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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 - Indexed Textures - Picking</title>
<style>
html, body {
height: 100%;
margin: 0;
font-family: sans-serif;
}
#c {
width: 100%; /* let our container decide our size */
height: 100%;
display: block;
}
#container {
position: relative; /* makes this the origin of its children */
width: 100%;
height: 100%;
overflow: hidden;
}
#labels {
position: absolute; /* let us position ourself inside the container */
z-index: 0; /* make a new stacking context so children don't sort with rest of page */
left: 0; /* make our position the top left of the container */
top: 0;
color: white;
}
#labels>div {
position: absolute; /* let us position them inside the container */
left: 0; /* make their default position the top left of the container */
top: 0;
cursor: pointer; /* change the cursor to a hand when over us */
font-size: small;
user-select: none; /* don't let the text get selected */
pointer-events: none; /* make us invisible to the pointer */
text-shadow: /* create a black outline */
-1px -1px 0 #000,
0 -1px 0 #000,
1px -1px 0 #000,
1px 0 0 #000,
1px 1px 0 #000,
0 1px 0 #000,
-1px 1px 0 #000,
-1px 0 0 #000;
}
#labels>div:hover {
color: red;
}
</style>
</head>
<body>
<div id="container">
<canvas id="c"></canvas>
<div id="labels"></div>
</div>
</body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>
<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({canvas});
const fov = 60;
const aspect = 2; // the canvas default
const near = 0.1;
const far = 10;
const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
camera.position.z = 2.5;
const controls = new OrbitControls(camera, canvas);
controls.enableDamping = true;
controls.enablePan = false;
controls.minDistance = 1.2;
controls.maxDistance = 4;
controls.update();
const scene = new THREE.Scene();
scene.background = new THREE.Color('#246');
const pickingScene = new THREE.Scene();
pickingScene.background = new THREE.Color(0);
{
const loader = new THREE.TextureLoader();
const geometry = new THREE.SphereGeometry(1, 64, 32);
const indexTexture = loader.load('resources/data/world/country-index-texture.png', render);
indexTexture.minFilter = THREE.NearestFilter;
indexTexture.magFilter = THREE.NearestFilter;
const pickingMaterial = new THREE.MeshBasicMaterial({map: indexTexture});
pickingScene.add(new THREE.Mesh(geometry, pickingMaterial));
const texture = loader.load('resources/data/world/country-outlines-4k.png', render);
const material = new THREE.MeshBasicMaterial({map: texture});
scene.add(new THREE.Mesh(geometry, material));
}
async function loadJSON(url) {
const req = await fetch(url);
return req.json();
}
let numCountriesSelected = 0;
let countryInfos;
async function loadCountryData() {
countryInfos = await loadJSON('resources/data/world/country-info.json'); /* threejs.org: url */
const lonFudge = Math.PI * 1.5;
const latFudge = Math.PI;
// these helpers will make it easy to position the boxes
// We can rotate the lon helper on its Y axis to the longitude
const lonHelper = new THREE.Object3D();
// We rotate the latHelper on its X axis to the latitude
const latHelper = new THREE.Object3D();
lonHelper.add(latHelper);
// The position helper moves the object to the edge of the sphere
const positionHelper = new THREE.Object3D();
positionHelper.position.z = 1;
latHelper.add(positionHelper);
const labelParentElem = document.querySelector('#labels');
for (const countryInfo of countryInfos) {
const {lat, lon, min, max, name} = countryInfo;
// adjust the helpers to point to the latitude and longitude
lonHelper.rotation.y = THREE.MathUtils.degToRad(lon) + lonFudge;
latHelper.rotation.x = THREE.MathUtils.degToRad(lat) + latFudge;
// get the position of the lat/lon
positionHelper.updateWorldMatrix(true, false);
const position = new THREE.Vector3();
positionHelper.getWorldPosition(position);
countryInfo.position = position;
// compute the area for each country
const width = max[0] - min[0];
const height = max[1] - min[1];
const area = width * height;
countryInfo.area = area;
// add an element for each country
const elem = document.createElement('div');
elem.textContent = name;
labelParentElem.appendChild(elem);
countryInfo.elem = elem;
}
requestRenderIfNotRequested();
}
loadCountryData();
const tempV = new THREE.Vector3();
const cameraToPoint = new THREE.Vector3();
const cameraPosition = new THREE.Vector3();
const normalMatrix = new THREE.Matrix3();
const settings = {
minArea: 20,
maxVisibleDot: -0.2,
};
function updateLabels() {
// exit if we have not loaded the data yet
if (!countryInfos) {
return;
}
const large = settings.minArea * settings.minArea;
// get a matrix that represents a relative orientation of the camera
normalMatrix.getNormalMatrix(camera.matrixWorldInverse);
// get the camera's position
camera.getWorldPosition(cameraPosition);
for (const countryInfo of countryInfos) {
const {position, elem, area, selected} = countryInfo;
const largeEnough = area >= large;
const show = selected || (numCountriesSelected === 0 && largeEnough);
if (!show) {
elem.style.display = 'none';
continue;
}
// Orient the position based on the camera's orientation.
