Actionscript 3.0完美碰撞檢測註冊點中心？

Question

嘿我碰撞檢測的問題我使用這個例子從一個網站http://www.freeactionscript.com/2009/05/pixel-perfect-collision-detection/，但它只適用於當你的對象的註冊點是在左上角我應該改變我的代碼如果我們說註冊點是在中心？

這裏是代碼：

package 
{ 
import flash.display.BitmapData; 
import flash.display.DisplayObjectContainer; 
import flash.geom.Matrix; 
import flash.geom.Point; 
import flash.geom.Rectangle; 

public class CollisionTest 
{ 
// vars 
private var _returnValue:Boolean; 

private var _onePoint:Point; 
private var _twoPoint:Point; 

private var _oneRectangle:Rectangle; 
private var _twoRectangle:Rectangle; 

private var _oneClipBmpData:BitmapData; 
private var _twoClipBmpData:BitmapData; 

private var _oneOffset:Matrix; 
private var _twoOffset:Matrix; 

/** 
* Simple collision test. Use this for objects that are not rotated. 
* @param clip1 Takes DisplayObjectContainer as argument. Can be a Sprite, MovieClip, etc. 
* @param clip2 Takes DisplayObjectContainer as argument. Can be a Sprite, MovieClip, etc. 
* @return Collision True/False 
*/ 
public function simple(clip1:DisplayObjectContainer, clip2:DisplayObjectContainer):Boolean 
{ 
    _returnValue = false; 

    _oneRectangle = clip1.getBounds(clip1); 
    _oneClipBmpData = new BitmapData(_oneRectangle.width, _oneRectangle.height, true, 0); 
    _oneClipBmpData.draw(clip1); 

    _twoRectangle = clip2.getBounds(clip2); 
    _twoClipBmpData = new BitmapData(_twoRectangle.width, _twoRectangle.height, true, 0); 
    _twoClipBmpData.draw(clip2); 

    _onePoint = new Point(clip1.x, clip1.y) 
    _twoPoint = new Point(clip2.x, clip2.y) 

    if (_oneClipBmpData.hitTest(_onePoint, 255, _twoClipBmpData, _twoPoint, 255)) 
    { 
     _returnValue = true; 
    } 

    return _returnValue; 
} 

/** 
* Complex collision test. Use this for objects that are rotated, scaled, skewed, etc 
* @param clip1 Takes DisplayObjectContainer as argument. Can be a Sprite, MovieClip, etc. 
* @param clip2 Takes DisplayObjectContainer as argument. Can be a Sprite, MovieClip, etc. 
* @return Collision True/False 
*/ 
public function complex(clip1:DisplayObjectContainer, clip2:DisplayObjectContainer):Boolean 
{ 
    _returnValue = false; 

    _twoRectangle = clip1.getBounds(clip1); 
    _oneOffset = clip1.transform.matrix; 
    _oneOffset.tx = clip1.x - clip2.x; 
    _oneOffset.ty = clip1.y - clip2.y; 

    _twoClipBmpData = new BitmapData(_twoRectangle.width, _twoRectangle.height, true, 0); 
    _twoClipBmpData.draw(clip1, _oneOffset);   

    _oneRectangle = clip2.getBounds(clip2); 
    _oneClipBmpData = new BitmapData(_oneRectangle.width, _oneRectangle.height, true, 0); 

    _twoOffset = clip2.transform.matrix; 
    _twoOffset.tx = clip2.x - clip2.x; 
    _twoOffset.ty = clip2.y - clip2.y; 

    _oneClipBmpData.draw(clip2, _twoOffset); 

    _onePoint = new Point(_oneRectangle.x, _oneRectangle.y); 
    _twoPoint = new Point(_twoRectangle.x, _twoRectangle.y); 

    if(_oneClipBmpData.hitTest(_onePoint, 255, _twoClipBmpData, _twoPoint, 255)) 
    { 
     _returnValue = true; 
    } 

    _twoClipBmpData.dispose(); 
    _oneClipBmpData.dispose(); 

    return _returnValue; 
} 

} 
} 

Answer 1

那麼讓我們把它像這樣：走多遠是從中心點左上角？

x += width * .5; 
y += height * .5; 

對不對？

因此，如果你上面發佈的代碼只處理左上角（無論什麼原因，我不知道爲什麼），爲什麼不強迫它用中心點來對待它呢？

也許像這樣？

_onePoint = new Point(clip1.x + _clip.width * .5, clip1.y + _clip.height * .5); 
_twoPoint = new Point(clip2.x + _clip2.width * .5, clip2.y + _clip2.height * .5);