srp

A software rendering pipeline that features:

• Pixel-perfect rasterization of all main primitive types (triangles, lines, points)
• Fully programmable vertex and fragment shaders (+uniforms)
• Sutherland-Hodgman triangle clipping & Liang-Barsky line clipping
• Perspective-correct, affine, and flat attribute interpolation
• Texture mapping
• Post-VS vertex caching
• A small math library to use in shader programming
• Image-based testing framework

The only dependency is stb_image.

If you want to use this library in your own project, you only need headers from include/srp directory.

Read the documentation for master branch here, or build the documentation yourself (see Building)

Building

git clone https://www.github.com/kitrofimov/srp
mkdir srp/build
cd srp/build
cmake .. -D CMAKE_BUILD_TYPE=Release
make
cd bin

BUILD_EXAMPLES, BUILD_DOCS, and BUILD_TESTS options are also available (i.e. -D BUILD_EXAMPLES=1 passed to cmake). Building the documentation requires having dot binary in PATH; building the tests requires numpy and pillow Python modules. After building, the examples, docs, and tests will appear in build/examples, build/docs, and build/tests.

Similar/related projects

• https://github.com/rswinkle/PortableGL
• https://github.com/NotCamelCase/SoftLit
• https://github.com/nikolausrauch/software-rasterizer
• https://github.com/niepp/srpbr

References

• General Computer Graphics concepts:
  • https://www.scratchapixel.com/
  • https://learnopengl.com/
• Triangle rasteization:
  • https://www.youtube.com/watch?v=k5wtuKWmV48
  • https://dl.acm.org/doi/pdf/10.1145/54852.378457
  • https://acta.uni-obuda.hu/Mileff_Nehez_Dudra_63.pdf
  • https://www.montis.pmf.ac.me/allissues/47/Mathematica-Montisnigri-47-13.pdf
• Perspective-correct interpolation:
  • https://www.comp.nus.edu.sg/%7Elowkl/publications/lowk_persp_interp_techrep.pdf
  • https://www.youtube.com/watch?v=F5X6S35SW2s

TODO

• Add interpolation with perspective correction

• Split the construction and rasterization of triangles in the pipeline

• Fix rasterization rules

• Get rid of dynamic memory allocation in the hot path (malloc and VLA)

• Make CW/CCW vertex order configurable

• Implement other primitives (lines, points, lines/triangles strip/adjacency etc.)

• Project refactoring

• Clipping

• Debug stutters (e.g. draw cube in line mode, stutters every 1.5-2 seconds)

• Add an example with .obj model loading

• Add wireframe rendering of triangles (polygon rendering mode)

• Use floats everywhere (instead of doubles)

• Check for bottlenecks & optimize

• Update the documentation

• Image-based testing framework

• Flat interpolation, per-varying perspective / affine / flat setting

• Implement single-threaded binning and tile system

• Scale to multiple threads

• Add multisampling

• Advanced texture techniques:

  • (Bi)linear filtering
  • Mipmapping
  • Anisotropic filtering
  • Transparent textures?