Turtle Graphics: Difference between revisions

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This is a very basic implementation of turtle graphics in JavaScript with [http://jsxgraph.org JSXGraph]. Here, we use SVG (on Firefox, Safari, Opera and Chrome) and VML (on Internet Explorer).
This is a very basic implementation of turtle graphics in JavaScript with [http://jsxgraph.org JSXGraph].  
[http://u2d.com/turtle_js/index.html CanvasTurtle] does the same on browsers which support the ''canvas'' element.
[http://u2d.com/turtle_js/index.html CanvasTurtle] does the same on browsers which support the ''canvas'' element.
===List of available commands===
 
There is a predefined turtle object ''t''. Therefore, all commands
* [[List of available commands]]
start with ''t'', like ''t.fd(100)'';
<source lang="javascript">
* t.forward(len); or t.fd(len);
* t.back(len); or t.bk(len);
* t.right(angle); or t.rt(angle); (<math>0\leq angle \leq 360</math>)
* t.left(angle); or t.lt(angle);
* t.penUp(); or t.pu();
* t.penDown(); or t.pd();
* t.clearScreen(); or t.cs();
* t.clean();
* t.setPos(x,y);
* t.home();
* t.hideTurtle(); or t.ht();
* t.showTurtle(); or t.st();
* t.setPenSize(size); (size: number)
* t.setPenColor(col); (col: colorString, e.g. 'red' or '#ff0000')
</source>


===Snowflake and Branches Example===
===Snowflake and Branches Example===
<html>
<html>
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/prototype.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxturtle.js"></script>
<form><textarea id="input1" rows=7 cols=35 wrap="off" style="width:300px; float:left;">
<form><textarea id="input1" rows=7 cols=35 wrap="off" style="width:300px; float:left;">
function side(size, level) {
function side(size, level) {
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function snowflake(size, level) {
function snowflake(size, level) {
     (3).times(function() {
     for (var i=0;i<3;i++) {
         side(size, level);
         side(size, level);
         t.rt(120);
         t.rt(120);
     });
     };
}
}


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<input type="button" value="run example 2" onClick="run(2)">  
<input type="button" value="run example 2" onClick="run(2)">  
</form>
</form>
<div id="box" class="jxgbox" style="width:600px; height:600px;"></div>
</html>
<script language="JavaScript">
<jsxgraph width="600" height="600" box="box">
var brd = JXG.JSXGraph.initBoard('box', {originX: 300, originY: 300, unitX: 1, unitY: 1});
var brd = JXG.JSXGraph.initBoard('box', {boundingbox: [-300, 300, 300, -300]});
var t = new JSXTurtleObj(brd);
var t = brd.create('turtle');
function run(nr) {
function run(nr) {
   brd.suspendUpdate();
   brd.suspendUpdate();
   eval($('input'+nr).value);
   eval(document.getElementById('input'+nr).value);
   brd.unsuspendUpdate();
   brd.unsuspendUpdate();
}
}
</script>
</jsxgraph>
</html>


===References===
===References===
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===The turtle graphics code===
===The turtle graphics code===
<source lang="html4strict">
<source lang="html4strict">
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/prototype.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxturtle.js"></script>
<div id="box" class="jxgbox" style="width:600px; height:600px;"></div>
<form><textarea id="input1" rows=7 cols=35 wrap="off" style="width:300px; float:left;">
<form><textarea id="input1" rows=7 cols=35 wrap="off" style="width:300px; float:left;">
turtle code...
turtle code...
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<source lang="javascript">
<source lang="javascript">
var brd = JXG.JSXGraph.initBoard('box', {originX: 300, originY: 300, unitX: 1, unitY: 1});
var brd = JXG.JSXGraph.initBoard('box', {boundingbox: [-300, 300, 300, -300]});
var t = new JSXTurtleObj(brd);
var t = brd.create('turtle');


function run(nr) {
function run(nr) {
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[[Category:Examples]]
[[Category:Examples]]
[[:Category:Turtle Graphics]]
[[Category:Turtle Graphics]]
[[Category:Fractals]]
[[Category:Fractals]]

Latest revision as of 07:40, 9 June 2011

This is a very basic implementation of turtle graphics in JavaScript with JSXGraph. CanvasTurtle does the same on browsers which support the canvas element.

Snowflake and Branches Example


References

  • The snowflake and branches example have been adapted from the excellent CanvasTurtle

The turtle graphics code

<form><textarea id="input1" rows=7 cols=35 wrap="off" style="width:300px; float:left;">
turtle code...
</textarea>
<input type="button" value="run example 1" onClick="run(1)">

var brd = JXG.JSXGraph.initBoard('box', {boundingbox: [-300, 300, 300, -300]});
var t = brd.create('turtle');

function run(nr) {
  brd.suspendUpdate();
  eval($('input'+nr).value);
  brd.unsuspendUpdate();
}
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