/*
*    Blowing Hair effect
*    P.Leskinen 12 January MMIX
*    Hairy Text Blowing in a Perlin Wind
*/

package {

import flash.display.Bitmap;
	import flash.display.BitmapData;
	import flash.display.BitmapDataChannel;
	import flash.display.BlendMode;
	import flash.display.Sprite;
	import flash.events.Event;

import flash.filters.BlurFilter;
	import flash.filters.ConvolutionFilter;
	import flash.filters.DisplacementMapFilter;

import flash.geom.ColorTransform;
	import flash.geom.Matrix;
	import flash.geom.Point;
	import flash.text.*;

public class BlowingInTheHair extends Sprite
	{
		
		public var source:*;

public var margin:int = 40; // white space around

//    controls the hair length
		public var hairLength:Number = 8.0;

//    density: 
		//    0.0 = solid
		//    0.99 = just a few hair
		public var density:Number = 0.85;
		public var contrast:Number = 1.5;

protected var bmd:BitmapData;
		protected var perlinMap:BitmapData;
		protected var canvas:BitmapData;
		protected var offsets:Array;

internal var i:int, j:int;
		internal const NEWMATRIX:Matrix= new Matrix();
		internal const NEWPOINT:Point= new Point();
		internal const NEWCOLORTRANSFORM:ColorTransform = new ColorTransform();
		internal const BLUR:BlurFilter = new BlurFilter(2,2); // or try (1,8);
		
		public function BlowingInTheHair ()
		{
			//    create a text element 
			with( source= new TextField() ) {
		            defaultTextFormat= new TextFormat(
		                "Arial", 
		                70, 
		                0x654321 );
			    htmlText="Hello world";
			    multiline = true;
			    width= 360.0;
			}
                        
			initStage();
		}
		
                // init bitmapdatas and listeners:
		private function initStage():void {
			var w:int, h:int;
                        
			bmd= new BitmapData(
			    w= source.width+2*margin,
			    h= source.height+2*margin,
			    true, 0x00);

perlinMap = new BitmapData(w,h, false);
			offsets= [new Point(), new Point(), new Point()];
			
			canvas = new BitmapData(w,h, true,0x00);
			
			addChild(new Bitmap(canvas));
			addEventListener(Event.ENTER_FRAME, generate);
			
		}
		
		
		private function generate(e:Event =null):void {
			
                        //    creating the 'blowing'
			offsets[0].x -= 8.0;
			offsets[1].x += 5.2;
			offsets[2].x += 2.8;
			
			offsets[0].y += 2.0;
			offsets[1].y -= 1.6;
			offsets[2].y -= 0.4;
		
			perlinMap.perlinNoise(perlinMap.width/2,perlinMap.height/2, 3,11,true,true, 
				BitmapDataChannel.BLUE + BitmapDataChannel.GREEN, false, offsets);

//    creating the effect:
			var displacer:DisplacementMapFilter = new DisplacementMapFilter(perlinMap,
				NEWPOINT,
				BitmapDataChannel.BLUE,BitmapDataChannel.GREEN,
				hairLength,hairLength); 
								
			canvas.lock();
			
			canvas.fillRect(canvas.rect, 0x00);
			canvas.draw(source, new Matrix(1,0,0,1,margin,margin));

//    pixelDissolve to set some pixels to completely transparent
			//    , without this would be a 'solid mass'
			canvas.pixelDissolve(canvas, canvas.rect, NEWPOINT, 11, 
				density*canvas.width*canvas.height, 
				0x000000);
					
			canvas.applyFilter(canvas, canvas.rect, NEWPOINT, BLUR);
			canvas.applyFilter(canvas, canvas.rect, NEWPOINT,
				new ConvolutionFilter(3,3,[0, 1, 1.5,
				-1, contrast, 1,
				-1.5, -1, 0],contrast, 0, true) );

//    repeat a serie of displacements to achieve a hair effect 
			//    number of iterations, bigger value for smoother hair, but slows down
			for (i=0; i!=5; i++) {
				
				displacer.scaleX = displacer.scaleY *= 1.4;
				bmd.applyFilter(canvas, bmd.rect, NEWPOINT, displacer);
				
				canvas.draw(bmd,NEWMATRIX ,
                                    //    modify to change the color:
					new ColorTransform(1.22,1.2,0.95,1.0), 
					BlendMode.LIGHTEN);
				
			}
			
			canvas.unlock();
		}
		
	}
}