Cell Growth · How it works & code
Each cell grows up in two, two subcells are separated in a random direction, each in half size (radi Ratified) ÷ √2)。
Runtime logic
Visiting `/generative/cellgrow`, DemoHost lazy-loads `demos/kits/kit-generative.js` (registry `mod: 'kit-generative'`) and calls `mount(host, { variant: 'cellgrow' })`. mount resolves the variant to family `cellgrow`; `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; S.clear — Clears with the background colour (translucent = trails); S.onFrame — Registers a per-frame callback; its return value feeds the info panel; ctx.beginPath() — Starts a new path; ctx.arc() — Adds a circular arc (center, radius, start/end angle); ctx.fill() — Fills the current path; 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.fillRect() — Fills a rectangle; ctx.drawImage() — Draws an image or offscreen canvas; ctx.save() — Saves the drawing state (transform, styles, clip); ctx.rect() — Adds a rectangle to the path; ctx.clip() — Turns the current path into the clipping region; ctx.restore() — Restores the saved drawing state
Source code
frontend/src/demos/kits/kit-generative.js: FAM.cellgrow (L476-L496)
Code walkthrough
L476-496: Calls the factory `gFam()` to produce the full definition (spec + doc + build) from the options below. L476-476: Title shown in the info and control panels: “Cell division”. L476-476: Range/default of the size slider: Cell radius. L476-476: Range/default of the count slider: Maximum generations. L477-477: Extra demo-specific slider/toggle: Colony count. L477-477: Default main colour. L477-477: Help text of the count parameter. L477-477: Preset buttons: name → parameter overrides (5). L478-478: Body of the “Notes” section. L478-478: Main formula of the “Formula” section. L478-478: Second formula line. L479-496: Per-frame draw function: draws with Canvas 2D `beginPath`, `arc`, `fill`, `stroke`; math via `Math.round`, `Math.min`, `Math.floor`, `Math.sin`, `Math.max`, `Math.cos` …; returns readouts `mode`, `cell` to the info panel.
Principles
4: g = 2^g Subcell radius = mother cell radius / √2 (area constant) 细胞分裂:每个细胞长大后一分为二,两个子细胞沿随机方向分开,体积各占一半(半径 ÷ √2)。# Every fungus experience # 1 → 2 → 4 → …」的分裂,然后淡出并重新开始。指针附近的细胞会被轻轻推开。 Generative Art = a simple mathematical rule + Random number/噪声,让电脑自己「画」出图案;改变参数就是改变规则。