indexed-textures-picking.html 11 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</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. <script type="importmap">
  62. {
  63. "imports": {
  64. "three": "../../build/three.module.js",
  65. "three/addons/": "../../examples/jsm/"
  66. }
  67. }
  68. </script>
  69. <script type="module">
  70. import * as THREE from 'three';
  71. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  72. function main() {
  73. const canvas = document.querySelector( '#c' );
  74. const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
  75. const fov = 60;
  76. const aspect = 2; // the canvas default
  77. const near = 0.1;
  78. const far = 10;
  79. const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
  80. camera.position.z = 2.5;
  81. const controls = new OrbitControls( camera, canvas );
  82. controls.enableDamping = true;
  83. controls.enablePan = false;
  84. controls.minDistance = 1.2;
  85. controls.maxDistance = 4;
  86. controls.update();
  87. const scene = new THREE.Scene();
  88. scene.background = new THREE.Color( '#246' );
  89. const pickingScene = new THREE.Scene();
  90. pickingScene.background = new THREE.Color( 0 );
  91. {
  92. const loader = new THREE.TextureLoader();
  93. const geometry = new THREE.SphereGeometry( 1, 64, 32 );
  94. const indexTexture = loader.load( 'resources/data/world/country-index-texture.png', render );
  95. indexTexture.minFilter = THREE.NearestFilter;
  96. indexTexture.magFilter = THREE.NearestFilter;
  97. const pickingMaterial = new THREE.MeshBasicMaterial( { map: indexTexture } );
  98. pickingScene.add( new THREE.Mesh( geometry, pickingMaterial ) );
  99. const texture = loader.load( 'resources/data/world/country-outlines-4k.png', render );
  100. const material = new THREE.MeshBasicMaterial( { map: texture } );
  101. scene.add( new THREE.Mesh( geometry, material ) );
  102. }
  103. async function loadJSON( url ) {
  104. const req = await fetch( url );
  105. return req.json();
  106. }
  107. let numCountriesSelected = 0;
  108. let countryInfos;
  109. async function loadCountryData() {
  110. countryInfos = await loadJSON( 'resources/data/world/country-info.json' ); /* threejs.org: url */
  111. const lonFudge = Math.PI * 1.5;
  112. const latFudge = Math.PI;
  113. // these helpers will make it easy to position the boxes
  114. // We can rotate the lon helper on its Y axis to the longitude
  115. const lonHelper = new THREE.Object3D();
  116. // We rotate the latHelper on its X axis to the latitude
  117. const latHelper = new THREE.Object3D();
  118. lonHelper.add( latHelper );
  119. // The position helper moves the object to the edge of the sphere
  120. const positionHelper = new THREE.Object3D();
  121. positionHelper.position.z = 1;
  122. latHelper.add( positionHelper );
  123. const labelParentElem = document.querySelector( '#labels' );
  124. for ( const countryInfo of countryInfos ) {
  125. const { lat, lon, min, max, name } = countryInfo;
  126. // adjust the helpers to point to the latitude and longitude
  127. lonHelper.rotation.y = THREE.MathUtils.degToRad( lon ) + lonFudge;
  128. latHelper.rotation.x = THREE.MathUtils.degToRad( lat ) + latFudge;
  129. // get the position of the lat/lon
  130. positionHelper.updateWorldMatrix( true, false );
  131. const position = new THREE.Vector3();
  132. positionHelper.getWorldPosition( position );
  133. countryInfo.position = position;
  134. // compute the area for each country
  135. const width = max[ 0 ] - min[ 0 ];
  136. const height = max[ 1 ] - min[ 1 ];
  137. const area = width * height;
  138. countryInfo.area = area;
  139. // add an element for each country
  140. const elem = document.createElement( 'div' );
  141. elem.textContent = name;
  142. labelParentElem.appendChild( elem );
  143. countryInfo.elem = elem;
  144. }
  145. requestRenderIfNotRequested();
  146. }
  147. loadCountryData();
  148. const tempV = new THREE.Vector3();
  149. const cameraToPoint = new THREE.Vector3();
  150. const cameraPosition = new THREE.Vector3();
  151. const normalMatrix = new THREE.Matrix3();
  152. const settings = {
  153. minArea: 20,
  154. maxVisibleDot: - 0.2,
  155. };
  156. function updateLabels() {
  157. // exit if we have not loaded the data yet
  158. if ( ! countryInfos ) {
  159. return;
  160. }
  161. const large = settings.minArea * settings.minArea;
  162. // get a matrix that represents a relative orientation of the camera
  163. normalMatrix.getNormalMatrix( camera.matrixWorldInverse );
  164. // get the camera's position
  165. camera.getWorldPosition( cameraPosition );
  166. for ( const countryInfo of countryInfos ) {
  167. const { position, elem, area, selected } = countryInfo;
  168. const largeEnough = area >= large;
  169. const show = selected || ( numCountriesSelected === 0 && largeEnough );
  170. if ( ! show ) {
  171. elem.style.display = 'none';
  172. continue;
  173. }
  174. // Orient the position based on the camera's orientation.
  175. // Since the sphere is at the origin and the sphere is a unit sphere
  176. // this gives us a camera relative direction vector for the position.
  177. tempV.copy( position );
  178. tempV.applyMatrix3( normalMatrix );
  179. // compute the direction to this position from the camera
  180. cameraToPoint.copy( position );
  181. cameraToPoint.applyMatrix4( camera.matrixWorldInverse ).normalize();
  182. // get the dot product of camera relative direction to this position
  183. // on the globe with the direction from the camera to that point.
