Pattern Waves

"use client"

import { useEffect, useMemo, useRef, type ComponentProps } from "react"
import { Mesh, Program, RenderTarget, Renderer, Texture, Triangle } from "ogl"
import { cn } from "@/lib/utils"

type SurfacePreset = "silk" | "ocean" | "pond" | "lines" | "terminal" | "mesh"
type PatternKind = "dot" | "square" | "plus" | "line" | "glyph"
type WaveKind = "silk" | "swell" | "ripple"
type FadeKind = "edges" | "center" | "bottom" | "top" | "none"
type Rgba = [number, number, number, number]

interface PresetValues {
  pattern: PatternKind
  wave: WaveKind
  spacing: number
  markSize: number
  depth: number
  light: number
  shine: number
  contrast: number
  speed: number
  scale: number
  direction: number
}

export type PatternWavesPreset = SurfacePreset
export type PatternWavesPattern = PatternKind
export type PatternWavesWave = WaveKind
export type PatternWavesFade = FadeKind

export interface PatternWavesProps extends Partial<PresetValues>, Omit<ComponentProps<"div">, "color"> {
  /** A starting look. Any other prop overrides what the preset sets for it. */
  preset?: SurfacePreset
  /** Colour of the marks. */
  color?: string
  /** Fill behind the marks. Use "transparent" to show what is underneath. */
  backgroundColor?: string
  opacity?: number
  /** Where the field fades out. */
  fade?: FadeKind
  fadeSize?: number
  /** Glyphs for the "glyph" pattern, dimmest first. */
  characters?: string
  /** Let the pointer ripple the surface. */
  interactive?: boolean
  cursorSize?: number
  cursorStrength?: number
  /** Rise in from the centre on mount. */
  intro?: boolean
  /** Freeze the animation. The last frame stays on screen. */
  paused?: boolean
}

interface Settings extends PresetValues {
  color: Rgba
  background: Rgba
  opacity: number
  fade: FadeKind
  fadeSize: number
  characters: string
  interactive: boolean
  cursorSize: number
  cursorStrength: number
  intro: boolean
  paused: boolean
}

interface RippleField {
  width: number
  height: number
  read: RenderTarget
  write: RenderTarget
}

const SURFACE_PRESETS: Record<SurfacePreset, PresetValues> = {
  silk: {
    pattern: "dot",
    wave: "silk",
    spacing: 9,
    markSize: 0.95,
    depth: 0.95,
    light: 0,
    shine: 0.8,
    contrast: 1.2,
    speed: 0.35,
    scale: 1,
    direction: 20,
  },
  ocean: {
    pattern: "dot",
    wave: "swell",
    spacing: 10,
    markSize: 0.9,
    depth: 0.42,
    light: 0,
    shine: 1,
    contrast: 1.2,
    speed: 0.5,
    scale: 1,
    direction: 100,
  },
  pond: {
    pattern: "dot",
    wave: "ripple",
    spacing: 10,
    markSize: 0.9,
    depth: 0.55,
    light: 0,
    shine: 1.2,
    contrast: 1.2,
    speed: 0.5,
    scale: 1,
    direction: 35,
  },
  lines: {
    pattern: "line",
    wave: "silk",
    spacing: 12,
    markSize: 0.42,
    depth: 0.9,
    light: 0,
    shine: 0.6,
    contrast: 1.2,
    speed: 0.3,
    scale: 1,
    direction: 20,
  },
  terminal: {
    pattern: "glyph",
    wave: "ripple",
    spacing: 13,
    markSize: 0.95,
    depth: 0.75,
    light: 0,
    shine: 0.9,
    contrast: 1.4,
    speed: 0.3,
    scale: 1.1,
    direction: 200,
  },
  mesh: {
    pattern: "plus",
    wave: "silk",
    spacing: 14,
    markSize: 0.8,
    depth: 0.95,
    light: 0,
    shine: 1,
    contrast: 1.45,
    speed: 0.4,
    scale: 1.1,
    direction: 325,
  },
}

const PATTERNS: Record<string, number> = { dot: 0, square: 1, plus: 2, line: 3, glyph: 4 }
const WAVES: Record<string, number> = { silk: 0, swell: 1, ripple: 2 }
const FADES: Record<string, number> = { none: 0, edges: 1, center: 2, bottom: 3, top: 4 }
const DEFAULT_CHARACTERS = ".:-=+*#%@"
const GLYPH_FONT = "ui-monospace, SFMono-Regular, Menlo, Consolas, monospace"
const ATLAS_TILE = 128
const WAVE_UNIT = 520
const RIPPLE_CELL = 8
const RIPPLE_RATE = 60
const PIXEL_BUDGET = 4.5e6
const INTRO_SECONDS = 2
// Must match what ogl's Renderer passes to getContext(), so the probe below and ogl share one context.
const CONTEXT_ATTRIBUTES = {
  alpha: true,
  depth: false,
  stencil: false,
  antialias: false,
  premultipliedAlpha: true,
  preserveDrawingBuffer: false,
  powerPreference: "default" as const,
}

const clamp = (value: number, min: number, max: number) => Math.min(Math.max(value, min), max)

const luminance = (rgba: number[]) => 0.2126 * rgba[0] + 0.7152 * rgba[1] + 0.0722 * rgba[2]

