Clyune Component GalleryNoise Fluid Background · How it works & code
Fluid background using FBM fractal noise with domain distortion.
Runtime logic
Visiting `/webgl/noise`, DemoHost lazy-loads `demos/kits/kit-webgl.js` (registry `mod: 'kit-webgl'`) and calls `mount(host, { variant: 'noise' })`. mount resolves the variant to family `noise`; `withControls` builds the control panel (several presets + sliders). `createCanvasStage` creates the `<canvas>` (HiDPI ≤ 2×, ResizeObserver) and the info panel. `makeGL` compiles this demo’s GLSL fragment shader on an offscreen WebGL canvas; each frame sets uniforms (u_t, u_m, u_col…), `drawArrays` renders a full-screen quad, then `drawImage` copies it onto the 2D stage. 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; WebGL 1: Offscreen WebGL canvas running a GLSL fragment shader; 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; hexRgb — Colour string → [r, g, b]; 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.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.fill() — Fills the current path; ctx.stroke() — Strokes the current path; ctx.drawImage() — Draws an image or offscreen canvas; ctx.fillRect() — Fills a rectangle; gl.createShader() — Creates a vertex/fragment shader; gl.shaderSource() — Sets shader source; gl.compileShader() — Compiles a GLSL shader; gl.getShaderParameter() — Queries shader compile status; gl.getShaderInfoLog() — Reads the shader compile log; gl.createProgram() — Creates a shader program
Source code
frontend/src/demos/kits/kit-webgl.js: FAM.noise (L124-L130)
Code walkthrough
L124-130: Calls the factory `glFam()` to produce the full definition (spec + doc + build) from the options below. L124-124: Title shown in the info and control panels: “Noise Fluid Background”. L124-124: Range/default of the size slider: Noise Scale. L124-124: Range/default of the count slider: Layer Count. L125-125: Extra demo-specific slider/toggle: Domain Distortion Strength. L125-125: Preset buttons: name → parameter overrides (4). L126-126: Body of the “Notes” section. L126-126: Main formula of the “Formula” section. L126-126: Second formula line. L127-130: GLSL fragment shader source (runs once per pixel on the GPU); uses uniforms `u_s`, `u_n`, `u_x`, `u_col`.
Principles
fbm(p) = Σ noise(p·2ⁱ) / 2ⁱ q = p + strength · fbm(p + t) FBM Fractal noise: supersing the noise at different frequencies (each frequency) ×2、Amplitude ÷2），再用噪声去扭曲坐标（域扭曲），得到流体般的背景。 Every pixel is here GPU Nowadays run the same snigger independently (fragment shader), Enter pixel coordinates uv And time t, Output the color of this pixel.