5365              *             face:'x',
5366              *             fixed: true,
5367              *             size: 3,
5368              *             label: {offset: [-30, 10], fontSize: 15}
5369              *         }),
5370              * B = board.create('glider', [0.7, f1(0.7), graph1], {
5371              *             name: 'f(x+Δx)',
5372              *             size: 3,
5373              *             label: {offset: [-60, 10], fontSize: 15}
5374              *         }),
5375              *
5376              * secant_line = board.create('line', [A,B],{dash: 1, color: 'green'}),
5377              * a_h_segment = board.create('segment', [A, [
5378              *                     function(){ return B.X() > A.X() ? B.X() : A.X()},
5379              *                     function(){ return B.X() > A.X() ? A.Y() : B.Y()}
5380              *                 ]],{ name: 'Δx', dash: 1, color: 'black'});
5381              *
5382              * b_v_segment = board.create('segment', [B, [
5383              *                     function(){ return B.X() > A.X() ? B.X() : A.X()},
5384              *                     function(){ return B.X() > A.X() ? A.Y() : B.Y()}
5385              *                 ]],{ name: 'Δy', dash: 1, color: 'black'}),
5386              *
5387              * ma = board.create('midpoint', [a_h_segment.point1, a_h_segment.point2
5388              *     ], {visible: false});
5389              *
5390              * board.create('text', [0, 0, function() {return '\\[\\Delta_x='+(B.X()-A.X()).toFixed(4)+'\\]'}], {
5391              *     anchor: ma, useMathJax: true, fixed: true, color: 'green', anchorY: 'top'
5392              * });
5393              *
5394              * mb = board.create('midpoint', [b_v_segment.point1, b_v_segment.point2], {visible: false});
5395              * board.create('text', [0, 0, function() {return '\\[\\Delta_y='+(B.Y()-A.Y()).toFixed(4)+'\\]'}], {
5396              *     anchor: mb, useMathJax: true, fixed: true, color: 'green'
5397              * });
5398              *
5399              * dval = board.create('text',[0.1, 0.8,
5400              *     function(){
5401              *         return '\\[\\frac{\\Delta_y}{\\Delta_x}=\\frac{' + ((B.Y()-A.Y()).toFixed(4)) + '}{' + ((B.X()-A.X()).toFixed(4)) +
5402              *             '}=' + (((B.Y()-A.Y()).toFixed(4))/((B.X()-A.X()).toFixed(4))).toFixed(4) + '\\]';
5403              *     }],{fontSize: 15, useMathJax: true});
5404              *
5405              * </pre>
5406              * <script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js" id="MathJax-script"></script>
5407              * <div id="JXG8c2b65e7-4fc4-43f7-b23c-5076a7fa9621" class="jxgbox" style="width: 400px; height: 400px;"></div>
5408              * <script type="text/javascript">
5409              *     (function() {
5410              *         var board = JXG.JSXGraph.initBoard('JXG8c2b65e7-4fc4-43f7-b23c-5076a7fa9621',
5411              *             {boundingbox: [-0.1, 1.1, 1.1, -0.1], axis: true, showcopyright: false, shownavigation: false});
5412              *     // function and its derivative
5413              *     var f1 = function(x) { return x * x * x; },
5414              *     graph1 = board.create('functiongraph', [f1, -0.1, 1.1]),
5415              *
5416              *     A = board.create('glider', [0.5, f1(0.5), graph1], {
5417              *                 name: 'f(x)',
5418              *                 color: 'black',
5419              *                 face:'x',
5420              *                 fixed: true,
5421              *                 size: 3,
5422              *                 label: {offset: [-30, 10], fontSize: 15}
5423              *             }),
5424              *     B = board.create('glider', [0.7, f1(0.7), graph1], {
5425              *                 name: 'f(x+Δx)',
5426              *                 size: 3,
5427              *                 label: {offset: [-60, 10], fontSize: 15}
5428              *             }),
5429              *
5430              *     secant_line = board.create('line', [A,B],{dash: 1, color: 'green'}),
5431              *     a_h_segment = board.create('segment', [A, [
5432              *                         function(){ return B.X() > A.X() ? B.X() : A.X()},
5433              *                         function(){ return B.X() > A.X() ? A.Y() : B.Y()}