// One 2D context resolves every CSS colour; a new canvas per parse would be garbage on every render.
let colorProbe: CanvasRenderingContext2D | null = null

const parseColor = (value: string, fallback: Rgba): Rgba => {
  try {
    colorProbe ??= document.createElement("canvas").getContext("2d")
    const ctx = colorProbe
    if (!ctx) return fallback
    ctx.fillStyle = "#000000"
    ctx.fillStyle = value
    const resolved = ctx.fillStyle
    if (resolved.startsWith("#")) {
      const n = parseInt(resolved.slice(1), 16)
      return [((n >> 16) & 255) / 255, ((n >> 8) & 255) / 255, (n & 255) / 255, 1]
    }
    const parts = resolved.match(/[\d.]+/g)
    if (!parts || parts.length < 3) return fallback
    return [Number(parts[0]) / 255, Number(parts[1]) / 255, Number(parts[2]) / 255, parts[3] ? Number(parts[3]) : 1]
  } catch {
    return fallback
  }
}

const buildAtlas = (characters: string) => {
  const glyphs = Array.from(characters && characters.length ? characters : DEFAULT_CHARACTERS)
  const columns = Math.ceil(Math.sqrt(glyphs.length))
  const lines = Math.ceil(glyphs.length / columns)
  const canvas = document.createElement("canvas")
  canvas.width = columns * ATLAS_TILE
  canvas.height = lines * ATLAS_TILE
  const ctx = canvas.getContext("2d")
  if (!ctx) return null
  ctx.fillStyle = "#ffffff"
  ctx.textAlign = "center"
  ctx.textBaseline = "middle"
  ctx.font = `500 ${Math.round(ATLAS_TILE * 0.86)}px ${GLYPH_FONT}`
  glyphs.forEach((glyph, index) => {
    const x = (index % columns) * ATLAS_TILE + ATLAS_TILE / 2
    const y = Math.floor(index / columns) * ATLAS_TILE + ATLAS_TILE / 2
    ctx.fillText(glyph, x, y)
  })
  return { canvas, columns, lines, count: glyphs.length }
}

const passVertex = `#version 300 es
in vec2 position;
void main() {
  gl_Position = vec4(position, 0.0, 1.0);
}
`

const fieldFragment = `#version 300 es
precision highp float;
precision highp int;
uniform vec2 uSize;
uniform float uDpr;
uniform vec2 uOrigin;
uniform vec2 uPitch;
uniform int uWave;
uniform float uTime;
uniform float uUnit;
uniform vec2 uHeading;
uniform float uAmp;
uniform float uDepth;
uniform vec3 uLight;
uniform float uShine;
uniform float uContrast;
uniform float uInk;
uniform float uOpacity;
uniform int uFade;
uniform float uFadeSize;
uniform float uAppear;
uniform sampler2D tRipple;
uniform float uRipple;
out vec4 fragColor;

const float FOLDS = 5.5;

uvec3 scramble(uvec3 v) {
  v = v * 1664525u + 1013904223u;
  v.x += v.y * v.z;
  v.y += v.z * v.x;
  v.z += v.x * v.y;
  v ^= v >> 16u;
  v.x += v.y * v.z;
  v.y += v.z * v.x;
  v.z += v.x * v.y;
  return v;
}

vec3 lattice(vec3 corner) {
  uvec3 h = scramble(uvec3(ivec3(corner) + 4096));
  return vec3(h & 65535u) / 32767.5 - 1.0;
}

float gradientNoise(vec3 p) {
  vec3 i = floor(p);
  vec3 f = p - i;
  vec3 u = f * f * f * (f * (f * 6.0 - 15.0) + 10.0);
  float n000 = dot(lattice(i), f);
  float n100 = dot(lattice(i + vec3(1.0, 0.0, 0.0)), f - vec3(1.0, 0.0, 0.0));
  float n010 = dot(lattice(i + vec3(0.0, 1.0, 0.0)), f - vec3(0.0, 1.0, 0.0));
  float n110 = dot(lattice(i + vec3(1.0, 1.0, 0.0)), f - vec3(1.0, 1.0, 0.0));
  float n001 = dot(lattice(i + vec3(0.0, 0.0, 1.0)), f - vec3(0.0, 0.0, 1.0));
  float n101 = dot(lattice(i + vec3(1.0, 0.0, 1.0)), f - vec3(1.0, 0.0, 1.0));
  float n011 = dot(lattice(i + vec3(0.0, 1.0, 1.0)), f - vec3(0.0, 1.0, 1.0));
  float n111 = dot(lattice(i + vec3(1.0, 1.0, 1.0)), f - vec3(1.0, 1.0, 1.0));
  return mix(
    mix(mix(n000, n100, u.x), mix(n010, n110, u.x), u.y),
    mix(mix(n001, n101, u.x), mix(n011, n111, u.x), u.y),
    u.z
  );
}

