{"name":"SplashCursor","title":"SplashCursor","description":"Liquid splash burst at cursor with curling ripples and waves.","type":"registry:component","add":"when-added","files":[{"type":"registry:component","role":"file","content":"<template>\n  <div class=\"fixed top-0 left-0 z-50 pointer-events-none w-full h-full\">\n    <canvas ref=\"canvasRef\" id=\"fluid\" class=\"w-screen h-screen block\"></canvas>\n  </div>\n</template>\n\n<script setup lang=\"ts\">\nimport { onMounted, withDefaults, useTemplateRef } from 'vue';\n\n/* ---------- types ---------- */\ninterface ColorRGB {\n  r: number;\n  g: number;\n  b: number;\n}\n\ninterface SplashCursorProps {\n  SIM_RESOLUTION?: number;\n  DYE_RESOLUTION?: number;\n  CAPTURE_RESOLUTION?: number;\n  DENSITY_DISSIPATION?: number;\n  VELOCITY_DISSIPATION?: number;\n  PRESSURE?: number;\n  PRESSURE_ITERATIONS?: number;\n  CURL?: number;\n  SPLAT_RADIUS?: number;\n  SPLAT_FORCE?: number;\n  SHADING?: boolean;\n  COLOR_UPDATE_SPEED?: number;\n  BACK_COLOR?: ColorRGB;\n  TRANSPARENT?: boolean;\n}\n\n/* ---------- props & defaults ---------- */\nconst props = withDefaults(defineProps<SplashCursorProps>(), {\n  SIM_RESOLUTION: 128,\n  DYE_RESOLUTION: 1440,\n  CAPTURE_RESOLUTION: 512,\n  DENSITY_DISSIPATION: 3.5,\n  VELOCITY_DISSIPATION: 2,\n  PRESSURE: 0.1,\n  PRESSURE_ITERATIONS: 20,\n  CURL: 3,\n  SPLAT_RADIUS: 0.2,\n  SPLAT_FORCE: 6000,\n  SHADING: true,\n  COLOR_UPDATE_SPEED: 10,\n  BACK_COLOR: () => ({ r: 0.5, g: 0, b: 0 }),\n  TRANSPARENT: true\n});\n\n/* ---------- refs ---------- */\nconst canvasRef = useTemplateRef<HTMLCanvasElement>('canvasRef');\n\n/* ---------- helper types ---------- */\ninterface Pointer {\n  id: number;\n  texcoordX: number;\n  texcoordY: number;\n  prevTexcoordX: number;\n  prevTexcoordY: number;\n  deltaX: number;\n  deltaY: number;\n  down: boolean;\n  moved: boolean;\n  color: ColorRGB;\n}\n\nfunction pointerPrototype(): Pointer {\n  return {\n    id: -1,\n    texcoordX: 0,\n    texcoordY: 0,\n    prevTexcoordX: 0,\n    prevTexcoordY: 0,\n    deltaX: 0,\n    deltaY: 0,\n    down: false,\n    moved: false,\n    color: { r: 0, g: 0, b: 0 }\n  };\n}\n\n/* ---------- main logic ---------- */\nonMounted(() => {\n  const canvas = canvasRef.value;\n  if (!canvas) return;\n\n  const pointers: Pointer[] = [pointerPrototype()];\n\n  const config = {\n    SIM_RESOLUTION: props.SIM_RESOLUTION!,\n    DYE_RESOLUTION: props.DYE_RESOLUTION!,\n    CAPTURE_RESOLUTION: props.CAPTURE_RESOLUTION!,\n    DENSITY_DISSIPATION: props.DENSITY_DISSIPATION!,\n    VELOCITY_DISSIPATION: props.VELOCITY_DISSIPATION!,\n    PRESSURE: props.PRESSURE!,\n    PRESSURE_ITERATIONS: props.PRESSURE_ITERATIONS!,\n    CURL: props.CURL!,\n    SPLAT_RADIUS: props.SPLAT_RADIUS!,\n    SPLAT_FORCE: props.SPLAT_FORCE!,\n    SHADING: props.SHADING,\n    COLOR_UPDATE_SPEED: props.COLOR_UPDATE_SPEED!,\n    PAUSED: false,\n    BACK_COLOR: props.BACK_COLOR,\n    TRANSPARENT: props.TRANSPARENT\n  };\n\n  /* ---------- WebGL context helpers ---------- */\n  const { gl, ext } = getWebGLContext(canvas);\n  if (!gl || !ext) return;\n\n  if (!ext.supportLinearFiltering) {\n    config.DYE_RESOLUTION = 256;\n    config.SHADING = false;\n  }\n\n  function getWebGLContext(canvasEl: HTMLCanvasElement) {\n    const params = {\n      alpha: true,\n      depth: false,\n      stencil: false,\n      antialias: false,\n      preserveDrawingBuffer: false\n    };\n\n    let gl = canvasEl.getContext('webgl2', params) as WebGL2RenderingContext | null;\n\n    if (!gl) {\n      gl = (canvasEl.getContext('webgl', params) ||\n        canvasEl.getContext('experimental-webgl', params)) as WebGL2RenderingContext | null;\n    }\n\n    if (!gl) {\n      throw new Error('Unable to initialize WebGL.');\n    }\n\n    const isWebGL2 = 'drawBuffers' in gl;\n\n    let supportLinearFiltering = false;\n    let halfFloat: OES_texture_half_float | null = null;\n\n    if (isWebGL2) {\n      (gl as WebGL2RenderingContext).getExtension('EXT_color_buffer_float');\n      supportLinearFiltering = !!(gl as WebGL2RenderingContext).getExtension('OES_texture_float_linear');\n    } else {\n      halfFloat = gl.getExtension('OES_texture_half_float');\n      supportLinearFiltering = !!gl.getExtension('OES_texture_half_float_linear');\n    }\n\n    gl.clearColor(0, 0, 0, 1);\n\n    const halfFloatTexType = isWebGL2\n      ? (gl as WebGL2RenderingContext).HALF_FLOAT\n      : (halfFloat && (halfFloat as OES_texture_half_float).HALF_FLOAT_OES) || 0;\n\n    let formatRGBA: { internalFormat: number; format: number } | null;\n    let formatRG: { internalFormat: number; format: number } | null;\n    let formatR: { internalFormat: number; format: number } | null;\n\n    if (isWebGL2) {\n      formatRGBA = getSupportedFormat(gl, (gl as WebGL2RenderingContext).RGBA16F, gl.RGBA, halfFloatTexType);\n      formatRG = getSupportedFormat(\n        gl,\n        (gl as WebGL2RenderingContext).RG16F,\n        (gl as WebGL2RenderingContext).RG,\n        