drifttype

Spatial text layouts for the web. Text that follows paths and responds to pointer input.

Zero dependencies. Accessibility built in.

Live demo

Repel

Attract

Orbit

Path layout

Text flows along an SVG bezier path. Each character is positioned and rotated to follow the curve tangent.

import { computePathLayout, createCanvasMeasure, renderToSvg, mountSemantic } from 'drifttype'

const measure = createCanvasMeasure('24px Georgia')
const layout = computePathLayout('Hello world', 'M 0 100 Q 150 0 300 100', measure)

renderToSvg(svgElement, layout, { font: '24px Georgia' })
mountSemantic(container, 'Hello world')

The layout engine is pure — it takes a string, a path, and a measurement function, and returns positioned glyphs. No DOM access, no side effects. Rendering is separate.

Pointer-reactive layout

Characters repel, attract, or orbit the cursor. Spring physics with inertia.

import { initPointerLayout, stepPointerLayout, isAtRest } from 'drifttype'

const measure = createCanvasMeasure('24px Georgia')
let state = initPointerLayout('Hello world', measure, 'repel')

// in your animation loop
state = stepPointerLayout(state, { x: mouseX, y: mouseY }, 120, 0.6, dt)

Three modes: repel, attract, orbit. Pass null as the pointer to let characters settle back.

React

import { PathText, PointerText } from 'drifttype/react'

<PathText path="M 0 100 Q 150 0 300 100" font="24px Georgia">
  Hello world
</PathText>

<PointerText mode="repel" font="24px Georgia">
  Hello world
</PointerText>

Canvas renderer

import { renderPathToCanvas, renderPointerToCanvas } from 'drifttype'

renderPathToCanvas(ctx, layout, { font: '24px Georgia' })
renderPointerToCanvas(ctx, pointerState, { font: '24px Georgia' })

Accessibility

Every visual output should have a semantic counterpart. mountSemantic creates a visually-hidden DOM node with the text content so screen readers can access it. The SVG renderer marks visual output aria-hidden="true" automatically.

const handle = mountSemantic(container, 'Hello world')
handle.update('New text')   // update content
handle.destroy()            // clean up

The React components handle this for you.

How it works

The layout engine parses SVG path data into bezier segments, builds an arc-length lookup table for each segment, then places characters at evenly-spaced distances along the curve. Character widths come from an injected measurement function — the engine itself never touches the DOM.

The pointer-reactive engine runs spring physics per character. Forces are computed from the character's base position relative to the pointer, with quadratic falloff inside a configurable radius. The animation loop is frame-rate independent.

API

computePathLayout(text, pathData, measure, spacing?, startOffset?, align?)

Returns a PathLayoutResult with positioned glyphs.

| Param | Type | Default | | |---|---|---|---| | text | string | | The text to lay out | | pathData | string | | SVG path data | | measure | MeasureFn | | Character measurement function | | spacing | number | 1 | Letter-spacing multiplier | | startOffset | number | 0 | Arc-length offset to start | | align | 'start' \| 'center' \| 'end' | 'start' | Text alignment along path |

initPointerLayout(text, measure, mode, spacing?)

Returns initial PointerLayoutState.

stepPointerLayout(state, pointer, radius, strength, dt?)

Advances the physics simulation by one frame. Returns new state.

createCanvasMeasure(font)

Creates a MeasureFn from a CSS font string using an offscreen canvas. Results are cached per character.

parsePath(d)

Parses an SVG path data string into a ParsedPath. Supports M, L, H, V, C, Q, S, T, Z (absolute and relative).

Install

npm install drifttype

React components require react >= 18 as a peer dependency.

Development

npm test

License

MIT