textmode.synth.js

A derivative work of hydra-synth by Olivia Jack, adapted for the textmode.js ecosystem.

Create procedural ASCII/text animations with a hydra-inspired, chainable visual synthesis system.

Features

• Procedural generation - Oscillators, noise, voronoi, and more
• Method chaining - Hydra-style fluent API for complex visuals
• Three-texture system - Independent control over characters, foreground, and background
• WebGL powered - Compiled to optimized GLSL shaders
• Feedback loops - Trails, motion blur, and recursive patterns
• Compositional API - Start from any aspect and build organically
• Extensible - Add your own sources, transforms, and more

Try it online first

To go along with the release of this library, we've created a live coding environment where you can explore everything in the browser: synth.textmode.art

It features IntelliSense & auto-completion, documentation on hover, curated examples to explore, and a lot more. The whole textmode.js ecosystem is available at your fingertips.

Prerequisites

• textmode.js v0.9.1+ - This library depends on the core textmode.js package v0.9.1 or higher.

Installation

npm install textmode.synth.js

Quick start

import { textmode } from 'textmode.js';
import { SynthPlugin, char, osc } from 'textmode.synth.js';

const t = textmode.create({
	width: window.innerWidth,
	height: window.innerHeight,
	fontSize: 16,
	plugins: [SynthPlugin],
});

const charChain = osc(1, -0.1, 0.5).kaleid(50);
const colorChain = osc(25, -0.1, 0.5).kaleid(50);

t.layers.base.synth(char(charChain).charMap('@#%*+=-:. ').charColor(colorChain).cellColor(colorChain.clone().invert()));

t.windowResized(() => {
	t.resizeCanvas(window.innerWidth, window.innerHeight);
});

Core concepts

Compositional API

textmode.js renders to three textures: characters, foreground colors, and background colors. textmode.synth.js provides functions to drive each independently:

Function	Purpose
char(source)	Character generation
charColor(source)	Foreground color
cellColor(source)	Background color
paint(source)	Both foreground & background

Start from any entry point and chain the others:

// From characters
char(noise(10))
	.charColor(osc(5))
	.cellColor(solid(0, 0, 0, 0.5));

// From colors
charColor(voronoi(5)).char(noise(10)).cellColor(gradient(0.5));

// Shorthand for pixel art style
paint(noise(10));

Pixel art mode

Use paint() to color both foreground and background identically, effectively hiding the characters:

t.fontSize(16);
t.layers.base.synth(paint(noise(10)));

Tip: With t.fontSize(1), you can recreate most hydra visuals 1:1.

Direct source usage

You can also pass a source directly to .synth() without any wrapper function:

t.layers.base.synth(noise(10));

This drives both characters and foreground colors from the same source (background defaults to black). In practice, using separate sources for characters often looks better - character cycling is more rapid than color changes.

Source generators

Generator	Description
osc(freq, sync, offset)	Sine wave patterns
noise(scale, offset)	Perlin noise
voronoi(scale, speed, blend)	Cellular patterns
gradient(speed)	Radial gradient
shape(sides, radius, smooth)	Geometric polygons
solid(r, g, b, a)	Solid colors
src(layer?)	Feedback / cross-layer sampling
...	...and many more..?

Transforms

Chain transforms to modify patterns:

Category	Methods
Geometry	rotate, scale, scroll, pixelate, repeat, kaleid, ...
Color	brightness, contrast, invert, hue, saturate, colorama, ...
Blend	add, sub, mult, blend, diff, layer, mask, ...
Modulate	modulate, modulateScale, modulateRotate, modulateKaleid, ...

Character mapping

Use .charMap() to define the character set. By default, all characters available in the layer's font are used.

char(noise(10)).charMap('@#%*+=-:. '); // ASCII gradient
char(voronoi(5)).charMap('█▓▒░ '); // Block characters

Documentation

There's a lot more to explore beyond this overview:

• Online documentation - Full guides and tutorials
• API reference - Complete API documentation
• synth.textmode.art - Live coding environment

License

Distributed under the AGPL-3.0 License. See LICENSE for more information.

Credits

This project is a derivative work of hydra-synth by Olivia Jack, adapted for the textmode.js ecosystem.

• hydra-synth: Core synthesis logic, GLSL shader generation, and functional API design.
• Modifications: Adapted for textmode.js's three-texture rendering pipeline (characters, foreground colors, background colors) and plugin system.