Skip to content

Instantly share code, notes, and snippets.

@greggman
Created April 16, 2025 21:56
Show Gist options
  • Save greggman/722b22d2adeb7bfba987cffe20efb899 to your computer and use it in GitHub Desktop.
Save greggman/722b22d2adeb7bfba987cffe20efb899 to your computer and use it in GitHub Desktop.
WebGL2 - Textures - (speed check, update 100 textures, no mips)

WebGL2 - Textures - (speed check, update 100 textures, no mips)

view on jsgist

@import url("https://webgl2fundamentals.org/webgl/resources/webgl-tutorials.css");
body {
margin: 0;
}
canvas {
width: 100vw;
height: 100vh;
display: block;
}
#ui {
width: 100px;
background-color: red;
padding: 0.25em;
}
body, document {
user-select: none;
-webkit-user-select: none;
-moz-user-select: none;
-o-user-select: none;
-ms-user-select: none;
}
#uiContainer {
left: 10px;
top: 130px;
}
#info {
position: absolute;
left: 0;
top: 0;
background-color: black;
color: white;
margin: 0;
padding: 0.5em;
}
<canvas id="canvas"></canvas>
<pre id="info"></pre>
<!--
for most samples webgl-utils only provides shader compiling/linking and
canvas resizing because why clutter the examples with code that's the same in every sample.
See https://webgl2fundamentals.org/webgl/lessons/webgl-boilerplate.html
and https://webgl2fundamentals.org/webgl/lessons/webgl-resizing-the-canvas.html
for webgl-utils, m3, m4, and webgl-lessons-ui.
-->
<script src="https://webgl2fundamentals.org/webgl/resources/webgl-utils.js"></script>
<script src="https://webgl2fundamentals.org/webgl/resources/m4.js"></script>
// WebGL2 - Textures - Mips - Depth
// from https://webgl2fundamentals.org/webgl/webgl-3d-textures-mips-tri-linear.html
import GUI from 'https://webgpufundamentals.org/3rdparty/muigui-0.x.module.js';
"use strict";
var vertexShaderSource = `#version 300 es
// an attribute is an input (in) to a vertex shader.
// It will receive data from a buffer
in vec4 a_position;
in vec2 a_texcoord;
// A matrix to transform the positions by
uniform mat4 u_matrix;
// a varying to pass the texture coordinates to the fragment shader
out vec2 v_texcoord;
// all shaders have a main function
void main() {
// Multiply the position by the matrix.
gl_Position = u_matrix * a_position;
// Pass the texcoord to the fragment shader.
v_texcoord = a_texcoord;
}
`;
var fragmentShaderSource = `#version 300 es
precision highp float;
// Passed in from the vertex shader.
in vec2 v_texcoord;
// The texture.
uniform sampler2D u_texture;
// we need to declare an output for the fragment shader
out vec4 outColor;
void main() {
outColor = texture(u_texture, v_texcoord);
}
`;
const maxTextures = 100;
var zDepth = 50;
function main() {
// Get A WebGL context
/** @type {HTMLCanvasElement} */
var canvas = document.querySelector("#canvas");
var gl = canvas.getContext("webgl2", {antialias: false});
if (!gl) {
return;
}
// Use our boilerplate utils to compile the shaders and link into a program
var program = webglUtils.createProgramFromSources(gl,
[vertexShaderSource, fragmentShaderSource]);
// look up where the vertex data needs to go.
var positionAttributeLocation = gl.getAttribLocation(program, "a_position");
var texcoordAttributeLocation = gl.getAttribLocation(program, "a_texcoord");
// look up uniform locations
var matrixLocation = gl.getUniformLocation(program, "u_matrix");
// Create a buffer
var positionBuffer = gl.createBuffer();
// Create a vertex array object (attribute state)
var vao = gl.createVertexArray();
// and make it the one we're currently working with
gl.bindVertexArray(vao);
// Turn on the attribute
gl.enableVertexAttribArray(positionAttributeLocation);
