webgl实现canvas跟随鼠标移动烟雾流体动画效果代码-html代码-BFW代码库

代码语言：html
所属分类：动画
代码描述：webgl实现canvas跟随鼠标移动烟雾流体动画效果代码，逼真的多彩烟雾流动交互效果。
下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开
<!DOCTYPE html>
<html lang="en" >

<head>
  <meta charset="UTF-8">
  


  <meta name="viewport" content="width=device-width, initial-scale=1">
  
  
  
<style>
html,
body {
  overflow: hidden;
}

body {
  margin: 0;
  position: absolute;
  width: 100%;
  height: 100%;
}

#container {
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
}

.a-title {
  position: absolute;
  color: transparent;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-image: conic-gradient(#ed0101, blue);
  pointer-events: none;
  mix-blend-mode: difference;
  filter: drop-shadow(2px 4px 6px black);
}
.a-second-title {
  position: absolute;
  margin-top: 25vh;
  pointer-events: none;
  -webkit-text-stroke: 1.3px white;
  letter-spacing: 1.125px;
  font-size: -webkit-xxx-large;
  font-weight: 900;
  mix-blend-mode: color-dodge;
}

canvas {
  width: 100%;
  height: 100%;
}
</style>


  
  
</head>

<body >
  <section id='container'>
  <h1 class='a-title'>Move the mouse</h1>
  <h2 class='a-second-title'>See the magic</h2>
  <canvas></canvas>
</section>

  
      <script>
'use strict';

const canvas = document.getElementsByTagName('canvas')[0];
canvas.width = canvas.clientWidth;
canvas.height = canvas.clientHeight;

let config = {
  TEXTURE_DOWNSAMPLE: 1,
  DENSITY_DISSIPATION: 0.98,
  VELOCITY_DISSIPATION: 0.99,
  PRESSURE_DISSIPATION: 0.8,
  PRESSURE_ITERATIONS: 25,
  CURL: 28,
  SPLAT_RADIUS: 0.004 };


let pointers = [];
let splatStack = [];

const { gl, ext } = getWebGLContext(canvas);

function getWebGLContext(canvas) {
  const params = { alpha: false, depth: false, stencil: false, antialias: false };

  let gl = canvas.getContext('webgl2', params);
  const isWebGL2 = !!gl;
  if (!isWebGL2)
  gl = canvas.getContext('webgl', params) || canvas.getContext('experimental-webgl', params);

  let halfFloat;
  let supportLinearFiltering;
  if (isWebGL2) {
    gl.getExtension('EXT_color_buffer_float');
    supportLinearFiltering = gl.getExtension('OES_texture_float_linear');
  } else {
    halfFloat = gl.getExtension('OES_texture_half_float');
    supportLinearFiltering = gl.getExtension('OES_texture_half_float_linear');
  }

  gl.clearColor(0.0, 0.0, 0.0, 1.0);

  const halfFloatTexType = isWebGL2 ? gl.HALF_FLOAT : halfFloat.HALF_FLOAT_OES;
  let formatRGBA;
  let formatRG;
  let formatR;

  if (isWebGL2)
  {
    formatRGBA = getSupportedFormat(gl, gl.RGBA16F, gl.RGBA, halfFloatTexType);
    formatRG = getSupportedFormat(gl, gl.RG16F, gl.RG, halfFloatTexType);
    formatR = getSupportedFormat(gl, gl.R16F, gl.RED, halfFloatTexType);
  } else

  {
    formatRGBA = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
    formatRG = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
    formatR = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
  }

  return {
    gl,
    ext: {
      formatRGBA,
      formatRG,
      formatR,
      halfFloatTexType,
      supportLinearFiltering } };


}

function getSupportedFormat(gl, internalFormat, format, type)
{
  if (!supportRenderTextureFormat(gl, internalFormat, format, type))
  {
    switch (internalFormat) {

      case gl.R16F:
        return getSupportedFormat(gl, gl.RG16F, gl.RG, type);
      case gl.RG16F:
        return getSupportedFormat(gl, gl.RGBA16F, gl.RGBA, type);
      default:
        return null;}

  }

  return {
    internalFormat,
    format };

}

function supportRenderTextureFormat(gl, internalFormat, format, type) {
  let texture = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_2D, texture);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
  gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, 4, 4, 0, format, type, null);

  let fbo = gl.createFramebuffer();
  gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
  gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);

  const status = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
  if (status != gl.FRAMEBUFFER_COMPLETE)
  return false;
  return true;
}

function pointerPrototype() {
  this.id = -1;
  this.x = 0;
  this.y = 0;
  this.dx = 0;
  this.dy = 0;
  this.down = false;
  this.moved = false;
  this.color = [30, 0, 300];
}

pointers.push(new pointerPrototype());

class GLProgram {
  constructor(vertexShader, fragmentShader) {
    this.uniforms = {};
    this.program = gl.createProgram();

    gl.attachShader(this.program, vertexShader);
    gl.attachShader(this.program, fragmentShader);
    gl.linkProgram(this.program);

    if (!gl.getProgramParameter(this.program, gl.LINK_STATUS))
    throw gl.getProgramInfoLog(this.program);

    const uniformCount = gl.getProgramParameter(this.program, gl.ACTIVE_UNIFORMS);
    for (let i = 0; i < uniformCount; i++) {
      const uniformName = gl.getActiveUniform(this.program, i).name;
      this.uniforms[uniformName] = gl.getUniformLocation(this.program, uniformName);
    }
  }

  bind() {
    gl.useProgram(this.program);
  }}


function compileShader(type, source) {
  const shader = gl.createShader(type);
  gl.shaderSource(shader, source);
  gl.compileShader(shader);