vec2 turn(vec2 v, float angle) {
  float c = cos(angle);
  float s = sin(angle);
  return vec2(c * v.x - s * v.y, s * v.x + c * v.y);
}

float surface(vec2 p, float t) {
  if (uWave == 0) {
    vec2 side = vec2(-uHeading.y, uHeading.x);
    float u = dot(p, uHeading);
    float v = dot(p, side);
    float bend = gradientNoise(vec3(v * 0.85, u * 0.3, t * 0.05)) * 1.7 + 0.4 * sin(v * 1.6 + t * 0.2);
    float phase = u * FOLDS + bend - t * 0.45;
    float swell = 0.6 + 0.4 * gradientNoise(vec3(u * 0.55 + 3.0, v * 0.45, t * 0.04));
    float fold = sin(phase) + 0.32 * sin(2.0 * phase + 1.3);
    float ripple = 0.16 * sin(u * FOLDS * 2.5 + bend * 1.9 - t * 0.9 + 2.1);
    return (fold + ripple) * swell;
  }
  if (uWave == 1) {
    float bend = gradientNoise(vec3(p * 0.6, t * 0.05)) * 0.6;
    float phase = dot(p, uHeading) * 15.0 + bend * 2.2 - t * 1.4;
    float swell = sin(phase) + 0.3 * sin(2.0 * phase - 0.8);
    float roll = 0.75 + 0.25 * gradientNoise(vec3(p * 0.9 + 11.0, t * 0.05));
    return 0.8 * swell * roll;
  }
  float r = length(p + uHeading * 1.2);
  float bend = gradientNoise(vec3(p * 1.2, t * 0.05)) * 0.1;
  return sin((r + bend) * 9.0 - t * 1.8) * (0.45 + 0.55 * exp(-(r - 0.6) * 0.8));
}

float heightAt(vec2 css) {
  float h = surface((css - 0.5 * uSize) / uUnit, uTime) * uAmp;
  if (uRipple > 0.0) h += texture(tRipple, css / uSize).r * uRipple;
  return h;
}

void main() {
  vec2 cell = floor(gl_FragCoord.xy);
  vec2 center = uOrigin + (cell + 0.5) * uPitch;
  vec2 css = center / uDpr;
  vec2 uv = css / uSize;
  float e = max(uPitch.y / uDpr, 4.0);
  float h = heightAt(css);
  float hx = (heightAt(css + vec2(e, 0.0)) - heightAt(css - vec2(e, 0.0))) / (2.0 * e);
  float hy = (heightAt(css + vec2(0.0, e)) - heightAt(css - vec2(0.0, e))) / (2.0 * e);
  vec2 grad = vec2(hx, hy) * uUnit * uDepth * 0.4;
  vec3 n = normalize(vec3(-grad, 1.0));

  float diffuse = clamp(dot(n, uLight), 0.0, 1.0);
  vec3 halfway = normalize(uLight + vec3(0.0, 0.0, 1.0));
  float spec = pow(clamp(dot(n, halfway), 0.0, 1.0), 160.0) * uShine * 1.15;
  float hollow = 0.7 + 0.3 * clamp(h * 0.5 + 0.5, 0.0, 1.0);
  float tone = clamp(diffuse * hollow * 0.78 + spec, 0.0, 1.0);
  tone = clamp((tone - 0.42) * uContrast + 0.42, 0.0, 1.0);

  float level = uInk > 0.5 ? pow(clamp(1.0 - tone / 0.46, 0.0, 1.0), 2.4) * 0.72 : pow(tone, 2.2);
  float emphasis = uInk > 0.5 ? smoothstep(0.55, 0.95, level) : clamp(spec * 1.6, 0.0, 1.0);

  float fade = 1.0;
  vec2 c = uv * 2.0 - 1.0;
  if (uFade == 1) {
    fade = 1.0 - smoothstep(1.0 - uFadeSize, 1.18, length(c));
  } else if (uFade == 2) {
    fade = mix(0.05, 1.0, smoothstep(0.08, 0.08 + uFadeSize, length(c * vec2(1.0, 1.35))));
  } else if (uFade == 3) {
    fade = smoothstep(0.0, uFadeSize, uv.y);
  } else if (uFade == 4) {
    fade = smoothstep(0.0, uFadeSize, 1.0 - uv.y);
  }

  float reach = length(css - 0.5 * uSize) / max(0.5 * length(uSize), 1.0);
  float appear = smoothstep(reach - 0.05, reach + 0.3, uAppear * 1.35);

