Clyune Component GalleryIcon Sprites · How it works & code
SVG sprite / use。
Runtime logic
Visiting `/svg/sprite`, DemoHost lazy-loads `demos/kits/kit-svg.js` (registry `mod: 'kit-svg'`) and calls `mount(host, { variant: 'sprite' })`. mount resolves the variant to family `sprite`; `withControls` builds the control panel (4 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°); TAU — Constant 2π; fmt — Number formatting (fixed decimals); F — Formula block HTML; 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.scale() — Scales the coordinate system; ctx.fill() — Fills the current path; ctx.beginPath() — Starts a new path; ctx.arc() — Adds a circular arc (center, radius, start/end angle); ctx.stroke() — Strokes the current path; ctx.restore() — Restores the saved drawing state; ctx.moveTo() — Moves the pen without drawing; ctx.arcTo() — Adds an arc using tangent lines; ctx.closePath() — Closes the current sub-path; ctx.fillRect() — Fills a rectangle; ctx.rect() — Adds a rectangle to the path; ctx.clip() — Turns the current path into the clipping region
Source code
frontend/src/demos/kits/kit-svg.js: FAM.sprite (L491-L505)
Code walkthrough
L491-505: Calls the factory `sFam()` to produce the full definition (spec + doc + build) from the options below. L491-491: Title shown in the info and control panels: “Icon Sprites”. L491-491: Range/default of the count slider. L491-491: Extra demo-specific slider/toggle: Hue step. L491-491: Range/default of the size slider. L491-491: Default main colour. L492-492: Help text of the count parameter. L492-492: Help text of the extra parameter. L492-492: Help text of the size parameter. L493-493: Preset buttons: name → parameter overrides (5). L494-494: Body of the “Notes” section. L495-495: Main formula of the “Formula” section. L495-495: Second formula line. L496-505: Per-frame draw function: draws with Canvas 2D `save`, `translate`, `rotate`, `scale`, `fill`, `beginPath` …; math via `Math.max`, `Math.round`, `Math.floor`, `Math.min`, `Math.abs`, `Math.sin`; returns readouts `mode`, `n`, `cell` to the info panel.
Principles
Actual exampleᵢ = use(#icon, translate(xᵢ, yᵢ) rotate(θᵢ) scale(sᵢ)) Hue i = Main + i · Hue step Icon Elf: in Inline Define the graphics once and use many more Reuse it in different positions; each You can have your own transform And colours (through currentColor 传入）。改一处定义，所有实例都会跟着变。这里每个实例错开时间做旋转和缩放，颜色按序号递增色相，指针悬停的实例会放大。 SVG It's "The Vector Chart in Text":<path d="M… L… C… A…"> 里 M Means moving to a point, L Draw straight lines, C Draw three Bézier curves, A Draw round a Elimination Translate. Here Canvas 的 Path2D Parsing the same path, then pressing time t 改变描边、形状、颜色等属性，效果与网页里的 SVG Animated same.