多彩飓风旋涡状彩带灯带变幻canvas特效动-html代码-BFW代码库

代码语言：html
所属分类：其他
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
<!D<<<YPEOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0,user-scalable=no,minimal-ui">
  <title>多彩飓风旋涡状彩带灯带变幻canvas特效动画</title>
     <style >
     body {
  margin:0;
}

canvas {
  position: fixed;
}
      </style>

</head>
<body>

<canvas id="webgl" width="500" height="1758"></canvas>


<script id="vertexShader" 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" type="x-shader/x-fragment">
  precision highp float;
  
  uniform vec2 u_resolution;
  uniform vec2 u_mouse;
  uniform float u_time;
  uniform sampler2D u_noise;
  
  uniform sampler2D u_buffer;
  uniform bool u_bufferpass;
  
  #define PI 3.14159265359
  #define TAU 6.28318530718
  
  // These awesome complex Math functions curtesy of 
  // https://github.com/mkovacs/reim/blob/master/reim.glsl
  vec2 cCis(float r);
  vec2 cLog(vec2 c); // principal value
  vec2 cInv(vec2 c);
  float cArg(vec2 c);
  float cAbs(vec2 c);
  
  vec2 cMul(vec2 a, vec2 b);
  vec2 cDiv(vec2 a, vec2 b);

  vec2 cCis(float r)
  {
    return vec2( cos(r), sin(r) );
  }
  vec2 cExp(vec2 c)
  {
    return exp(c.x) * cCis(c.y);
  }
  vec2 cConj(vec2 c)
  {
    return vec2(c.x, -c.y);
  }
  vec2 cInv(vec2 c)
  {
    return cConj(c) / dot(c, c);
  }
  vec2 cLog(vec2 c)
  {
    return vec2( log( cAbs(c) ), cArg(c) );
  }
  float cArg(vec2 c)
  {
    return atan(c.y, c.x);
  }
  float cAbs(vec2 c)
  {
    return length(c);
  }
  vec2 cMul(vec2 a, vec2 b)
  {
    return vec2(a.x*b.x - a.y*b.y, a.x*b.y + a.y*b.x);
  }
  vec2 cDiv(vec2 a, vec2 b)
  {
    return cMul(a, cInv(b));
  }
  
  float r1 = 0.1;
  float r2 = 0.3;
  
  vec2 Droste(vec2 uv) {
    
    // r1 = .1 + u_mouse.x;
    r2 = .15 + max(u_mouse.y + .5, -.0);
    
    // float c = cos(u_time);
    // float s = sin(u_time);
    // uv *= mat2(c, -s, s, c);
    
    // 5. Take the tiled strips back to ordinary space.
    uv = cLog(uv); 
    // 4. Scale and rotate the strips
    float scale = log(r2/r1);
    float angle = atan(scale/PI);
    uv = cDiv(uv, cExp(vec2(0,angle))*cos(angle));
    // 3. this simulates zooming in the tile
    // uv -= u_time;
    // 2. Tile the strips
    uv.x = mod(uv.x,log(r2/r1)); 
    // 1. Take the annulus to a strip
    uv = cExp(uv)*r1;
    
    return uv;
  }
  
  vec3 hash3( vec2 p ) {
      vec3 q = vec3( dot(p,vec2(127.1,311.7)), 
             dot(p,vec2(269.5,183.3)), 
             dot(p,vec2(419.2,371.9)) );
    return fract(sin(q)*43758.5453);
  }
  
  vec2 getScreenSpace() {
    vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy) / min(u_resolution.y, u_resolution.x);
    
    return uv;
  }
  
  const float colours = 3.;
  const vec4 colour1 = vec4(.1,.2,.8, 1.);
  const vec4 colour2 = vec4(.8,.3,.2, 1.);
  const vec4 colour3 = vec4(.1,.7,.2, 1.);
  
  vec4 getColour(float r) {
    float or = r;
    r = floor(r*(colours+1.));
    if(r == 0.) {
      return colour1;
    } else if(r == 1.) {
      return colour2+vec4(0, (sin(u_time*3. + or*10.) * or + or), 0., 0.);
    } else if(r == 2.) {
      return colour3;
    }
  }
  
  vec4 render(vec2 uv) {
    // uv *= 10.;
    
