indexed-textures-picking-and-highlighting.html 14 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 - Indexed Textures - Picking and Highlighting</title>
  8. <style>
  9. html, body {
  10. height: 100%;
  11. margin: 0;
  12. font-family: sans-serif;
  13. }
  14. #c {
  15. width: 100%; /* let our container decide our size */
  16. height: 100%;
  17. display: block;
  18. }
  19. #container {
  20. position: relative; /* makes this the origin of its children */
  21. width: 100%;
  22. height: 100%;
  23. overflow: hidden;
  24. }
  25. #labels {
  26. position: absolute; /* let us position ourself inside the container */
  27. z-index: 0; /* make a new stacking context so children don't sort with rest of page */
  28. left: 0; /* make our position the top left of the container */
  29. top: 0;
  30. color: white;
  31. }
  32. #labels>div {
  33. position: absolute; /* let us position them inside the container */
  34. left: 0; /* make their default position the top left of the container */
  35. top: 0;
  36. cursor: pointer; /* change the cursor to a hand when over us */
  37. font-size: small;
  38. user-select: none; /* don't let the text get selected */
  39. pointer-events: none; /* make us invisible to the pointer */
  40. text-shadow: /* create a black outline */
  41. -1px -1px 0 #000,
  42. 0 -1px 0 #000,
  43. 1px -1px 0 #000,
  44. 1px 0 0 #000,
  45. 1px 1px 0 #000,
  46. 0 1px 0 #000,
  47. -1px 1px 0 #000,
  48. -1px 0 0 #000;
  49. }
  50. #labels>div:hover {
  51. color: red;
  52. }
  53. </style>
  54. </head>
  55. <body>
  56. <div id="container">
  57. <canvas id="c"></canvas>
  58. <div id="labels"></div>
  59. </div>
  60. </body>
  61. <!-- Import maps polyfill -->
  62. <!-- Remove this when import maps will be widely supported -->
  63. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  64. <script type="importmap">
  65. {
  66. "imports": {
  67. "three": "../../build/three.module.js",
  68. "three/addons/": "../../examples/jsm/"
  69. }
  70. }
  71. </script>
  72. <script type="module">
  73. import * as THREE from 'three';
  74. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  75. function main() {
  76. const canvas = document.querySelector( '#c' );
  77. const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
  78. const fov = 60;
  79. const aspect = 2; // the canvas default
  80. const near = 0.1;
  81. const far = 10;
  82. const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
  83. camera.position.z = 2.5;
  84. const controls = new OrbitControls( camera, canvas );
  85. controls.enableDamping = true;
  86. controls.enablePan = false;
  87. controls.minDistance = 1.2;
  88. controls.maxDistance = 4;
  89. controls.update();
  90. const scene = new THREE.Scene();
  91. scene.background = new THREE.Color( '#246' );
  92. const pickingScene = new THREE.Scene();
  93. pickingScene.background = new THREE.Color( 0 );
  94. const tempColor = new THREE.Color();
  95. function get255BasedColor( color ) {
  96. tempColor.set( color );
  97. const base = tempColor.toArray().map( v => v * 255 );
  98. base.push( 255 ); // alpha
  99. return base;
  100. }
  101. const maxNumCountries = 512;
  102. const paletteTextureWidth = maxNumCountries;
  103. const paletteTextureHeight = 1;
  104. const palette = new Uint8Array( paletteTextureWidth * 4 );
  105. const paletteTexture = new THREE.DataTexture( palette, paletteTextureWidth, paletteTextureHeight );
  106. paletteTexture.minFilter = THREE.NearestFilter;
  107. paletteTexture.magFilter = THREE.NearestFilter;
  108. paletteTexture.colorSpace = THREE.SRGBColorSpace;
  109. const selectedColor = get255BasedColor( 'red' );
  110. const unselectedColor = get255BasedColor( '#444' );
