tint

Apply visual shaders — colour, animation, character substitution — to text in your terminal. Tint is a small Go library and CLI that treats a block of text as a 2D grid of cells and lets a "shader" decide how each cell should be rendered as truecolor ANSI.

CLI

echo "HELLO" | tint rainbow
figlet "FIRE" | tint fire --fps 30
echo "HELLO" | tint matrix --once > frame.ans

By default, tint animates when stdout is a terminal (looping until Ctrl-C or --timeout) and renders a single frame otherwise. That means piping to a file, pager, or another command gives you one clean frame without extra flags, while running interactively Just Works.

Built-in shaders:

Shader	Description
rainbow	Horizontal hue gradient that shifts across frames
fire	Warm vertical gradient with animated shimmer
matrix	Parallax katakana rain on multiple depth planes
solid	A single foreground colour

Flags:

  --once          render a single frame and exit, even on a terminal
  --animate       force animation even when stdout is not a terminal
                  (useful for streaming frames to another tool)
  --fps N         animation frame rate (default: 10)
  --timeout N     stop animation after N seconds (default: no limit)
  --pad N         add N cells of margin around the text

--once and --animate are mutually exclusive.

Library

import "github.com/ryanlewis/tint"

func main() {
    _ = tint.Apply(os.Stdout, "HELLO\nWORLD", "rainbow", 0)
}

A shader is anything that implements the Shader interface:

type Shader interface {
    Shade(Cell) Output
}

Cell carries the rune, its grid coordinates, the grid dimensions and the current animation frame. Output is what the shader decides for that cell: the (possibly substituted) rune, foreground and background colours, and a style bitfield (bold, italic, underline, etc.).

Register a custom shader once and it becomes available to both the library and the CLI:

tint.Register("invert", func(w, h int) tint.Shader {
    return invertShader{}
})

Install

go install github.com/ryanlewis/tint/cmd/tint@latest

Or build from source:

just build

Development

just            # list targets
just test       # run tests
just lint       # run golangci-lint
just ci         # lint + test + build

License

MIT