    // uv.x += u_time;
    
    float row = floor(uv.y);
    
    if(mod(row, 2.) == 0.) return vec4(0,0,0,1);
    
    vec4 rowval = texture2D(u_noise, vec2(.5, row/110.));
    float nf = rowval.r;
    nf *= nf;
    nf *= 5.;
    
    uv.x += u_time * nf * 3.;
    
    float noiseloopval = sin(uv.x*PI*.1)*floor(uv.y);
    noiseloopval = mod(uv.x*row, row*2.);
    
    vec2 uvid = floor(vec2( floor(noiseloopval), uv.y ));
    vec3 uvseed = hash3(uvid/PI);
    
    float shapefield = sin(fract(uv.y)*3.) * sin(fract(uv.x)*10.);
    vec4 colour = getColour(rowval.g*(1.-rowval.g*(sin(u_time*3.)*.5+.5))) * smoothstep(.2,.6,shapefield);
    colour += smoothstep(.9,1.,shapefield);
    colour += smoothstep(.99,1.,shapefield)*5.;
    
    // colour *= uvseed.x;
    
    return mix(vec4(0,0,0,1), colour, colour.a);
  }
  
  vec4 render_effect(vec2 uv, vec4 prev) {
    vec2 polar = vec2(atan(uv.x, uv.y)/PI, length(uv));

    vec4 c = render(polar);
    c += render(polar * vec2(2., .6) + vec2(0.,1./.6));
    c += render(polar * vec2(1., 1.2) + vec2(0.,1./1.2));

    uv = Droste(getScreenSpace())*20.;
    polar = vec2(atan(uv.x, uv.y)/PI, length(uv));

    c += render(polar * vec2(1., 2.2) + vec2(0.,2./2.2));
    
    return c;
  }

  void main() {
    vec4 prev = texture2D(u_buffer, gl_FragCoord.xy/u_resolution);
    if(u_bufferpass) {
      vec2 uv = Droste(getScreenSpace())*10.;
      // uv = mix(uv, getScreenSpace()*10., sin(u_time*2.)*.5+.5);
      // uv = getScreenSpace()*10.;

      gl_FragColor = prev * .94 + render_effect(uv, prev) * .05;
    } else {
      vec2 uv = Droste(getScreenSpace())*50.;
      
      gl_FragColor = prev;
    }
  }
  
</script>
<!-- partial -->
  <script >
      /**
 * A basic Web GL class. This provides a very basic setup for GLSL shader code.
 * Currently it doesn't support anything except for clip-space 3d, but this was
 * done so that we could start writing fragments right out of the gate. My
 * Intention is to update it with particle and polygonal 3d support later on.
 *
 * @class WTCGL
 * @author Liam Egan <liam@wethecollective.com>
 * @version 0.0.8
 * @created Jan 16, 2019
 */
class WTCGL {

  /**
              * The WTCGL Class constructor. If construction of the webGL context fails 
               * for any reason this will return null.
               * 
               * @TODO make the dimension properties properly optional
               * @TODO provide the ability to allow for programmable buffers
              *
              * @constructor
              * @param {HTMLElement} el The canvas element to use as the root
              * @param {string} vertexShaderSource The vertex shader source
              * @param {string} fragmentShaderSource The fragment shader source
               * @param {number} [width] The width of the webGL context. This will default to the canvas dimensions
               * @param {number} [height] The height of the webGL context. This will default to the canvas dimensions
               * @param {number} [pxratio=1] The pixel aspect ratio of the canvas
               * @param {boolean} [styleElement] A boolean indicating whether to apply a style property to the canvas (resizing the canvas by the inverse of the pixel ratio)
               * @param {boolean} [webgl2] A boolean indicating whether to try to create a webgl2 context instead of a regulart context
              */
  constructor(el, vertexShaderSource, fragmentShaderSource, width, height, pxratio, styleElement, webgl2) {
    this.run = this.run.bind(this);

    this._onRun = () => {};

    // Destructure if an object is aprovided instead a series of parameters
    if (el instanceof Object && el.el) {
      ({ el, vertexShaderSource, fragmentShaderSource, width, height, pxratio, webgl2, styleElement } = el);
    }