5434              *                     ]],{ name: 'Δx', dash: 1, color: 'black'});
5435              *
5436              *     b_v_segment = board.create('segment', [B, [
5437              *                         function(){ return B.X() > A.X() ? B.X() : A.X()},
5438              *                         function(){ return B.X() > A.X() ? A.Y() : B.Y()}
5439              *                     ]],{ name: 'Δy', dash: 1, color: 'black'}),
5440              *
5441              *     ma = board.create('midpoint', [a_h_segment.point1, a_h_segment.point2
5442              *         ], {visible: false});
5443              *
5444              *     board.create('text', [0, 0, function() {return '\\[\\Delta_x='+(B.X()-A.X()).toFixed(4)+'\\]'}], {
5445              *         anchor: ma, useMathJax: true, fixed: true, color: 'green', anchorY: 'top'
5446              *     });
5447              *
5448              *     mb = board.create('midpoint', [b_v_segment.point1, b_v_segment.point2], {visible: false});
5449              *     board.create('text', [0, 0, function() {return '\\[\\Delta_y='+(B.Y()-A.Y()).toFixed(4)+'\\]'}], {
5450              *         anchor: mb, useMathJax: true, fixed: true, color: 'green'
5451              *     });
5452              *
5453              *     dval = board.create('text',[0.1, 0.8,
5454              *         function(){
5455              *             return '\\[\\frac{\\Delta_y}{\\Delta_x}=\\frac{' + ((B.Y()-A.Y()).toFixed(4)) + '}{' + ((B.X()-A.X()).toFixed(4)) +
5456              *                 '}=' + (((B.Y()-A.Y()).toFixed(4))/((B.X()-A.X()).toFixed(4))).toFixed(4) + '\\]';
5457              *         }],{fontSize: 15, useMathJax: true});
5458              *
5459              *     })();
5460              *
5461              * </script><pre>
5462              *
5463              * @example
5464              * var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-1, 10, 11, -2], axis: true});
5465              * board.options.text.useMathjax = true;
5466              *
5467              * a = board.create('slider',[[-0.7,1.5],[5,1.5],[0,0.5,1]], {
5468              *     suffixlabel:'\\(t_1=\\)',
5469              *     unitLabel: ' \\(\\text{ ms}\\)',
5470              *     snapWidth:0.01}),
5471              *
5472              * func = board.create('functiongraph',[function(x){return (a.Value()*x*x)}], {strokeColor: "red"});
5473              * text1 = board.create('text', [5, 1, function(){
5474              *             return '\\(a(t)= { 1 \\over ' + a.Value().toFixed(3) + '}\\)';
5475              *         }], {fontSize: 15, fixed:true, strokeColor:'red', anchorY: 'top', parse: false});
5476              * 
5477              * </pre><div id="JXGf8bd01db-fb6a-4a5c-9e7f-8823f7aa5ac6" class="jxgbox" style="width: 300px; height: 300px;"></div>
5478              * <script type="text/javascript">
5479              *     (function() {
5480              *         var board = JXG.JSXGraph.initBoard('JXGf8bd01db-fb6a-4a5c-9e7f-8823f7aa5ac6',
5481              *             {boundingbox: [-1, 10, 11, -2], axis: true, showcopyright: false, shownavigation: false});
5482              *     board.options.text.useMathjax = true;
5483              *
5484              *     a = board.create('slider',[[-0.7,1.5],[5,1.5],[0,0.5,1]], {
5485              *         suffixlabel:'\\(t_1=\\)',
5486              *         unitLabel: ' \\(\\text{ ms}\\)',
5487              *         snapWidth:0.01}),
5488              *     
5489              *     func = board.create('functiongraph',[function(x){return (a.Value()*x*x)}], {strokeColor: "red"});
5490              *     text1 = board.create('text', [5, 1, function(){
5491              *                 return '\\(a(t)= { 1 \\over ' + a.Value().toFixed(3) + '}\\)';
5492              *             }], {fontSize: 15, fixed:true, strokeColor:'red', anchorY: 'top', parse: false});
5493              * 
5494              *     })();
5495              *
5496              * </script><pre>
5497              *
5498              */
5499             useMathJax: false,
5500 
5501             /**
5502              *
5503              * If true, KaTeX will be used to render the input string.
5504              * For this feature, katex.min.js and katex.min.css have to be included.
5505              * <p>
5506              * The example below does not work, because there is a conflict with
5507              * the MathJax library which is used below.
