go-ppm-renderer

A minimal software renderer written in Go that generates images in the PPM (Portable Pixmap) format using a CPU-based framebuffer.

Overview

This project implements a simple 2D rendering pipeline from scratch — no external graphics libraries. It writes pixels directly into an in-memory framebuffer and serializes the result as a binary PPM (P6) file.

Features

• Framebuffer management with fill/clear support
• Rectangle drawing
• Line drawing via Bresenham's line algorithm
• PPM P6 (binary) file output

Getting Started

Prerequisites

• Go 1.25+

Run

go run main.go

This generates an image.ppm file in the current directory.

View the output

Most image viewers support PPM files. Alternatively, convert it with ImageMagick:

convert image.ppm image.png

Project Structure

main.go       # All rendering logic and entry point
image.ppm     # Generated output image
go.mod        # Go module definition

API

Function	Description
newColor(r, g, b)	Creates an RGB color value
clearBuffer(fb, color)	Fills the entire framebuffer with a color
writePixel(fb, x, y, color)	Sets a single pixel (bounds-checked)
drawRect(fb, x, y, w, h, color)	Draws a filled rectangle
drawLine(fb, x0, y0, x1, y1, color)	Draws a line between two points
savePPM(filename, fb)	Writes the framebuffer to a PPM file

License

MIT