Polygon Collision Detection and Response

Hello.

To express my regret for not having posted recently, I'm going to explain my method of polygon collision detection and response.

It's quite simple really. For polygons described in a series of points and a single test point, here's a description of the algorithm I use to move that point the shortest distance outside the polygon:

• Assume the current closest point is infinitely far away.
• For every single line segment between the points:
  • Find the point closest to the test point on that segment. You can use whatever method you wish for this part. This part's just a little bit of vector calculus. Here's a hint: if the closest point is not one of the endpoints on the segment, the vector to it from the test point will be perpendicular to the segment.
  • If that point is closer to the test point then the current closest point, then it becomes the current closest point
• The current closest point is the fastest way out of the polygon.

There's a lot of math involved, but it's simple linear algebra and vector stuff. I'm sure you can figure it out.