meow

A 2D software renderer written in C++ from scratch. No graphics libraries: the CPU fills a pixel array, and the program saves it as an image.

Renders

• Framebuffer with bounds-checked setpixel
• Alpha blending (semi-transparent shapes mix with what's underneath)
• Anti-aliased circles (4x4 sampling per pixel)
• Rectangles and lines (Bresenham, all directions)
• Scene as data: a std::vector<std::variant<Circle, Rectangle, Triangle>> drawn by render()
• PPM image output

g++ -std=c++17 -Wall -Wextra main.cpp src/renderer.cpp -o main
./main

The image is written to images/. PPM isn't previewed by most viewers, so open it with IrfanView or GIMP, or convert it: magick images/castle.ppm images/castle.png.

lib/renderer.h     types and function declarations
src/renderer.cpp   rasterizer, blending, render()
main.cpp           builds a scene and saves it

• Framebuffer, shapes, PPM output
• Alpha blending
• Anti-aliased circles
• Scene as a list of shapes
• Line drawing (Bresenham)
• Scanline triangle fill (any triangle)
• Polygons
• Transforms (move, scale, rotate)
• Window and frame loop (SDL2)
• Save and load scenes from a file