Rasterizer

Software 3D rasterizer based on the course 3D Programming from Scratch taught by Pikuma (Gustavo Pezzi).

The rasterizer features:

• SDL2 based renderer
• Complete graphics pipeline transformation
• Perspective-correct texture interpolation
• Top-left and DDA rasterization algorithms
• .obj + .png loading for scene population
• Visual debugging tools through ImGui
• Cross-platform compilation support, including WASM

All assets are provided by Pikuma as part of the coursework. JetBrains Mono is made available free of charge by JetBrains.

Project Structure

rasterizer/
├── assets/        # Provided assets
├── src/           # Source code
├── wasm/          # WASM specific files
├── external/      # Included external libraries
├── external/      # Included external libraries
└── README.md      # Project README

Environment - CMake

A CMake + Ninja setup is assumed. Both SDL2 and GLM are required to be available as CMake packages. On Windows you can use MSYS2, on MacOS Homebrew and on Linux the package manager of choice (eg: apt for Ubuntu).

Build - CMake

The following commands were tested using Clang, though all compilers with good C++23 coverage (eg: GCC) should work.

cmake -DCMAKE_BUILD_TYPE={Debug|Release} -DCMAKE_MAKE_PROGRAM=Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -G Ninja -S . -B ./cmake-build-{debug|release}
cmake --build cmake-build-{debug|release} --target rasterizer -j 14

Run - CMake

./bin/rasterizer-{debug|release}

Environment - WASM

Emscripten is used to build the WebAssembly (WASM) target. SDL2 is provided as a built-in port. Copying GLM into <emcc-folder>/system/include is recommended as it simplifies the build step. Otherwise, it can be added to the /external folder and manually reference it.

Can be built using MSYS2's Emscripten package.

Build - WASM

em++ src/main.cpp -std=c++23 -s USE_SDL=2 -s USE_SDL_IMAGE=2 -s SDL2_IMAGE_FORMATS='["png"]' -s USE_WEBGL2=1 -s FULL_ES2=1 -I./external/imgui $(find ./external/imgui -name "*.cpp") -O2 -DNDEBUG -fexceptions -s EXPORTED_RUNTIME_METHODS="['FS']" -s ALLOW_MEMORY_GROWTH=1 -s ENVIRONMENT=web -DRESOLUTION_SCALE=1 -o ./bin/rasterizer-wasm.html --preload-file ./assets --shell-file ./wasm/index.html

If GLM was not included as part of Emscripten's system libraries, it can be manually copied into ./external/glm and included by adding -I./externa/glm to the build command.

Run - WASM

cd bin
python3 -m http.server 8000

Afterwards, navigate to http://localhost:8000/rasterizer-wasm.html with the browser of choice.

Controls

Key(s)	Action
W / A / S / D	Move frustum eye around
↑ / ↓ / ← / →	Rotate frustum forward direction
C	Toggle backface culling
X / Z	DDA / Top-Left rasterization
Esc	Close app (WASM simply stops updating)

Technologies

• C++: >= C++23
• CMake: >= 3.28
• SDL: >= 2.30.9
• GLM: >= 1.0.1
• ImGui: >= v1.91.8 (Bundled)

TODOs

• Implement a floating-point rasterization algorithm