canvas-textured-cube-qix.html 4.2 KB

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  1. <!-- Licensed under a BSD license. See license.html for license -->
  2. <!DOCTYPE html>
  3. <html>
  4. <head>
  5. <meta charset="utf-8">
  6. <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
  7. <title>Three.js - Canvas Textured Cube</title>
  8. <style>
  9. html, body {
  10. height: 100%;
  11. margin: 0;
  12. }
  13. #c {
  14. width: 100%;
  15. height: 100%;
  16. display: block;
  17. }
  18. </style>
  19. </head>
  20. <body>
  21. <canvas id="c"></canvas>
  22. </body>
  23. <!-- Import maps polyfill -->
  24. <!-- Remove this when import maps will be widely supported -->
  25. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  26. <script type="importmap">
  27. {
  28. "imports": {
  29. "three": "../../build/three.module.js"
  30. }
  31. }
  32. </script>
  33. <script type="module">
  34. import * as THREE from 'three';
  35. function main() {
  36. const canvas = document.querySelector( '#c' );
  37. const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
  38. const fov = 75;
  39. const aspect = 2; // the canvas default
  40. const near = 0.1;
  41. const far = 5;
  42. const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
  43. camera.position.z = 2;
  44. const scene = new THREE.Scene();
  45. const boxWidth = 1;
  46. const boxHeight = 1;
  47. const boxDepth = 1;
  48. const geometry = new THREE.BoxGeometry( boxWidth, boxHeight, boxDepth );
  49. const cubes = []; // just an array we can use to rotate the cubes
  50. const ctx = document.createElement( 'canvas' ).getContext( '2d' );
  51. ctx.canvas.width = 256;
  52. ctx.canvas.height = 256;
  53. ctx.fillStyle = '#FFF';
  54. ctx.fillRect( 0, 0, ctx.canvas.width, ctx.canvas.height );
  55. const texture = new THREE.CanvasTexture( ctx.canvas );
  56. const material = new THREE.MeshBasicMaterial( {
  57. map: texture,
  58. } );
  59. const cube = new THREE.Mesh( geometry, material );
  60. scene.add( cube );
  61. cubes.push( cube ); // add to our list of cubes to rotate
  62. function resizeRendererToDisplaySize( renderer ) {
  63. const canvas = renderer.domElement;
  64. const width = canvas.clientWidth;
  65. const height = canvas.clientHeight;
  66. const needResize = canvas.width !== width || canvas.height !== height;
  67. if ( needResize ) {
  68. renderer.setSize( width, height, false );
  69. }
  70. return needResize;
  71. }
  72. function rand( min, max ) {
  73. if ( max === undefined ) {
  74. max = min;
  75. min = 0;
  76. }
  77. return Math.random() * ( max - min ) + min;
  78. }
  79. function randVelocity() {
  80. return rand( 2, 4 ) * ( rand( 2 ) < 1 ? - 1 : 1 );
  81. }
  82. const maxLines = 60;
  83. const points = [
  84. { position: [ rand( 256 ), rand( 256 ) ], direction: [ randVelocity(), randVelocity() ] },
  85. { position: [ rand( 256 ), rand( 256 ) ], direction: [ randVelocity(), randVelocity() ] },
  86. ];
  87. const lineHistory = [];
  88. let lineCursor = 0;
  89. function drawCurrentLine() {
  90. const line = lineHistory[ lineCursor ];
  91. ctx.beginPath();
  92. ctx.moveTo( ...line[ 0 ] );
  93. ctx.lineTo( ...line[ 1 ] );
  94. ctx.stroke();
  95. }
  96. function drawLines( time ) {
  97. points.forEach( ( point ) => {
  98. point.position.forEach( ( position, ndx ) => {
  99. const newPosition = position + point.direction[ ndx ];
  100. if ( newPosition > 255 ) {
  101. point.direction[ ndx ] = rand( - 2, - 4 );
  102. } else if ( newPosition < 0 ) {
  103. point.direction[ ndx ] = rand( 2, 4 );
  104. }
  105. point.position[ ndx ] = newPosition;
  106. } );
  107. } );
  108. if ( lineHistory.length === maxLines ) {
  109. ctx.lineWidth = 3;
  110. ctx.strokeStyle = '#FFF';
  111. drawCurrentLine();
  112. }
  113. lineHistory[ lineCursor ] = points.map( point => point.position.slice() );
  114. ctx.lineWidth = 1;
  115. ctx.strokeStyle = hsl( time, 1, .5 );
  116. drawCurrentLine();
  117. lineCursor = ( lineCursor + 1 ) % maxLines;
  118. }
  119. function hsl( h, s, l ) {
  120. return `hsl(${h * 360 | 0},${s * 100 | 0}%,${l * 100 | 0}%)`;
  121. }
  122. function render( time ) {
  123. time *= 0.001;
  124. if ( resizeRendererToDisplaySize( renderer ) ) {
  125. const canvas = renderer.domElement;
  126. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  127. camera.updateProjectionMatrix();
  128. }
  129. drawLines( time * 0.1 );
  130. texture.needsUpdate = true;
  131. cubes.forEach( ( cube, ndx ) => {
  132. const speed = .2 + ndx * .1;
  133. const rot = time * speed;
  134. cube.rotation.x = rot;
  135. cube.rotation.y = rot;
  136. } );
  137. renderer.render( scene, camera );
  138. requestAnimationFrame( render );
  139. }
  140. requestAnimationFrame( render );
  141. }
  142. main();
  143. </script>
  144. </html>