halfFloatTexType\n      );\n      formatR = getSupportedFormat(\n        gl,\n        (gl as WebGL2RenderingContext).R16F,\n        (gl as WebGL2RenderingContext).RED,\n        halfFloatTexType\n      );\n    } else {\n      formatRGBA = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);\n      formatRG = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);\n      formatR = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);\n    }\n\n    return {\n      gl,\n      ext: {\n        formatRGBA,\n        formatRG,\n        formatR,\n        halfFloatTexType,\n        supportLinearFiltering\n      }\n    };\n  }\n\n  function getSupportedFormat(\n    gl: WebGLRenderingContext | WebGL2RenderingContext,\n    internalFormat: number,\n    format: number,\n    type: number\n  ): { internalFormat: number; format: number } | null {\n    if (!supportRenderTextureFormat(gl, internalFormat, format, type)) {\n      if ('drawBuffers' in gl) {\n        const gl2 = gl as WebGL2RenderingContext;\n        switch (internalFormat) {\n          case gl2.R16F:\n            return getSupportedFormat(gl2, gl2.RG16F, gl2.RG, type);\n          case gl2.RG16F:\n            return getSupportedFormat(gl2, gl2.RGBA16F, gl2.RGBA, type);\n          default:\n            return null;\n        }\n      }\n      return null;\n    }\n    return { internalFormat, format };\n  }\n\n  function supportRenderTextureFormat(\n    gl: WebGLRenderingContext | WebGL2RenderingContext,\n    internalFormat: number,\n    format: number,\n    type: number\n  ) {\n    const texture = gl.createTexture();\n    if (!texture) return false;\n\n    gl.bindTexture(gl.TEXTURE_2D, texture);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);\n    gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, 4, 4, 0, format, type, null);\n\n    const fbo = gl.createFramebuffer();\n    if (!fbo) return false;\n\n    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);\n    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);\n    const status = gl.checkFramebufferStatus(gl.FRAMEBUFFER);\n    return status === gl.FRAMEBUFFER_COMPLETE;\n  }\n\n  function hashCode(s: string) {\n    if (!s.length) return 0;\n    let hash = 0;\n    for (let i = 0; i < s.length; i++) {\n      hash = (hash << 5) - hash + s.charCodeAt(i);\n      hash |= 0;\n    }\n    return hash;\n  }\n\n  function addKeywords(source: string, keywords: string[] | null) {\n    if (!keywords) return source;\n    let keywordsString = '';\n    for (const keyword of keywords) {\n      keywordsString += `#define ${keyword}\\n`;\n    }\n    return keywordsString + source;\n  }\n\n  function compileShader(type: number, source: string, keywords: string[] | null = null): WebGLShader | null {\n    const shaderSource = addKeywords(source, keywords);\n    const shader = gl.createShader(type);\n    if (!shader) return null;\n    gl.shaderSource(shader, shaderSource);\n    gl.compileShader(shader);\n    if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {\n      console.trace(gl.getShaderInfoLog(shader));\n    }\n    return shader;\n  }\n\n  function createProgram(vertexShader: WebGLShader | null, fragmentShader: WebGLShader | null): WebGLProgram | null {\n    if (!vertexShader || !fragmentShader) return null;\n    const program = gl.createProgram();\n    if (!program) return null;\n    gl.attachShader(program, vertexShader);\n    gl.attachShader(program, fragmentShader);\n    gl.linkProgram(program);\n    if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {\n      console.trace(gl.getProgramInfoLog(program));\n    }\n    return program;\n  }\n\n  function getUniforms(program: WebGLProgram) {\n    const uniforms: Record<string, WebGLUniformLocation | null> = {};\n    const uniformCount = gl.getProgramParameter(program, gl.ACTIVE_UNIFORMS);\n    for (let i = 0; i < uniformCount; i++) {\n      const uniformInfo = gl.getActiveUniform(program, i);\n      if (uniformInfo) {\n        uniforms[uniformInfo.name] = gl.getUniformLocation(program, uniformInfo.name);\n      }\n    }\n    return uniforms;\n  }\n\n  class Program {\n    program: WebGLProgram | null;\n    uniforms: Record<string, WebGLUniformLocation | null>;\n\n    constructor(vertexShader: WebGLShader | null, fragmentShader: WebGLShader | null) {\n      this.program = createProgram(vertexShader, fragmentShader);\n      this.uniforms = this.program ? getUniforms(this.program) : {};\n    }\n\n    bind() {\n      if (this.program) gl.useProgram(this.program);\n    }\n  }\n\n  class Material {\n    vertexShader: WebGLShader | null;\n    fragmentShaderSource: string;\n    programs: Record<number, WebGLProgram | null>;\n    activeProgram: WebGLProgram | null;\n    uniforms: Record<string, WebGLUniformLocation | null>;\n\n    constructor(vertexShader: WebGLShader | null, fragmentShaderSource: string) {\n      this.vertexShader = vertexShader;\n      this.fragmentShaderSource = fragmentShaderSource;\n      this.programs = {};\n      this.activeProgram = null;\n      