<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
<title>Three.js - Canvas Textured Cube</title>
<style>
html, body {
height: 100%;
margin: 0;
}
#c {
width: 100%;
height: 100%;
display: block;
}
</style>
</head>
<body>
<canvas id="c"></canvas>
</body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.8.0/dist/es-module-shims.js"></script>
<script type="importmap">
{
"imports": {
"three": "../../build/three.module.js"
}
}
</script>
<script type="module">
import * as THREE from 'three';
function main() {
const canvas = document.querySelector( '#c' );
const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
const fov = 75;
const aspect = 2; // the canvas default
const near = 0.1;
const far = 5;
const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
camera.position.z = 2;
const scene = new THREE.Scene();
const boxWidth = 1;
const boxHeight = 1;
const boxDepth = 1;
const geometry = new THREE.BoxGeometry( boxWidth, boxHeight, boxDepth );
const cubes = []; // just an array we can use to rotate the cubes
const ctx = document.createElement( 'canvas' ).getContext( '2d' );
ctx.canvas.width = 256;
ctx.canvas.height = 256;
ctx.fillStyle = '#FFF';
ctx.fillRect( 0, 0, ctx.canvas.width, ctx.canvas.height );
const texture = new THREE.CanvasTexture( ctx.canvas );
const material = new THREE.MeshBasicMaterial( {
map: texture,
} );
const cube = new THREE.Mesh( geometry, material );
scene.add( cube );
cubes.push( cube ); // add to our list of cubes to rotate
function resizeRendererToDisplaySize( renderer ) {
const canvas = renderer.domElement;
const width = canvas.clientWidth;
const height = canvas.clientHeight;
const needResize = canvas.width !== width || canvas.height !== height;
if ( needResize ) {
renderer.setSize( width, height, false );
}
return needResize;
}
function rand( min, max ) {
if ( max === undefined ) {
max = min;
min = 0;
}
return Math.random() * ( max - min ) + min;
}
function randVelocity() {
return rand( 2, 4 ) * ( rand( 2 ) < 1 ? - 1 : 1 );
}
const maxLines = 60;
const points = [
{ position: [ rand( 256 ), rand( 256 ) ], direction: [ randVelocity(), randVelocity() ] },
{ position: [ rand( 256 ), rand( 256 ) ], direction: [ randVelocity(), randVelocity() ] },
];
const lineHistory = [];
let lineCursor = 0;
function drawCurrentLine() {
const line = lineHistory[ lineCursor ];
ctx.beginPath();
ctx.moveTo( ...line[ 0 ] );
ctx.lineTo( ...line[ 1 ] );
ctx.stroke();
}
function drawLines( time ) {
points.forEach( ( point ) => {
point.position.forEach( ( position, ndx ) => {
const newPosition = position + point.direction[ ndx ];
if ( newPosition > 255 ) {
point.direction[ ndx ] = rand( - 2, - 4 );
} else if ( newPosition < 0 ) {
point.direction[ ndx ] = rand( 2, 4 );
}
point.position[ ndx ] = newPosition;
} );
} );
if ( lineHistory.length === maxLines ) {
ctx.lineWidth = 3;
ctx.strokeStyle = '#FFF';
drawCurrentLine();
}
lineHistory[ lineCursor ] = points.map( point => point.position.slice() );
ctx.lineWidth = 1;
ctx.strokeStyle = hsl( time, 1, .5 );
drawCurrentLine();
lineCursor = ( lineCursor + 1 ) % maxLines;
}
function hsl( h, s, l ) {
return `hsl(${h * 360 | 0},${s * 100 | 0}%,${l * 100 | 0}%)`;
}
function render( time ) {
time *= 0.001;
if ( resizeRendererToDisplaySize( renderer ) ) {
const canvas = renderer.domElement;
camera.aspect = canvas.clientWidth / canvas.clientHeight;
camera.updateProjectionMatrix();
}
drawLines( time * 0.1 );
texture.needsUpdate = true;
cubes.forEach( ( cube, ndx ) => {
const speed = .2 + ndx * .1;
const rot = time * speed;
cube.rotation.x = rot;
cube.rotation.y = rot;
} );
renderer.render( scene, camera );
requestAnimationFrame( render );
}
requestAnimationFrame( render );
}
main();
</script>
</html>