// forked from fladdict's FITC: Cool Japan side A / Particle sample of SMOKE /** * * Sample code for FITC * Smoke particle effect * */ package { import flash.display.Sprite; import flash.display.Bitmap; import flash.display.BitmapData; import flash.display.BlendMode; import flash.events.Event; import flash.filters.BlurFilter; import flash.geom.ColorTransform; import flash.geom.Matrix; import flash.geom.Point; import flash.utils.ByteArray; public class FlashTest extends Sprite { //View protected var canvas:BitmapData; protected var canvasBitmap:Bitmap; //BitmapData that contains the actual froce that is applied to particles. protected var forceMap:BitmapData; //BitmapData that contains the force of the storm. protected var stormMap0:BitmapData; protected var stormMap1:BitmapData; //BitmapData that contains the mouse repulsion force of the stage. protected var repulsionMap:BitmapData; protected var repulsionHistoryMap:BitmapData; protected var repulsionFadeMap:BitmapData; //the number of particles. 5000-200000 protected var particleNum:int = 10000; protected var particles:Vector.<Particle> // protected var stormScaleRatioX:Number; protected var stormScaleRatioY:Number; protected var stormCycle:Number = 0; //color transform that guradually changes canvas. protected var fadeCanvasColt:ColorTransform; protected var canvasBlurFilter:BlurFilter; //temporaly variables protected var tempColt:ColorTransform = new ColorTransform(); protected var tempPt:Point = new Point(); protected var tempMat:Matrix = new Matrix(); public function FlashTest() { init(); reset(); } protected function init():void { //build View canvasBitmap = new Bitmap(null, "auto", false); // because canvas is 25% size of screen, we make view 400% bigger. canvasBitmap.scaleX = 4; canvasBitmap.scaleY = 4; addChild(canvasBitmap); //initialize the map that contains force of the storm; stormMap0 = new BitmapData(256,256,false,0x000000); stormMap0.perlinNoise(128,128,3,Math.random()*100,false,true,3,false); stormMap1 = new BitmapData(256,256,false,0x000000); stormMap1.perlinNoise(128,128,3,Math.random()*100,false,true,3,false); // forceMap = new BitmapData(256,256,false,0x000000); //initialize repulsionMap repulsionHistoryMap = new BitmapData(256,256,false,0x000000); repulsionFadeMap = new BitmapData(256,256,true,0x20808000); repulsionMap = new BitmapData(256,256,false,0); /** * First we preculculate the repulsion force field that mouse cursor generates as a bitmapdata. * Red channel of bitmap data contains horizontal force. * Green channel of bitmap data contains vertical force. */ var dx:int, dy:int; var dist:Number, fx:Number, fy:Number; var col:int; for(var yy:int=0; yy<256; yy++) { for(var xx:int=0; xx<256; xx++){ dx = xx-128; dy = yy-128; dist = Math.sqrt(dx*dx+dy*dy); if(dist<1){ fx = 0; fy = 0; }else{ fx = dx / dist / dist / dist * 50000; fy = dy / dist / dist / dist * 50000; } fx = (fx<-128)? -128 : (fx>127)? 127 : fx; fy = (fy<-128)? -128 : (fy>127)? 127 : fy; fx += 128; fy += 128; col = (fx<<16) + (fy<<8) repulsionMap.setPixel(xx,yy,col); } } //You can see canvasBitmap.bitmapData = repulsionMap; //initialize particle particles = new Vector.<Particle>(particleNum); var particle:Particle; var rr:int; for(var i:int=0; i<particleNum; i++) { particle = new Particle(); particle.x = Math.random() * stage.stageWidth >> 2; particle.y = Math.random() * stage.stageHeight >> 2; //Customize the range of the particle color according to the amount of the particle and stage size. particle.r = particle.g = particle.b = Math.min(Math.random()*8+4,255); //Customize the rage of the scaleFactor according to the amount of the particle and stage size. particle.scaleFactor = (Math.random()*0.1 + 0.95) * 0.003; particles[i] = particle; } fadeCanvasColt = new ColorTransform(1,1,1,1,-2,-1,-1,0); canvasBlurFilter = new BlurFilter(2,2,3); //set event listeners stage.addEventListener(Event.ENTER_FRAME, enterFrameHandler); stage.addEventListener(Event.RESIZE, resizeHandler); } /** * * Called when you need reset the