5508              * </p>
5509              *
5510              * @name useKatex
5511              * @memberOf Text.prototype
5512              * @default false
5513              * @type Boolean
5514              *
5515              *
5516              * @example
5517              * JXG.Options.text.useKatex = true;
5518              *
5519              * const board = JXG.JSXGraph.initBoard('jxgbox', {
5520              *     boundingbox: [-2, 5, 8, -5], axis:true
5521              * });
5522              *
5523              * var a = board.create('slider',[[-0.7,1.5],[5,1.5],[0,0.5,1]], {
5524              *     suffixlabel:'t_1=',
5525              *     unitLabel: ' \\text{ ms}',
5526              *     snapWidth:0.01});
5527              *
5528              * func = board.create('functiongraph',[function(x){return (a.Value()*x*x)}], {strokeColor: "red"});
5529              * text1 = board.create('text', [5, 1, function(){
5530              *             return 'a(t)= { 1 \\over ' + a.Value().toFixed(3) + '}';
5531              *         }], {fontSize: 15, fixed:true, strokeColor:'red', anchorY: 'top'});
5532              * 
5533              * </pre>
5534              * <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.13.10/dist/katex.min.css" integrity="sha384-0cCFrwW/0bAk1Z/6IMgIyNU3kfTcNirlObr4WjrUU7+hZeD6ravdYJ3kPWSeC31M" crossorigin="anonymous">
5535              * <script src="https://cdn.jsdelivr.net/npm/katex@0.13.10/dist/katex.min.js" integrity="sha384-dtFDxK2tSkECx/6302Z4VN2ZRqt6Gis+b1IwCjJPrn0kMYFQT9rbtyQWg5NFWAF7" crossorigin="anonymous"></script>
5536              * <div id="JXG497f065c-cfc1-44c3-ba21-5fa581668869" class="jxgbox" style="width: 300px; height: 300px;"></div>
5537              * <script type="text/javascript">
5538              *     (function() {
5539              *         var board = JXG.JSXGraph.initBoard('JXG497f065c-cfc1-44c3-ba21-5fa581668869',
5540              *             {boundingbox: [-2, 5, 8, -5], axis: true, showcopyright: false, shownavigation: false});
5541              *     board.options.useKatex = true;
5542              *     var a = board.create('slider',[[-0.7,1.5],[5,1.5],[0,0.5,1]], {
5543              *         suffixlabel:'t_1=',
5544              *         unitLabel: ' \\text{ ms}',
5545              *         snapWidth:0.01});
5546              *     
5547              *     func = board.create('functiongraph',[function(x){return (a.Value()*x*x)}], {strokeColor: "red"});
5548              *     text1 = board.create('text', [5, 1, function(){
5549              *                 return 'a(t)= { 1 \\over ' + a.Value().toFixed(3) + '}';
5550              *             }], {fontSize: 15, fixed:true, strokeColor:'red', anchorY: 'top'});
5551              * 
5552              *     })();
5553              *
5554              * </script><pre>
5555              */
5556             useKatex: false,
5557 
5558             /**
5559              * Determines the rendering method of the text. Possible values
5560              * include <tt>'html'</tt> and <tt>'internal</tt>.
5561              *
5562              * @name display
5563              * @memberOf Text.prototype
5564              * @default 'html'
5565              * @type String
5566              */
5567             display: 'html',
5568 
5569             /**
5570              * Anchor element {@link Point}, {@link Text} or {@link Image} of the text. If it exists, the coordinates of the text are relative
5571              * to this anchor element.
5572              *
5573              * @name anchor
5574              * @memberOf Text.prototype
5575              * @default null
5576              * @type Object
5577              */
5578             anchor: null,
5579 
5580             /**
5581              * The horizontal alignment of the text. Possible values include <tt>'auto</tt>, <tt>'left'</tt>, <tt>'middle'</tt>, and
5582              * <tt>'right'</tt>.
5583              *
5584              * @name anchorX
5585              * @memberOf Text.prototype
5586              * @default 'left'
5587              * @type String
5588              */
5589             anchorX: 'left',
5590 
5591             /**
5592              * The vertical alignment of the text. Possible values include <tt>'auto</tt>, <tt>'top'</tt>, <tt>'middle'</tt>, and
5593              * <tt>'bottom'</tt>.
5594              *
5595              * @name anchorY
5596              * @memberOf Text.prototype
5597              * @default 'auto'
5598              * @type String
5599              */
5600             anchorY: 'middle',
5601 
5602             /**
5603              * CSS class of the text in non-highlighted view.