    // If the HTML element isn't a canvas, return null
    if (!el instanceof HTMLElement || el.nodeName.toLowerCase() !== 'canvas') {
      console.log('Provided element should be a canvas element');
      return null;
    }

    this._el = el;
    // The context should be either webgl2, webgl or experimental-webgl
    if (webgl2 === true) {
      this.isWebgl2 = true;
      this._ctx = this._el.getContext("webgl2", this.webgl_params) || this._el.getContext("webgl", this.webgl_params) || this._el.getContext("experimental-webgl", this.webgl_params);
    } else {
      this.isWebgl2 = false;
      this._ctx = this._el.getContext("webgl", this.webgl_params) || this._el.getContext("experimental-webgl", this.webgl_params);
    }

    // Set up the extensions
    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');

    // We can't make the context so return an error
    if (!this._ctx) {
      console.log('Browser doesn\'t support WebGL ');
      return null;
    }

    // Create the shaders
    this._vertexShader = WTCGL.createShaderOfType(this._ctx, this._ctx.VERTEX_SHADER, vertexShaderSource);
    this._fragmentShader = WTCGL.createShaderOfType(this._ctx, this._ctx.FRAGMENT_SHADER, fragmentShaderSource);

    // Create the program and link the shaders
    this._program = this._ctx.createProgram();
    this._ctx.attachShader(this._program, this._vertexShader);
    this._ctx.attachShader(this._program, this._fragmentShader);
    this._ctx.linkProgram(this._program);

    // If we can't set up the params, this means the shaders have failed for some reason
    if (!this._ctx.getProgramParameter(this._program, this._ctx.LINK_STATUS)) {
      console.log('Unable to initialize the shader program: ' + this._ctx.getProgramInfoLog(this._program));
      return null;
    }

    // Initialise the vertex buffers
    this.initBuffers([
    -1.0, 1.0, -1.,
    1.0, 1.0, -1.,
    -1.0, -1.0, -1.,
    1.0, -1.0, -1.]);


    // Initialise the frame buffers
    this.frameBuffers = [];

    // The program information object. This is essentially a state machine for the webGL instance
    this._programInfo = {
      attribs: {
        vertexPosition: this._ctx.getAttribLocation(this._program, 'a_position') },

      uniforms: {
        projectionMatrix: this._ctx.getUniformLocation(this._program, 'u_projectionMatrix'),
        modelViewMatrix: this._ctx.getUniformLocation(this._program, 'u_modelViewMatrix'),
        resolution: this._ctx.getUniformLocation(this._program, 'u_resolution'),
        time: this._ctx.getUniformLocation(this._program, 'u_time') } };



    // Tell WebGL to use our program when drawing
    this._ctx.useProgram(this._program);

    this.pxratio = pxratio;

    this.styleElement = styleElement !== true;

    this.resize(width, height);
  }


  /**
     * Public methods
     */

  addFrameBuffer(w, h, tiling = 0, buffertype = 0) {
    // create to render to
    const gl = this._ctx;
    const targetTextureWidth = w * this.pxratio;
    const targetTextureHeight = h * this.pxratio;
    const targetTexture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, targetTexture);
    {
      // define size and format of level 0
      const level = 0;
      let internalFormat = gl.RGBA;
      const border = 0;
      let format = gl.RGBA;
      let t;
      if (buffertype & WTCGL.TEXTYPE_FLOAT) {
        const e = gl.getExtension('OES_texture_float');
        window.extension = e;
        t = e.FLOAT;
        // internalFormat = gl.RGBA32F;
      } else if (buffertype & WTCGL.TEXTYPE_HALF_FLOAT_OES) {
        // t = gl.renderer.isWebgl2 ? e.HALF_FLOAT : e.HALF_FLOAT_OES;
        //     gl.renderer.extensions['OES_texture_half_float'] ? gl.renderer.extensions['OES_texture_half_float'].HALF_FLOAT_OES : 
        //     gl.UNSIGNED_BYTE;
        const e = gl.getExtension('OES_texture_half_float');
        t = this.isWebgl2 ? gl.HALF_FLOAT : e.HALF_FLOAT_OES;
        // format = gl.RGBA;
        // internalFormat = gl.RGB32F;
        // format = gl.RGB32F;
        // window.gl = gl
        // t = e.HALF_FLOAT_OES;
      } else {
        t = gl.UNSIGNED_BYTE;
      }
      const type = t;
      const data = null;
      gl.texImage2D(gl.TEXTURE_2D, level, internalFormat,
      targetTextureWidth, targetTextureHeight, border,
      format, type, data);
      // gl.generateMipmap(gl.TEXTURE_2D);