  float alpha = uOpacity * fade * appear * (0.22 + 0.78 * level);
  float lift = clamp(h * uDepth * 0.42, -0.48, 0.48);
  fragColor = vec4(level, alpha, emphasis, lift + 0.5);
}
`

const rippleFragment = `#version 300 es
precision highp float;
uniform sampler2D tState;
uniform vec2 uTexel;
uniform vec2 uSize;
uniform vec2 uFrom;
uniform vec2 uTo;
uniform float uRadius;
uniform float uImpulse;
uniform float uDamping;
out vec4 fragColor;

void main() {
  vec2 uv = gl_FragCoord.xy * uTexel;
  vec2 state = texture(tState, uv).rg;
  float left = texture(tState, uv - vec2(uTexel.x, 0.0)).r;
  float right = texture(tState, uv + vec2(uTexel.x, 0.0)).r;
  float below = texture(tState, uv - vec2(0.0, uTexel.y)).r;
  float above = texture(tState, uv + vec2(0.0, uTexel.y)).r;
  float next = ((left + right + below + above) * 0.5 - state.g) * uDamping;
  vec2 p = uv * uSize;
  vec2 segment = uTo - uFrom;
  float along = clamp(dot(p - uFrom, segment) / max(dot(segment, segment), 1e-4), 0.0, 1.0);
  float d = length(p - uFrom - segment * along) / uRadius;
  next -= uImpulse * exp(-d * d * 2.0);
  fragColor = vec4(next, state.r, 0.0, 1.0);
}
`

const markFragment = `#version 300 es
precision highp float;
precision highp int;
uniform sampler2D tField;
uniform sampler2D tAtlas;
uniform vec2 uOrigin;
uniform vec2 uPitch;
uniform vec2 uGrid;
uniform int uPattern;
uniform float uMarkSize;
uniform float uStroke;
uniform vec3 uColor;
uniform vec3 uAccent;
uniform vec4 uBackground;
uniform vec3 uAtlas;
out vec4 fragColor;

float box(vec2 p, vec2 b, float r) {
  vec2 q = abs(p) - b + r;
  return length(max(q, 0.0)) + min(max(q.x, q.y), 0.0) - r;
}

float coverage(vec2 local, float level) {
  float span = uPitch.y * uMarkSize;
  float area = max(sqrt(level), 0.14);
  if (uPattern == 0) {
    return clamp(0.5 - (length(local) - 0.5 * span * area), 0.0, 1.0);
  }
  if (uPattern == 1) {
    float extent = 0.5 * span * area;
    return clamp(0.5 - box(local, vec2(extent), extent * 0.3), 0.0, 1.0);
  }
  if (uPattern == 2) {
    float arm = 0.5 * span * mix(0.3, 1.0, level);
    float width = 0.5 * uStroke;
    return clamp(0.5 - min(box(local, vec2(arm, width), width), box(local, vec2(width, arm), width)), 0.0, 1.0);
  }
  if (uAtlas.z < 1.0) return 0.0;
  vec2 g = local / span + 0.5;
  if (g.x < 0.0 || g.y < 0.0 || g.x > 1.0 || g.y > 1.0) return 0.0;
  float index = min(floor(level * uAtlas.z), uAtlas.z - 1.0);
  vec2 tile = vec2(mod(index, uAtlas.x), floor(index / uAtlas.x));
  vec2 atlasUv = (tile + vec2(g.x, 1.0 - g.y)) / uAtlas.xy;
  vec2 texel = 1.0 / (span * uAtlas.xy);
  return textureGrad(tAtlas, atlasUv, vec2(texel.x, 0.0), vec2(0.0, texel.y)).a;
}

vec4 lineInk(vec2 rel) {
  float fx = rel.x / uPitch.x - 0.5;
  float c0 = clamp(floor(fx), 0.0, uGrid.x - 1.0);
  float c1 = min(c0 + 1.0, uGrid.x - 1.0);
  float t = clamp(fx - c0, 0.0, 1.0);
  float row = floor(rel.y / uPitch.y);
  vec4 ink = vec4(0.0);
  for (int k = -1; k <= 1; k++) {
    float cy = row + float(k);
    if (cy < 0.0 || cy >= uGrid.y) continue;
    vec4 a = texelFetch(tField, ivec2(int(c0), int(cy)), 0);
    vec4 b = texelFetch(tField, ivec2(int(c1), int(cy)), 0);
    vec4 f = mix(a, b, t);
    if (f.g < 0.002) continue;
    float y = (cy + 0.5 + f.a - 0.5) * uPitch.y;
    float slope = (b.a - a.a) * uPitch.y / uPitch.x;
    float thickness = max(uStroke, uPitch.y * uMarkSize * f.r);
    float d = abs(rel.y - y) / sqrt(1.0 + slope * slope) - 0.5 * thickness;
    float alpha = clamp(0.5 - d, 0.0, 1.0) * f.g;
    if (alpha > ink.a) ink = vec4(mix(uColor, uAccent, f.b) * alpha, alpha);
  }
  return ink;
}