5604              *
5605              * @name cssClass
5606              * @memberOf Text.prototype
5607              * @type String
5608              */
5609             cssClass: 'JXGtext',
5610 
5611             /**
5612              * CSS class of the text in highlighted view.
5613              *
5614              * @name highlightCssClass
5615              * @memberOf Text.prototype
5616              * @type String
5617              */
5618             highlightCssClass: 'JXGtext',
5619 
5620             /**
5621              * Sensitive area for dragging the text.
5622              * Possible values are 'all', or something else.
5623              * If set to 'small', a sensitivity margin at the right and left border is taken.
5624              * This may be extended to left, right, ... in the future.
5625              *
5626              * @name Text#dragArea
5627              * @type String
5628              * @default 'all'
5629              */
5630             dragArea: 'all',
5631 
5632             withLabel: false,
5633 
5634             /**
5635              * Text rotation in degrees.
5636              * Works for non-zero values only in combination with display=='internal'.
5637              *
5638              * @name Text#rotate
5639              * @type Number
5640              * @default 0
5641              */
5642             rotate: 0,
5643 
5644             visible: true,
5645 
5646             /**
5647              * Defines together with {@link Text#snapSizeY} the grid the text snaps on to.
5648              * The text will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
5649              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
5650              * of the default ticks of the default x axes of the board.
5651              *
5652              * @name snapSizeX
5653              * @memberOf Text.prototype
5654              *
5655              * @see Point#snapToGrid
5656              * @see Text#snapSizeY
5657              * @see JXG.Board#defaultAxes
5658              * @type Number
5659              * @default 1
5660              */
5661             snapSizeX: 1,
5662 
5663             /**
5664              * Defines together with {@link Text#snapSizeX} the grid the text snaps on to.
5665              * The text will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction.
5666              * If this value is equal to or less than <tt>0</tt>, it will use the grid displayed by the major ticks
5667              * of the default ticks of the default y axes of the board.
5668              *
5669              * @name snapSizeY
5670              * @memberOf Text.prototype
5671              *
5672              * @see Point#snapToGrid
5673              * @see Text#snapSizeX
5674              * @see JXG.Board#defaultAxes
5675              * @type Number
5676              * @default 1
5677              */
5678             snapSizeY: 1,
5679 
5680             /**
5681              * List of attractor elements. If the distance of the text is less than
5682              * attractorDistance the text is made to glider of this element.
5683              *
5684              * @name attractors
5685              * @memberOf Text.prototype
5686              * @type Array
5687              * @default empty
5688              */
5689             attractors: []
5690 
5691             /**#@-*/
5692         },
5693 
5694         /* special options for trace curves */
5695         tracecurve: {
5696             /**#@+
5697              * @visprop
5698              */
5699             strokeColor: '#000000',
5700             fillColor: 'none',
5701 
5702             /**
5703              * The number of evaluated data points.
5704              * @memberOf Tracecurve.prototype
5705              * @default 100
5706              * @name numberPoints
5707              * @type Number
5708              */
5709             numberPoints: 100
5710 
5711             /**#@-*/
5712         },
5713 
5714         /*special turtle options */
5715         turtle: {
5716             /**#@+
5717              * @visprop
5718              */
5719 
5720             strokeWidth: 1,
5721             fillColor: 'none',
5722             strokeColor: '#000000',
5723 
5724             /**
5725              * Attributes for the turtle arrow.
5726              *
5727              * @type Curve
5728              * @name Turtle#arrow
5729              */
5730             arrow: {
5731                 strokeWidth: 2,
5732                 withLabel: false,
5733                 strokeColor: Color.palette.red,
5734                 lastArrow: true
5735             }
5736             /**#@-*/
5737         },
5738 
5739         /**
5740          * Abbreviations of attributes. Setting the shortcut means setting abbreviated properties
5741          * to the same value.
5742          * It is used in {@link JXG.GeometryElement#setAttribute} and in
5743          * the constructor {@link JXG.GeometryElement}.
5744          * Attention: In Options.js abbreviations are not allowed.
