webgl实现canvas流沙动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：粒子

代码描述：webgl实现canvas流沙动画效果代码

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;
  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;
}
/* } */
</style>

</head>

<body >
  <script id="vertexShader_particle" type="x-shader/x-vertex">
  attribute vec4 a_position;
  attribute vec3 a_colour;
  attribute vec2 a_reference;
  
  uniform vec2 u_resolution;
  
  uniform sampler2D b_velocity;
  uniform sampler2D b_position;
  uniform sampler2D b_blur;
  
  varying vec3 v_colour;
  varying float v_fogDepth;
  
  float rand(vec2 n) { 
    return fract(sin(dot(n, vec2(12.9898, 4.1414))) * 43758.5453);
  }
  
  vec3 hsv2rgb(vec3 c) {
    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
  }
  
  void main() {
    vec2 position = texture2D(b_position, a_reference).xy;
    vec2 velocity = texture2D(b_velocity, a_reference).xy;
    float size = texture2D(b_blur, position).r;
    
    vec4 pos = vec4(position / u_resolution * 2. - 1., 0., 1.);
    
    gl_Position = pos;
    gl_PointSize = 2.+size*.02;
    v_colour = vec3(1);
  }
</script>
<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_velocity" type="x-shader/x-fragment">
  #extension GL_OES_standard_derivatives : enable
  precision highp float;
  
  #define PI 3.141592653589793
  #define HPI 1.5707963267948966
  #define TAU 6.283185307179586
  #define G 0.67408
  
  uniform vec2 u_resolution;
  uniform vec2 u_mouse;
  uniform float u_time;
  uniform sampler2D s_noise;
  
  uniform sampler2D b_velocity;
  uniform sampler2D b_position;
  
  //	Simplex 3D Noise 
  //	by Ian McEwan, Ashima Arts
  //
  vec4 permute(vec4 x){return mod(((x*34.0)+1.0)*x, 289.0);}
  vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;}
  
  float rand(float n){return fract(sin(n) * 43758.5453123);}
  float rand(vec2 n) { 
    return fract(sin(dot(n, vec2(12.9898, 4.1414))) * 43758.5453);
  }
  float snoise(vec3 v){ 
    const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;
    const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);

  // First corner
    vec3 i  = floor(v + dot(v, C.yyy) );
    vec3 x0 =   v - i + dot(i, C.xxx) ;

  // Other corners
    vec3 g = step(x0.yzx, x0.xyz);
    vec3 l = 1.0 - g;
    vec3 i1 = min( g.xyz, l.zxy );
    vec3 i2 = max( g.xyz, l.zxy );

    //  x0 = x0 - 0. + 0.0 * C 
    vec3 x1 = x0 - i1 + 1.0 * C.xxx;
    vec3 x2 = x0 - i2 + 2.0 * C.xxx;
    vec3 x3 = x0 - 1. + 3.0 * C.xxx;

  // Permutations
    i = mod(i, 289.0 ); 
    vec4 p = permute( permute( permute( 
               i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
             + i.y + vec4(0.0, i1.y, i2.y, 1.0 )) 
             + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));

  // Gradients
  // ( N*N points uniformly over a square, mapped onto an octahedron.)
    float n_ = 1.0/7.0; // N=7
    vec3  ns = n_ * D.wyz - D.xzx;

    vec4 j = p - 49.0 * floor(p * ns.z *ns.z);  //  mod(p,N*N)

    vec4 x_ = floor(j * ns.z);
    vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)

    vec4 x = x_ *ns.x + ns.yyyy;
    vec4 y = y_ *ns.x + ns.yyyy;
    vec4 h = 1.0 - abs(x) - abs(y);

    vec4 b0 = vec4( x.xy, y.xy );
    vec4 b1 = vec4( x.zw, y.zw );

    vec4 s0 = floor(b0)*2.0 + 1.0;
    vec4 s1 = floor(b1)*2.0 + 1.0;
    vec4 sh = -step(h, vec4(0.0));

    vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
    vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;

    vec3 p0 = vec3(a0.xy,h.x);
    vec3 p1 = vec3(a0.zw,h.y);
    vec3 p2 = vec3(a1.xy,h.z);
    vec3 p3 = vec3(a1.zw,h.w);

  //Normalise gradients
    vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
    p0 *= norm.x;
    p1 *= norm.y;
    p2 *= norm.z;
    p3 *= norm.w;

  // Mix final noise value
    vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
    m = m * m;
    return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), 
                                  dot(p2,x2), dot(p3,x3) ) );
  }
  
  float noise21(vec2 n) {
    const vec2 d = vec2(0.0, 1.0);
    vec2 b = floor(n), f = smoothstep(vec2(0.0), vec2(1.0), fract(n));
    return mix(mix(rand(b), rand(b + d.yx), f.x), mix(rand(b + d.xy), rand(b + d.yy), f.x), f.y);
  }
  
  void main() {
    vec2 uv = gl_FragCoord.xy / u_resolution.xy;
    vec2 position = texture2D(b_position, uv).xy;
    vec2 v.........完整代码请登录后点击上方下载按钮下载查看