Clyune Component GalleryRainbow Bounce · How it works & code
Each character bounces up and down (|sin| curve, like a bouncing ball), with colors flowing along the hue ring. The first character's hue is the primary color, and the entire phrase spans...
Runtime logic
Visiting `/text-fx/rainbow`, DemoHost lazy-loads `demos/kits/kit-text.js` (registry `mod: 'kit-text'`) and calls `mount(host, { variant: 'rainbow' })`. mount resolves the variant to family `rainbow`; `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; 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.scale() — Scales the coordinate system; ctx.fillText() — Draws filled text; ctx.restore() — Restores the saved drawing state; ctx.beginPath() — Starts a new 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.stroke() — Strokes the current path; ctx.measureText() — Measures text width; ctx.fillRect() — Fills a rectangle; ctx.rect() — Adds a rectangle to the path
Source code
frontend/src/demos/kits/kit-text.js: FAM.rainbow (L409-L416)
Code walkthrough
L409-416: Calls the factory `tFam()` to produce the full definition (spec + doc + build) from the options below. L409-409: Title shown in the info and control panels: “Rainbow Bounce”. L409-409: Range/default of the count slider. L409-409: Extra demo-specific slider/toggle: Hue Span. L409-409: Default main colour. L409-409: Help text of the extra parameter. L409-409: Preset buttons: name → parameter overrides (5). L410-410: Body of the “Notes” section. L410-410: Main formula of the “Formula” section. L410-410: Second formula line. L411-416: Per-frame draw function: draws with Canvas 2D `save`, `translate`, `scale`, `fillText`, `restore`; math via `Math.hypot`, `Math.abs`, `Math.sin`, `Math.max`, `Math.round`; returns readouts `mode`, `g` to the info panel.
Principles
High jump hᵢ = A · |sin(3t − 0.4i)| Hue i = Main + Range · i / n + 60t Rainbow jumps: each word jumps up and falls down in turn (|sin| Curves, like a ball that bounces), while the colour flows along the colour ring, the first word having the main color and the whole sentence crossing the "chromatic span". The pointer dances higher. 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.