  111. const oceanColor = get255BasedColor( 'rgb(100,200,255)' );
  112. resetPalette();
  113. function setPaletteColor( index, color ) {
  114. palette.set( color, index * 4 );
  115. }
  116. function resetPalette() {
  117. // make all colors the unselected color
  118. for ( let i = 1; i < maxNumCountries; ++ i ) {
  119. setPaletteColor( i, unselectedColor );
  120. }
  121. // set the ocean color (index #0)
  122. setPaletteColor( 0, oceanColor );
  123. paletteTexture.needsUpdate = true;
  124. }
  125. {
  126. const loader = new THREE.TextureLoader();
  127. const geometry = new THREE.SphereGeometry( 1, 64, 32 );
  128. const indexTexture = loader.load( 'resources/data/world/country-index-texture.png', render );
  129. indexTexture.minFilter = THREE.NearestFilter;
  130. indexTexture.magFilter = THREE.NearestFilter;
  131. const pickingMaterial = new THREE.MeshBasicMaterial( { map: indexTexture } );
  132. pickingScene.add( new THREE.Mesh( geometry, pickingMaterial ) );
  133. const fragmentShaderReplacements = [
  134. {
  135. from: '#include <common>',
  136. to: `
  137. #include <common>
  138. uniform sampler2D indexTexture;
  139. uniform sampler2D paletteTexture;
  140. uniform float paletteTextureWidth;
  141. `,
  142. },
  143. {
  144. from: '#include <color_fragment>',
  145. to: `
  146. #include <color_fragment>
  147. {
  148. vec4 indexColor = texture2D(indexTexture, vMapUv);
  149. float index = indexColor.r * 255.0 + indexColor.g * 255.0 * 256.0;
  150. vec2 paletteUV = vec2((index + 0.5) / paletteTextureWidth, 0.5);
  151. vec4 paletteColor = texture2D(paletteTexture, paletteUV);
  152. // diffuseColor.rgb += paletteColor.rgb; // white outlines
  153. diffuseColor.rgb = paletteColor.rgb - diffuseColor.rgb; // black outlines
  154. }
  155. `,
  156. },
  157. ];
  158. const texture = loader.load( 'resources/data/world/country-outlines-4k.png', render );
  159. const material = new THREE.MeshBasicMaterial( { map: texture } );
  160. material.onBeforeCompile = function ( shader ) {
  161. fragmentShaderReplacements.forEach( ( rep ) => {
  162. shader.fragmentShader = shader.fragmentShader.replace( rep.from, rep.to );
  163. } );
  164. shader.uniforms.paletteTexture = { value: paletteTexture };
  165. shader.uniforms.indexTexture = { value: indexTexture };
  166. shader.uniforms.paletteTextureWidth = { value: paletteTextureWidth };
  167. };
  168. scene.add( new THREE.Mesh( geometry, material ) );
  169. }
  170. async function loadJSON( url ) {
  171. const req = await fetch( url );
  172. return req.json();
  173. }
  174. let numCountriesSelected = 0;
  175. let countryInfos;
  176. async function loadCountryData() {
  177. countryInfos = await loadJSON( 'resources/data/world/country-info.json' ); /* threejs.org: url */
  178. const lonFudge = Math.PI * 1.5;
  179. const latFudge = Math.PI;
  180. // these helpers will make it easy to position the boxes
  181. // We can rotate the lon helper on its Y axis to the longitude
  182. const lonHelper = new THREE.Object3D();
  183. // We rotate the latHelper on its X axis to the latitude
  184. const latHelper = new THREE.Object3D();
  185. lonHelper.add( latHelper );
  186. // The position helper moves the object to the edge of the sphere
  187. const positionHelper = new THREE.Object3D();
  188. positionHelper.position.z = 1;
  189. latHelper.add( positionHelper );
  190. const labelParentElem = document.querySelector( '#labels' );
  191. for ( const countryInfo of countryInfos ) {
  192. const { lat, lon, min, max, name } = countryInfo;
  193. // adjust the helpers to point to the latitude and longitude
  194. lonHelper.rotation.y = THREE.MathUtils.degToRad( lon ) + lonFudge;
