Clyune Component GalleryMagnetic Letters · How it works & code
Characters float freely in the scene with noise; the pointer acts like a magnet, pulling characters closer to their original positions in the sentence and aligning them as they get nearer.
Runtime logic
Visiting `/text-fx/magnetic`, DemoHost lazy-loads `demos/kits/kit-text.js` (registry `mod: 'kit-text'`) and calls `mount(host, { variant: 'magnetic' })`. mount resolves the variant to family `magnetic`; `withControls` builds the control panel (6 presets + sliders). `createCanvasStage` creates the `<canvas>` (HiDPI ≤ 2×, ResizeObserver) and the info panel. The family’s `build(S)` initialises state and returns the per-frame callback. Every `requestAnimationFrame`: read controls, advance a speed-scaled clock (dt ≤ 50 ms), run the frame callback; returned readouts go to the info panel. Changing parameters: colour/speed/size apply live; structural ones remount; leaving the page cancels rAF, removes listeners and frees resources.
Environment
Canvas 2D: 2D canvas drawing; requestAnimationFrame: Display-synced animation loop; ResizeObserver: Canvas follows container size; Pointer Events: Unified mouse/touch/pen events; devicePixelRatio: Crisp HiDPI rendering (capped at 2×) · react 18.3.1, react-router-dom 6.30.6, vite 5.4.21
Dependencies
react 18.3.1
Imported APIs
withControls — Wraps the demo in the shared control panel (presets, sliders, reset); hot-updates or remounts on change; paramsFromSpec — Turns the spec (colour/speed/size/count/extras) into control-panel parameter definitions; createCanvasStage — Shared Canvas 2D stage: canvas + info panel, HiDPI, one rAF loop, pointer state, idle auto-pointer; hueOf — Hue of a colour (0–360°); clamp — Clamps a value to a range; TAU — Constant 2π; fmt — Number formatting (fixed decimals); F — Formula block HTML; getLang — Current UI language (zh/en); S.clear — Clears with the background colour (translucent = trails); S.onFrame — Registers a per-frame callback; its return value feeds the info panel; ctx.save() — Saves the drawing state (transform, styles, clip); ctx.translate() — Translates the coordinate system; ctx.rotate() — Rotates the coordinate system; ctx.fillText() — Draws filled text; ctx.restore() — Restores the saved drawing state; ctx.beginPath() — Starts a new path; ctx.arc() — Adds a circular arc (center, radius, start/end angle); ctx.stroke() — Strokes the current path; ctx.moveTo() — Moves the pen without drawing; ctx.arcTo() — Adds an arc using tangent lines; ctx.closePath() — Closes the current sub-path; ctx.fill() — Fills the current path; ctx.measureText() — Measures text width
Source code
frontend/src/demos/kits/kit-text.js: FAM.magnetic (L397-L407)
Code walkthrough
L397-407: Calls the factory `tFam()` to produce the full definition (spec + doc + build) from the options below. L397-397: Title shown in the info and control panels: “Magnetic Letters”. L397-397: Range/default of the count slider. L397-397: Extra demo-specific slider/toggle: Magnetic Range. L397-397: Default main colour. L397-397: Help text of the extra parameter. L397-397: Preset buttons: name → parameter overrides (5). L398-398: Body of the “Notes” section. L398-398: Main formula of the “Formula” section. L398-398: Second formula line. L399-407: Per-frame draw function: draws with Canvas 2D `save`, `translate`, `rotate`, `fillText`, `restore`, `beginPath` …; math via `Math.sin`, `Math.cos`, `Math.hypot`; returns readouts `mode`, `g` to the info panel.
Principles
Adsorption m = slow motion (1 -d) / Magnetic Range Capacity) = floating position · (1-m) + position in sentence · m Magnetic insulation: Words float freely with noise in the image; the pointer is like a magnet, and the closer to the pointer, the closer it is to suck back into its position in the sentence and set it right. Move the pointer so you can "sweep" a line. 文字被拆成一个个字（字形），每个字的位置、颜色、透明度都由「字的序号 i + Time t」Count it out so you can make animated verbatim.