Created
August 20, 2012 07:10
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Fractal Tree Generation using HTML5 Canvas and Random Numbers
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<html> | |
<head> | |
<script type="text/javascript"> | |
window.onload = draw; | |
function draw(){ | |
var canvas = document.getElementById('myCanvas'); | |
if (canvas.getContext){ | |
var context = canvas.getContext('2d'); | |
drawFractalTree(context); | |
} | |
else{ | |
alert("HTML5 Canvas isn't supported by your browser!"); | |
} | |
} | |
function drawFractalTree(context){ | |
drawTree(context, 800, 800, -90, 11); | |
} | |
function drawTree(context, x1, y1, angle, depth){ | |
var BRANCH_LENGTH = random(0, 20); | |
if (depth != 0){ | |
var x2 = x1 + (cos(angle) * depth * BRANCH_LENGTH); | |
var y2 = y1 + (sin(angle) * depth * BRANCH_LENGTH); | |
drawLine(context, x1, y1, x2, y2, depth); | |
drawTree(context, x2, y2, angle - random(15,20), depth - 1); | |
drawTree(context, x2, y2, angle + random(15,20), depth - 1); | |
} | |
} | |
function drawLine(context, x1, y1, x2, y2, thickness){ | |
context.fillStyle = '#000'; | |
if(thickness > 6) | |
context.strokeStyle = 'rgb(139,126, 102)'; //Brown | |
else | |
context.strokeStyle = 'rgb(34,139,34)'; //Green | |
context.lineWidth = thickness * 1.5; | |
context.beginPath(); | |
context.moveTo(x1,y1); | |
context.lineTo(x2, y2); | |
context.closePath(); | |
context.stroke(); | |
} | |
function cos (angle) { | |
return Math.cos(deg_to_rad(angle)); | |
} | |
function sin (angle) { | |
return Math.sin(deg_to_rad(angle)); | |
} | |
function deg_to_rad(angle){ | |
return angle*(Math.PI/180.0); | |
} | |
function random(min, max){ | |
return min + Math.floor(Math.random()*(max+1-min)); | |
} | |
</script> | |
<style type="text/css"> | |
canvas { border: 1px solid white; } | |
</style> | |
</head> | |
<body> | |
<canvas id="myCanvas" width="1500" height="800"></canvas> | |
</body> | |
</html> |
Very nice
Too cool! Wrapping the recursive calls in a setTimeout() yields a nice effect, as does setting the globalAplha on the canvas, I've found.
Also if you change depth from 1 to ~14 in setTimeout iterations, you can get an interesting animation.
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Too cool! Wrapping the recursive calls in a setTimeout() yields a nice effect, as does setting the globalAplha on the canvas, I've found.