5745          * @type Object
5746          * @name JXG.Options#shortcuts
5747          *
5748          */
5749         shortcuts: {
5750             color: ['strokeColor', 'fillColor'],
5751             opacity: ['strokeOpacity', 'fillOpacity'],
5752             highlightColor: ['highlightStrokeColor', 'highlightFillColor'],
5753             highlightOpacity: ['highlightStrokeOpacity', 'highlightFillOpacity'],
5754             strokeWidth: ['strokeWidth', 'highlightStrokeWidth']
5755         }
5756     };
5757 
5758     /**
5759      * Holds all possible properties and the according validators for geometry elements.
5760      * A validator is either a function
5761      * which takes one parameter and returns true, if the value is valid for the property,
5762      * or it is false if no validator is required.
5763      */
5764     JXG.Validator = (function () {
5765         var i,
5766             validatePixel = function (v) {
5767                 return (/^[0-9]+px$/).test(v);
5768             },
5769             validateDisplay = function (v) {
5770                 return (v  === 'html' || v === 'internal');
5771             },
5772             validateColor = function (v) {
5773                 // for now this should do it...
5774                 return Type.isString(v);
5775             },
5776             validatePointFace = function (v) {
5777                 return Type.exists(JXG.normalizePointFace(v));
5778             },
5779             validateInteger = function (v) {
5780                 return (Math.abs(v - Math.round(v)) < Mat.eps);
5781             },
5782             validateNotNegativeInteger = function (v) {
5783                 return validateInteger(v) && v >= 0;
5784             },
5785             validatePositiveInteger = function (v) {
5786                 return validateInteger(v) && v > 0;
5787             },
5788             validateScreenCoords = function (v) {
5789                 return v.length >= 2 && validateInteger(v[0]) && validateInteger(v[1]);
5790             },
5791             validateRenderer = function (v) {
5792                 return (v === 'vml' || v === 'svg' || v === 'canvas' || v === 'no');
5793             },
5794             validatePositive = function (v) {
5795                 return v > 0;
5796             },
5797             validateNotNegative = function (v) {
5798                 return v >= 0;
5799             },
5800             v = {},
5801             validators = {
5802                 attractorDistance: validateNotNegative,
5803                 color: validateColor,
5804                 defaultDistance: Type.isNumber,
5805                 display: validateDisplay,
5806                 doAdvancedPlot: false,
5807                 draft: false,
5808                 drawLabels: false,
5809                 drawZero: false,
5810                 face: validatePointFace,
5811                 factor: Type.isNumber,
5812                 fillColor: validateColor,
5813                 fillOpacity: Type.isNumber,
5814                 firstArrow: false,
5815                 fontSize: validateInteger,
5816                 dash: validateInteger,
5817                 gridX: Type.isNumber,
5818                 gridY: Type.isNumber,
5819                 hasGrid: false,
5820                 highlightFillColor: validateColor,
5821                 highlightFillOpacity: Type.isNumber,
5822                 highlightStrokeColor: validateColor,
5823                 highlightStrokeOpacity: Type.isNumber,
5824                 insertTicks: false,
5825                 //: validateScreenCoords,
5826                 lastArrow: false,
5827                 layer: validateNotNegativeInteger,
5828                 majorHeight: validateInteger,
5829                 minorHeight: validateInteger,
5830                 minorTicks: validateNotNegative,
5831                 minTicksDistance: validatePositiveInteger,
5832                 numberPointsHigh: validatePositiveInteger,
5833                 numberPointsLow: validatePositiveInteger,
5834                 opacity: Type.isNumber,
5835                 radius: Type.isNumber,
5836                 RDPsmoothing: false,
5837                 renderer: validateRenderer,
5838                 right: validatePixel,
5839                 showCopyright: false,
5840                 showInfobox: false,
5841                 showNavigation: false,
5842                 size: validateNotNegative, //validateInteger,
5843                 snapSizeX: validatePositive,
5844                 snapSizeY: validatePositive,
5845                 snapWidth: Type.isNumber,
5846                 snapToGrid: false,
5847                 snatchDistance: validateNotNegative,
5848                 straightFirst: false,
5849                 straightLast: false,
5850                 stretch: false,
5851                 strokeColor: validateColor,
5852                 strokeOpacity: Type.isNumber,
5853                 strokeWidth: validateNotNegative, //validateInteger,
5854                 takeFirst: false,
5855                 takeSizeFromFile: false,
5856                 to10: false,
5857                 toOrigin: false,
5858                 translateTo10: false,
5859                 translateToOrigin: false,
5860                 useASCIIMathML: false,
5861                 useDirection: false,
5862                 useMathJax: false,
5863                 withLabel: false,
5864                 withTicks: false,
5865                 zoom: false
5866             };
5867 
5868         // this seems like a redundant step but it makes sure that
5869         // all properties in the validator object have lower case names
5870         // and the validator object is easier to read.
