Canvas

canvas is a lightweight, Processing-like 2D animation and creative coding library for Go.

It combines the power and simplicity of fogleman/gg (2D vector drawing) with gopxl/pixel for window management and real-time graphics rendering.

Features

• Simple & Intuitive: Start animating with familiar Setup and Draw callbacks—no window or loop boilerplate.
• Rich 2D Vector Drawing: Full 2D vector graphics (shapes, paths, text, images, colors, and transformations) powered by gg.
• Interactive: Built-in mouse and keyboard handling for interactive sketches, simulations, and creative coding.
• Easy Recording & Export: Built-in automated animated GIF recording (RecordGIF) and sequential PNG frame capture (SaveFrameSeq).

Installation

go get github.com/h8gi/canvas

Quick Start

package main

import (
	"github.com/h8gi/canvas"
	"golang.org/x/image/colornames"
)

func main() {
	c := canvas.NewCanvas(&canvas.CanvasConfig{
		Width:     640,
		Height:    400,
		FrameRate: 60,
		Title:     "Hello Canvas!",
	})

	c.Setup(func(ctx *canvas.Context) {
		ctx.Background(colornames.White)
		ctx.SetColor(colornames.Green)
		ctx.SetLineWidth(5)
	})

	c.Draw(func(ctx *canvas.Context) {
		ctx.Push()
		if ctx.IsMouseDragged {
			ctx.SetColor(colornames.Red)
		}
		ctx.DrawLine(ctx.Mouse.X, ctx.Mouse.Y, ctx.PMouse.X, ctx.PMouse.Y)
		ctx.Stroke()
		ctx.Pop()

		if ctx.IsKeyPressed(canvas.KeyUp) {
			ctx.Background(colornames.White)
		}
	})
}

Showcase

Perlin Flow Field	Boids Flocking	Particle Fountain
Fractal Tree	Noise Landscape	Generative Grid

Explore all complete, runnable programs in the examples directory.

Built With

• gg - 2D graphics library
• pixel - 2D OpenGL game engine

License

MIT License © 2019-2026 Hiroki Yagi (h8gi)