なんとかディウスっぽい背景

by gyuque 21 Dec 2008

• Related works: 18
Embed

package
{
    import flash.display.*;
    import flash.geom.*;
    import flash.events.*;

    [SWF(width="320", height="240", backgroundColor="0x000000", frameRate="30")]  
    public class Nemesis extends Sprite
    {
        public static const W:int = 320;
        public static const H:int = 240;

        private var mScroll:int = 0;
        private var mMyPos:Point;
        private var mBGen:MountainGen = new MountainGen(160);
        private var mTGen:MountainGen = new MountainGen(160, 1);

        private var mBGScreen:BitmapData = new BitmapData(W, H, true, 0);
        private var mBGScreenBmp:Bitmap;
        private var mBGScreenBmp2:Bitmap;

        private var mStarbg:StarBG = new StarBG(W, H, 30);
        function Nemesis()
        {
            addChild(mStarbg);

            mBGScreenBmp = new Bitmap(mBGScreen);
            addChild(mBGScreenBmp);

            mBGScreenBmp2 = new Bitmap(mBGScreen);
            addChild(mBGScreenBmp2);

            var i:int;
            mBGen.step();
            mTGen.step();
            for (i = 0;i < W;i++) {
                mBGen.step();
                mTGen.step();
                mBGen.draw(mBGScreen, i, 80);
                mTGen.draw(mBGScreen, i, 0, false);
            }

            addEventListener(Event.ENTER_FRAME, tick);
        }

        private var _clrrc:Rectangle = new Rectangle(0, 0, 1, H);
        private function tick(e:Event):void
        {
            var ox:int = mScroll % W;
            _clrrc.x = ox;
            mBGScreen.fillRect(_clrrc, 0);

            mStarbg.tick();
            mBGen.step();
            mTGen.step();


            mStarbg.draw();
            mBGen.draw(mBGScreen, ox, 80);
            mTGen.draw(mBGScreen, ox, 0, false);

            mBGScreenBmp.x = -ox;
            mBGScreenBmp2.x = W-ox;

            mScroll++;
        }
    }
}

class MountainGen
{
    import flash.display.*;

    private var mPrevBuffer:Array;
    private var mHeight:int;
    private var mCount:int = 0;

    private var tmpBuffer:Array;
    private var mGenFunc:Function;
    function MountainGen(h:int, generator:int = 0)
    {
        mHeight = h;
        mGenFunc = generator ? genWav2 : genWav;
        mPrevBuffer = new Array(h);
        tmpBuffer   = new Array(h);
    }

    public function draw(b:BitmapData, x:int, y:int, rev:Boolean = true):void
    {
        var i:int;
        for (i = 0;i < mHeight;i++) {
            if (tmpBuffer[i]) {
                var c:int = tmpBuffer[i];
                b.setPixel32(x, rev ? (y+mHeight-i) : (y+i), 0xff000000 | (c/3+11) | ((c/5 + 170)<<16) | ((c/2+60) << 8));
            }

        }        
    }

    public function step():void
    {
        var t:Number = Number(mCount) * 0.02;
        var h:int = mGenFunc(t) * mHeight;
        var i:int, k:int, m:int;

        for (i = 0;i < mHeight;i++) {
            mPrevBuffer[i] = tmpBuffer[i];
        }
        
        for (i = 0;i < mHeight;i++) {
            tmpBuffer[i] = (i < h) ? (Math.random()*80 + 80) : 0;

            if (tmpBuffer[i]) {
                if (mPrevBuffer[i])
                    tmpBuffer[i] = (tmpBuffer[i] + mPrevBuffer[i]*7)/8;

                if (mPrevBuffer[i] == 0 || i == (h-1)) {
                    m = 50;
                    for (k = i;k >= 0 && m > 0;k--, m-=4) {
                        if (m > 33) m--;
                        tmpBuffer[k] += m;

                        m += Math.random()*7;
                    }
                }

                if (mPrevBuffer[i+1] && i == (h-1)) {
                    m = -48;
                    for (k = i;k >= 0 && m < 0;k--, m++) {
                        tmpBuffer[k] += m;
                        if (tmpBuffer[k]<1) tmpBuffer[k] = 1;
                    }
                }

           }
        }

       for (i = 0;i < mHeight;i++)
            tmpBuffer[i] = (tmpBuffer[i] < 0) ? 0 : (tmpBuffer[i] > 255) ? 255 : tmpBuffer[i];

        mCount++;
    }

    private static function genWav(t:Number, nest:int = 0):Number
    {
        var v:Number = Math.sin(t);
        v += Math.cos(t*3) * 0.1;
        v += Math.cos(0.1 + t*10) * 0.02;
        v *= Math.cos(t*0.1);

        if (nest < 5)
            v += genWav(t+1, ++nest);

        v = v*0.2 + 0.3;

        return (v<0) ? 0 : (v>1) ? 1 : v;
    }

    private static function genWav2(t:Number, nest:int = 0):Number
    {
        var v:Number = Math.sin(t);
        v += Math.cos(t*3) * 0.1;
        v += Math.cos(0.1 + t*9) * 0.02;
        v *= Math.cos(0.2 + t*0.15);

        if (nest < 5)
            v += genWav2(t+1, ++nest);

        v = v*0.2 + 0.2;

        return (v<0) ? 0 : (v>1) ? 1 : v;
    }
}

class StarBG extends flash.display.Sprite
{
    import flash.display.*;
    import flash.geom.Point;

    private var mWidth:int;
    private var mHeight:int;

    private var mStars:Array;
    private var mStarVs:Array;
    private var mN:int;

    function StarBG(w:int, h:int, n:int)
    {
        mWidth = w;
        mHeight = h;
        mN = n;

        mStars  = new Array(n);
        mStarVs = new Array(n);
        for (var i:int = 0;i < n;i++) {
            mStars[i] = new Point(int( Math.random()*w ), int( Math.random()*h ));
            mStarVs[i] = Math.random() + 0.2;
        }
    }

    public function tick():void
    {
        var n:int = mN;

        for (var i:int = 0;i < n;i++) {
            mStars[i].x -= Number(mStarVs[i]);

            if (mStars[i].x < 0) {
                mStars[i].x += mWidth;
                mStars[i].y = int( Math.random()*mHeight );
            }
        }
    }

    public function draw():void
    {
        var g:Graphics = graphics;
        var n:int = mN;

        g.clear();
        for (var i:int = 0;i < n;i++) {
            g.beginFill(0xffffff);
            g.drawCircle( mStars[i].x, mStars[i].y , 0.4);
        }   
    }
}