webgl实现canvas无限循环动画效果代码-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无限循环动画效果代码
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
<html lang="en"><head>

  <meta charset="UTF-8">

  
  
  
<style>
body {
  background: #666;
  margin: 0;
  overflow: hidden;
}
canvas {
  height: 100vh;
  width: 100vw;
  object-fit: contain;
  touch-action: none;
}
.osc {
  left: 0px;
  position: fixed;
  top: 0px;
}

.button {
  position: fixed;
  z-index: 10;
  right: 0;
  bottom: 0;
}
.controls {
  position: fixed;
  z-index: 10;
  left: 0;
  bottom: 0;
}
.playpause {
  background: #AAB;
  padding: 10px;
}
.playpause label {
  display: block;
  box-sizing: border-box;

  width: 0;
  height: 20px;

  cursor: pointer;

  border-color: transparent transparent transparent #202020;
  transition: 100ms all ease;
  will-change: border-width;

  border-style: double;
  border-width: 0px 0 0px 20px;
}
.playpause input[type='checkbox'] {
  visibility: hidden;
}
.playpause.checked label {
  border-style: double;
  border-width: 0px 0 0px 20px;
}
.playpause label {
  border-style: solid;
  border-width: 10px 0 10px 20px;
}
/* } */


#container {
  display: grid;
  justify-content: center;
  align-content: center;
}
</style>



</head>

<body translate="no">
  <script id="vertexShader_buffer" type="x-shader/x-vertex">attribute vec4 a_position;  
  uniform mat4 u_modelViewMatrix;
  uniform mat4 u_projectionMatrix;
  
  void main() {
    gl_Position = a_position;
  }
</script>
<script id="fragmentShader_buffer" type="x-shader/x-vertex">
  precision highp float;
  
  uniform vec2 u_resolution;
  uniform float u_time;
  uniform vec2 u_mouse;
  uniform sampler2D u_noise;
  
  uniform sampler2D b_loop;
  
  vec2 getScreenSpace() {
    vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy) / min(u_resolution.y, u_resolution.x);
    
    return uv;
  }
  float hash21(vec2 p) {
    p = fract(p * vec2(233.34, 851.74));
    p += dot(p, p + 23.45);
    p = fract(p);
    return texture2D(u_noise, p).x;
  }
  void main() {
    vec2 uv = abs(getScreenSpace());
    float t = u_time * .5;
    float s = sin(t);
    float c = cos(t);
    mat2 m = mat2(c, s, -s, c-s*.1);
    vec2 u = abs(uv-.5);
    
    vec2 samp = gl_FragCoord.xy / u_resolution;
    float n = hash21(samp+u_time);
    
    vec4 a = texture2D(b_loop, (fract(samp)*1.05*(m)-.5)) * (.99 - n*.05);
    float cl = smoothstep(0.0, 0.005, max(uv.x, uv.y) - .485);
    float al = clamp(cl + (smoothstep(.03, .0, min(u.y, u.x)) * (1.+n*.5)), 0., 1.);
    vec4 b = vec4(vec3(cl), al);
    
    gl_FragColor = mix(a,b,b.w);
  }
</script>
<script id="fragmentShader_under" type="x-shader/x-vertex">
  precision highp float;
  
  uniform vec2 u_resolution;
  uniform float u_time;
  uniform vec2 u_mouse;
  uniform sampler2D u_noise;
  
  uniform sampler2D b_loop;
  
  vec2 getScreenSpace() {
    vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy) / min(u_resolution.y, u_resolution.x);
    
    return uv;
  }
  void main() {
    vec2 uv = abs(getScreenSpace());
    
    gl_FragColor = vec4(
      mix(
        texture2D(b_loop, gl_FragCoord.xy / u_resolution.xy).rgb,
        vec3(abs(sin(u_time*5.))),
        0. //smoothstep(0.0, 0.002, max(uv.x,uv.y) - .47)
    ), 1.);
  }
</script>