  195. latHelper.rotation.x = THREE.MathUtils.degToRad( lat ) + latFudge;
  196. // get the position of the lat/lon
  197. positionHelper.updateWorldMatrix( true, false );
  198. const position = new THREE.Vector3();
  199. positionHelper.getWorldPosition( position );
  200. countryInfo.position = position;
  201. // compute the area for each country
  202. const width = max[ 0 ] - min[ 0 ];
  203. const height = max[ 1 ] - min[ 1 ];
  204. const area = width * height;
  205. countryInfo.area = area;
  206. // add an element for each country
  207. const elem = document.createElement( 'div' );
  208. elem.textContent = name;
  209. labelParentElem.appendChild( elem );
  210. countryInfo.elem = elem;
  211. }
  212. requestRenderIfNotRequested();
  213. }
  214. loadCountryData();
  215. const tempV = new THREE.Vector3();
  216. const cameraToPoint = new THREE.Vector3();
  217. const cameraPosition = new THREE.Vector3();
  218. const normalMatrix = new THREE.Matrix3();
  219. const settings = {
  220. minArea: 20,
  221. maxVisibleDot: - 0.2,
  222. };
  223. function updateLabels() {
  224. // exit if we have not loaded the data yet
  225. if ( ! countryInfos ) {
  226. return;
  227. }
  228. const large = settings.minArea * settings.minArea;
  229. // get a matrix that represents a relative orientation of the camera
  230. normalMatrix.getNormalMatrix( camera.matrixWorldInverse );
  231. // get the camera's position
  232. camera.getWorldPosition( cameraPosition );
  233. for ( const countryInfo of countryInfos ) {
  234. const { position, elem, area, selected } = countryInfo;
  235. const largeEnough = area >= large;
  236. const show = selected || ( numCountriesSelected === 0 && largeEnough );
  237. if ( ! show ) {
  238. elem.style.display = 'none';
  239. continue;
  240. }
  241. // Orient the position based on the camera's orientation.
  242. // Since the sphere is at the origin and the sphere is a unit sphere
  243. // this gives us a camera relative direction vector for the position.
  244. tempV.copy( position );
  245. tempV.applyMatrix3( normalMatrix );
  246. // compute the direction to this position from the camera
  247. cameraToPoint.copy( position );
  248. cameraToPoint.applyMatrix4( camera.matrixWorldInverse ).normalize();
  249. // get the dot product of camera relative direction to this position
  250. // on the globe with the direction from the camera to that point.
  251. // -1 = facing directly towards the camera
  252. // 0 = exactly on tangent of the sphere from the camera
  253. // > 0 = facing away
  254. const dot = tempV.dot( cameraToPoint );
  255. // if the orientation is not facing us hide it.
  256. if ( dot > settings.maxVisibleDot ) {
  257. elem.style.display = 'none';
  258. continue;
  259. }
  260. // restore the element to its default display style
  261. elem.style.display = '';
  262. // get the normalized screen coordinate of that position
  263. // x and y will be in the -1 to +1 range with x = -1 being
  264. // on the left and y = -1 being on the bottom
  265. tempV.copy( position );
  266. tempV.project( camera );
  267. // convert the normalized position to CSS coordinates
  268. const x = ( tempV.x * .5 + .5 ) * canvas.clientWidth;
  269. const y = ( tempV.y * - .5 + .5 ) * canvas.clientHeight;
  270. // move the elem to that position
  271. elem.style.transform = `translate(-50%, -50%) translate(${x}px,${y}px)`;
  272. // set the zIndex for sorting
  273. elem.style.zIndex = ( - tempV.z * .5 + .5 ) * 100000 | 0;
  274. }
  275. }
  276. class GPUPickHelper {
  277. constructor() {
  278. // create a 1x1 pixel render target
  279. this.pickingTexture = new THREE.WebGLRenderTarget( 1, 1 );
  280. this.pixelBuffer = new Uint8Array( 4 );
  281. }