void main() {
  vec2 rel = gl_FragCoord.xy - uOrigin;
  vec4 background = vec4(uBackground.rgb * uBackground.a, uBackground.a);
  vec4 ink = vec4(0.0);
  if (uPattern == 3) {
    ink = lineInk(rel);
  } else {
    float cx = floor(rel.x / uPitch.x);
    float row = floor(rel.y / uPitch.y);
    if (cx >= 0.0 && cx < uGrid.x) {
      for (int k = -1; k <= 1; k++) {
        float cy = row + float(k);
        if (cy < 0.0 || cy >= uGrid.y) continue;
        vec4 f = texelFetch(tField, ivec2(int(cx), int(cy)), 0);
        if (f.g < 0.002) continue;
        vec2 center = (vec2(cx, cy) + 0.5) * uPitch + vec2(0.0, (f.a - 0.5) * uPitch.y);
        float alpha = coverage(rel - center, f.r) * f.g;
        if (alpha > ink.a) ink = vec4(mix(uColor, uAccent, f.b) * alpha, alpha);
      }
    }
  }
  fragColor = ink + background * (1.0 - ink.a);
}
`

export function PatternWaves({
  preset = "silk",
  pattern,
  wave,
  spacing,
  markSize,
  depth,
  light,
  shine,
  contrast,
  speed,
  scale,
  direction,
  color = "#ffffff",
  backgroundColor = "#000000",
  opacity = 1,
  fade = "edges",
  fadeSize = 0.5,
  characters = DEFAULT_CHARACTERS,
  interactive = true,
  cursorSize = 50,
  cursorStrength = 0.6,
  intro = true,
  paused = false,
  className,
  style,
  ...rest
}: PatternWavesProps) {
  const containerRef = useRef<HTMLDivElement>(null)
  const settingsRef = useRef<Settings | null>(null)
  const wakeRef = useRef<(() => void) | null>(null)

  const base = SURFACE_PRESETS[preset] || SURFACE_PRESETS.silk
  const pick = <K extends keyof PresetValues>(value: PresetValues[K] | undefined, key: K): PresetValues[K] =>
    value === undefined || value === null ? base[key] : value

  const colors = useMemo(
    () => ({
      color: parseColor(color, [1, 1, 1, 1]),
      background: parseColor(backgroundColor, [0, 0, 0, 1]),
    }),
    [color, backgroundColor],
  )

  useEffect(() => {
    settingsRef.current = {
      ...colors,
      pattern: pick(pattern, "pattern"),
      wave: pick(wave, "wave"),
      spacing: pick(spacing, "spacing"),
      markSize: pick(markSize, "markSize"),
      depth: pick(depth, "depth"),
      light: pick(light, "light"),
      shine: pick(shine, "shine"),
      contrast: pick(contrast, "contrast"),
      speed: pick(speed, "speed"),
      scale: pick(scale, "scale"),
      direction: pick(direction, "direction"),
      opacity,
      fade,
      fadeSize,
      characters,
      interactive,
      cursorSize,
      cursorStrength,
      intro,
      paused,
    }
    wakeRef.current?.()
  })

  useEffect(() => {
    const container = containerRef.current
    if (!container) return undefined

    // ogl throws when no context can be created (jsdom, GPU-less browsers), so probe first with the
    // same attributes it will use. A second getContext() call then returns that same context.
    const canvas = document.createElement("canvas")
    if (!canvas.getContext("webgl2", CONTEXT_ATTRIBUTES)) return undefined
    const renderer = new Renderer({ canvas, ...CONTEXT_ATTRIBUTES })
    const gl = renderer.gl
    if (!renderer.isWebgl2) {
      gl.getExtension("WEBGL_lose_context")?.loseContext()
      return undefined
    }
    gl.clearColor(0, 0, 0, 0)
    canvas.style.display = "block"
    canvas.style.width = "100%"
    canvas.style.height = "100%"
    canvas.setAttribute("aria-hidden", "true")
    container.appendChild(canvas)

    const geometry = new Triangle(gl)
    const blank = new Texture(gl)
    const floatTargets = !!gl.getExtension("EXT_color_buffer_float")

    const dispose = (target: RenderTarget) => {
      gl.deleteFramebuffer(target.buffer)
      gl.deleteTexture(target.texture.texture)
    }

    const fieldTargetFor = (w: number, h: number) =>
      new RenderTarget(gl, { width: w, height: h, depth: false, minFilter: gl.NEAREST, magFilter: gl.NEAREST })

    const rippleTargetFor = (w: number, h: number) =>
      new RenderTarget(gl, {
        width: w,
        height: h,
        depth: false,
        type: (gl as unknown as WebGL2RenderingContext).HALF_FLOAT,
        format: gl.RGBA,
        internalFormat: (gl as unknown as WebGL2RenderingContext).RGBA16F,
        minFilter: gl.LINEAR,
        magFilter: gl.LINEAR,
      })

