Collision Detection: Minimum Goals

Introduction

When writing a Real Time Strategy game, or a Creature Simulation there is a need for a system to efficiently detect when items are near or touching each other.  This would be a minimal Collision Engine.

Goals

The minimum useful interesting Collision Engine would be:

• 2 dimensional.
• All moving objects are represented with circular bounding containers
• All fixed objects are represented as either circular, line segments, points (very small circles) or collections of these.
• Collision objects can be physical boundaries (actual collisions) or notification boundaries (like doorways or line of sight limits)
• Minimum of "physical" simulation: objects have mass, surfaces have restitution(*), but no friction, and no rotational momentum, or spinning.

(*) Restitution or "Coefficient of Restitution" is the "bounciness" of the surface.  See Wikipedia.