canvas实现无尽循环动画效果代码-html代码-BFW代码库

canvas实现无尽循环动画效果代码

代码语言：html

所属分类：动画

代码描述：canvas实现无尽循环动画效果代码

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

<!DOCTYPE html>
<html lang="en" >

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


  
</head>

<body translate="no">
  
  
      <script  >
const dpr = Math.max(1, .5 * window.devicePixelRatio);
const canvas = document.createElement("canvas");

document.body.innerHTML = "";
document.body.appendChild(canvas);
document.body.style = "margin:0;overflow:hidden;";
canvas.style.width = "100%";
canvas.style.height = "auto";
canvas.style.objectFit = "contain";

const vertexSource = `#version 300 es
#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif

in vec4 position;

void main(void) {
    gl_Position = position;
}
`;
const fragmentSource = `#version 300 es
/*********
 * made by Matthias Hurrle (@atzedent) 
 */
precision highp float;
out vec4 O;
uniform vec2 resolution;
uniform float time;
#define R resolution
#define T time
#define TAU 6.312853
#define hue(a) (.6+.6*cos(25.13*(a)+vec3(0,83,21)))

void main(void) {
  vec2 uv = (gl_FragCoord.xy-.5*R)/min(R.x, R.y);
  vec3 col = vec3(0);
  const float steps = 140.;
  float n = steps;

  for (float i = .0; i < steps; i++) {
    float k = i/steps;
    vec2 p = vec2(sin(k*TAU), cos(k*TAU));
    p *= sin(-T+k*42.)*.35;
    float d = pow(distance(p, uv)*.5, i);
    if (d < n) {
      col = vec3(1.-k);
      n = d;
    }
  }

  col = hue(sqrt(col));

  O = vec4(col, 1);
}
`;
function compile(shader, source) {
  gl.shaderSource(shader, source);
  gl.compileShader(shader);

  if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
    console.error(gl.getShaderInfoLog(shader));
  }
}

let gl,programs = [],vertices,buffer;

function setup() {
  gl = canvas.getContext("webgl2");
  const vs = gl.createShader(gl.VERTEX_SHADER);

  compile(vs, vertexSource);

  shaders = [fragmentSource];
  programs = shaders.map(() => gl.createProgra.........完整代码请登录后点击上方下载按钮下载查看