    let fieldTarget = fieldTargetFor(1, 1)
    let ripple: RippleField | null = null

    const atlasTexture = new Texture(gl, {
      generateMipmaps: true,
      minFilter: gl.LINEAR_MIPMAP_LINEAR,
      magFilter: gl.LINEAR,
      flipY: false,
    })

    const fieldUniforms = {
      uSize: { value: [1, 1] },
      uDpr: { value: 1 },
      uOrigin: { value: [0, 0] },
      uPitch: { value: [1, 1] },
      uWave: { value: 0 },
      uTime: { value: 0 },
      uUnit: { value: WAVE_UNIT },
      uHeading: { value: [1, 0] },
      uAmp: { value: 0 },
      uDepth: { value: 0.5 },
      uLight: { value: [0, 0, 1] },
      uShine: { value: 0.8 },
      uContrast: { value: 1 },
      uInk: { value: 0 },
      uOpacity: { value: 1 },
      uFade: { value: 0 },
      uFadeSize: { value: 0.5 },
      uAppear: { value: 0 },
      tRipple: { value: blank },
      uRipple: { value: 0 },
    }
    const fieldMesh = new Mesh(gl, {
      geometry,
      program: new Program(gl, {
        vertex: passVertex,
        fragment: fieldFragment,
        uniforms: fieldUniforms,
        depthTest: false,
        depthWrite: false,
      }),
    })

    const rippleUniforms = {
      tState: { value: blank },
      uTexel: { value: [1, 1] },
      uSize: { value: [1, 1] },
      uFrom: { value: [0, 0] },
      uTo: { value: [0, 0] },
      uRadius: { value: 40 },
      uImpulse: { value: 0 },
      uDamping: { value: 0.975 },
    }
    const rippleMesh = new Mesh(gl, {
      geometry,
      program: new Program(gl, {
        vertex: passVertex,
        fragment: rippleFragment,
        uniforms: rippleUniforms,
        depthTest: false,
        depthWrite: false,
      }),
    })

    const markUniforms = {
      tField: { value: fieldTarget.texture },
      tAtlas: { value: atlasTexture },
      uOrigin: { value: [0, 0] },
      uPitch: { value: [1, 1] },
      uGrid: { value: [1, 1] },
      uPattern: { value: 0 },
      uMarkSize: { value: 0.9 },
      uStroke: { value: 2 },
      uColor: { value: [1, 1, 1] },
      uAccent: { value: [1, 1, 1] },
      uBackground: { value: [0, 0, 0, 1] },
      uAtlas: { value: [1, 1, 0] },
    }
    const markMesh = new Mesh(gl, {
      geometry,
      program: new Program(gl, {
        vertex: passVertex,
        fragment: markFragment,
        uniforms: markUniforms,
        depthTest: false,
        depthWrite: false,
      }),
    })

    const reducedMotion = window.matchMedia?.("(prefers-reduced-motion: reduce)").matches ?? false

    let width = 1
    let height = 1
    let raf = 0
    let last = performance.now()
    let time = 0
    let introClock = 0
    let visible = true
    let alive = true
    let dirty = true
    let rippleUntil = 0
    let rippleLive = false
    let rippleClock = 0
    let atlasKey = ""
    const pointer = { x: 0, y: 0, inside: false, placed: false, lastX: 0, lastY: 0, burst: 0 }

    const buildRipple = () => {
      if (!floatTargets) return
      const w = clamp(Math.ceil(width / RIPPLE_CELL), 4, 512)
      const h = clamp(Math.ceil(height / RIPPLE_CELL), 4, 512)
      if (ripple && ripple.width === w && ripple.height === h) return
      if (ripple) {
        dispose(ripple.read)
        dispose(ripple.write)
      }
      ripple = { width: w, height: h, read: rippleTargetFor(w, h), write: rippleTargetFor(w, h) }
      rippleLive = false
    }

    const clearRipple = () => {
      if (!ripple) return
      ;[ripple.read, ripple.write].forEach((target) => {
        renderer.bindFramebuffer(target)
        gl.viewport(0, 0, target.width, target.height)
        gl.clear(gl.COLOR_BUFFER_BIT)
      })
      renderer.bindFramebuffer()
    }

    const refreshAtlas = (s: Settings) => {
      if (s.characters === atlasKey) return
      atlasKey = s.characters
      const built = buildAtlas(s.characters)
      if (!built) return
      atlasTexture.image = built.canvas
      markUniforms.uAtlas.value = [built.columns, built.lines, built.count]
    }

    const resize = () => {
      width = Math.max(1, container.clientWidth)
      height = Math.max(1, container.clientHeight)
      renderer.dpr = Math.min(window.devicePixelRatio || 1, 2, Math.sqrt(PIXEL_BUDGET / (width * height)))
      renderer.setSize(width, height)
      buildRipple()
      dirty = true
      start()
    }