  if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS))
  throw gl.getShaderInfoLog(shader);

  return shader;
};

const baseVertexShader = compileShader(gl.VERTEX_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    attribute vec2 aPosition;
    varying vec2 vUv;
    varying vec2 vL;
    varying vec2 vR;
    varying vec2 vT;
    varying vec2 vB;
    uniform vec2 texelSize;

    void main () {
        vUv = aPosition * 0.5 + 0.5;
        vL = vUv - vec2(texelSize.x, 0.0);
        vR = vUv + vec2(texelSize.x, 0.0);
        vT = vUv + vec2(0.0, texelSize.y);
        vB = vUv - vec2(0.0, texelSize.y);
        gl_Position = vec4(aPosition, 0.0, 1.0);
    }
`);

const clearShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    uniform sampler2D uTexture;
    uniform float value;

    void main () {
        gl_FragColor = value * texture2D(uTexture, vUv);
    }
`);

const displayShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    uniform sampler2D uTexture;

    void main () {
        gl_FragColor = texture2D(uTexture, vUv);
    }
`);

const splatShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    uniform sampler2D uTarget;
    uniform float aspectRatio;
    uniform vec3 color;
    uniform vec2 point;
    uniform float radius;

    void main () {
        vec2 p = vUv - point.xy;
        p.x *= aspectRatio;
        vec3 splat = exp(-dot(p, p) / radius) * color;
        vec3 base = texture2D(uTarget, vUv).xyz;
        gl_FragColor = vec4(base + splat, 1.0);
    }
`);

const advectionManualFilteringShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    uniform sampler2D uVelocity;
    uniform sampler2D uSource;
    uniform vec2 texelSize;
    uniform float dt;
    uniform float dissipation;

    vec4 bilerp (in sampler2D sam, in vec2 p) {
        vec4 st;
        st.xy = floor(p - 0.5) + 0.5;
        st.zw = st.xy + 1.0;
        vec4 uv = st * texelSize.xyxy;
        vec4 a = texture2D(sam, uv.xy);
        vec4 b = texture2D(sam, uv.zy);
        vec4 c = texture2D(sam, uv.xw);
        vec4 d = texture2D(sam, uv.zw);
        vec2 f = p - st.xy;
        return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
    }

    void main () {
        vec2 coord = gl_FragCoord.xy - dt * texture2D(uVelocity, vUv).xy;
        gl_FragColor = dissipation * bilerp(uSource, coord);
        gl_FragColor.a = 1.0;
    }
`);

const advectionShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    uniform sampler2D uVelocity;
    uniform sampler2D uSource;
    uniform vec2 texelSize;
    uniform float dt;
    uniform float dissipation;

    void main () {
        vec2 coord = vUv - dt * texture2D(uVelocity, vUv).xy * texelSize;
        gl_FragColor = dissipation * texture2D(uSource, coord);
        gl_FragColor.a = 1.0;
    }
`);

const divergenceShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    varying vec2 vL;
    varying vec2 vR;
    varying vec2 vT;
    varying vec2 vB;
    uniform sampler2D uVelocity;

    vec2 sampleVelocity (in vec2 uv) {
        vec2 multiplier = vec2(1.0, 1.0);
        if (uv.x < 0.0) { uv.x = 0.0; multiplier.x = -1.0; }
        if (uv.x > 1.0) { uv.x = 1.0; multiplier.x = -1.0; }
        if (uv.y < 0.0) { uv.y = 0.0; multiplier.y = -1.0; }
        if (uv.y > 1.0) { uv.y = 1.0; multiplier.y = -1.0; }
        return multiplier * texture2D(uVelocity, uv).xy;
    }

    void main () {
        float L = sampleVelocity(vL).x;
        float R = sampleVelocity(vR).x;
        float T = sampleVelocity(vT).y;
        float B = sampleVelocity(vB).y;
        float div = 0.5 * (R - L + T - B);
        gl_FragColor = vec4(div, 0.0, 0.0, 1.0);
    }
`);

const curlShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    varying vec2 vL;
    varying vec2 vR;
    varying vec2 vT;
    varying vec2 vB;
    uniform sampler2D uVelocity;

    void main () {
        float L = texture2D(uVelocity, vL).y;
        float R = texture2D(uVelocity, vR).y;
        float T = texture2D(uVelocity, vT).x;
        float B = texture2D(uVelocity, vB).x;
        float vorticity = R - L - T + B;
        gl_FragColor = vec4(vorticity, 0.0, 0.0, 1.0);
    }
`);

const vorticityShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    varying vec2 vT;
    varying vec2 vB;
    uniform sampler2D uVelocity;
    uniform sampler2D uCurl;
    uniform float curl;
    uniform float dt;

    void main () {
        float T = texture2D(uCurl, vT).x;
        float B = texture2D(uCurl, vB).x;
        float C = texture2D(uCurl, vUv).x;
        vec2 force = vec2(abs(T) - abs(B), 0.0);
        force *= 1.0 / length(force + 0.00001) * curl * C;
        vec2 vel = texture2D(uVelocity, vUv).xy;
        gl_FragColor = vec4(vel + force * dt, 0.0, 1.0);
    }
`);

const pressureShader = compileShader(gl.FRAGMENT_SHADER, `
    precision highp float;
    precision mediump sampler2D;

    varying vec2 vUv;
    varying vec2 vL;
    varying vec2 vR;
    varying vec2 vT;
    varying vec2 vB;
    uniform sampler2D uPressure;
    uniform sampler2D uDivergence;

    vec2 boundary (in vec2 uv) {
        uv = min(max(uv, 0.0), 1.0);
        return uv;
  .........完整代码请登录后点击上方下载按钮下载查看