Tim Tait http://timtait.co.nz pew pew pew posterous.com Mon, 21 Feb 2011 02:44:00 -0800 HTML5 canvas fancy Mandelbrot Set http://timtait.co.nz/html5-canvas-fancy-mandelbrot-set http://timtait.co.nz/html5-canvas-fancy-mandelbrot-set

Added a few buttons and fields to the Mandelbrot Set generator.

I'll add some decent zooming / panning functionality one day.

Warning: it may take a few seconds.

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]]> http://files.posterous.com/user_profile_pics/507997/2eec67fa648a9fcdfcfeb13e90b3e6ad.jpeg http://posterous.com/users/5emluwidDJBv Tim Tait Tim Tim Tait Wed, 16 Feb 2011 18:30:00 -0800 HTML5 canvas Mandelbrot Set http://timtait.co.nz/43228745 http://timtait.co.nz/43228745

After playing around with the HTML5 canvas element I had a quick go at rendering a Mandelbrot Set. Why? because they look fucking awesome.

Warning: it may take a few seconds.

Great success.

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<!doctype html>

<canvas id="c" width="350" height="200" style="border:1px solid #000;">

<script>
	var c = document.getElementById("c");
	var ctx = c.getContext("2d");

	var x0,y0,x,y,xtemp,iteration,cp;
	var max_iteration = 100;

	var xi0 = -2.5;
	var xi1 = 1;
	var yi0 = -1;
	var yi1 = 1;

	var difx = xi1-xi0;
	var dify = yi1-yi0;

	c.addEventListener("click", makeMandelbrot, false);

	ctx.fillText("Click here to draw the Mandelbrot Set", 85, 100);

	function makeMandelbrot() {
		c.removeEventListener("click", makeMandelbrot, false);

		for (var i = 0; i < c.width; i++) {
			for (var j = 0; j < c.height; j++) {

				x0 = xi0+(difx*(i/c.width));//scaled x co-ordinate of pixel (must be scaled to lie somewhere in the interval (-2.5 to 1)
				y0 = yi0+(dify*(j/c.height));//scaled y co-ordinate of pixel (must be scaled to lie somewhere in the interval (-1, 1)

				x = 0;
				y = 0;

				iteration = 0;

				while ( x*x + y*y <= (2*2)  &&  iteration < max_iteration )
				{
					xtemp = x*x - y*y + x0;
					y = 2*x*y + y0;

					x = xtemp;

					iteration++;
				}

				x0 = ((2.5+x0)/difx)*c.width;
				y0 = ((1+y0)/dify)*c.height;

				if ( iteration == max_iteration ) {
					ctx.fillStyle = "rgb(0,0,0)";
				} else {
					ctx.fillStyle = "rgb(255,255,255)";
				}

				ctx.fillRect(x0,y0,1,1);			
			}
		}		
	}
</script>

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]]> http://files.posterous.com/user_profile_pics/507997/2eec67fa648a9fcdfcfeb13e90b3e6ad.jpeg http://posterous.com/users/5emluwidDJBv Tim Tait Tim Tim Tait Mon, 14 Feb 2011 20:00:00 -0800 HTML5 canvas shapes http://timtait.co.nz/43101237 http://timtait.co.nz/43101237

Yesterday I was in a workshop with Mark Pilgrim on HTML 5, I was mucking around with the Canvas and ended up with this. It's quite cool in full screen.

 

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<!doctype html>
<style>
body {padding:0;margin:0;overflow:hidden;}
</style>

<div id="controls" style="position:absolute;width:106px;height:95px;background-color:#fff;">
	<input type="checkbox" id="circles" checked="checked" />Circles<br />
	<input type="checkbox" id="squares" checked="checked" />Squares<br />
	<input type="button" id="clear" value="Clear" onclick="btnClear();" /><br />
	<input type="button" id="close" value="Hide this panel" onclick="btnClose();" />
</div>
<canvas id="c" width="1000" height="1000">


<script>
	var c = document.getElementById("c");
	var ctx = c.getContext("2d");

	document.body.onresize = function (){
		resizeCanvas();
	}

	resizeCanvas();

	var maxHeight = 100;
	var maxWidth = 100;

	function resizeCanvas() {
		ctx.canvas.width  = window.innerWidth;
		ctx.canvas.height = window.innerHeight;
	}

	function drawShape() {
		ctx.fillStyle = "rgba(" + Math.ceil(Math.random()*200) + "," + Math.ceil(Math.random()*200) + "," + Math.ceil(Math.random()*200) + "," + Math.random() + ")";			
		if (Math.random() > .5) {
			if (document.getElementById("squares").checked)
				ctx.fillRect(Math.random()*c.width, Math.random()*c.height, Math.random()*maxWidth, Math.random()*maxHeight);
		} else {
			if (document.getElementById("circles").checked) {
				ctx.beginPath();
				ctx.arc(Math.random()*c.width, Math.random()*c.height,Math.random()*maxHeight,0,Math.PI*2,true);
				ctx.closePath();
				ctx.fill();
			}
		}
	}

	function btnClose() {
		document.getElementById('controls').style.visibility = 'hidden';
	}

	function btnClear() {
		ctx.fillStyle = "rgb(255,255,255)";			
		ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
	}

	function timer()
	{	
		t=setTimeout("timer()",10);
		drawShape();
	}	

	timer();
</script>

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]]> http://files.posterous.com/user_profile_pics/507997/2eec67fa648a9fcdfcfeb13e90b3e6ad.jpeg http://posterous.com/users/5emluwidDJBv Tim Tait Tim Tim Tait