view. E.G. resizing screen. */ protected function reset():void { if(canvas) canvas.dispose(); //build view, to optimize we use 25% size BitmapData of actual screensize. canvas = new BitmapData((stage.stageWidth>>2)+1, (stage.stageHeight>>2)+1, false, 0x000000); canvasBitmap.bitmapData = canvas; //precalculate ratio that converts screen coordinate to stomMapBitmap coodinate; stormScaleRatioX = 1 / (stage.stageWidth>>2)*255; stormScaleRatioY = 1 / (stage.stageHeight>>2)*255; //canvasBitmap.bitmapData = stormMap1; //if you want to see stormMap; //canvasBitmap.bitmapData = repulsionHistoryMap; //canvasBitmap.bitmapData = forceMap; //if you want to see forceMap; //canvasBitmap.scaleX = 1; //canvasBitmap.scaleY = 1; } //We rebuild screen when swf is reseized. //It is not required if you only run it on wonderfl. protected function resizeHandler(e:Event):void { reset(); } //Update storm and particle every frame. protected function enterFrameHandler(e:Event):void { updateStormMap(); updateRepulsionMap(); updateForceMap(); updateParticles(); } /** * We calculate current forcefielde's state by blending two stormMap. * Therefore force field gradually changes every frame. */ protected function updateStormMap():void { stormCycle++; if(stormCycle == 180){ stormMap0.perlinNoise(256,256,3,Math.random()*100,false,true,3,false); }else if(stormCycle==360){ stormMap1.perlinNoise(256,256,3,Math.random()*100,false,true,3,false); stormCycle = 0; } } /** * We update repulsionMap according to the current mouse position. */ protected function updateRepulsionMap():void { tempMat.a = 1; tempMat.b = 0; tempMat.c = 0; tempMat.d = 1; tempMat.tx = 0; tempMat.ty = 0; repulsionHistoryMap.draw(repulsionFadeMap, tempMat); tempMat.translate(-128,-128); tempMat.scale(1/stormScaleRatioX, 1/stormScaleRatioY); tempMat.translate(mouseX/4*stormScaleRatioX, mouseY/4*stormScaleRatioY); repulsionHistoryMap.draw(repulsionMap, tempMat, null, BlendMode.HARDLIGHT); } protected function updateForceMap():void { //generate current force fieldes state with blending two stormMaps. forceMap.copyPixels(stormMap1, stormMap0.rect, tempPt); tempColt.alphaMultiplier = Math.cos(stormCycle*Math.PI/180)*0.5+0.5; forceMap.draw(stormMap0, null, tempColt); //add mouse repulsion force forceMap.draw(repulsionHistoryMap,null,null,BlendMode.HARDLIGHT); forceMap.draw(repulsionHistoryMap,null,null,BlendMode.HARDLIGHT); } protected function updateParticles():void { var forceBytes:ByteArray = forceMap.getPixels(forceMap.rect); var stageW:int = canvas.width; var stageH:int = canvas.height; var loopW:int = stageW-1; var loopH:int = stageH-1; var byteIndex:int; canvas.lock(); canvas.colorTransform(canvas.rect, fadeCanvasColt); //Update Paritcle position and draw. var col:int, r:int, g:int, b:int; for(var i:int=0; i<particleNum; i++) { var prt:Particle = particles[i]; byteIndex = (int(prt.y*stormScaleRatioY)*256 + int(prt.x*stormScaleRatioX))<<2; prt.vx = prt.vx * 0.96 + (forceBytes[byteIndex+1]-128)*prt.scaleFactor; prt.vy = prt.vy * 0.96 + (forceBytes[byteIndex+2]-128)*prt.scaleFactor; prt.x += prt.vx; prt.y += prt.vy; if(prt.x<0){ prt.x = loopW; }else if(prt.x > loopW){ prt.x = 1; } if(prt.y<0){ prt.y = loopH; }else if(prt.y > loopH){ prt.y = 1; } //Self implimentation of addtive color blend mode. //Because there is too many particle, blending particle with low brightness color is much effective. col = canvas.getPixel(int(prt.x), int(prt.y)); r = (col>>16&0xff) + prt.r; g = (col>>8&0xff) + prt.g; b = (col&0xff) + prt.b; r = (r<0xff)? r : 0xff; g = (g<0xff)? g : 0xff; b = (b<0xff)? b : 0xff; canvas.setPixel(int(prt.x), int(prt.y), (r<<16)|(g<<8)|b); } canvas.applyFilter(canvas, canvas.rect, tempPt, canvasBlurFilter); canvas.unlock(); } } } class Particle { //particle position public var x:Number = 0; public var y:Number = 0; public var vx:Number = 0; public var vy:Number = 0; //particle color public var r:int; public var g:int; public var b:int; //scale factor that affects the force applied to the particle. public var scaleFactor:Number; }