forked from: いっぱい丸出す

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

// forked from gbone's いっぱい丸出す
//
// 使い方いまいちわからない。学習しながらつかう
//
package {
    //importってたぶんincludeみたいなもの
    import flash.display.Sprite;
    import flash.display.*;
    import flash.events.*;
    import flash.geom.*;
    
    //iroirosettei
    [SWF(width=465, height=465, backgroundColor=0xFFFFFF, frameRate=50)]

    //entry point兼ねてるらしい
    public class Main extends Sprite {
        //画面大きさとか
        private const WIDTH:int = 465;
        private const HEIGHT:int = 465;
        
        //toriaezu
        private var canvas:BitmapData;
        private var time:Number = 12;
        
        //速くなる？わからない
        private var x1:Number;
        private var y1:Number;
        private var dx:Number;
        private var dy:Number;
        private var sn:Number;
        private var cn:Number; 
        private var t10:Number;
        private var col:Number;
        
        //ep
        public function Main():void {
            //描画箇所作ってbitmap作成して割り当てるっぽい
            canvas = new BitmapData(WIDTH, HEIGHT, false, 0x0);
            addChild(new Bitmap(canvas)) as Bitmap;
            
            //CreateThreadみたいなかんじ？
            addEventListener(Event.ENTER_FRAME, update);
        }

        //こいつがなんどもコールされるらしい
        private function update(e:Event):void {
            var x:int;
            var y:int;
            var scale:int = 2;
            t10 = time * 0.15;    
            sn = Math.sin(t10) * 0.5;
            cn = Math.cos(t10) * 0.5;
            time += 0.01666666 * 0.1;

            //inchiki
            dx = 2.0 / WIDTH;
            dy = 2.0 / HEIGHT;
            
            //draw
            canvas.lock();
            //canvas.fillRect(canvas.rect, 0x2F0F2F);

            //ラスタライザ遅いので何とかしないと
            y1 = -1.0;
            for(y = 0 ; y < HEIGHT; y += scale) {
                x1 = -1.0;
                for(x = 0 ; x < WIDTH; x += scale) {
                    //shader
                    shader(x1, y1)
                    var col:int = (1-col) * 255;
                    //yo
                    canvas.setPixel(x, y, col << 8);
                    x1 += dx * scale;
                 }    
                 y1 += dy * scale;
            }
            canvas.unlock();

        }
        
        //とりあえず実験。vectorがあればなあ
        private function shader(u:Number, v:Number):void{
          var ret:Number = 1;
          
          //position
          var ex:Number = 0.5;
          var ey:Number = 0.5;// + u * v * 2.5;// + Math.cos(u * v);
          var ez:Number = -time * 0.1;

          
          //direction ray
          var rx:Number = u;
          var ry:Number = v;
          var rz:Number = 1;
        
          var tx:Number = cn * rx + sn * rz;
          var ty:Number = ry;
          var tz:Number = cn * rz - sn * rx;
          rx = tx;  ry = tz;  rz = ty;
           
          //もっかい
          tx = cn * rx + sn * rz;
          ty = ry;
          tz = cn * rz - sn * rx;
          rx = tx; ry = tz; rz = ty;
          /* */
          var i:Number = 0;
          
          //視点から適当に光線のばして衝突判定
          for(i = 0.01; i < 0.2; i += 0.01) {
            var px:Number = ex + rx * i;
            var py:Number = ey + ry * i;
            var pz:Number = ez + rz * i;
            
            var d:Number = Math.sin(px * 200) + Math.sin(pz * 200);
            if(py < d) {
                  //大当たり。まあ遅い
              ret = d * 0.3;
              break;
            }
            
            //当たらなかったので視点方向に目を移動
            ex = px;
            ey = py;
            ez = pz;
          }
          
          col = (ret > 1.0) ? 1 : (ret < 0) ? 0 : ret;
          
        }
    }
}