5871         for (i in validators) {
5872             if (validators.hasOwnProperty(i)) {
5873                 v[i.toLowerCase()] = validators[i];
5874             }
5875         }
5876 
5877         return v;
5878     }());
5879 
5880     /**
5881      * All point faces can be defined with more than one name, e.g. a cross faced point can be given
5882      * by face equal to 'cross' or equal to 'x'. This method maps all possible values to fixed ones to
5883      * simplify if- and switch-clauses regarding point faces. The translation table is as follows:
5884      * <table>
5885      * <tr><th>Input</th><th>Output</th></tr>
5886      * <tr><td>cross, x</td><td>x</td></tr>
5887      * <tr><td>circle, o</td><td>o</td></tr>
5888      * <tr><td>square, []</td><td>[]</td></tr>
5889      * <tr><td>plus, +</td><td>+</td></tr>
5890      * <tr><td>diamond, <></td><td><></td></tr>
5891      * <tr><td>triangleup, a, ^</td><td>A</td></tr>
5892      * <tr><td>triangledown, v</td><td>v</td></tr>
5893      * <tr><td>triangleleft, <</td><td><</td></tr>
5894      * <tr><td>triangleright, ></td><td>></td></tr>
5895      * </table>
5896      * @param {String} s A string which should determine a valid point face.
5897      * @returns {String} Returns a normalized string or undefined if the given string is not a valid
5898      * point face.
5899      */
5900     JXG.normalizePointFace = function (s) {
5901         var map = {
5902             cross: 'x',
5903             x: 'x',
5904             circle: 'o',
5905             o: 'o',
5906             square: '[]',
5907             '[]': '[]',
5908             plus: '+',
5909             '+': '+',
5910             diamond: '<>',
5911             '<>': '<>',
5912             triangleup: '^',
5913             a: '^',
5914             '^': '^',
5915             triangledown: 'v',
5916             v: 'v',
5917             triangleleft: '<',
5918             '<': '<',
5919             triangleright: '>',
5920             '>': '>'
5921         };
5922 
5923         return map[s];
5924     };
5925 
5926 
5927     /**
5928      * Apply the options stored in this object to all objects on the given board.
5929      * @param {JXG.Board} board The board to which objects the options will be applied.
5930      */
5931     JXG.useStandardOptions = function (board) {
5932         var el, t, p, copyProps,
5933             o = JXG.Options,
5934             boardHadGrid = board.hasGrid;
5935 
5936         board.options.grid.hasGrid = o.grid.hasGrid;
5937         board.options.grid.gridX = o.grid.gridX;
5938         board.options.grid.gridY = o.grid.gridY;
5939         board.options.grid.gridColor = o.grid.gridColor;
5940         board.options.grid.gridOpacity = o.grid.gridOpacity;
5941         board.options.grid.gridDash = o.grid.gridDash;
5942         board.options.grid.snapToGrid = o.grid.snapToGrid;
5943         board.options.grid.snapSizeX = o.grid.SnapSizeX;
5944         board.options.grid.snapSizeY = o.grid.SnapSizeY;
5945         board.takeSizeFromFile = o.takeSizeFromFile;
5946 
5947         copyProps = function (p, o) {
5948             p.visProp.fillcolor = o.fillColor;
5949             p.visProp.highlightfillcolor = o.highlightFillColor;
5950             p.visProp.strokecolor = o.strokeColor;
5951             p.visProp.highlightstrokecolor = o.highlightStrokeColor;
5952         };
5953 
5954         for (el in board.objects) {
5955             if (board.objects.hasOwnProperty(el)) {
5956                 p = board.objects[el];
5957                 if (p.elementClass === Const.OBJECT_CLASS_POINT) {
5958                     copyProps(p, o.point);
5959                 } else if (p.elementClass === Const.OBJECT_CLASS_LINE) {
5960                     copyProps(p, o.line);
5961 
5962                     for (t = 0; t < p.ticks.length; t++) {
5963                         p.ticks[t].majorTicks = o.line.ticks.majorTicks;
5964                         p.ticks[t].minTicksDistance = o.line.ticks.minTicksDistance;