  
      <script  type="module">
function _defineProperty(obj, key, value) {if (key in obj) {Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true });} else {obj[key] = value;}return obj;}function _classPrivateFieldSet(receiver, privateMap, value) {var descriptor = privateMap.get(receiver);if (!descriptor) {throw new TypeError("attempted to set private field on non-instance");}if (descriptor.set) {descriptor.set.call(receiver, value);} else {if (!descriptor.writable) {throw new TypeError("attempted to set read only private field");}descriptor.value = value;}return value;}function _classPrivateFieldGet(receiver, privateMap) {var descriptor = privateMap.get(receiver);if (!descriptor) {throw new TypeError("attempted to get private field on non-instance");}if (descriptor.get) {return descriptor.get.call(receiver);}return descriptor.value;}function _classStaticPrivateFieldSpecGet(receiver, classConstructor, descriptor) {if (receiver !== classConstructor) {throw new TypeError("Private static access of wrong provenance");}if (descriptor.get) {return descriptor.get.call(receiver);}return descriptor.value;}import { Vec2, Vec3, Mat2, Mat3, Mat4, Quat } from 'https://cdn.skypack.dev/wtc-math';

import gifJs from 'https://cdn.skypack.dev/gif.js';

console.clear();

const setup = function () {
  const px = 1;
  const dimensions = [1024, 1024];

  const canvas = document.createElement('canvas');
  const c = document.createElement('div');
  c.id = 'container';
  document.body.appendChild(c);
  c.appendChild(canvas);

  const renderer = new Renderer(canvas, { width: dimensions[0], height: dimensions[1], alpha: false, premultipliedAlpha: true, preserveDrawingBuffer: true, pxRatio: 1 });
  const ctx = renderer.ctx;

  let drawing = new Float32Array([-1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0]);

  const drawBuffer = new Buffer(ctx, drawing);

  const vertexShader_buffer = document.getElementById('vertexShader_buffer').innerText;

  const programMain = new Program(ctx, vertexShader_buffer, document.getElementById('fragmentShader_under').innerText, {
    clearColour: [.15, .15, 0.25, 1.],
    renderType: Program.RENDER_STRIP });

  const programBuffer = new Program(ctx, vertexShader_buffer, document.getElementById('fragmentShader_buffer').innerText, {
    clearColour: [.15, .15, 0.25, 1.],
    renderType: Program.RENDER_STRIP });


  const loopBuffer = new FrameBuffer(renderer, 'loop', {
    width: dimensions[0],
    height: dimensions[1],
    tiling: Texture.IMAGETYPE_TILE,
    texdepth: FrameBuffer.TEXTYPE_FLOAT,
    pxRatio: 1 });

  window.loopBuffer = loopBuffer;
  console.log(loopBuffer.texture, renderer.width);

  const time = new Uniform(ctx, 'time', Uniform.TYPE_FLOAT, 100);
  const uDelta = new Uniform(ctx, 'delta', Uniform.TYPE_FLOAT, 100);
  const mouse = new Uniform(ctx, 'mouse', Uniform.TYPE_V2, [0., 0.]);

  const noise = new Texture(ctx, 'noise', {
    textureType: Texture.IMAGETYPE_TILE,
    url: '//repo.bfw.wiki/bfwrepo/image/5dfd8574f13f0.png' });


  noise.preload().then(n => {
    requestAnimationFrame(run);
  });

  let pointerdown = false;
  let lastPos = new Vec2();
  window.addEventListener('pointerdown', e => {
    pointerdown = true;
    lastPos = new Vec2(e.x, e.y);
  });
  window.addEventListener('pointerup', e => {
    pointerdown = false;
  });
  window.addEventListener('pointermove', e => {
    if (pointerdown) {
      let newPos = new Vec2(e.x, e.y);
      mouse.value = newPos.array;
    }
  });

  let playing = true;
  const setPlaying = value => {
    playing = value;
  };

  let autoTransitionTimer = 0;
  let timeToTransition = 0;
  const setupValues = i => {
    dimensions[0] = window.innerWidth;
    dimensions[1] = window.innerHeight;

    time.value = -100;
  };

  setupValues(0);

  let timeout;

  const opx = renderer.pxRatio;
  let then = 0;
  // let framenum = 0;
  // let framesPerFrame = 10;
  // let gif = new gifJs({
  //   workers: 2,
  //   quality: 10
  // });
  // gif.on('finished', function(blob) {
  //   console.log('ss')
  //   window.open(URL.createObjectURL(blob));
  // });

