Raycasting engine in C
A Wolfenstein-style 3D renderer written from scratch in C, with grid ray traversal, texture mapping, fisheye correction and collision detection.
- C
- raylib
- Make
- Linear algebra
Problem
I wanted to understand how early 3D games produced a convincing first-person view on hardware with no GPU. The best way to learn it was to build the whole renderer myself, without a game engine.
Approach
- raylib only for the window and drawing rectangles. Ray traversal, projection, texturing and collision are all my own C code.
- Grid traversal: each ray jumps straight to the next vertical or horizontal grid line (snapping to whichever comes first) instead of moving forward in tiny steps.
- Fisheye correction: wall height comes from the perpendicular distance to the camera plane, computed as a dot product with the view direction.
- Texture mapping: the exact hit point on the wall picks the texture column, and screen height picks the row. Walls can also have a different solid color per side.
- Delta-time movement, collision detection, distance shading, and a live minimap that draws every ray.
- Redraws only when the player moves.
Result
A real-time first-person view (60 FPS target) in about 400 lines of C. Along the way I dealt with floating-point edge cases (rays landing exactly on grid corners), perspective math, and keeping a render loop cheap.