forked from: Bubbles

/**
 * Copyright Xalaraz ( http://wonderfl.net/user/Xalaraz )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/wllV
 */

// forked from kazutoyo's Bubbles
package 
{
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.display.GradientType;
    import flash.events.StatusEvent;
    import flash.geom.Matrix;
    
    /**
     * ...
     * @author kazutoyo@富山商船コンピュータ部
     * 富山高専に合併したので、富山高専(射水)コンピュータ部になりました。
     */
    public class Main extends Sprite 
    {
        private const w:Number = stage.stageWidth;
        private const h:Number = stage.stageHeight;
        private const bigBubbleNum:int = 8;
        private var background:Sprite = new Sprite();
        private var bubbles:Array = new Array();
        private var count:int = 0;
        
        public function Main():void 
        {
            if (stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);
        }
        
        private function init(e:Event = null):void 
        {
            removeEventListener(Event.ADDED_TO_STAGE, init);
            // entry point
            //背景を描くよ
            var gradType:String = GradientType.LINEAR;
            var colors:Array = [0x990000, 0x000000];
            var alphas:Array = [1, 1];
            var ratios:Array = [127, 255];
            var angle:Number = 90 * Math.PI / 180;
            var mtx:Matrix = new Matrix();
            mtx.rotate(angle);
            background.graphics.beginGradientFill(gradType, colors, alphas, ratios, mtx);
            background.graphics.drawRect(0, 0, w, h);
            this.addChildAt(background,0);
            this.initBubbles();
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
        
        //泡々つくる
        private function initBubbles():void {
            var n:int = 20;
            var i:int;
            for (i = 0; i < n; i++) {
                //大きいのと小さいのつくる
                if(i < bigBubbleNum){
                    bubbles[i] = makeBubble(Math.random() * w, Math.random() * h);
                }else {
                    bubbles[i] = makeCircle(0x5A0000,
                                          0,
                                          0,
                                          Math.random() * 10+5);
                    bubbles[i].x = Math.random() * w;
                    bubbles[i].y = Math.random() * h;
                    background.addChild(bubbles[i]);
                }
            }
        }
        
        private function onEnterFrame(e:Event):void {
            var n:int = bubbles.length;
            var i:int;
            for (i = 0; i < n; i++) {
                bubbles[i].y -= bubbles[i].width / 20;
                //適当にうごかすちょ
                if ( i < bigBubbleNum) bubbles[i].x += Math.cos(count / bubbles[i].width) * 5;
                //泡が上までいったとき
                if (bubbles[i].y + bubbles[i].height < 0) {
                    if (i < bigBubbleNum) {
                        background.removeChild(bubbles[i]);
                        bubbles[i] = makeBubble(0, 0);
                    }
                    bubbles[i].y = h;
                    bubbles[i].x = Math.random() * w;
                    bubbles[i].alpha = 1.0;
                }
            }
            count += 1;
            if (count >= 360) count = 0;
        }
        
        private function makeBubble(x:Number, y:Number ):Sprite {
            var n:int = Math.random() * 8 + 2;
            var i:int;
            var s:Sprite = makeCircle(0x5A0000, 0, 0, n * 10);
            s.x = x;
            s.y = y; 
            background.addChild(s);
            for (i = n; i > 0; i--) {
                var bb:Sprite;
                if (i % 2 != 0) {
                    bb = makeCircle(0x990000, 0, 0, initSize(i, n));
                    bb.x = 0;
                    bb.y = 0;
                    s.addChildAt(bb, s.numChildren);
                }else {
                    bb = makeCircle(0x2D0000, 0, 0, initSize(i, n));
                    bb.x = 0;
                    bb.y = 0;
                    s.addChildAt(bb, s.numChildren);
                }
            }
            return s;
        }
        
        private function initSize(i:int, n:int):Number {
            var size:Number = i * 5 + Math.random() * i * 5;
            if (size < 5) size = i * 5 + Math.random() * i * 5; //半径5より小さいとだめ！
            if (size > n*2) size = i * 5 + Math.random() * i * 5; //大きすぎてもだめ！
            return size;
        }
        
        //円をつくるよー
        private function makeCircle(color:uint = 0x000000, x:Number = 0, y:Number = 0, radius:Number = 0, alpha:uint = 1.0):Sprite {
            var b:Sprite = new Sprite();
            b.graphics.beginFill(color, alpha);
            b.graphics.drawCircle(x, y, radius);
            b.graphics.endFill();
            
            return b;
        }
        
    }
    
}