      // set the filtering so we don't need mips
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);

      // Set the parameters based on the passed type
      if (tiling === WTCGL.IMAGETYPE_TILE) {
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);
      } else if (tiling === WTCGL.IMAGETYPE_MIRROR) {
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.MIRRORED_REPEAT);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.MIRRORED_REPEAT);
      } else if (tiling === WTCGL.IMAGETYPE_REGULAR) {
        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);
      }
    }

    // Create and bind the framebuffer
    const fb = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fb);

    // attach the texture as the first color attachment
    const attachmentPoint = gl.COLOR_ATTACHMENT0;
    const level = 0;
    gl.framebufferTexture2D(gl.FRAMEBUFFER, attachmentPoint, gl.TEXTURE_2D, targetTexture, level);

    return {
      w: w * this.pxratio,
      h: h * this.pxratio,
      fb: fb,
      frameTexture: targetTexture };

  }


  /**
     * Resizes the canvas to a specified width and height, respecting the pixel ratio
     *
     * @param  {number} w The width of the canvas
     * @param  {number} h The height of the canvas
     * @return {Void}
     */
  resize(w, h) {
    this._el.width = w * this.pxratio;
    this._el.height = h * this.pxratio;
    this._size = [w * this.pxratio, h * this.pxratio];
    if (this.styleElement) {
      this._el.style.width = w + 'px';
      this._el.style.height = h + 'px';
    }

    this._ctx.viewportWidth = w * this.pxratio;
    this._ctx.viewportHeight = h * this.pxratio;

    this._ctx.uniform2fv(this._programInfo.uniforms.resolution, this._size);

    this.initBuffers(this._positions);
  }

  /**
     * Initialise a provided vertex buffer
     *
     * @param  {array} positions The vertex positions to initialise
     * @return {Void}
     */
  initBuffers(positions) {
    this._positions = positions;
    this._positionBuffer = this._ctx.createBuffer();

    this._ctx.bindBuffer(this._ctx.ARRAY_BUFFER, this._positionBuffer);

    this._ctx.bufferData(this._ctx.ARRAY_BUFFER,
    new Float32Array(positions),
    this._ctx.STATIC_DRAW);
  }

  /**
     * Add a uniform to the program. At this time the following types are supported:
      * - Float - WTCGL.TYPE_FLOAT
      * - Vector 2 - WTCGL.TYPE_V2
      * - Vector 3 - WTCGL.TYPE_V3
      * - Vector 4 - WTCGL.TYPE_V4
     *
     * @param  {string} name The name of the uniform. N.B. your name will be prepended with a `u_` in your shaders. So providing a name of `foo` here will result in a uniform named `u_foo`
     * @param  {WTCGL.UNIFORM_TYPE} type The unfiform type 
     * @param  {number|array} value The unfiform value. The type depends on the uniform type being created 
     * @return {WebGLUniformLocation} The uniform location for later reference
     */
  addUniform(name, type, value) {
    let uniform = this._programInfo.uniforms[name];
    uniform = this._ctx.getUniformLocation(this._program, `u_${name}`);
    switch (type) {
      case WTCGL.TYPE_INT:
        if (!isNaN(value)) this._ctx.uniform1i(uniform, value);
        break;
      case WTCGL.TYPE_FLOAT:
        if (!isNaN(value)) this._ctx.uniform1f(uniform, value);
        break;
      case WTCGL.TYPE_V2:
        if (value instanceof Array && value.length === 2.) this._ctx.uniform2fv(uniform, value);
        break;
      case WTCGL.TYPE_V3:
        if (value instanceof Array && value.length === 3.) this._ctx.uniform3fv(uniform, value);
        break;
      case WTCGL.TYPE_V4:
        if (value instanceof Array && value.length === 4.) this._ctx.uniform4fv(uniform, value);
        break;
      case WTCGL.TYPE_BOOL:
        if (!isNaN(value)) this._ctx.uniform1i(uniform, value);
        break;}

    this._programInfo.uniforms[name] = uniform;
    return uniform;
  }

  /**
     * Adds a texture to the program and links it to a named uniform. Providing the type changes the tiling properties of the texture. Possible values for type:
     * - WTCGL.IMAGETYPE_REGULAR - No .........完整代码请登录后点击上方下载按钮下载查看