webgl+canvas实现shader着色器喷绘背景动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：动画

代码描述：webgl+canvas实现shader着色器喷绘背景动画效果代码

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

<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
<link type="text/css" rel="stylesheet" href="//repo.bfw.wiki/bfwrepo/css/reset.min.css">
<style>
    html, body {
  padding: 0px;
  margin: 0px;
  overflow: hidden;
}

canvas {
  width: 100%;
  height: 100%;
}
</style>
</head>
<body>
<!-- partial:index.partial.html -->
<script id="2d-fragment-shader" type="x-shader/x-fragment">// <![CDATA[
  #ifdef GL_ES
  precision highp float;
  #endif

  #define PI 3.14159265359;

  uniform vec2 u_resolution;
  uniform vec2 u_mouse;
  uniform float u_time;
  uniform float u_xpos;
  uniform float u_ypos;

vec3 mod289(vec3 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 mod289(vec4 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 permute(vec4 x) {
     return mod289(((x*34.0)+1.0)*x);
}

vec4 taylorInvSqrt(vec4 r)
{
  return 1.79284291400159 - 0.85373472095314 * r;
}

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);

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

  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 );

  vec3 x1 = x0 - i1 + C.xxx;
  vec3 x2 = x0 - i2 + C.yyy;
  vec3 x3 = x0 - D.yyy;

  i = mod289(i); 
  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 ));

  float n_ = 0.142857142857;
  vec3  ns = n_ * D.wyz - D.xzx;

  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);

  vec4 x_ = floor(j * ns.z);
  vec4 y_ = floor(j - 7.0 * x_ );

  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);

  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;

  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) ) );
  }

  void main() {
    vec3 color1 = vec3(75.0/255.0,144.0/255.0,210.0/255.0);
    vec3 color2 = vec3(252.0/255.0,244.0/255.0,111.0/255.0);
    vec3 color3 = vec3(244.0/255.0,238.0/255.0,87.0/255.0);
    vec3 color4 = vec3(242.0/255.0,232.0/255.0,99.0/255.0);
    vec3 color5 = vec3(242.0/255.0,205.0/255.0,96.0/255.0);
    vec3 color6 = vec3(255.0/255.0,255.0/255.0,255.0/255.0);
    vec2 lt = vec2(gl_FragCoord.x + u_xpos, gl_FragCoord.y + u_ypos);
    vec2 st = lt.xy/u_resolution.xy;
    st.x *= u_resolution.x/u_resolution.y;
    vec3 color = vec3(0.0);
    vec2 pos = vec2(st*0.6);
    float DF = 0.0;
    float a = 0.0;
    vec2 vel = vec2(u_time*.1);
    st.xy *= 0.4;
    float r = snoise(vec3(st.x,st.y,u_time * 0.1));
	  
	if(r > 0.60){
		color = color5;
	} else if(r > 0.20){
		color = color4;
	} else if(r > -0.20){
		color = color3;
	} else if(r > -0.60){
		color = color2;
	} else if(r > -2.0){
		color = color1;
	}
	  
    gl_FragColor = vec4(color,1.0);
  }
// ]]></script>
<script id="2d-vertex-shader" type="x-shader/x-vertex">// <![CDATA[
	attribute vec2 a_position;
	void main() {
		gl_Position = vec4(a_position, 0, 1);
	}
	// ]]></script>
<canvas id="glscreen"></canvas>
<!-- partial -->
<script type="text/javascript" src="//repo.bfw.wiki/bfwrepo/js/jquery-3.2.1.min.js"></script><script  >
      // set up global javascript variables

var canvas, gl; // canvas and webgl context

var shaderScript;
var shaderSource;
var vertexShader; // Vertex shader.  Not much happens in that shader, it just creates the vertex's to be drawn on
var fragmentShader; // this shader is where the magic happens. Fragment = pixel.  Vertex = kind of like "faces&qu.........完整代码请登录后点击上方下载按钮下载查看