  // const offscreenCanvas = document.createElement("canvas");
  // offscreenCanvas.className = 'osc';
  // offscreenCanvas.width = canvas.width;
  // offscreenCanvas.height = canvas.height;
  // const osctx = offscreenCanvas.getContext("2d");
  // document.body.appendChild(offscreenCanvas);

  let gifDone = false;
  const run = delta => {

    //   if(framenum < 10 * framesPerFrame) {
    //     if(framenum % framesPerFrame == 0) {
    //       // gif.addFrame(canvas, {delay: 100});

    //       osctx.drawImage(canvas,0,0);

    //       gif.addFrame(offscreenCanvas, {copy: true, delay: 100});
    //       // gif.addFrame(ctx, {copy: true});
    //     }
    //     framenum++;
    //   } else if(gifDone === false) {
    //     console.log(framenum)

    //     gif.render();

    //     window.gif = gif;

    //     gifDone = true;
    //   }

    let now = Date.now() / 1000;
    let _delta = now - then;
    then = now;

    if (_delta > 1000) {
      requestAnimationFrame(run);
      return;
    }

    if (playing) {
      uDelta.value = Math.min(_delta, 0.5);
      time.value += _delta * .05;

      renderer.setViewport();
      renderer.setupProgram(programBuffer, [drawBuffer], [], [time, mouse, loopBuffer]);
      loopBuffer.render(4);

      renderer.setupProgram(programMain, [drawBuffer], [], [time, mouse, loopBuffer]);
      renderer.render(4);

      requestAnimationFrame(run);
    }
  };
};

// Determine whether a number is a power of 2
function powerOf2(v) {
  return v && !(v & v - 1);
}
// Return the next greatest power of 2
function nextPow2(v) {
  v--;
  v |= v >> 1;
  v |= v >> 2;
  v |= v >> 4;
  v |= v >> 8;
  v |= v >> 16;
  v++;
  return v;
}
// Update a provided image to the nearest power of 2 in size.
const pow2Image = c => {
  const newWidth = powerOf2(c.width) ? c.width : nextPow2(c.width);
  const newHeight = powerOf2(c.height) ? c.height : nextPow2(c.height);
  const _c = document.createElement('canvas');
  const ctx = _c.getContext('2d');
  _c.width = newWidth;
  _c.height = newHeight;
  ctx.drawImage(c, 0, 0, newWidth, newHeight);
  return _c;
};
const asyncImageLoad = function (img, src) {
  return new Promise((resolve, reject) => {
    img.onload = () => resolve(img);
    img.onerror = reject;
    img.src = src;
  });
};
const glEnumToString = function () {
  const haveEnumsForType = {};
  const enums = {};

  function addEnums(gl) {
    const type = gl.constructor.name;
    if (!haveEnumsForType[type]) {
      for (const key in gl) {
        if (typeof gl[key] === 'number') {
          const existing = enums[gl[key]];
          enums[gl[key]] = existing ? `${existing} | ${key}` : key;
        }
      }
      haveEnumsForType[type] = true;
    }
  }

  return function glEnumToString(gl, value) {
    addEnums(gl);
    return enums[value] || (typeof value === 'number' ? `0x${value.toString(16)}` : value);
  };
}();
const addExtensions = ctx => {
  // Set up the extensions
  ctx.getExtension('OES_standard_derivatives');
  ctx.getExtension('EXT_shader_texture_lod');
  ctx.getExtension('OES_texture_float');
  ctx.getExtension('WEBGL_color_buffer_float');
  ctx.getExtension('OES_texture_float_linear');
  ctx.getExtension('EXT_color_buffer_float');
};
function createContext(c, opt_attribs, params) {
  const ctx = c.getContext("webgl", params) || this._el.getContext("experimental-webgl", params);

  addExtensions(ctx);

  return ctx;
}

const quatToMat4 = q => {
  if (q.array) q = q.array; // This just transforms a provided vector into to an array.

