<html>
<head><title>Mandelbrot Fractal Using HTML5 Canvas</title></head>
<body>
<canvas id="canvas" width="500" height="500">
Your browser does not support HTML5 Canvas.
</canvas>
<script type="text/javascript">
// FB - 20121227
// Tested only using Firefox
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
var xr = context.canvas.width;
var yr = context.canvas.height;
var imgd = context.createImageData(xr, yr);
var pix = imgd.data;
var xmin = -2.0; var xmax = 1.0;
var ymin = -1.5; var ymax = 1.5;
// these are for coloring the image
var mr0 = 0; var mg0 = 0; var mb0 = 0;
while(mr0 == mg0 || mr0 == mb0 || mg0 == mb0)
{
mr0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
mg0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
mb0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
}
var mr1 = 256 / mr0; var mg1 = 256 / mg0; var mb1 = 256 / mb0;
var maxIt = 256;
var x = 0.0; var y = 0.0;
var zx = 0.0; var zx0 = 0.0; var zy = 0.0;
var zx2 = 0.0; var zy2 = 0.0;
for (var ky = 0; ky < yr; ky++)
{
y = ymin + (ymax - ymin) * ky / yr;
for(var kx = 0; kx < xr; kx++)
{
x = xmin + (xmax - xmin) * kx / xr;
zx = x; zy = y;
for(var i = 0; i < maxIt; i++)
{
zx2 = zx * zx; zy2 = zy * zy;
if(zx2 + zy2 > 4.0) break;
zx0 = zx2 - zy2 + x;
zy = 2.0 * zx * zy + y;
zx = zx0;
}
var p = (xr * ky + kx) * 4;
pix[p] = i % mr0 * mr1; // red
pix[p + 1] = i % mg0 * mg1; // green
pix[p + 2] = i % mb0 * mb1; // blue
pix[p + 3] = 255; // alpha
}
}
context.putImageData(imgd, 0, 0);
</script>
</body>
</html>
Diff to Previous Revision
--- revision 2 2010-06-30 22:18:54
+++ revision 3 2012-12-28 01:01:09
@@ -1,33 +1,39 @@
<html>
-<head><title>HTML5 Canvas Mandelbrot Fractal</title></head>
+<head><title>Mandelbrot Fractal Using HTML5 Canvas</title></head>
<body>
<canvas id="canvas" width="500" height="500">
-This text is displayed if your browser does not support HTML5 Canvas.
+Your browser does not support HTML5 Canvas.
</canvas>
<script type="text/javascript">
-// FB - 201006303
-// Tested only using Firefox 3.5
+// FB - 20121227
+// Tested only using Firefox
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
var xr = context.canvas.width;
var yr = context.canvas.height;
-var imgd = context.createImageData(xr,yr);
+var imgd = context.createImageData(xr, yr);
var pix = imgd.data;
-var xmin = -2.0;
-var xmax = 1.0;
-var ymin = -1.5;
-var ymax = 1.5;
+var xmin = -2.0; var xmax = 1.0;
+var ymin = -1.5; var ymax = 1.5;
+
+// these are for coloring the image
+var mr0 = 0; var mg0 = 0; var mb0 = 0;
+while(mr0 == mg0 || mr0 == mb0 || mg0 == mb0)
+{
+ mr0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
+ mg0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
+ mb0 = Math.pow(2, Math.ceil(Math.random() * 3 + 3));
+}
+var mr1 = 256 / mr0; var mg1 = 256 / mg0; var mb1 = 256 / mb0;
var maxIt = 256;
-var x = 0.0;
-var y = 0.0;
-var zx = 0.0;
-var zx0 = 0.0;
-var zy = 0.0;
+var x = 0.0; var y = 0.0;
+var zx = 0.0; var zx0 = 0.0; var zy = 0.0;
+var zx2 = 0.0; var zy2 = 0.0;
for (var ky = 0; ky < yr; ky++)
{
@@ -35,25 +41,24 @@
for(var kx = 0; kx < xr; kx++)
{
x = xmin + (xmax - xmin) * kx / xr;
- zx = x;
- zy = y;
+ zx = x; zy = y;
for(var i = 0; i < maxIt; i++)
{
- if( zx * zx + zy * zy > 4.0) break;
- zx0 = zx * zx - zy * zy + x;
+ zx2 = zx * zx; zy2 = zy * zy;
+ if(zx2 + zy2 > 4.0) break;
+ zx0 = zx2 - zy2 + x;
zy = 2.0 * zx * zy + y;
zx = zx0;
}
- var p = (yr * ky + kx) * 4;
- pix[p] = i % 8 * 32; // red
- pix[p+1] = i % 16 * 16; // green
- pix[p+2] = i % 32 * 8; // blue
- pix[p+3] = 255; // alpha
+ var p = (xr * ky + kx) * 4;
+ pix[p] = i % mr0 * mr1; // red
+ pix[p + 1] = i % mg0 * mg1; // green
+ pix[p + 2] = i % mb0 * mb1; // blue
+ pix[p + 3] = 255; // alpha
}
}
-context.putImageData(imgd, 0,0);
-
+context.putImageData(imgd, 0, 0);
</script>
</body>
</html>