  184. // 1 = facing directly towards the camera
  185. // 0 = exactly on tangent of the sphere from the camera
  186. // < 0 = facing away
  187. const dot = tempV.dot( cameraToPoint );
  188. // if the orientation is not facing us hide it.
  189. if ( dot > settings.maxVisibleDot ) {
  190. elem.style.display = 'none';
  191. continue;
  192. }
  193. // restore the element to its default display style
  194. elem.style.display = '';
  195. // get the normalized screen coordinate of that position
  196. // x and y will be in the -1 to +1 range with x = -1 being
  197. // on the left and y = -1 being on the bottom
  198. tempV.copy( position );
  199. tempV.project( camera );
  200. // convert the normalized position to CSS coordinates
  201. const x = ( tempV.x * .5 + .5 ) * canvas.clientWidth;
  202. const y = ( tempV.y * - .5 + .5 ) * canvas.clientHeight;
  203. // move the elem to that position
  204. elem.style.transform = `translate(-50%, -50%) translate(${x}px,${y}px)`;
  205. // set the zIndex for sorting
  206. elem.style.zIndex = ( - tempV.z * .5 + .5 ) * 100000 | 0;
  207. }
  208. }
  209. class GPUPickHelper {
  210. constructor() {
  211. // create a 1x1 pixel render target
  212. this.pickingTexture = new THREE.WebGLRenderTarget( 1, 1 );
  213. this.pixelBuffer = new Uint8Array( 4 );
  214. }
  215. pick( cssPosition, scene, camera ) {
  216. const { pickingTexture, pixelBuffer } = this;
  217. // set the view offset to represent just a single pixel under the mouse
  218. const pixelRatio = renderer.getPixelRatio();
  219. camera.setViewOffset(
  220. renderer.getContext().drawingBufferWidth, // full width
  221. renderer.getContext().drawingBufferHeight, // full top
  222. cssPosition.x * pixelRatio | 0, // rect x
  223. cssPosition.y * pixelRatio | 0, // rect y
  224. 1, // rect width
  225. 1, // rect height
  226. );
  227. // render the scene
  228. renderer.setRenderTarget( pickingTexture );
  229. renderer.render( scene, camera );
  230. renderer.setRenderTarget( null );
  231. // clear the view offset so rendering returns to normal
  232. camera.clearViewOffset();
  233. //read the pixel
  234. renderer.readRenderTargetPixels(
  235. pickingTexture,
  236. 0, // x
  237. 0, // y
  238. 1, // width
  239. 1, // height
  240. pixelBuffer );
  241. const id =
  242. ( pixelBuffer[ 0 ] << 0 ) |
  243. ( pixelBuffer[ 1 ] << 8 ) |
  244. ( pixelBuffer[ 2 ] << 16 );
  245. return id;
  246. }
  247. }
  248. const pickHelper = new GPUPickHelper();
  249. function getCanvasRelativePosition( event ) {
  250. const rect = canvas.getBoundingClientRect();
  251. return {
  252. x: ( event.clientX - rect.left ) * canvas.width / rect.width,
  253. y: ( event.clientY - rect.top ) * canvas.height / rect.height,
  254. };
  255. }
  256. function pickCountry( event ) {
  257. // exit if we have not loaded the data yet
  258. if ( ! countryInfos ) {
  259. return;
  260. }
  261. const position = getCanvasRelativePosition( event );
  262. const id = pickHelper.pick( position, pickingScene, camera );
  263. if ( id > 0 ) {
  264. // we clicked a country. Toggle its 'selected' property
  265. const countryInfo = countryInfos[ id - 1 ];
  266. const selected = ! countryInfo.selected;
  267. // if we're selecting this country and modifiers are not
  268. // pressed unselect everything else.
  269. if ( selected && ! event.shiftKey && ! event.ctrlKey && ! event.metaKey ) {
  270. unselectAllCountries();
  271. }
  272. numCountriesSelected += selected ? 1 : - 1;
  273. countryInfo.selected = selected;
  274. } else if ( numCountriesSelected ) {
  275. unselectAllCountries();
  276. }
  277. requestRenderIfNotRequested();
  278. }
  279. function unselectAllCountries() {
  280. numCountriesSelected = 0;
  281. countryInfos.forEach( ( countryInfo ) => {
  282. countryInfo.selected = false;
  283. } );
  284. }
  285. canvas.addEventListener( 'pointerup', pickCountry );
  286. function resizeRendererToDisplaySize( renderer ) {
  287. const canvas = renderer.domElement;
  288. const width = canvas.clientWidth;
  289. const height = canvas.clientHeight;
  290. const needResize = canvas.width !== width || canvas.height !== height;
  291. if ( needResize ) {
  292. renderer.setSize( width, height, false );
  293. }
  294. return needResize;
  295. }
  296. let renderRequested = false;
  297. function render() {
  298. renderRequested = undefined;
  299. if ( resizeRendererToDisplaySize( renderer ) ) {
  300. const canvas = renderer.domElement;
  301. camera.aspect = canvas.clientWidth / canvas.clientHeight;
  302. camera.updateProjectionMatrix();
  303. }
  304. controls.update();
  305. updateLabels();
  306. renderer.render( scene, camera );
  307. }
  308. render();
  309. function requestRenderIfNotRequested() {
  310. if ( ! renderRequested ) {
  311. renderRequested = true;
  312. requestAnimationFrame( render );
  313. }
  314. }
  315. controls.addEventListener( 'change', requestRenderIfNotRequested );
  316. window.addEventListener( 'resize', requestRenderIfNotRequested );
  317. }
  318. main();
  319. </script>
  320. </html>