forked from: forked from: Ray casting test

/**
 * Copyright hemingway ( http://wonderfl.net/user/hemingway )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/xhA9b
 */

// forked from phi16's forked from: Ray casting test
// forked from bennett.yeates's Ray casting test
package
{
    import flash.utils.Proxy;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.geom.Point;
    import flash.ui.Keyboard;
    import net.hires.debug.Stats;

    [SWF(backgroundColor=0x0)]
    public class RayCastTest extends Sprite
    {
        private const FOV            :int = 360;
        private const STEP_LENGTH    :int = 1; //length of the ray to step by
        
        private var player            :Sprite;
        
        private var ray_drawer        :Sprite;
        private var dist_drawer       :Sprite;
        private var squares           :Array = [];
        private const POSITIONS:Array = [ {x:0, y:0}, {x:0, y:stage.stageHeight/2}, {x:stage.stageWidth-100, y:stage.stageHeight/2 - 50}, 
                                          {x:stage.stageWidth/2, y:stage.stageHeight - 100}, {x:stage.stageWidth-100, y:stage.stageHeight - 100} ];
        public function RayCastTest()
        {
            ray_drawer = new Sprite();
            dist_drawer = new Sprite();
            
            var i:int;
            for ( ; i < 5; ++i ) {
                var square:Sprite = new Sprite();
                square.graphics.beginFill(0);
                square.graphics.drawRect(0,0,100,100);
                
                square.x = POSITIONS[i].x;
                square.y = POSITIONS[i].y;
                
                addChild( square );    
                squares.push( square );
            }
            player = new Sprite();
            player.graphics.beginFill(0x0000FF);
            player.graphics.drawRect(0,0,5,5);
            
            player.x = stage.stageWidth/2 - 2.5;
            player.y = stage.stageHeight/2 - 2.5;
            addChild( player );
            addChild( ray_drawer );
            //addChild( dist_drawer );
            addChild( new Stats() );
                        
            stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
            addEventListener( Event.ENTER_FRAME, oef );
        }
        
        public function onKeyDown( e:KeyboardEvent ):void {
            if ( e.keyCode == Keyboard.LEFT ) { player.rotation -= 2; }
            else if ( e.keyCode == Keyboard.RIGHT ) { player.rotation += 2; }
        }
        public function distance(p:Point) : Number {
            var l:Number=-1;
            for(var i:int=0;i<squares.length;i++){
                var square:Sprite = squares[i];
                var pos:Point = new Point(square.x+50,square.y+50);
                
                var ps:Point = new Point(p.x-pos.x,p.y-pos.y);
                ps.x=Math.abs(ps.x)-50,ps.y=Math.abs(ps.y)-50;
                
                var len:Number=Math.min(Math.max(ps.x,ps.y),0);
                ps.x=Math.max(ps.x,0),ps.y=Math.max(ps.y,0);
                len+=Math.sqrt(ps.x*ps.x+ps.y*ps.y);
                
                if(i==0 || len<l)l=len;
            }
            return l;
        }

        public function oef( e:Event ):void {
            ray_drawer.graphics.clear();
            dist_drawer.graphics.clear();
            ray_drawer.graphics.lineStyle( 2, 0xFF0000 , 0.3 );
            dist_drawer.graphics.lineStyle( 2, 0x0000FF );
            
            var startRotation:Number = player.rotation - FOV/2;
            var endRotation:Number = player.rotation + FOV/2;
            
            var hit:Boolean;
            var length:Number;
            var center:Boolean=true;
            while( startRotation < endRotation ) {
                center = Math.abs(startRotation-player.rotation)<1.0;
                if(center)ray_drawer.graphics.lineStyle( 2, 0xFF0000 );
                hit = false;
                                
                var pos:Point = new Point( player.x, player.y );
                while( !hit ) {
                    length = distance(pos);
                    if(center){
                        dist_drawer.graphics.drawCircle(pos.x,pos.y,length);
                    }
                    pos.x += length * Math.cos( startRotation * Math.PI / 180 );
                    pos.y += length * Math.sin( startRotation * Math.PI / 180 );
                    if(length <= 0.01 )hit=true;
                    if ( pos.x >= stage.stageWidth || pos.x < 0 || pos.y < 0 || pos.y >= stage.stageHeight ) {
                        hit = true;
                    }
                }
                ray_drawer.graphics.moveTo( player.x, player.y );
                ray_drawer.graphics.lineTo( pos.x, pos.y );
                ++startRotation;
                if(center)ray_drawer.graphics.lineStyle( 2, 0xFF0000 , 0.3 );
            }
        }
    }
}