// Bind it to ARRAY_BUFFER (think of it as ARRAY_BUFFER = positionBuffer)
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
// Set Geometry.
setGeometry(gl);
// Tell the attribute how to get data out of positionBuffer (ARRAY_BUFFER)
{
const size = 3; // 3 components per iteration
const type = gl.FLOAT; // the data is 32bit floats
const normalize = false; // don't normalize the data
const stride = 0; // 0 = move forward size * sizeof(type) each iteration to get the next position
const offset = 0; // start at the beginning of the buffer
gl.vertexAttribPointer(
positionAttributeLocation, size, type, normalize, stride, offset);
}
// create the texcoord buffer, make it the current ARRAY_BUFFER
// and copy in the texcoord values
var texcoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, texcoordBuffer);
setTexcoords(gl);
// Turn on the attribute
gl.enableVertexAttribArray(texcoordAttributeLocation);
// Tell the attribute how to get data out of texcoordBuffer (ARRAY_BUFFER)
{
const size = 2; // 2 components per iteration
const type = gl.FLOAT; // the data is 32bit floating point values
const normalize = true; // convert from 0-255 to 0.0-1.0
const stride = 0; // 0 = move forward size * sizeof(type) each iteration to get the next color
const offset = 0; // start at the beginning of the buffer
gl.vertexAttribPointer(
texcoordAttributeLocation, size, type, normalize, stride, offset);
}
const size = 2048;
const half = size / 2;
const ctx = document.createElement('canvas').getContext('2d');
ctx.canvas.width = size;
ctx.canvas.height = size;
const hsl = (h, s, l) => `hsl(${h * 360 | 0}, ${s * 100}%, ${l * 100 | 0}%)`;
function update2DCanvas(time) {
time *= 0.0001;
ctx.fillStyle = hsl(time * 0.1 + 0.5, 1, 0.125)
ctx.fillRect(0, 0, size, size);
ctx.font = `${size * 0.5 | 0}px monospace`;
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.save();
ctx.translate(half, half);
const num = 20;
const t = (time * 1000).toFixed(0);
ctx.scale(0.1, 0.1);
for (let i = 0; i < num; ++i) {
ctx.fillStyle = hsl(i / num * 0.4 + time * 0.1, 1, i % 2 * 0.5);
ctx.fillText(t, 0, 0);
ctx.translate(0, size / num * 0.5);
ctx.scale(1.1, 1.1);
}
ctx.restore();
}
update2DCanvas(0);
const textures = [];
for (let i = 0; i < maxTextures; ++i) {
// Create a texture.
const texture = gl.createTexture();
// use texture unit 0
gl.activeTexture(gl.TEXTURE0 + 0);
// bind to the TEXTURE_2D bind point of texture unit 0
gl.bindTexture(gl.TEXTURE_2D, texture);
// Now that the image has loaded make copy it to the texture.
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texStorage2D(gl.TEXTURE_2D, 1, gl.RGBA8, size, size);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, ctx.canvas);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
//gl.generateMipmap(gl.TEXTURE_2D);
textures.push(texture);
}
function degToRad(d) {
return d * Math.PI / 180;
}
// First let's make some variables
// to hold the translation,
var fieldOfViewRadians = degToRad(60);
let ticks = [{time: 0, deltaTime: 1/60}];
let deltaAvg = 0;
const info = document.querySelector('#info');
const params = {
copyCount: 40,
};
const gui = new GUI();
gui.add(params, 'copyCount', 1, maxTextures, 1);
function render(time) {
let last = ticks[ticks.length - 1]
let deltaCur = time - last.time;
deltaAvg = ((deltaAvg * ticks.length) + deltaCur) / (ticks.length + 1)
ticks.push({time: time, deltaTime: deltaCur})
if (ticks.length > 60) {
deltaAvg = ((deltaAvg * ticks.length) - ticks[0].deltaTime) / (ticks.length - 1)
ticks.shift()
}
info.textContent = `fps: ${(1000 / deltaAvg).toFixed(0)}`;
webglUtils.resizeCanvasToDisplaySize(gl.canvas, window.devicePixelRatio);