this.uniforms = {};\n    }\n\n    setKeywords(keywords: string[]) {\n      let hash = 0;\n      for (const kw of keywords) {\n        hash += hashCode(kw);\n      }\n      let program = this.programs[hash];\n      if (program == null) {\n        const fragmentShader = compileShader(gl.FRAGMENT_SHADER, this.fragmentShaderSource, keywords);\n        program = createProgram(this.vertexShader, fragmentShader);\n        this.programs[hash] = program;\n      }\n      if (program === this.activeProgram) return;\n      if (program) {\n        this.uniforms = getUniforms(program);\n      }\n      this.activeProgram = program;\n    }\n\n    bind() {\n      if (this.activeProgram) {\n        gl.useProgram(this.activeProgram);\n      }\n    }\n  }\n\n  /* ---------- shaders ---------- */\n  const baseVertexShader = compileShader(\n    gl.VERTEX_SHADER,\n    `\n      precision highp float;\n      attribute vec2 aPosition;\n      varying vec2 vUv;\n      varying vec2 vL;\n      varying vec2 vR;\n      varying vec2 vT;\n      varying vec2 vB;\n      uniform vec2 texelSize;\n      void main () {\n        vUv = aPosition * 0.5 + 0.5;\n        vL = vUv - vec2(texelSize.x, 0.0);\n        vR = vUv + vec2(texelSize.x, 0.0);\n        vT = vUv + vec2(0.0, texelSize.y);\n        vB = vUv - vec2(0.0, texelSize.y);\n        gl_Position = vec4(aPosition, 0.0, 1.0);\n      }\n    `\n  );\n\n  const copyShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      uniform sampler2D uTexture;\n      void main () {\n        gl_FragColor = texture2D(uTexture, vUv);\n      }\n    `\n  );\n\n  const clearShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      uniform sampler2D uTexture;\n      uniform float value;\n      void main () {\n        gl_FragColor = value * texture2D(uTexture, vUv);\n      }\n    `\n  );\n\n  const displayShaderSource = `\n      precision highp float;\n      precision highp sampler2D;\n      varying vec2 vUv;\n      varying vec2 vL;\n      varying vec2 vR;\n      varying vec2 vT;\n      varying vec2 vB;\n      uniform sampler2D uTexture;\n      uniform sampler2D uDithering;\n      uniform vec2 ditherScale;\n      uniform vec2 texelSize;\n      vec3 linearToGamma (vec3 color) {\n          color = max(color, vec3(0));\n          return max(1.055 * pow(color, vec3(0.416666667)) - 0.055, vec3(0));\n      }\n      void main () {\n          vec3 c = texture2D(uTexture, vUv).rgb;\n          #ifdef SHADING\n              vec3 lc = texture2D(uTexture, vL).rgb;\n              vec3 rc = texture2D(uTexture, vR).rgb;\n              vec3 tc = texture2D(uTexture, vT).rgb;\n              vec3 bc = texture2D(uTexture, vB).rgb;\n              float dx = length(rc) - length(lc);\n              float dy = length(tc) - length(bc);\n              vec3 n = normalize(vec3(dx, dy, length(texelSize)));\n              vec3 l = vec3(0.0, 0.0, 1.0);\n              float diffuse = clamp(dot(n, l) + 0.7, 0.7, 1.0);\n              c *= diffuse;\n          #endif\n          float a = max(c.r, max(c.g, c.b));\n          gl_FragColor = vec4(c, a);\n      }\n    `;\n\n  const splatShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision highp float;\n      precision highp sampler2D;\n      varying vec2 vUv;\n      uniform sampler2D uTarget;\n      uniform float aspectRatio;\n      uniform vec3 color;\n      uniform vec2 point;\n      uniform float radius;\n      void main () {\n          vec2 p = vUv - point.xy;\n          p.x *= aspectRatio;\n          vec3 splat = exp(-dot(p, p) / radius) * color;\n          vec3 base = texture2D(uTarget, vUv).xyz;\n          gl_FragColor = vec4(base + splat, 1.0);\n      }\n    `\n  );\n\n  const advectionShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision highp float;\n      precision highp sampler2D;\n      varying vec2 vUv;\n      uniform sampler2D uVelocity;\n      uniform sampler2D uSource;\n      uniform vec2 texelSize;\n      uniform vec2 dyeTexelSize;\n      uniform float dt;\n      uniform float dissipation;\n      vec4 bilerp (sampler2D sam, vec2 uv, vec2 tsize) {\n          vec2 st = uv / tsize - 0.5;\n          vec2 iuv = floor(st);\n          vec2 fuv = fract(st);\n          vec4 a = texture2D(sam, (iuv + vec2(0.5, 0.5)) * tsize);\n          vec4 b = texture2D(sam, (iuv + vec2(1.5, 0.5)) * tsize);\n          vec4 c = texture2D(sam, (iuv + vec2(0.5, 1.5)) * tsize);\n          vec4 d = texture2D(sam, (iuv + vec2(1.5, 1.5)) * tsize);\n          return mix(mix(a, b, fuv.x), mix(c, d, fuv.x), fuv.y);\n      }\n      void main () {\n          #ifdef MANUAL_FILTERING\n              vec2 coord = vUv - dt * bilerp(uVelocity, vUv, texelSize).xy * texelSize;\n              vec4 result = bilerp(uSource, coord, dyeTexelSize);\n          #else\n              vec2 coord = vUv - dt * texture2D(uVelocity, vUv).xy * texelSize;\n              vec4 result = texture2D(uSource, coord);\n          #endif\n          float decay = 1.0 + dissipation * dt;\n          gl_FragColor = result / decay;\n      }\n    `,\n    ext.supportLinearFiltering ? null : ['MANUAL_FILTERING']\n  );\n\n  const divergenceShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      varying highp vec2 vL;\n      varying highp vec2 vR;\n      varying highp vec2 vT;\n      varying highp vec2 vB;\n      uniform sampler2D uVelocity;\n      void main () {\n          float L = texture2D(uVelocity, vL).x;\n          float R = texture2D(uVelocity, vR).x;\n          float T = texture2D(uVelocity, vT).y;\n          float B = texture2D(uVelocity, vB).y;\n          vec2 C = texture2D(uVelocity, vUv).xy;\n          if (vL.x < 0.0) { L = -C.x; }\n          if (vR.x > 1.0) { R = -C.x; }\n          if (vT.y > 1.0) { T = -C.y; }\n          if (vB.y < 0.0) { B = -C.y; }\n          float div = 0.5 * (R - L + T - B);\n          gl_FragColor = vec4(div, 0.0, 0.0, 1.0);\n      }\n    `\n  );\n\n  const curlShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      varying highp vec2 vL;\n      varying highp vec2 vR;\n      varying highp vec2 vT;\n      varying highp vec2 vB;\n      uniform sampler2D uVelocity;\n      void main () {\n          float L = texture2D(uVelocity, vL).y;\n          float R = texture2D(uVelocity, vR).y;\n          float T = texture2D(uVelocity, vT).x;\n          float B = texture2D(uVelocity, vB).x;\n          float vorticity = R - L - T + B;\n          gl_FragColor = vec4(0.5 * vorticity, 0.0, 0.0, 1.0);\n      }\n    `\n  );\n\n  const vorticityShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision highp float;\n      precision highp sampler2D;\n      varying vec2 vUv;\n      varying vec2 vL;\n      varying vec2 vR;\n      varying vec2 vT;\n      varying vec2 vB;\n      uniform sampler2D uVelocity;\n      uniform sampler2D uCurl;\n      uniform float curl;\n      uniform float dt;\n      void main () {\n          float L = texture2D(uCurl, vL).x;\n          float R = texture2D(uCurl, vR).x;\n          float T = texture2D(uCurl, vT).x;\n          float B = texture2D(uCurl, vB).x;\n          float C = texture2D(uCurl, vUv).x;\n          vec2 force = 0.5 * vec2(abs(T) - abs(B), abs(R) - abs(L));\n          force /= length(force) + 0.0001;\n          force *= curl * C;\n          force.y *= -1.0;\n          vec2 velocity = texture2D(uVelocity, vUv).xy;\n          velocity += force * dt;\n          velocity = min(max(velocity, -1000.0), 1000.0);\n          gl_FragColor = vec4(velocity, 0.0, 1.0);\n      }\n    `\n  );\n\n  const pressureShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      varying highp vec2 vL;\n      varying highp vec2 vR;\n      varying highp vec2 vT;\n      varying highp vec2 vB;\n      uniform sampler2D uPressure;\n      uniform sampler2D uDivergence;\n      void main () {\n          float L = texture2D(uPressure, vL).x;\n          float R = texture2D(uPressure, vR).x;\n          float T = texture2D(uPressure, vT).x;\n          float B = texture2D(uPressure, vB).x;\n          float C = texture2D(uPressure, vUv).x;\n          float divergence = texture2D(uDivergence, vUv).x;\n          float pressure = (L + R + B + T - divergence) * 0.25;\n          gl_FragColor = vec4(pressure, 0.0, 0.0, 1.0);\n      }\n    `\n  );\n\n  const gradientSubtractShader = compileShader(\n    gl.FRAGMENT_SHADER,\n    `\n      precision mediump float;\n      precision mediump sampler2D;\n      varying highp vec2 vUv;\n      varying highp vec2 vL;\n      varying highp vec2 vR;\n      varying highp vec2 vT;\n      varying highp vec2 vB;\n      uniform sampler2D uPressure;\n      uniform sampler2D uVelocity;\n      void main () {\n          float L = texture2D(uPressure, vL).x;\n          float R = texture2D(uPressure, vR).x;\n          float T = texture2D(uPressure, vT).x;\n          float B = texture2D(uPressure, vB).x;\n          vec2 velocity = texture2D(uVelocity, vUv).xy;\n          velocity.xy -= vec2(R - L, T - B);\n          gl_FragColor = vec4(velocity, 0.0, 1.0);\n      }\n    `\n  );\n\n  /* ---------- geometry helper ---------- */\n  const blit = (() => {\n    const buffer = gl.createBuffer()!;\n    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);\n    gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, -1, 1, 1, 1, 1, -1]), gl.STATIC_DRAW);\n    const elemBuffer = gl.createBuffer()!;\n    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elemBuffer);\n    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([0, 1, 2, 0, 2, 3]), gl.STATIC_DRAW);\n    gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);\n    gl.enableVertexAttribArray(0);\n    return (target: FBO | null, doClear = false) => {\n      if (!gl) return;\n      if (!target) {\n        gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);\n        gl.bindFramebuffer(gl.FRAMEBUFFER, null);\n      } else {\n        gl.viewport(0, 0, target.width, target.height);\n        gl.bindFramebuffer(gl.FRAMEBUFFER, target.fbo);\n      }\n      if (doClear) {\n        gl.clearColor(0, 0, 0, 1);\n        gl.clear(gl.COLOR_BUFFER_BIT);\n      }\n      gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0);\n    };\n  })();\n\n  /* ---------- frame-buffer object helpers ---------- */\n  interface FBO {\n    texture: WebGLTexture;\n    fbo: WebGLFramebuffer;\n    width: number;\n    height: number;\n    texelSizeX: number;\n    texelSizeY: number;\n    attach: (id: number) => number;\n  }\n\n  interface DoubleFBO {\n    width: number;\n    height: number;\n    texelSizeX: number;\n    texelSizeY: number;\n    read: FBO;\n    write: FBO;\n    swap: () => void;\n  }\n\n  let dye: DoubleFBO;\n  let velocity: DoubleFBO;\n  let divergence: FBO;\n  let curl: FBO;\n  let pressure: DoubleFBO;\n\n  const copyProgram = new Program(baseVertexShader, copyShader);\n  const clearProgram = new Program(baseVertexShader, clearShader);\n  const splatProgram = new Program(baseVertexShader, splatShader);\n  const advectionProgram = new Program(baseVertexShader, advectionShader);\n  const divergenceProgram = new Program(baseVertexShader, divergenceShader);\n  const curlProgram = new Program(baseVertexShader, curlShader);\n  const vorticityProgram = new Program(baseVertexShader, vorticityShader);\n  const pressureProgram = new Program(baseVertexShader, pressureShader);\n  const gradienSubtractProgram = new Program(baseVertexShader, gradientSubtractShader);\n  const displayMaterial = new Material(baseVertexShader, displayShaderSource);\n\n  function createFBO(w: number, h: number, internalFormat: number, format: number, type: number, param: number): FBO {\n    gl.activeTexture(gl.TEXTURE0);\n    const texture = gl.createTexture()!;\n    gl.bindTexture(gl.TEXTURE_2D, texture);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, param);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, param);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);\n    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);\n    gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, w, h, 0, format, type, null);\n    const fbo = gl.createFramebuffer()!;\n    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);\n    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);\n    gl.viewport(0, 0, w, h);\n    gl.clear(gl.COLOR_BUFFER_BIT);\n    const texelSizeX = 1 / w;\n    const texelSizeY = 1 / h;\n    return {\n      texture,\n      fbo,\n      width: w,\n      height: h,\n      texelSizeX,\n      texelSizeY,\n      attach(id: number) {\n        gl.activeTexture(gl.TEXTURE0 + id);\n        gl.bindTexture(gl.TEXTURE_2D, texture);\n        return id;\n      }\n    };\n  }\n\n  function createDoubleFBO(\n    w: number,\n    h: number,\n    internalFormat: number,\n    format: number,\n    type: number,\n    param: number\n  ): DoubleFBO {\n    const fbo1 = createFBO(w, h, internalFormat, format, type, param);\n    const fbo2 = createFBO(w, h, internalFormat, format, type, param);\n    return {\n      width: w,\n      height: h,\n      texelSizeX: fbo1.texelSizeX,\n      texelSizeY: fbo1.texelSizeY,\n      read: fbo1,\n      write: fbo2,\n      swap() {\n        const tmp = this.read;\n        this.read = this.write;\n        this.write = tmp;\n      }\n    };\n  }\n\n  function resizeFBO(\n    target: FBO,\n    w: number,\n    h: number,\n    internalFormat: number,\n    format: number,\n    type: number,\n    param: number\n  ) {\n    const newFBO = createFBO(w, h, internalFormat, format, type, param);\n    copyProgram.bind();\n    if (copyProgram.uniforms.uTexture) gl.uniform1i(copyProgram.uniforms.uTexture, target.attach(0));\n    blit(newFBO, false);\n    return newFBO;\n  }\n\n  function resizeDoubleFBO(\n    target: DoubleFBO,\n    w: number,\n    h: number,\n    internalFormat: number,\n    format: number,\n    type: number,\n    param: number\n  ) {\n    if (target.width === w && target.height === h) return target;\n    target.read = resizeFBO(target.read, w, h, internalFormat, format, type, param);\n    target.write = createFBO(w, h, internalFormat, format, type, param);\n    target.width = w;\n    target.height = h;\n    target.texelSizeX = 1 / w;\n    target.texelSizeY = 1 / h;\n    return target;\n  }\n\n  function initFramebuffers() {\n    const simRes = getResolution(config.SIM_RESOLUTION!);\n    const dyeRes = getResolution(config.DYE_RESOLUTION!);\n    const texType = ext.halfFloatTexType;\n    const rgba = ext.formatRGBA;\n    const rg = ext.formatRG;\n    const r = ext.formatR;\n    const filtering = ext.supportLinearFiltering ? gl.LINEAR : gl.NEAREST;\n    gl.disable(gl.BLEND);\n\n    if (!rgba) return;\n\n    if (!dye) {\n      dye = createDoubleFBO(dyeRes.width, dyeRes.height, rgba.internalFormat, rgba.format, texType, filtering);\n    } else {\n      dye = resizeDoubleFBO(dye, dyeRes.width, dyeRes.height, rgba.internalFormat, rgba.format, texType, filtering);\n    }\n\n    if (!rg) return;\n\n    if (!velocity) {\n      velocity = createDoubleFBO(simRes.width, simRes.height, rg.internalFormat, rg.format, texType, filtering);\n    } else {\n      velocity = resizeDoubleFBO(\n        velocity,\n        simRes.width,\n        simRes.height,\n        rg.internalFormat,\n        rg.format,\n        texType,\n        filtering\n      );\n    }\n\n    if (!r) return;\n\n    divergence = createFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);\n    curl = createFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);\n    pressure = createDoubleFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);\n  }\n\n  function updateKeywords() {\n    const displayKeywords: string[] = [];\n    if (config.SHADING) displayKeywords.push('SHADING');\n    displayMaterial.setKeywords(displayKeywords);\n  }\n\n  function getResolution(resolution: number) {\n    const w = gl.drawingBufferWidth;\n    const h = gl.drawingBufferHeight;\n    const aspectRatio = w / h;\n    const aspect = aspectRatio < 1 ? 1 / aspectRatio : aspectRatio;\n    const min = Math.round(resolution);\n    const max = Math.round(resolution * aspect);\n    if (w > h) {\n      return { width: max, height: min };\n    }\n    return { width: min, height: max };\n  }\n\n  function scaleByPixelRatio(input: number) {\n    const pixelRatio = window.devicePixelRatio || 1;\n    return Math.floor(input * pixelRatio);\n  }\n\n  updateKeywords();\n  initFramebuffers();\n\n  let lastUpdateTime = Date.now();\n  let colorUpdateTimer = 0.0;\n\n  function updateFrame() {\n    const dt = calcDeltaTime();\n    if (resizeCanvas()) initFramebuffers();\n    updateColors(dt);\n    applyInputs();\n    step(dt);\n    render(null);\n    requestAnimationFrame(updateFrame);\n  }\n\n  function calcDeltaTime() {\n    const now = Date.now();\n    let dt = (now - lastUpdateTime) / 1000;\n    dt = Math.min(dt, 0.016666);\n    lastUpdateTime = now;\n    return dt;\n  }\n\n  function resizeCanvas() {\n    const width = scaleByPixelRatio(canvas!.clientWidth);\n    const height = scaleByPixelRatio(canvas!.clientHeight);\n    if (canvas!.width !== width || canvas!.height !== height) {\n      canvas!.width = width;\n      canvas!.height = height;\n      return true;\n    }\n    return false;\n  }\n\n  function updateColors(dt: number) {\n    colorUpdateTimer += dt * config.COLOR_UPDATE_SPEED;\n    if (colorUpdateTimer >= 1) {\n      colorUpdateTimer = wrap(colorUpdateTimer, 0, 1);\n      pointers.forEach(p => {\n        p.color = generateColor();\n      });\n    }\n  }\n\n  function applyInputs() {\n    for (const p of pointers) {\n      if (p.moved) {\n        p.moved = false;\n        splatPointer(p);\n      }\n    }\n  }\n\n  /* ---------- simulation step ---------- */\n  function step(dt: number) {\n    gl.disable(gl.BLEND);\n\n    curlProgram.bind();\n    if (curlProgram.uniforms.texelSize) {\n      gl.uniform2f(curlProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (curlProgram.uniforms.uVelocity) {\n      gl.uniform1i(curlProgram.uniforms.uVelocity, velocity.read.attach(0));\n    }\n    blit(curl);\n\n    vorticityProgram.bind();\n    if (vorticityProgram.uniforms.texelSize) {\n      gl.uniform2f(vorticityProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (vorticityProgram.uniforms.uVelocity) {\n      gl.uniform1i(vorticityProgram.uniforms.uVelocity, velocity.read.attach(0));\n    }\n    if (vorticityProgram.uniforms.uCurl) {\n      gl.uniform1i(vorticityProgram.uniforms.uCurl, curl.attach(1));\n    }\n    if (vorticityProgram.uniforms.curl) {\n      gl.uniform1f(vorticityProgram.uniforms.curl, config.CURL);\n    }\n    if (vorticityProgram.uniforms.dt) {\n      gl.uniform1f(vorticityProgram.uniforms.dt, dt);\n    }\n    blit(velocity.write);\n    velocity.swap();\n\n    divergenceProgram.bind();\n    if (divergenceProgram.uniforms.texelSize) {\n      gl.uniform2f(divergenceProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (divergenceProgram.uniforms.uVelocity) {\n      gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.read.attach(0));\n    }\n    blit(divergence);\n\n    clearProgram.bind();\n    if (clearProgram.uniforms.uTexture) {\n      gl.uniform1i(clearProgram.uniforms.uTexture, pressure.read.attach(0));\n    }\n    if (clearProgram.uniforms.value) {\n      gl.uniform1f(clearProgram.uniforms.value, config.PRESSURE);\n    }\n    blit(pressure.write);\n    pressure.swap();\n\n    pressureProgram.bind();\n    if (pressureProgram.uniforms.texelSize) {\n      gl.uniform2f(pressureProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (pressureProgram.uniforms.uDivergence) {\n      gl.uniform1i(pressureProgram.uniforms.uDivergence, divergence.attach(0));\n    }\n    for (let i = 0; i < config.PRESSURE_ITERATIONS; i++) {\n      if (pressureProgram.uniforms.uPressure) {\n        gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.read.attach(1));\n      }\n      blit(pressure.write);\n      pressure.swap();\n    }\n\n    gradienSubtractProgram.bind();\n    if (gradienSubtractProgram.uniforms.texelSize) {\n      gl.uniform2f(gradienSubtractProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (gradienSubtractProgram.uniforms.uPressure) {\n      