forked from: Fast texture extraction

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

// forked from makc3d's Fast texture extraction
package {
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.display.LoaderInfo;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.filters.GlowFilter;
    import flash.geom.Point;
    import flash.net.URLRequest;
    import flash.system.LoaderContext;
    
    /**
     * Another drawTriangles based homography test
     * @see http://twitter.com/makc3d/status/27978300665
     */
    public class HTest extends Sprite {
        public function HTest () {
            var loader:Loader = new Loader;
            loader.contentLoaderInfo.addEventListener (Event.COMPLETE, onComplete);
            loader.load (new URLRequest (/*"basilica.jpg"*/"http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs061.snc4/34435_824223712001_9021630_46770431_3138463_n.jpg"), new LoaderContext (true));
        }
        public var image:BitmapData;
        public var anchors:Vector.<Anchor>;
        public var homography:Homography;
        public function onComplete (e:Event):void {
            var info:LoaderInfo = LoaderInfo (e.target);
            info.removeEventListener (Event.COMPLETE, onComplete);
            addChild (info.content);
            image = Bitmap (info.content).bitmapData;
            anchors = new Vector.<Anchor> (8, true);
            addChild (anchors [4] = new Anchor (100, 257));
            addChild (anchors [5] = new Anchor (122, 218));
            addChild (anchors [6] = new Anchor (200, 251));
            addChild (anchors [7] = new Anchor (111, 296));
            addChild (anchors [4] = new Anchor (150, 307));
            addChild (anchors [5] = new Anchor (172, 168));
            addChild (anchors [6] = new Anchor (250, 301));
            addChild (anchors [7] = new Anchor (161, 346));
        

            addChild (homography = new Homography);
            homography.x = homography.y = 350;
            homography.filters = [ new GlowFilter (0xFF7F00, 1, 2, 2, 200, 2) ];
            stage.addEventListener (MouseEvent.MOUSE_MOVE, onMouseMove);
            onMouseMove (null);
        }
        public function onMouseMove (e:MouseEvent):void {
            if ((e == null) || e.buttonDown) {
                homography.setTransform (image,
                    new Point (anchors [0].x, anchors [0].y),
                    new Point (anchors [1].x, anchors [1].y),
                    new Point (anchors [2].x, anchors [2].y),
                    new Point (anchors [3].x, anchors [3].y),
                    new Point (anchors [4].x, anchors [4].y),
                    new Point (anchors [5].x, anchors [5].y),
                    new Point (anchors [6].x, anchors [6].y),
                    new Point (anchors [7].x, anchors [7].y));
            }
        }
    }
}

import flash.display.Sprite;
import flash.events.MouseEvent;
class Anchor extends Sprite {
    public function Anchor (x0:int, y0:int) {
        x = x0; y = y0;
        graphics.beginFill (0xFF7F00, 1);
        graphics.drawRect (-4, -4, 8, 8);
        graphics.drawRect (-2, -2, 4, 4);
        graphics.beginFill (0xFF7F00, 0);
        graphics.drawRect (-2, -2, 4, 4);
        useHandCursor = buttonMode = true;
        addEventListener (MouseEvent.MOUSE_DOWN, startDragMe);
        addEventListener (MouseEvent.MOUSE_UP, stopDragMe);
    }
    public function startDragMe (e:MouseEvent):void {
        startDrag ();
    }
    public function stopDragMe (e:MouseEvent):void {
        stopDrag ();
    }
}

/**
 * @author zeh, original idea
 * @author makc, inverted transform
 * @see http://zehfernando.com/2010/the-best-drawplane-distortimage-method-ever/
 */
import flash.display.BitmapData;
import flash.display.Graphics;
import flash.display.Shape;
import flash.geom.Point;
class Homography extends Shape {
    private var v6:Vector.<int> = Vector.<int> ([0, 1, 2, 0, 2, 3]);
    private var v8:Vector.<Number> = new Vector.<Number> (8, true);
    private var v12:Vector.<Number> = new Vector.<Number> (12, true);

    public function setTransform (src:BitmapData,
        p0:Point, p1:Point, p2:Point, p3:Point, p4:Point, p5:Point, p6:Point, p7:Point,
        destWidth:int = 100, destHeight:int = 100):void {

        // Find diagonals intersection point
        var pc:Point = new Point;

        var a1:Number = p2.y - p0.y;
        var b1:Number = p0.x - p2.x;
        var a2:Number = p3.y - p1.y;
        var b2:Number = p1.x - p3.x;

        var denom:Number = a1 * b2 - a2 * b1;
        if (denom == 0) {
            // something is better than nothing
            pc.x = 0.25 * (p0.x + p1.x + p2.x + p3.x);
            pc.y = 0.25 * (p0.y + p1.y + p2.y + p3.y);
        } else {
            var c1:Number = p2.x * p0.y - p0.x * p2.y;
            var c2:Number = p3.x * p1.y - p1.x * p3.y;
            pc.x = (b1 * c2 - b2 * c1) / denom;
            pc.y = (a2 * c1 - a1 * c2) / denom;
        }

        // Lengths of first diagonal
        var ll1:Number = Point.distance(p0, pc);
        var ll2:Number = Point.distance(pc, p2);

        // Lengths of second diagonal
        var lr1:Number = Point.distance(p1, pc);
        var lr2:Number = Point.distance(pc, p3);

        // Ratio between diagonals
        var f:Number = (ll1 + ll2) / (lr1 + lr2);

        var sw:Number = src.width, sh:Number = src.height;
        var dw:Number = destWidth, dh:Number = destHeight;

        v8 [2] = dw; v8 [4] = dw; v8 [5] = dh; v8 [7] = dh;

        v12 [0] = p0.x / sw; v12 [ 1] = p0.y / sh; v12 [ 2] = ll2 / f;
        v12 [3] = p1.x / sw; v12 [ 4] = p1.y / sh; v12 [ 5] = lr2;
        v12 [6] = p2.x / sw; v12 [ 7] = p2.y / sh; v12 [ 8] = ll1 / f;
        v12 [9] = p3.x / sw; v12 [10] = p3.y / sh; v12 [11] = lr1;

        graphics.clear ();
        graphics.beginBitmapFill (src, null, false, true);
        graphics.drawTriangles (v8, v6, v12);
    }
}