update2DCanvas(time);
for (let i = 0; i < params.copyCount; ++i) {
gl.bindTexture(gl.TEXTURE_2D, textures[i]);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, ctx.canvas);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
//gl.generateMipmap(gl.TEXTURE_2D);
}
gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
gl.clearColor(0, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
// turn on depth testing
gl.enable(gl.DEPTH_TEST);
// tell webgl to cull faces
gl.enable(gl.CULL_FACE);
// Tell it to use our program (pair of shaders)
gl.useProgram(program);
// Bind the attribute/buffer set we want.
gl.bindVertexArray(vao);
// Compute the matrix
const aspect = gl.canvas.clientWidth / gl.canvas.clientHeight;
const zNear = 1;
const zFar = 2000;
const projectionMatrix = m4.perspective(fieldOfViewRadians, aspect, zNear, zFar);
const cameraPosition = [0, 0, 2];
const up = [0, 1, 0];
const target = [0, 0, 0];
// Compute the camera's matrix using look at.
const cameraMatrix = m4.lookAt(cameraPosition, target, up);
// Make a view matrix from the camera matrix.
const viewMatrix = m4.inverse(cameraMatrix);
const viewProjectionMatrix = m4.multiply(projectionMatrix, viewMatrix);
const settings = [
{ x: -1, y: 1, zRot: 0, magFilter: gl.NEAREST, minFilter: gl.NEAREST, },
{ x: 0, y: 1, zRot: 0, magFilter: gl.LINEAR, minFilter: gl.LINEAR, },
{ x: 1, y: 1, zRot: 0, magFilter: gl.LINEAR, minFilter: gl.NEAREST_MIPMAP_NEAREST, },
{ x: -1, y: -1, zRot: 1, magFilter: gl.LINEAR, minFilter: gl.LINEAR_MIPMAP_NEAREST, },
{ x: 0, y: -1, zRot: 1, magFilter: gl.LINEAR, minFilter: gl.NEAREST_MIPMAP_LINEAR, },
{ x: 1, y: -1, zRot: 1, magFilter: gl.LINEAR, minFilter: gl.LINEAR_MIPMAP_LINEAR, },
];
const xSpacing = 1.2;
const ySpacing = 0.7;
for (let j = 0; j < maxTextures; j += 6) {
settings.forEach(function(s, i) {
if (j + i >= maxTextures) {
return;
}
gl.bindTexture(gl.TEXTURE_2D, textures[j + i]);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, s.minFilter);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, s.magFilter);
let matrix = m4.translate(viewProjectionMatrix, s.x * xSpacing + j * 0.1, s.y * ySpacing, -zDepth * 0.5);
matrix = m4.zRotate(matrix, s.zRot * Math.PI);
matrix = m4.scale(matrix, 1, 1, zDepth);
// Set the matrix.
gl.uniformMatrix4fv(matrixLocation, false, matrix);
// Draw the geometry.
gl.drawArrays(gl.TRIANGLES, 0, 1 * 6);
});
}
requestAnimationFrame(render);
}
requestAnimationFrame(render);
}
// Fill the current ARRAY_BUFFER buffer
// with the values that define a plane.
function setGeometry(gl) {
var positions = new Float32Array([
-0.5, 0.5, -0.5,
0.5, 0.5, -0.5,
-0.5, 0.5, 0.5,
-0.5, 0.5, 0.5,
0.5, 0.5, -0.5,
0.5, 0.5, 0.5,
]);
gl.bufferData(gl.ARRAY_BUFFER, positions, gl.STATIC_DRAW);
}
// Fill the current ARRAY_BUFFER buffer
// with texture coordinates for a plane
function setTexcoords(gl) {
gl.bufferData(
gl.ARRAY_BUFFER,
new Float32Array([
0, 0,
1, 0,
0, zDepth,
0, zDepth,
1, 0,
1, zDepth,
]),
gl.STATIC_DRAW);
}
main();
// This is needed if the images are not on the same domain
// NOTE: The server providing the images must give CORS permissions
// in order to be able to use the image with WebGL. Most sites
// do NOT give permission.
// See: http://webgl2fundamentals.org/webgl/lessons/webgl-cors-permission.html
function requestCORSIfNotSameOrigin(img, url) {
if ((new URL(url, window.location.href)).origin !== window.location.origin) {
img.crossOrigin = "";
}
}
{"name":"WebGL2 - Textures - (speed check, update 100 textures, no mips) ","settings":{},"filenames":["index.html","index.css","index.js"]}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment