Draw primitives
Lines, shapes, images, transforms, text, and stroke styles.
Ruby sketching · immediate mode
Make a sketch. Let it run.
A compact Processing-style drawing DSL for Ruby, with interactive windows and deterministic headless frames.
gem install gesso
A small loop with room to play.
Shapes, color, time, and output stay close to the sketch.
Shape the palette
RGB and HSB colors; corner, center, and radius modes.
Keep the frame
Seeded random values, smooth noise, and headless PNG rendering.
A small first step
Start with one example.
Install the gem, then follow the project guide for platform requirements and the full API.
require "gesso"
sketch = Gesso.run(width: 320, height: 200) do
setup { background 16, 24, 39 }
draw do
fill 240, 120, 80
circle width / 2, height / 2, 30
end
end
sketch.canvas.write("shot.png")