gl.uniform1i(gradienSubtractProgram.uniforms.uPressure, pressure.read.attach(0));\n    }\n    if (gradienSubtractProgram.uniforms.uVelocity) {\n      gl.uniform1i(gradienSubtractProgram.uniforms.uVelocity, velocity.read.attach(1));\n    }\n    blit(velocity.write);\n    velocity.swap();\n\n    advectionProgram.bind();\n    if (advectionProgram.uniforms.texelSize) {\n      gl.uniform2f(advectionProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    if (!ext.supportLinearFiltering && advectionProgram.uniforms.dyeTexelSize) {\n      gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, velocity.texelSizeX, velocity.texelSizeY);\n    }\n    const velocityId = velocity.read.attach(0);\n    if (advectionProgram.uniforms.uVelocity) {\n      gl.uniform1i(advectionProgram.uniforms.uVelocity, velocityId);\n    }\n    if (advectionProgram.uniforms.uSource) {\n      gl.uniform1i(advectionProgram.uniforms.uSource, velocityId);\n    }\n    if (advectionProgram.uniforms.dt) {\n      gl.uniform1f(advectionProgram.uniforms.dt, dt);\n    }\n    if (advectionProgram.uniforms.dissipation) {\n      gl.uniform1f(advectionProgram.uniforms.dissipation, config.VELOCITY_DISSIPATION);\n    }\n    blit(velocity.write);\n    velocity.swap();\n\n    if (!ext.supportLinearFiltering && advectionProgram.uniforms.dyeTexelSize) {\n      gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, dye.texelSizeX, dye.texelSizeY);\n    }\n    if (advectionProgram.uniforms.uVelocity) {\n      gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.read.attach(0));\n    }\n    if (advectionProgram.uniforms.uSource) {\n      gl.uniform1i(advectionProgram.uniforms.uSource, dye.read.attach(1));\n    }\n    if (advectionProgram.uniforms.dissipation) {\n      gl.uniform1f(advectionProgram.uniforms.dissipation, config.DENSITY_DISSIPATION);\n    }\n    blit(dye.write);\n    dye.swap();\n  }\n\n  /* ---------- render ---------- */\n  function render(target: FBO | null) {\n    gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);\n    gl.enable(gl.BLEND);\n    drawDisplay(target);\n  }\n\n  function drawDisplay(target: FBO | null) {\n    const width = target ? target.width : gl.drawingBufferWidth;\n    const height = target ? target.height : gl.drawingBufferHeight;\n    displayMaterial.bind();\n    if (config.SHADING && displayMaterial.uniforms.texelSize) {\n      gl.uniform2f(displayMaterial.uniforms.texelSize, 1 / width, 1 / height);\n    }\n    if (displayMaterial.uniforms.uTexture) {\n      gl.uniform1i(displayMaterial.uniforms.uTexture, dye.read.attach(0));\n    }\n    blit(target, false);\n  }\n\n  /* ---------- splats ---------- */\n  function splatPointer(pointer: Pointer) {\n    const dx = pointer.deltaX * config.SPLAT_FORCE;\n    const dy = pointer.deltaY * config.SPLAT_FORCE;\n    splat(pointer.texcoordX, pointer.texcoordY, dx, dy, pointer.color);\n  }\n\n  function clickSplat(pointer: Pointer) {\n    const color = generateColor();\n    color.r *= 10;\n    color.g *= 10;\n    color.b *= 10;\n    const dx = 10 * (Math.random() - 0.5);\n    const dy = 30 * (Math.random() - 0.5);\n    splat(pointer.texcoordX, pointer.texcoordY, dx, dy, color);\n  }\n\n  function splat(x: number, y: number, dx: number, dy: number, color: ColorRGB) {\n    splatProgram.bind();\n    if (splatProgram.uniforms.uTarget) {\n      gl.uniform1i(splatProgram.uniforms.uTarget, velocity.read.attach(0));\n    }\n    if (splatProgram.uniforms.aspectRatio) {\n      gl.uniform1f(splatProgram.uniforms.aspectRatio, canvas!.width / canvas!.height);\n    }\n    if (splatProgram.uniforms.point) {\n      gl.uniform2f(splatProgram.uniforms.point, x, y);\n    }\n    if (splatProgram.uniforms.color) {\n      gl.uniform3f(splatProgram.uniforms.color, dx, dy, 0);\n    }\n    if (splatProgram.uniforms.radius) {\n      gl.uniform1f(splatProgram.uniforms.radius, correctRadius(config.SPLAT_RADIUS / 100)!);\n    }\n    blit(velocity.write);\n    velocity.swap();\n\n    if (splatProgram.uniforms.uTarget) {\n      gl.uniform1i(splatProgram.uniforms.uTarget, dye.read.attach(0));\n    }\n    if (splatProgram.uniforms.color) {\n      gl.uniform3f(splatProgram.uniforms.color, color.r, color.g, color.b);\n    }\n    blit(dye.write);\n    dye.swap();\n  }\n\n  function correctRadius(radius: number) {\n    const aspectRatio = canvas!.width / canvas!.height;\n    if (aspectRatio > 1) radius *= aspectRatio;\n    return radius;\n  }\n\n  /* ---------- pointer helpers ---------- */\n  function updatePointerDownData(pointer: Pointer, id: number, posX: number, posY: number) {\n    pointer.id = id;\n    pointer.down = true;\n    pointer.moved = false;\n    pointer.texcoordX = posX / canvas!.width;\n    pointer.texcoordY = 1 - posY / canvas!.height;\n    pointer.prevTexcoordX = pointer.texcoordX;\n    pointer.prevTexcoordY = pointer.texcoordY;\n    pointer.deltaX = 0;\n    pointer.deltaY = 0;\n    pointer.color = generateColor();\n  }\n\n  function updatePointerMoveData(pointer: Pointer, posX: