Software rendering in 500 lines of bare C++
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A 500-line C++ software renderer teaches how 3D graphics APIs work internally.
The author presents a series of lectures to build a software renderer from scratch in about 500 lines of C++ with no third-party graphics libraries. Students typically need 10-20 hours to produce a renderer that outputs a TGA image from a triangulated mesh and textures. The starting code provides only a TGA file class and pixel-setting; line and triangle drawing are implemented manually. The goal is to show how OpenGL, Vulkan, Metal, and DirectX work, not how to write GPU applications. Complete code is on GitHub.
What commenters are saying
Commenters focus on triangle clipping as the hardest part of software rendering. One commenter notes that ignoring all frustum clipping except the near plane can work, though it may draw off-screen pixels. Another describes a detailed approach using Sutherland-Hodgman clipping in clip space, where plane equations are simple (e.g., x = ±w). A third discusses tile-based rasterization and deferred attribute synthesis to avoid geometric clipping. A fourth mentions guard band clipping as a common GPU technique, rejecting 2D rasterization blocks outside the scissor rect.