    const stepRipple = (field: RippleField, s: Settings, dt: number) => {
      rippleClock = Math.min(rippleClock + dt * RIPPLE_RATE, 4)
      const strength = clamp(s.cursorStrength, 0, 1)
      const moved = Math.hypot(pointer.x - pointer.lastX, pointer.y - pointer.lastY)
      let impulse = (pointer.inside ? Math.min(moved / 14, 1) * 0.35 * strength : 0) + pointer.burst * strength
      pointer.burst = 0
      rippleUniforms.uTexel.value = [1 / field.width, 1 / field.height]
      rippleUniforms.uSize.value = [width, height]
      rippleUniforms.uFrom.value = [pointer.lastX, height - pointer.lastY]
      rippleUniforms.uTo.value = [pointer.x, height - pointer.y]
      rippleUniforms.uRadius.value = clamp(s.cursorSize, 8, 400)
      while (rippleClock >= 1) {
        rippleClock -= 1
        rippleUniforms.tState.value = field.read.texture
        rippleUniforms.uImpulse.value = impulse
        renderer.render({ scene: rippleMesh, target: field.write, clear: false })
        const next = field.read
        field.read = field.write
        field.write = next
        impulse = 0
      }
      pointer.lastX = pointer.x
      pointer.lastY = pointer.y
    }

    const frame = (now: number) => {
      raf = 0
      if (!alive) return
      const s = settingsRef.current
      const dt = Math.min(0.05, Math.max(1 / 240, (now - last) / 1000))
      last = now
      if (!s) return

      const moving = !s.paused && !reducedMotion && s.speed !== 0
      if (moving) time += dt * s.speed
      introClock = s.intro && !reducedMotion ? Math.min(1, introClock + dt / INTRO_SECONDS) : 1
      const appear = 1 - Math.pow(1 - clamp(introClock / 0.75, 0, 1), 3)
      const rise = clamp((introClock - 0.1) / 0.9, 0, 1)
      const amp = rise * rise * (3 - 2 * rise)

      const rippling = s.interactive && !reducedMotion && !!ripple && s.cursorStrength > 0
      if (rippling && pointer.inside && !pointer.placed) {
        pointer.lastX = pointer.x
        pointer.lastY = pointer.y
        pointer.placed = true
      }
      if (rippling && (pointer.inside || pointer.burst > 0)) rippleUntil = now + 5000
      const rippleActive = rippling && now < rippleUntil
      if (rippleActive && ripple) {
        stepRipple(ripple, s, dt)
        rippleLive = true
      } else if (rippleLive) {
        clearRipple()
        rippleLive = false
      }

      const patternIndex = PATTERNS[s.pattern] ?? 0
      if (patternIndex === 4) refreshAtlas(s)

      const canvasW = gl.canvas.width
      const canvasH = gl.canvas.height
      const dpr = canvasW / width
      const pitchY = Math.max(4, Math.round(clamp(s.spacing, 4, 120) * dpr))
      const pitchX = patternIndex === 3 ? Math.max(2, Math.round(pitchY / 4)) : pitchY
      const cols = Math.min(4096, Math.ceil(canvasW / pitchX) + 1)
      const rows = Math.min(4096, Math.ceil(canvasH / pitchY) + 2)
      const origin = [Math.floor((canvasW - cols * pitchX) / 2), Math.floor((canvasH - rows * pitchY) / 2)]
      if (fieldTarget.width !== cols || fieldTarget.height !== rows) {
        dispose(fieldTarget)
        fieldTarget = fieldTargetFor(cols, rows)
        markUniforms.tField.value = fieldTarget.texture
      }
      const heading = (s.direction * Math.PI) / 180
      const lightAngle = ((s.direction + 180 + clamp(s.light, -90, 90)) * Math.PI) / 180
      const background = s.background
      const ink = background[3] > 0.02 ? luminance(s.color) < luminance(background) : luminance(s.color) < 0.5

      fieldUniforms.uSize.value = [width, height]
      fieldUniforms.uDpr.value = dpr
      fieldUniforms.uOrigin.value = origin
      fieldUniforms.uPitch.value = [pitchX, pitchY]
      fieldUniforms.uWave.value = WAVES[s.wave] ?? 0
      fieldUniforms.uTime.value = time
      fieldUniforms.uUnit.value = WAVE_UNIT * clamp(s.scale, 0.2, 5)
      fieldUniforms.uHeading.value = [Math.cos(heading), Math.sin(heading)]
      fieldUniforms.uAmp.value = amp
      fieldUniforms.uDepth.value = clamp(s.depth, 0, 1.5)
      fieldUniforms.uLight.value = [Math.cos(lightAngle) * 0.78, Math.sin(lightAngle) * 0.78, 0.62]
      fieldUniforms.uShine.value = clamp(s.shine, 0, 2)
      fieldUniforms.uContrast.value = clamp(s.contrast, 0.3, 3)
      fieldUniforms.uInk.value = ink ? 1 : 0
      fieldUniforms.uOpacity.value = clamp(s.opacity, 0, 1)
      fieldUniforms.uFade.value = FADES[s.fade] ?? 0
      fieldUniforms.uFadeSize.value = clamp(s.fadeSize, 0.05, 1)
      fieldUniforms.uAppear.value = appear
      fieldUniforms.tRipple.value = ripple && rippleLive ? ripple.read.texture : blank
      fieldUniforms.uRipple.value = rippleLive ? 0.32 : 0
      renderer.render({ scene: fieldMesh, target: fieldTarget })

