Little project I developed over the course of one week to learn more about OpenGL and sit down to write C++. You can watch the youtube video here.
The project grew as wildly as an unmanaged garden. Everything is a header file, since linking in Dev-C++ was a pain in the butt.
| script | function |
|---|---|
| playerEntity.hpp | class that manages the player by handling the input through a callback, updating the player position and camera. |
| gameObject.hpp | unity knockoff entity. it's basically an object class in the gameworld, with position rotation and so on. components can be attached to gameObjects. |
| mesh.hpp | first component I've made. attaches to a gameObject and keeps track of mesh data to be rendered. |
| rigidbody.hpp | physics component. whenever attached to a gameObject that gameObject will receive physics (just gravity for now). |
| world.hpp | generic world class. it's meant to be static but I guess there aren't statics in C++. handles collisions and keeps track off all entities. |
| camera.hpp | simple camera class with some utility functions. it's managed by the player. |
| renderer.hpp | drawing mesh logic. |
Since I was very short on time, I didn't think it was possible to materially comprehend SAT and implement it (I didn't want the easy route with AABB). I came up with the escamotage of handling solely the player, since it would've been the only moving thing in the demo anyways.
The player is a sphere and it's checked with each mesh in the scene for collisions. There are some optimizations in place to avoid unnecessary computations. The algorithm does the following:
- Loop through each mesh in the scene
- Loop through each triangle in the mesh
- Is the triangle face pointing towards the face? (eligible for collision? if not break)
- Project the player position on the triangle's plane
- Is the projected point within the triangle's region? (barycentric coordinates. if not break)
- Check distance from triangle's center to player
- If the distance is less than the radius of the player's sphere collider resolve by simply adding an offset along the face's normal
It's basically "Collide and Slide". The "projected point" part has obviously some issues, and some co llisions will go undetected and result snappy when the sphere's center eventually projects. I solved this with some lazy interpolation.
I'm sorry but I can't include the original textures, as they featured some parts of the textures of the game "The Wizard of Oz: Beyond the Yellow Brick Road".
The makefile is garbage. That's about it. It works.
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
Version 2, December 2004
Copyright (C) 2004 Sam Hocevar [email protected]
Everyone is permitted to copy and distribute verbatim or modified copies of this license document, and changing it is allowed as long as the name is changed.
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
- You just DO WHAT THE FUCK YOU WANT TO.
If you can credit me I would be glad but don't worry about it otherwise ;)