Wolfenstein 3D is a big milestone in id Software’s evolution and PC gaming in general. In addition, because its technology is more primitive, the source code is more approachable for study and implementation. The game doesn’t have a real 3D engine but rather simulates a 3D world from a 2D map using a technique called Ray Casting. All the drawing is done by directly putting pixels on the screen. - Rustenstein 3D: Game programming like it’s 1992 / HN

• 2d Visibility (Red Blob Games
• Game Engine Black Books
  • Wolfenstein 3D

• Lode’s Computer Graphics Tutorial

• A first-person engine in 265 lines

• Raycaster Game Help
  • Mot’s Wolf3D engine - The code is amazingly well documented as it’s intended to be used to make your own game out of.