5965                         p.ticks[t].visProp.minorheight = o.line.ticks.minorHeight;
5966                         p.ticks[t].visProp.majorheight = o.line.ticks.majorHeight;
5967                     }
5968                 } else if (p.elementClass === Const.OBJECT_CLASS_CIRCLE) {
5969                     copyProps(p, o.circle);
5970                 } else if (p.type === Const.OBJECT_TYPE_ANGLE) {
5971                     copyProps(p, o.angle);
5972                 } else if (p.type === Const.OBJECT_TYPE_ARC) {
5973                     copyProps(p, o.arc);
5974                 } else if (p.type === Const.OBJECT_TYPE_POLYGON) {
5975                     copyProps(p, o.polygon);
5976                 } else if (p.type === Const.OBJECT_TYPE_CONIC) {
5977                     copyProps(p, o.conic);
5978                 } else if (p.type === Const.OBJECT_TYPE_CURVE) {
5979                     copyProps(p, o.curve);
5980                 } else if (p.type === Const.OBJECT_TYPE_SECTOR) {
5981                     p.arc.visProp.fillcolor = o.sector.fillColor;
5982                     p.arc.visProp.highlightfillcolor = o.sector.highlightFillColor;
5983                     p.arc.visProp.fillopacity = o.sector.fillOpacity;
5984                     p.arc.visProp.highlightfillopacity = o.sector.highlightFillOpacity;
5985                 }
5986             }
5987         }
5988 
5989         board.fullUpdate();
5990         if (boardHadGrid && !board.hasGrid) {
5991             board.removeGrids(board);
5992         } else if (!boardHadGrid && board.hasGrid) {
5993             board.create('grid', []);
5994         }
5995     };
5996 
5997     /**
5998      * Converts all color values to greyscale and calls useStandardOption to put them onto the board.
5999      * @param {JXG.Board} board The board to which objects the options will be applied.
6000      * @see #useStandardOptions
6001      */
6002     JXG.useBlackWhiteOptions = function (board) {
6003         var o = JXG.Options;
6004         o.point.fillColor = Color.rgb2bw(o.point.fillColor);
6005         o.point.highlightFillColor = Color.rgb2bw(o.point.highlightFillColor);
6006         o.point.strokeColor = Color.rgb2bw(o.point.strokeColor);
6007         o.point.highlightStrokeColor = Color.rgb2bw(o.point.highlightStrokeColor);
6008 
6009         o.line.fillColor = Color.rgb2bw(o.line.fillColor);
6010         o.line.highlightFillColor = Color.rgb2bw(o.line.highlightFillColor);
6011         o.line.strokeColor = Color.rgb2bw(o.line.strokeColor);
6012         o.line.highlightStrokeColor = Color.rgb2bw(o.line.highlightStrokeColor);
6013 
6014         o.circle.fillColor = Color.rgb2bw(o.circle.fillColor);
6015         o.circle.highlightFillColor = Color.rgb2bw(o.circle.highlightFillColor);
6016         o.circle.strokeColor = Color.rgb2bw(o.circle.strokeColor);
6017         o.circle.highlightStrokeColor = Color.rgb2bw(o.circle.highlightStrokeColor);
6018 
6019         o.arc.fillColor = Color.rgb2bw(o.arc.fillColor);
6020         o.arc.highlightFillColor = Color.rgb2bw(o.arc.highlightFillColor);
6021         o.arc.strokeColor = Color.rgb2bw(o.arc.strokeColor);
6022         o.arc.highlightStrokeColor = Color.rgb2bw(o.arc.highlightStrokeColor);
6023 
6024         o.polygon.fillColor = Color.rgb2bw(o.polygon.fillColor);
6025         o.polygon.highlightFillColor  = Color.rgb2bw(o.polygon.highlightFillColor);
6026 
6027         o.sector.fillColor = Color.rgb2bw(o.sector.fillColor);
6028         o.sector.highlightFillColor  = Color.rgb2bw(o.sector.highlightFillColor);
6029 
6030         o.curve.strokeColor = Color.rgb2bw(o.curve.strokeColor);
6031         o.grid.gridColor = Color.rgb2bw(o.grid.gridColor);
6032 
6033         JXG.useStandardOptions(board);
6034     };
6035 
6036     // needs to be exported
6037     JXG.Options.normalizePointFace = JXG.normalizePointFace;
6038 
6039     return JXG.Options;
6040 });
6041