检测非矩形形状的点击 [英] Detecting clicks in a non-rectangular shape
问题描述
我对 XNA 4.0 还很陌生，但有一个我似乎无法弄清楚的问题.到目前为止，我一直通过创建矩形并检查 rectangle.contains 方法来检测鼠标点击，但是如果我不想检查矩形内部怎么办?
I am pretty new to XNA 4.0 and have a problem I can't seem to figure out. So far I have been detecting mouse clicks by creating rectangles and checking the rectangle.contains method, but what if I don't want to check inside a rectangle?
在我的地图的一部分中，我有一个三角形按钮，我想让用户点击它，但如果它实际上在三角形内，我只想将其计为一次点击.如果我在三角形周围创建一个矩形，如果您知道我的意思，用户将能够在纹理区域外单击.
In one part of my map I have a triangle button that I want to let the user click, but I want to only count it as a click if it is actually inside the triangle. If I create a rectangle around the triangle the user will be able to click outside the texture area, if you know what I mean.
我该怎么做?
推荐答案
您将不得不使用 Point在多边形算法中用于更复杂的形状:
You will have to use a Point in Polygon Algorithm for more complex shapes:
检查凸多边形(您的三角形)比检查凹多边形更简单(请参阅第一篇链接文章).
The check for convex polygons (your triangle) is simpler than for concave ones (see first linked article).
如果您必须进行大量检查并达到性能限制，请考虑使用某种层次结构，四叉树或LOD系统.例如，您可以为非常复杂的多边形计算一个额外的边界矩形，如果点位于矩形内，则只对多边形进行昂贵的检查.
If you have to do lots of checks and are hitting performance limits, consider using some kind of hierarchy, a Quadtree or an LOD system. For example, you can calculate an additional bounding rectangle for very complex polygons and only do the expensive in-check with the polygon if the point lies inside the rectangle.
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