  282. pick( cssPosition, scene, camera ) {
  283. const { pickingTexture, pixelBuffer } = this;
  284. // set the view offset to represent just a single pixel under the mouse
  285. const pixelRatio = renderer.getPixelRatio();
  286. camera.setViewOffset(
  287. renderer.getContext().drawingBufferWidth, // full width
  288. renderer.getContext().drawingBufferHeight, // full top
  289. cssPosition.x * pixelRatio | 0, // rect x
  290. cssPosition.y * pixelRatio | 0, // rect y
  291. 1, // rect width
  292. 1, // rect height
  293. );
  294. // render the scene
  295. renderer.setRenderTarget( pickingTexture );
  296. renderer.render( scene, camera );
  297. renderer.setRenderTarget( null );
  298. // clear the view offset so rendering returns to normal
  299. camera.clearViewOffset();
  300. //read the pixel
  301. renderer.readRenderTargetPixels(
  302. pickingTexture,
  303. 0, // x
  304. 0, // y
  305. 1, // width
  306. 1, // height
  307. pixelBuffer );
  308. const id =
  309. ( pixelBuffer[ 0 ] << 0 ) |
  310. ( pixelBuffer[ 1 ] << 8 ) |
  311. ( pixelBuffer[ 2 ] << 16 );
  312. return id;
  313. }
  314. }
  315. const pickHelper = new GPUPickHelper();
  316. function getCanvasRelativePosition( event ) {
  317. const rect = canvas.getBoundingClientRect();
  318. return {
  319. x: ( event.clientX - rect.left ) * canvas.width / rect.width,
  320. y: ( event.clientY - rect.top ) * canvas.height / rect.height,
  321. };
  322. }
  323. function pickCountry( event ) {
  324. // exit if we have not loaded the data yet
  325. if ( ! countryInfos ) {
  326. return;
  327. }
  328. const position = getCanvasRelativePosition( event );
  329. const id = pickHelper.pick( position, pickingScene, camera );
  330. if ( id > 0 ) {
  331. const countryInfo = countryInfos[ id - 1 ];
  332. const selected = ! countryInfo.selected;
  333. if ( selected && ! event.shiftKey && ! event.ctrlKey && ! event.metaKey ) {
  334. unselectAllCountries();
  335. }
  336. numCountriesSelected += selected ? 1 : - 1;
  337. countryInfo.selected = selected;
  338. setPaletteColor( id, selected ? selectedColor : unselectedColor );
  339. paletteTexture.needsUpdate = true;
  340. } else if ( numCountriesSelected ) {
  341. unselectAllCountries();
  342. }
  343. requestRenderIfNotRequested();
  344. }
  345. function unselectAllCountries() {
  346. numCountriesSelected = 0;
  347. countryInfos.forEach( ( countryInfo ) => {
  348. countryInfo.selected = false;
  349. } );
  350. resetPalette();
  351. }
  352. canvas.addEventListener( 'pointerup', pickCountry );
  353. function resizeRendererToDisplaySize( renderer ) {
  354. const canvas = renderer.domElement;
  355. const width = canvas.clientWidth;
  356. const height = canvas.clientHeight;
  357. const needResize = canvas.width !== width || canvas.height !== height;
  358. if ( needResize ) {
  359. renderer.setSize( width, height, false );
  360. }
  361. return needResize;
  362. }
  363. let renderRequested = false;
  364. function render() {
  365. renderRequested = undefined;
  366. if ( resizeRendererToDisplaySize( renderer ) ) {
  367. const canvas = renderer.domElement;
  368. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  369. camera.updateProjectionMatrix();
  370. }
  371. controls.update();
  372. updateLabels();
  373. renderer.render( scene, camera );
  374. }
  375. render();
  376. function requestRenderIfNotRequested() {
  377. if ( ! renderRequested ) {
  378. renderRequested = true;
  379. requestAnimationFrame( render );
  380. }
  381. }
  382. controls.addEventListener( 'change', requestRenderIfNotRequested );
  383. window.addEventListener( 'resize', requestRenderIfNotRequested );
  384. }
  385. main();
  386. </script>
  387. </html>