/*
 * Pixastic Lib - Blur Fast - v0.1.0
 * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
 * MIT License [http://www.opensource.org/licenses/mit-license.php]
 */

Pixastic.Actions.blurfast = {
	process : function(params) {

		var amount = parseFloat(params.options.amount)||0;

		amount = Math.max(0,Math.min(5,amount));

		if (Pixastic.Client.hasCanvas()) {
			var rect = params.options.rect;

			var ctx = params.canvas.getContext("2d");
			ctx.save();
			ctx.beginPath();
			ctx.moveTo(rect.left,rect.top);
			ctx.lineTo(rect.left+rect.width,rect.top);
			ctx.lineTo(rect.left+rect.width,rect.top+rect.height);
			ctx.lineTo(rect.left,rect.top+rect.height);
			ctx.lineTo(rect.left,rect.top);
			ctx.closePath();
			ctx.clip();

			var scale = 2;
			var smallWidth = Math.round(params.width / scale);
			var smallHeight = Math.round(params.height / scale);

			var copy = document.createElement("canvas");
			copy.width = smallWidth;
			copy.height = smallHeight;

			var clear = true;
			var steps = Math.round(amount * 20);

			var copyCtx = copy.getContext("2d");
			for (var i=0;i<steps;i++) {
				var scaledWidth = Math.max(1,Math.round(smallWidth - i));
				var scaledHeight = Math.max(1,Math.round(smallHeight - i));
	
				copyCtx.clearRect(0,0,smallWidth,smallHeight);
	
				copyCtx.drawImage(
					params.canvas,
					0,0,params.width,params.height,
					0,0,scaledWidth,scaledHeight
				);
	
				if (clear)
					ctx.clearRect(rect.left,rect.top,rect.width,rect.height);
	
				ctx.drawImage(
					copy,
					0,0,scaledWidth,scaledHeight,
					0,0,params.width,params.height
				);
			}

			ctx.restore();

			params.useData = false;
			return true;
		} else if (Pixastic.Client.isIE()) {
			var radius = 10 * amount;
			params.image.style.filter += " progid:DXImageTransform.Microsoft.Blur(pixelradius=" + radius + ")";

			if (params.options.fixMargin || 1) {
				params.image.style.marginLeft = (parseInt(params.image.style.marginLeft,10)||0) - Math.round(radius) + "px";
				params.image.style.marginTop = (parseInt(params.image.style.marginTop,10)||0) - Math.round(radius) + "px";
			}

			return true;
		}
	},
	checkSupport : function() {
		return (Pixastic.Client.hasCanvas() || Pixastic.Client.isIE());
	}
}