St0wy / StowyPhysicsEngine

A simple 2D physics engine.

GPR4400-PhysicsEngine

This project is a 2D physics engine written in C++.

Please note that this is an old project that I did with less than 1 year of experience with C++. I would not make the same choices today if I had to make a project like that again :)

The wiki is hosted on Read The Docs and the API Documentation (Doxygen) on GitHub Pages.

It has :

• Circle -> Circle collisions
• Circle -> AABB collisions
• AABB -> AABB collisions
• A failed attempt at SAT
• A failed attempt at GJK
• Broad phase collision detection with a grid

Getting started

1. Get a C++20 compiler
2. Build with CMake :

cmake -S . -B .\build\
cmake --build .\build\

When building in Debug mode, you need to rename freetyped.dll to freetype.dll in the folder where Demo.exe is located. I don't know why this is necessary, but I guess it's a problem with my CMake setup with SFML.

By default the demo isn't built and only the library is. To change that you must switch the CMake option SPE_BUILD_DEMO to ON. This can be done either in the GUI, or in the terminal by adding -DSPE_BUILD_DEMO=ON to the command. You could also change the line in the CMakeLists.txt.

Dependencies

The physics engine doesn't have any dependencies, and can be built alone as a library.

The demo scene has a dependency on SFML but it is retrieved using CMake's FetchContent so you don't have to use something like vcpkg.

Folder structure

There are two main folders in this project :

• StowyPhysicsEngine
• Demo

StowyPhysicsEngine is the physics engine in itself. It is setup as a CMake library.

Demo is the SFML project to visualise the physics engine.

They each have their own CMakeList.txt but there is also a main one that includes both to be able to build everything at once.