number, posY: number, color: ColorRGB) {\n    pointer.prevTexcoordX = pointer.texcoordX;\n    pointer.prevTexcoordY = pointer.texcoordY;\n    pointer.texcoordX = posX / canvas!.width;\n    pointer.texcoordY = 1 - posY / canvas!.height;\n    pointer.deltaX = correctDeltaX(pointer.texcoordX - pointer.prevTexcoordX)!;\n    pointer.deltaY = correctDeltaY(pointer.texcoordY - pointer.prevTexcoordY)!;\n    pointer.moved = Math.abs(pointer.deltaX) > 0 || Math.abs(pointer.deltaY) > 0;\n    pointer.color = color;\n  }\n\n  function updatePointerUpData(pointer: Pointer) {\n    pointer.down = false;\n  }\n\n  function correctDeltaX(delta: number) {\n    const aspectRatio = canvas!.width / canvas!.height;\n    if (aspectRatio < 1) delta *= aspectRatio;\n    return delta;\n  }\n\n  function correctDeltaY(delta: number) {\n    const aspectRatio = canvas!.width / canvas!.height;\n    if (aspectRatio > 1) delta /= aspectRatio;\n    return delta;\n  }\n\n  /* ---------- color helpers ---------- */\n  function generateColor(): ColorRGB {\n    const c = HSVtoRGB(Math.random(), 1.0, 1.0);\n    c.r *= 0.15;\n    c.g *= 0.15;\n    c.b *= 0.15;\n    return c;\n  }\n\n  function HSVtoRGB(h: number, s: number, v: number): ColorRGB {\n    let r = 0,\n      g = 0,\n      b = 0;\n    const i = Math.floor(h * 6);\n    const f = h * 6 - i;\n    const p = v * (1 - s);\n    const q = v * (1 - f * s);\n    const t = v * (1 - (1 - f) * s);\n    switch (i % 6) {\n      case 0:\n        r = v;\n        g = t;\n        b = p;\n        break;\n      case 1:\n        r = q;\n        g = v;\n        b = p;\n        break;\n      case 2:\n        r = p;\n        g = v;\n        b = t;\n        break;\n      case 3:\n        r = p;\n        g = q;\n        b = v;\n        break;\n      case 4:\n        r = t;\n        g = p;\n        b = v;\n        break;\n      case 5:\n        r = v;\n        g = p;\n        b = q;\n        break;\n    }\n    return { r, g, b };\n  }\n\n  function wrap(value: number, min: number, max: number) {\n    const range = max - min;\n    if (range === 0) return min;\n    return ((value - min) % range) + min;\n  }\n\n  /* ---------- input events ---------- */\n  window.addEventListener('mousedown', e => {\n    const pointer = pointers[0];\n    const posX = scaleByPixelRatio(e.clientX);\n    const posY = scaleByPixelRatio(e.clientY);\n    updatePointerDownData(pointer, -1, posX, posY);\n    clickSplat(pointer);\n  });\n\n  function handleFirstMouseMove(e: MouseEvent) {\n    const pointer = pointers[0];\n    const posX = scaleByPixelRatio(e.clientX);\n    const posY = scaleByPixelRatio(e.clientY);\n    const color = generateColor();\n    updateFrame();\n    updatePointerMoveData(pointer, posX, posY, color);\n    document.body.removeEventListener('mousemove', handleFirstMouseMove);\n  }\n  document.body.addEventListener('mousemove', handleFirstMouseMove);\n\n  window.addEventListener('mousemove', e => {\n    const pointer = pointers[0];\n    const posX = scaleByPixelRatio(e.clientX);\n    const posY = scaleByPixelRatio(e.clientY);\n    const color = pointer.color;\n    updatePointerMoveData(pointer, posX, posY, color);\n  });\n\n  function handleFirstTouchStart(e: TouchEvent) {\n    const touches = e.targetTouches;\n    const pointer = pointers[0];\n    for (let i = 0; i < touches.length; i++) {\n      const posX = scaleByPixelRatio(touches[i].clientX);\n      const posY = scaleByPixelRatio(touches[i].clientY);\n      updateFrame();\n      updatePointerDownData(pointer, touches[i].identifier, posX, posY);\n    }\n    document.body.removeEventListener('touchstart', handleFirstTouchStart);\n  }\n  document.body.addEventListener('touchstart', handleFirstTouchStart);\n\n  window.addEventListener(\n    'touchstart',\n    e => {\n      const touches = e.targetTouches;\n      const pointer = pointers[0];\n      for (let i = 0; i < touches.length; i++) {\n        const posX = scaleByPixelRatio(touches[i].clientX);\n        const posY = scaleByPixelRatio(touches[i].clientY);\n        updatePointerDownData(pointer, touches[i].identifier, posX, posY);\n      }\n    },\n    false\n  );\n\n  window.addEventListener(\n    'touchmove',\n    e => {\n      const touches = e.targetTouches;\n      const pointer = pointers[0];\n      for (let i = 0; i < touches.length; i++) {\n        const posX = scaleByPixelRatio(touches[i].clientX);\n        const posY = scaleByPixelRatio(touches[i].clientY);\n        updatePointerMoveData(pointer, posX, posY, pointer.color);\n      }\n    },\n    false\n  );\n\n  window.addEventListener('touchend', e => {\n    const touches = e.changedTouches;\n    const pointer = pointers[0];\n    for (let i = 0; i < touches.length; i++) {\n      updatePointerUpData(pointer);\n    }\n  });\n});\n</script>\n","path":"SplashCursor/SplashCursor.vue","_imports_":[],"registryDependencies":[],"dependencies":[],"devDependencies":[]}],"registryDependencies":[],"dependencies":[],"devDependencies":[],"categories":["Animations"]}