forked from: forked from: forked from: flash on 2009-4-22

original code from Bit101
Blob(AS3 version)

by janssend 23 Apr 2009

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blob random
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// forked from yasuo_from_BDM's Blob
/*
original code from Bit101
Blob(AS3 version)

*/
package {
    import flash.display.Sprite;
    public class FlashTest extends Sprite {
        public function FlashTest() {
            // write as3 code here..
            var _blob:Blob = new Blob();
            addChild(_blob);
        }
    }f
}

import flash.display.*; 
import flash.text.TextField 
import flash.events.*;

class Blob extends Sprite
{
	
	private var speed    :Number = .01;
	private var grav     :Number = .25;
	private var dist     :Number = 27;
	private var k        :Number = .55;
	private var damp     :Number = .99;
	private var cx       :Number = 370;
	private var cy       :Number = 0;
	private var points   :Array  = [];
	private var mids     :Array  = [];
	private var numPoints:Number = 30;
	private var oneSlice :Number = Math.PI * 2 / numPoints;
	private var radius   :Number = 100;
	
	public function Blob()
	{
		for (var i:Number = 0; i < numPoints; i++)
		{
			var angle:Number = oneSlice * i;
			var obj:Object = {x:Math.cos(angle) * radius + cx, y:Math.sin(angle) * radius + cy, a:angle - Math.PI / 2, wave:i*.08, vx:0, vy:0};
			points[i] = obj;
		}
		
		this.addEventListener(Event.ENTER_FRAME, update);
		
	}
	
	private function update(event:Event):void
	{
		this.graphics.clear();
		this.graphics.lineStyle(1, 0x666666, 50);
		this.graphics.beginFill(0x000000, 100);
		for (var i:Number = 0; i < numPoints-1; i++)
		{
			mids[i] = {x:(points[i].x + points[i + 1].x) / 2, y:(points[i].y + points[i + 1].y) / 2};
		}
		mids[i] = {x:(points[i].x + points[0].x) / 2, y:(points[i].y + points[0].y) / 2};
		this.graphics.moveTo(mids[0].x, mids[0].y);
		for (var j:Number = 0; j < numPoints - 1; j++)
		{
			this.graphics.curveTo(points[j+1].x, points[j+1].y, mids[j+1].x, mids[j+1].y);
		}
		this.graphics.curveTo(points[0].x, points[0].y, mids[0].x, mids[0].y);
		this.graphics.endFill();
		
		var point:Object;
		for (var k:Number = 0; k < numPoints - 1; k++)
		{
			point = points[k];
			spring(point, points[k + 1]);
			mouseSpring(point);
		}
		spring(points[k], points[0]);
		mouseSpring(points[k]);
		
		for (var l:Number = 0; l < numPoints; l++)
		{
			point = points[l];
			point.vx *= damp;
			point.vy *= damp;
			point.vy += grav;
			point.x += point.vx;
			point.y += point.vy;
			
			if (point.y > stage.stageHeight)
			{
				point.y = stage.stageHeight;
				point.vy = 0;
			}
			if (point.x < 20)
			{
				point.x = 20;
				point.vx = 0;
			}
			else if (point.x > stage.stageWidth)
			{
				point.x = stage.stageWidth;
				point.vx = 0;
			}
		}
	}
	
	private function spring(p0:Object, p1:Object):void
	{
		var dx:Number = p0.x - p1.x;
		var dy:Number = p0.y - p1.y;
		var angle:Number = p0.a+Math.sin(p0.wave += speed)*2;
		var tx:Number = p1.x + dist * Math.cos(angle);
		var ty:Number = p1.y + dist * Math.sin(angle);
		var ax:Number = (tx - p0.x) * k;
		var ay:Number = (ty - p0.y) * k;
		p0.vx += ax * .5;
		p0.vy += ay * .5;
		p1.vx -= ax * .5;
		p1.vy -= ay * .5;
	}
	
	private function mouseSpring(p:Object):void
	{
		var dx:Number = p.x - stage.mouseX;
		var dy:Number = p.y - stage.mouseY;
		var dist:Number = Math.sqrt(dx * dx + dy * dy);
		if (dist < 40)
		{
			var angle:Number = Math.atan2(dy, dx);
			var tx:Number = stage.mouseX + Math.cos(angle) * 40;
			var ty:Number = stage.mouseY + Math.sin(angle) * 40;
			p.vx += (tx - p.x) * k;
			p.vy += (ty - p.y) * k;
		}
	}
	
}