twgl.js/examples/2d-lines.html
Gregg Tavares 67551111b4 Fix CSS
There was a time when 100vh was correct but mobile browsers changed.
2025-10-13 14:54:12 -07:00

179 lines
5.3 KiB
HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf8">
<!--
@license twgl.js Copyright (c) 2015, Gregg Tavares All Rights Reserved.
Available via the MIT license.
see: http://github.com/greggman/twgl.js for details
-->
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
<meta property="og:title" content="TWGL.js - 2d-lines" />
<meta property="og:type" content="website" />
<meta property="og:image" content="http://twgljs.org/examples/screenshots/2d-lines.png" />
<meta property="og:description" content="TWGL.js - 2d-lines" />
<meta property="og:url" content="http://twgljs.org" />
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:site" content="@greggman">
<meta name="twitter:creator" content="@greggman">
<meta name="twitter:domain" content="twgljs.org">
<meta name="twitter:title" content="TWGL.js - 2d-lines">
<meta name="twitter:url" content="http://twgljs.org/examples/2d-lines.html">
<meta name="twitter:description" content="TWGL.js - 2d-lines">
<meta name="twitter:image:src" content="http://twgljs.org/examples/screenshots/2d-lines.png">
<link href="/resources/images/twgljs-icon.png" rel="shortcut icon" type="image/png">
<title>twgl.js - 2d lines</title>
<style>
html, body {
margin: 0;
font-family: monospace;
height: 100%;
}
canvas {
display: block;
width: 100%;
height: 100%;
}
#b {
position: absolute;
top: 10px;
width: 100%;
text-align: center;
z-index: 2;
color: white;
}
a:visited, a:link, a:active {
color: white;
}
</style>
</head>
<body>
<canvas id="c"></canvas>
<div id="b"><a href="http://twgljs.org">twgl.js - 2d lines</a></div>
</body>
<script src="../3rdparty/chroma.min.js"></script>
<script type="module">
import * as twgl from '../dist/7.x/twgl-full.module.js';
const m4 = twgl.m4;
twgl.setDefaults({attribPrefix: "a_"});
const gl = document.getElementById("c").getContext("webgl");
const vs = `
uniform mat4 u_matrix;
uniform vec4 u_offsets;
uniform vec4 u_centers;
uniform vec4 u_mult;
attribute vec2 a_position;
attribute vec4 a_color;
varying vec4 v_color;
#define PI 3.14159
void main() {
vec2 offset = mix(u_offsets.xz, u_offsets.yw, a_position.y);
float a = u_mult.x * a_position.x * PI * 2.0 + offset.x;//mix(u_offsets.x, u_offsets.y, a_position.y);
float c = cos(a * u_mult.y);
vec2 xy = vec2(
cos(a),
sin(a)) * c * offset.y +
mix(u_centers.xy, u_centers.zw, a_position.y);
gl_Position = u_matrix * vec4(xy, 0, 1);
v_color = a_color;
}
`;
const fs = `
precision mediump float;
varying vec4 v_color;
void main() {
gl_FragColor = v_color;
}
`;
const programInfo = twgl.createProgramInfo(gl, [vs, fs]);
const numLines = 100;
const arrays = {
position: twgl.primitives.createAugmentedTypedArray(2, numLines * 2),
color: twgl.primitives.createAugmentedTypedArray(3, numLines * 2, Uint8Array),
};
function rand(min, max) {
return min + Math.random() * (max - min);
}
const hue = rand(0, 360);
for (let ii = 0; ii < numLines; ++ii) {
const u = ii / numLines;
const h = (360 + hue + (Math.abs(u - 0.5) * 100)) % 360;
const s = Math.sin(u * Math.PI * 2) * 0.25 + 0.75;
const v = 1;
const color = chroma.hsv(h, s, v);
arrays.position.push(u, 1);
arrays.color.push(color.rgb());
arrays.position.push(u, 0);
arrays.color.push(color.brighten().desaturate().rgb());
}
const bufferInfo = twgl.createBufferInfoFromArrays(gl, arrays);
const offsets = [0, 0, 0, 1];
const centers = [0, 0, 0, 0];
const mult = [1, 2, 0, 0];
const uniforms = {
u_matrix: m4.identity(),
u_offsets: offsets,
u_centers: centers,
u_mult: mult,
};
function render(time) {
time *= 0.001;
twgl.resizeCanvasToDisplaySize(gl.canvas);
gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
gl.enable(gl.DEPTH_TEST);
gl.enable(gl.CULL_FACE);
gl.clearColor(0, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
offsets[0] = Math.sin(time);
offsets[1] = Math.sin(time * 0.13) * Math.PI * 2;
offsets[2] = Math.sin(time * 0.43) * 0.5 + 1.0;
offsets[3] = Math.cos(time * 0.17) * 0.5 + 0.5;
centers[0] = Math.sin(time * 0.163) * 0.5;
centers[1] = Math.cos(time * 0.267) * 0.5;
centers[2] = Math.sin(time * 0.367) * 0.5;
centers[3] = Math.cos(time * 0.497) * 0.5;
mult[1] = (Math.sin(time * 0.1) * 0.5 + 0.5) * 3;
const aspect = gl.canvas.clientWidth / gl.canvas.clientHeight;
m4.ortho(-aspect, aspect, 1, -1, -1, 1, uniforms.u_matrix);
gl.useProgram(programInfo.program);
twgl.setBuffersAndAttributes(gl, programInfo, bufferInfo);
twgl.setUniforms(programInfo, uniforms);
twgl.drawBufferInfo(gl, bufferInfo, gl.LINES);
requestAnimationFrame(render);
}
requestAnimationFrame(render);
</script>
</html>