Clyune Component GalleryFlip Cards · How it works & code
Turn the cards around the vertical middle line at 180 degrees, turn at 90 degrees and side to us, and then see the back.
Runtime logic
Visiting `/gsap/flipcard`, DemoHost lazy-loads `demos/kits/kit-gsap.js` (registry `mod: 'kit-gsap'`) and calls `mount(host, { variant: 'flipcard' })`. mount resolves the variant to family `flipcard`; `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; S.clear — Clears with the background colour (translucent = trails); S.onFrame — Registers a per-frame callback; its return value feeds the info panel; ctx.setLineDash() — Sets the dash pattern for strokes; ctx.stroke() — Strokes the current path; ctx.fill() — Fills the current path; ctx.save() — Saves the drawing state (transform, styles, clip); ctx.translate() — Translates the coordinate system; ctx.scale() — Scales the coordinate system; ctx.restore() — Restores the saved drawing state; ctx.fillText() — Draws filled text; 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.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-gsap.js: FAM.flipcard (L357-L370)
Code walkthrough
L357-370: Calls the factory `gFam()` to produce the full definition (spec + doc + build) from the options below. L357-357: Title shown in the info and control panels: “Flip Cards”. L357-357: Range/default of the count slider. L357-357: Extra demo-specific slider/toggle: Stagger gap. L357-357: Range/default of the size slider. L357-357: Default main colour. L358-358: Help text of the count parameter. L358-358: Help text of the extra parameter. L358-358: Help text of the size parameter. L359-359: Preset buttons: name → parameter overrides (5). L360-360: Body of the “Notes” section. L361-361: Main formula of the “Formula” section. L361-361: Second formula line. L362-370: Per-frame draw function: draws with Canvas 2D `setLineDash`, `stroke`, `fill`, `save`, `translate`, `scale` …; math via `Math.min`, `Math.cos`, `Math.max`, `Math.abs`, `Math.sin`, `Math.round`; returns readouts `mode`, `cell` to the info panel.
Principles
Visible width = kaboon |cos (angels) | 90° display on the back gsap.to(".card", { rotationY: 180, duration: 0.6, ease: "power2.inOut", stagger: 0.12 }) Flip card rotatey: Turn the card around a straight middle line at 180 degrees, turn 90 degrees and side to us, then see the back. On a plane canvas, the Y-axis rotation can be simulated by "Zoom horizontally = cos (angular)". All the cards turn to the back, stop and turn back on the face. There's no load here GSAP 库，而是用几十行代码复刻了它最核心的几个概念：补间（tween，从 A Smooth transition of value B Value, slow motion ease，Control the slow pace of transition, the time axis timeline，Sort multi-part patches in order) and staggered ( stagger，让一组元素依次出发）。每一帧都直接根据「当前时间」算出画面，所以拖动右侧滑条会立即看到变化。公式区给出了对应的 GSAP In writing, you can move directly to the real project.