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- <!-- 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 Labels Scale to Fit</title>
- <style>
- html, body {
- height: 100%;
- margin: 0;
- }
- #c {
- width: 100%;
- height: 100%;
- display: block;
- }
- </style>
- </head>
- <body>
- <canvas id="c"></canvas>
- </body>
- <script type="importmap">
- {
- "imports": {
- "three": "../../build/three.module.js",
- "three/addons/": "../../examples/jsm/"
- }
- }
- </script>
- <script type="module">
- import * as THREE from 'three';
- import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
- 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 = 50;
- const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
- camera.position.set( 0, 2, 5 );
- const controls = new OrbitControls( camera, canvas );
- controls.target.set( 0, 2, 0 );
- controls.update();
- const scene = new THREE.Scene();
- scene.background = new THREE.Color( 'white' );
- function addLight( position ) {
- const color = 0xFFFFFF;
- const intensity = 3;
- const light = new THREE.DirectionalLight( color, intensity );
- light.position.set( ...position );
- scene.add( light );
- scene.add( light.target );
- }
- addLight( [ - 3, 1, 1 ] );
- addLight( [ 2, 1, .5 ] );
- const bodyRadiusTop = .4;
- const bodyRadiusBottom = .2;
- const bodyHeight = 2;
- const bodyRadialSegments = 6;
- const bodyGeometry = new THREE.CylinderGeometry(
- bodyRadiusTop, bodyRadiusBottom, bodyHeight, bodyRadialSegments );
- const headRadius = bodyRadiusTop * 0.8;
- const headLonSegments = 12;
- const headLatSegments = 5;
- const headGeometry = new THREE.SphereGeometry(
- headRadius, headLonSegments, headLatSegments );
- const labelGeometry = new THREE.PlaneGeometry( 1, 1 );
- function makeLabelCanvas( baseWidth, size, name ) {
- const borderSize = 2;
- const ctx = document.createElement( 'canvas' ).getContext( '2d' );
- const font = `${size}px bold sans-serif`;
- ctx.font = font;
- // measure how long the name will be
- const textWidth = ctx.measureText( name ).width;
- const doubleBorderSize = borderSize * 2;
- const width = baseWidth + doubleBorderSize;
- const height = size + doubleBorderSize;
- ctx.canvas.width = width;
- ctx.canvas.height = height;
- // need to set font again after resizing canvas
- ctx.font = font;
- ctx.textBaseline = 'middle';
- ctx.textAlign = 'center';
- ctx.fillStyle = 'blue';
- ctx.fillRect( 0, 0, width, height );
- // scale to fit but don't stretch
- const scaleFactor = Math.min( 1, baseWidth / textWidth );
- ctx.translate( width / 2, height / 2 );
- ctx.scale( scaleFactor, 1 );
- ctx.fillStyle = 'white';
- ctx.fillText( name, 0, 0 );
- return ctx.canvas;
- }
- function makePerson( x, labelWidth, size, name, color ) {
- const canvas = makeLabelCanvas( labelWidth, size, name );
- const texture = new THREE.CanvasTexture( canvas );
- // because our canvas is likely not a power of 2
- // in both dimensions set the filtering appropriately.
- texture.minFilter = THREE.LinearFilter;
- texture.wrapS = THREE.ClampToEdgeWrapping;
- texture.wrapT = THREE.ClampToEdgeWrapping;
- const labelMaterial = new THREE.MeshBasicMaterial( {
- map: texture,
- side: THREE.DoubleSide,
- transparent: true,
- } );
- const bodyMaterial = new THREE.MeshPhongMaterial( {
- color,
- flatShading: true,
- } );
- const root = new THREE.Object3D();
- root.position.x = x;
- const body = new THREE.Mesh( bodyGeometry, bodyMaterial );
- root.add( body );
- body.position.y = bodyHeight / 2;
- const head = new THREE.Mesh( headGeometry, bodyMaterial );
- root.add( head );
- head.position.y = bodyHeight + headRadius * 1.1;
- const label = new THREE.Mesh( labelGeometry, labelMaterial );
- root.add( label );
- label.position.y = bodyHeight * 4 / 5;
- label.position.z = bodyRadiusTop * 1.01;
- // if units are meters then 0.01 here makes size
- // of the label into centimeters.
- const labelBaseScale = 0.01;
- label.scale.x = canvas.width * labelBaseScale;
- label.scale.y = canvas.height * labelBaseScale;
- scene.add( root );
- return root;
- }
- makePerson( - 3, 150, 32, 'Purple People Eater', 'purple' );
- makePerson( - 0, 150, 32, 'Green Machine', 'green' );
- makePerson( + 3, 150, 32, 'Red Menace', 'red' );
- 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 render() {
- if ( resizeRendererToDisplaySize( renderer ) ) {
- const canvas = renderer.domElement;
- camera.aspect = canvas.clientWidth / canvas.clientHeight;
- camera.updateProjectionMatrix();
- }
- renderer.render( scene, camera );
- requestAnimationFrame( render );
- }
- requestAnimationFrame( render );
- }
- main();
- </script>
- </html>
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