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# SDL Raycaster
A Wolfenstein 3D-style raycasting renderer in C, chasing the same trick old engines like Wolfenstein 3D and early Doom builds used to fake 3D on hardware that couldn't really do 3D: cast one ray per screen column into a 2D grid map, and draw a vertical wall strip whose height depends on how far that ray traveled before hitting something. No GPU pipeline, no triangles, just trigonometry and a grid.
Getting the ray-casting step right was most of the project. It walks a ray outward along vertical and horizontal grid-line crossings separately, picking whichever hits a wall first, and has to correct the returned distance for the fisheye effect you'd otherwise get from measuring along the ray angle instead of straight ahead. A 2D minimap drawn alongside the 3D view, showing the map grid with every cast ray overlaid on it, made that math a lot easier to debug. You could actually watch the rays fan out and see exactly where one was going wrong.
There's also a separate little map editor (`maker.c`) for painting out wall layouts by hand instead of hardcoding a test map into the renderer: click tiles, pick a wall type with the number keys, save it out as a plaintext `.map` file.
Movement, collision, and a working minimap all came together; enemies and weapons were the natural next step.
## Controls
Renderer (`doom`):
- `W` / `S`: move forward/back
- `A` / `D`: strafe
- `Q` / `E`: turn
- Mouse: look
Map maker (`maker`):
- Number keys: pick a wall type
- Click: paint the hovered tile
- Saves the layout to a `.map` file for the renderer to load
## Building
Needs SDL2, SDL2_ttf, and libm.
```sh
make # builds the renderer -> ./doom
make maker # builds the map editor -> ./maker
```
## License
GPLv3, see `LICENSE`.
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