Difference between revisions of "The HSV color scheme"

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Line 24: Line 24:
  
 
var c2 = brd.createElement('curve',[
 
var c2 = brd.createElement('curve',[
           function(t){return r1*Math.sin(t);},
+
           function(t){return Math.sin(t);},
           function(t){return r1*Math.cos(t)-0.5;},
+
           function(t){return Math.cos(t)-0.5;},
 
           0, 2*Math.PI],
 
           0, 2*Math.PI],
 
           {fillcolor:function(){ return JXG.hsv2rgb(H.Value(),S.Value(),V.Value()); },
 
           {fillcolor:function(){ return JXG.hsv2rgb(H.Value(),S.Value(),V.Value()); },
           highlightFillcolor:function(){ return JXG.hsv2rgb(H.Value(),S.Value(),V.Value()); },
+
           highlightFillcolor:function(){ return JXG.hsv2rgb(180+H.Value(),S.Value(),V.Value()); },
 
           strokeColor:'black',strokeWidth:3});
 
           strokeColor:'black',strokeWidth:3});
 
/*           
 
/*           

Revision as of 17:08, 24 September 2009

The HSV color scheme consists of three values:

  • Hue (base color): between 0 and 360
  • Saturation (purity): between 0 and 1
  • Value (brightness): between 0 and 1

Here, you can experiment with these values.

The underlying JavaScript code

<jsxgraph width=600 height=500>
var brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2,4,8,-4]});
var H = brd.createElement('slider',[[0,3.5],[5,3.5],[0,1,360]], {name:'H'});
var S = brd.createElement('slider',[[0,3],[5,3],[0,1,1]], {name:'S'});
var V = brd.createElement('slider',[[0,2.5],[5,2.5],[0,1,1]], {name:'V'});
var rct = brd.createElement('curve',[[-1,-1,5,5,-1],[-2,2,2,-2,-2]],
                 {strokeColor:'black', 
                  fillcolor:function(){ return JXG.hsv2rgb(H.Value(),S.Value(),V.Value()); }
                 }
          );
</jsxgraph>

External links