      markUniforms.uOrigin.value = origin
      markUniforms.uPitch.value = [pitchX, pitchY]
      markUniforms.uGrid.value = [cols, rows]
      markUniforms.uPattern.value = patternIndex
      markUniforms.uMarkSize.value = clamp(s.markSize, 0.05, 1)
      markUniforms.uStroke.value = patternIndex === 3 ? 0.9 * dpr : Math.max(1.1 * dpr, pitchY * 0.08)
      const tint = ink ? 0 : 1
      const blend = ink ? 0.35 : 0.55
      markUniforms.uColor.value = s.color.slice(0, 3)
      markUniforms.uAccent.value = s.color.slice(0, 3).map((channel) => channel + (tint - channel) * blend)
      markUniforms.uBackground.value = background
      renderer.render({ scene: markMesh })
      dirty = false

      if (visible && (moving || introClock < 1 || rippleActive || dirty)) raf = requestAnimationFrame(frame)
    }

    const start = () => {
      if (raf || !visible || !alive) return
      last = performance.now()
      raf = requestAnimationFrame(frame)
    }

    const locate = (e: PointerEvent) => {
      const rect = container.getBoundingClientRect()
      const x = e.clientX - rect.left
      const y = e.clientY - rect.top
      return { x, y, inside: x >= 0 && y >= 0 && x <= rect.width && y <= rect.height }
    }

    const onPointerMove = (e: PointerEvent) => {
      const spot = locate(e)
      pointer.x = spot.x
      pointer.y = spot.y
      if (spot.inside !== pointer.inside) pointer.placed = false
      pointer.inside = spot.inside
      if (spot.inside) start()
    }

    const onPointerDown = (e: PointerEvent) => {
      const spot = locate(e)
      if (!spot.inside) return
      pointer.x = spot.x
      pointer.y = spot.y
      if (!pointer.inside) {
        pointer.lastX = spot.x
        pointer.lastY = spot.y
      }
      pointer.burst = 1.2
      start()
    }

    const onPointerLeave = () => {
      pointer.inside = false
      pointer.placed = false
      start()
    }

    const onPointerOut = (e: PointerEvent) => {
      if (!e.relatedTarget) onPointerLeave()
    }

    const onPointerUp = (e: PointerEvent) => {
      if (e.pointerType === "touch") onPointerLeave()
    }

    const onVisibility = () => {
      if (!document.hidden) start()
    }

    window.addEventListener("pointermove", onPointerMove, { passive: true })
    window.addEventListener("pointerdown", onPointerDown, { passive: true })
    window.addEventListener("pointerout", onPointerOut, { passive: true })
    window.addEventListener("pointerup", onPointerUp, { passive: true })
    window.addEventListener("blur", onPointerLeave)
    document.addEventListener("visibilitychange", onVisibility)

    const resizeObserver = new ResizeObserver(resize)
    resizeObserver.observe(container)
    const intersectionObserver = new IntersectionObserver(([entry]) => {
      visible = entry.isIntersecting
      start()
    })
    intersectionObserver.observe(container)

    wakeRef.current = () => {
      dirty = true
      start()
    }
    resize()

    return () => {
      alive = false
      visible = false
      cancelAnimationFrame(raf)
      resizeObserver.disconnect()
      intersectionObserver.disconnect()
      window.removeEventListener("pointermove", onPointerMove)
      window.removeEventListener("pointerdown", onPointerDown)
      window.removeEventListener("pointerout", onPointerOut)
      window.removeEventListener("pointerup", onPointerUp)
      window.removeEventListener("blur", onPointerLeave)
      document.removeEventListener("visibilitychange", onVisibility)
      wakeRef.current = null
      if (ripple) {
        dispose(ripple.read)
        dispose(ripple.write)
      }
      dispose(fieldTarget)
      gl.deleteTexture(atlasTexture.texture)
      gl.getExtension("WEBGL_lose_context")?.loseContext()
      if (canvas.parentNode) canvas.parentNode.removeChild(canvas)
    }
  }, [])

  return (
    <div
      ref={containerRef}
      data-slot="pattern-waves"
      className={cn("relative h-full w-full overflow-hidden", className)}
      style={style}
      {...rest}
    />
  )
}