Introduction

This is a 2D physics engine made for the GPR4400 module at SAE Institute.

You can see the doxygen documentation here.

Core concepts

Body

A body is an object in the physics engine. The engine has a collision body and a rigid body.

Rigidbody

A rigidbody is a body affected by dynamics. It cannot be deformed, that is the distance between any two points on the body is constant.

World

In this engine, the word world refers to the class that contains the list of bodies and handle the collisions and / or dynamics between them.

Collider

A collider defines the shape that will collide with other objects. It can be of many shapes and they dictate how collisions are solved between objects.

Manifold

In this physics engine, the term manifold refers to the points that are usefull to solve a collision. Technically the manifold is all the points that are involved in a collision, but in my case, it’s more of a MTV (Minimum Translation Vector)

Solver

A solver is responsible for reacting to collisions and moving the objects away from eachother.

Transform

The transform of an object is its position, scale and rotation.

Dynamics

In this documentation I often mention “With Dynamics” and “Without Dynamics”. Having dynamics means that after a collision is detected, it is solved by a solver to make the objects not collide anymore. Using the “Without Dynamics” version means that the collisions will be detected, but that’s all. It is similar to the concept of “triggers” in Unity for example.