multiple-scenes-copy-canvas.html 5.6 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 - Multiple Scenes - Copy</title>
  8. <style>
  9. canvas {
  10. width: 100%;
  11. height: 100%;
  12. display: block;
  13. }
  14. *[data-diagram] {
  15. display: inline-block;
  16. width: 5em;
  17. height: 3em;
  18. }
  19. .left {
  20. float: left;
  21. margin-right: .25em;
  22. }
  23. .right {
  24. float: right;
  25. margin-left: .25em;
  26. }
  27. p {
  28. margin: 1em auto;
  29. max-width: 500px;
  30. font-size: xx-large;
  31. }
  32. </style>
  33. </head>
  34. <body>
  35. <p>
  36. <span data-diagram="box" class="left"></span>
  37. I love boxes. Presents come in boxes.
  38. When I find a new box I'm always excited to find out what's inside.
  39. </p>
  40. <p>
  41. <span data-diagram="pyramid" class="right"></span>
  42. When I was a kid I dreamed of going on an expedition inside a pyramid
  43. and finding a undiscovered tomb full of mummies and treasure.
  44. </p>
  45. </body>
  46. <!-- Import maps polyfill -->
  47. <!-- Remove this when import maps will be widely supported -->
  48. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  49. <script type="importmap">
  50. {
  51. "imports": {
  52. "three": "../../build/three.module.js"
  53. }
  54. }
  55. </script>
  56. <script type="module">
  57. import * as THREE from 'three';
  58. import {TrackballControls} from '../../examples/jsm/controls/TrackballControls.js';
  59. function main() {
  60. const canvas = document.createElement('canvas');
  61. const renderer = new THREE.WebGLRenderer({canvas, alpha: true});
  62. renderer.setScissorTest(true);
  63. const sceneElements = [];
  64. function addScene(elem, fn) {
  65. const ctx = document.createElement('canvas').getContext('2d');
  66. elem.appendChild(ctx.canvas);
  67. sceneElements.push({elem, ctx, fn});
  68. }
  69. function makeScene(elem) {
  70. const scene = new THREE.Scene();
  71. const fov = 45;
  72. const aspect = 2; // the canvas default
  73. const near = 0.1;
  74. const far = 5;
  75. const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  76. camera.position.set(0, 1, 2);
  77. camera.lookAt(0, 0, 0);
  78. scene.add(camera);
  79. const controls = new TrackballControls(camera, elem);
  80. controls.noZoom = true;
  81. controls.noPan = true;
  82. {
  83. const color = 0xFFFFFF;
  84. const intensity = 1;
  85. const light = new THREE.DirectionalLight(color, intensity);
  86. light.position.set(-1, 2, 4);
  87. camera.add(light);
  88. }
  89. return {scene, camera, controls};
  90. }
  91. const sceneInitFunctionsByName = {
  92. 'box': (elem) => {
  93. const {scene, camera, controls} = makeScene(elem);
  94. const geometry = new THREE.BoxGeometry(1, 1, 1);
  95. const material = new THREE.MeshPhongMaterial({color: 'red'});
  96. const mesh = new THREE.Mesh(geometry, material);
  97. scene.add(mesh);
  98. return (time, rect) => {
  99. mesh.rotation.y = time * .1;
  100. camera.aspect = rect.width / rect.height;
  101. camera.updateProjectionMatrix();
  102. controls.handleResize();
  103. controls.update();
  104. renderer.render(scene, camera);
  105. };
  106. },
  107. 'pyramid': (elem) => {
  108. const {scene, camera, controls} = makeScene(elem);
  109. const radius = .8;
  110. const widthSegments = 4;
  111. const heightSegments = 2;
  112. const geometry = new THREE.SphereGeometry(radius, widthSegments, heightSegments);
  113. const material = new THREE.MeshPhongMaterial({
  114. color: 'blue',
  115. flatShading: true,
  116. });
  117. const mesh = new THREE.Mesh(geometry, material);
  118. scene.add(mesh);
  119. return (time, rect) => {
  120. mesh.rotation.y = time * .1;
  121. camera.aspect = rect.width / rect.height;
  122. camera.updateProjectionMatrix();
  123. controls.handleResize();
  124. controls.update();
  125. renderer.render(scene, camera);
  126. };
  127. },
  128. };
  129. document.querySelectorAll('[data-diagram]').forEach((elem) => {
  130. const sceneName = elem.dataset.diagram;
  131. const sceneInitFunction = sceneInitFunctionsByName[sceneName];
  132. const sceneRenderFunction = sceneInitFunction(elem);
  133. addScene(elem, sceneRenderFunction);
  134. });
  135. function render(time) {
  136. time *= 0.001;
  137. for (const {elem, fn, ctx} of sceneElements) {
  138. // get the viewport relative position of this element
  139. const rect = elem.getBoundingClientRect();
  140. const {left, right, top, bottom, width, height} = rect;
  141. const rendererCanvas = renderer.domElement;
  142. const isOffscreen =
  143. bottom < 0 ||
  144. top > window.innerHeight ||
  145. right < 0 ||
  146. left > window.innerWidth;
  147. if (!isOffscreen) {
  148. // make sure the renderer's canvas is big enough
  149. if (rendererCanvas.width < width || rendererCanvas.height < height) {
  150. renderer.setSize(width, height, false);
  151. }
  152. // make sure the canvas for this area is the same size as the area
  153. if (ctx.canvas.width !== width || ctx.canvas.height !== height) {
  154. ctx.canvas.width = width;
  155. ctx.canvas.height = height;
  156. }
  157. renderer.setScissor(0, 0, width, height);
  158. renderer.setViewport(0, 0, width, height);
  159. fn(time, rect);
  160. // copy the rendered scene to this element's canvas
  161. ctx.globalCompositeOperation = 'copy';
  162. ctx.drawImage(
  163. rendererCanvas,
  164. 0, rendererCanvas.height - height, width, height, // src rect
  165. 0, 0, width, height); // dst rect
  166. }
  167. }
  168. requestAnimationFrame(render);
  169. }
  170. requestAnimationFrame(render);
  171. }
  172. main();
  173. </script>
  174. </html>