  if (q instanceof Array && q.length >= 4) {
    const [x, y, z, w] = q;
    const [x2, y2, z2] = q.map(x => x * 2.);

    const xx = x * x2,
    yx = y * x2,
    yy = y * y2,
    zx = z * x2,
    zy = z * y2,
    zz = z * z2,
    wx = w * x2,
    wy = w * y2,
    wz = w * z2;

    return new Mat4(
    1 - yy - zz, yx - wz, zx + wy, 0,
    yx + wz, 1 - xx - zz, zy - wx, 0,
    zx - wy, zy + wx, 1 - xx - yy, 0,
    0, 0, 0, 1);

  }
};var _blending = new WeakMap();var _blendingEnabled = new WeakMap();var _buffers = new WeakMap();

class Renderer {






















  constructor(canvas, options) {_defineProperty(this, "isWebgl2", false);_blending.set(this, { writable: true, value: void 0 });_blendingEnabled.set(this, { writable: true, value: false });_buffers.set(this, { writable: true, value: [] });
    options = Object.assign({}, _classStaticPrivateFieldSpecGet(Renderer, Renderer, _defaultOptions), options);
    this.width = options.width;
    this.height = options.height;
    this.pxRatio = options.pxRatio;
    this.clearing = options.clearing;
    this.depthTesting = options.depthTesting;
    this.canvas = canvas || document.createElement('canvas');
    this.canvas.width = this.width * this.pxRatio;
    this.canvas.height = this.height * this.pxRatio;
    this.premultipliedAlpha = options.premultipliedAlpha;

    this.ctx = this.canvas.getContext("webgl", options) || this.canvas.getContext("experimental-webgl", options);

    this.ctx.viewportWidth = this.canvas.width;
    this.ctx.viewportHeight = this.canvas.height;

    this.uniformResolution = new Uniform(this.ctx, 'resolution', Uniform.TYPE_V2, [this.canvas.width, this.canvas.height]);

    this.addExtensions();
  }
  resize(w, h, ratio) {
    this.width = w;
    this.height = h;
    this.pxRatio = ratio || this.pxRatio;
    this.canvas.width = this.width * this.pxRatio;
    this.canvas.height = this.height * this.pxRatio;

    this.ctx.viewportWidth = this.canvas.width;
    this.ctx.viewportHeight = this.canvas.height;

    this.uniformResolution = new Uniform(this.ctx, 'resolution', Uniform.TYPE_V2, [this.canvas.width, this.canvas.height]);
  }
  setViewport(dimensions) {
    let w = this.width * this.pxRatio;
    let h = this.height * this.pxRatio;
    if (dimensions) {
      w = dimensions[0];
      h = dimensions[1];
    }
    this.ctx.viewport(0, 0, w, h);
    this.uniformResolution = new Uniform(this.ctx, 'resolution', Uniform.TYPE_V2, [w, h]);
  }
  addExtensions() {
    this.ctx.getExtension('OES_standard_derivatives');
    this.ctx.getExtension('EXT_shader_texture_lod');
    this.ctx.getExtension('OES_texture_float');
    this.ctx.getExtension('WEBGL_color_buffer_float');
    this.ctx.getExtension('OES_texture_float_linear');
    this.ctx.getExtension('EXT_color_buffer_float');
  }
  linkBuffer(buffer) {
    let hasBuffer = false;
    _classPrivateFieldGet(this, _buffers).forEach(b => {
      if (buffer === b) hasBuffer = true;
    });
    if (!hasBuffer) {
      this.ctx.bindBuffer(this.ctx.ARRAY_BUFFER, buffer.buffer);
      this.ctx.bufferData(
      this.ctx.ARRAY_BUFFER,
      buffer.data,
      buffer.drawType);
    }
    buffer.link(this.currentProgram.program);
  }
  setupProgram(program, buffers, attributes, uniforms) {
    this.currentProgram = program;
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