// Since the sphere is at the origin and the sphere is a unit sphere
// this gives us a camera relative direction vector for the position.
tempV.copy(position);
tempV.applyMatrix3(normalMatrix);
// compute the direction to this position from the camera
cameraToPoint.copy(position);
cameraToPoint.applyMatrix4(camera.matrixWorldInverse).normalize();
// get the dot product of camera relative direction to this position
// on the globe with the direction from the camera to that point.
// 1 = facing directly towards the camera
// 0 = exactly on tangent of the sphere from the camera
// < 0 = facing away
const dot = tempV.dot(cameraToPoint);
// if the orientation is not facing us hide it.
if (dot > settings.maxVisibleDot) {
elem.style.display = 'none';
continue;
}
// restore the element to its default display style
elem.style.display = '';
// get the normalized screen coordinate of that position
// x and y will be in the -1 to +1 range with x = -1 being
// on the left and y = -1 being on the bottom
tempV.copy(position);
tempV.project(camera);
// convert the normalized position to CSS coordinates
const x = (tempV.x * .5 + .5) * canvas.clientWidth;
const y = (tempV.y * -.5 + .5) * canvas.clientHeight;
// move the elem to that position
elem.style.transform = `translate(-50%, -50%) translate(${x}px,${y}px)`;
// set the zIndex for sorting
elem.style.zIndex = (-tempV.z * .5 + .5) * 100000 | 0;
}
}
class GPUPickHelper {
constructor() {
// create a 1x1 pixel render target
this.pickingTexture = new THREE.WebGLRenderTarget(1, 1);
this.pixelBuffer = new Uint8Array(4);
}
pick(cssPosition, scene, camera) {
const {pickingTexture, pixelBuffer} = this;
// set the view offset to represent just a single pixel under the mouse
const pixelRatio = renderer.getPixelRatio();
camera.setViewOffset(
renderer.getContext().drawingBufferWidth, // full width
renderer.getContext().drawingBufferHeight, // full top
cssPosition.x * pixelRatio | 0, // rect x
cssPosition.y * pixelRatio | 0, // rect y
1, // rect width
1, // rect height
);
// render the scene
renderer.setRenderTarget(pickingTexture);
renderer.render(scene, camera);
renderer.setRenderTarget(null);
// clear the view offset so rendering returns to normal
camera.clearViewOffset();
//read the pixel
renderer.readRenderTargetPixels(
pickingTexture,
0, // x
0, // y
1, // width
1, // height
pixelBuffer);
const id =
(pixelBuffer[0] << 0) |
(pixelBuffer[1] << 8) |
(pixelBuffer[2] << 16);
return id;
}
}
const pickHelper = new GPUPickHelper();
function getCanvasRelativePosition(event) {
const rect = canvas.getBoundingClientRect();
return {
x: (event.clientX - rect.left) * canvas.width / rect.width,
y: (event.clientY - rect.top ) * canvas.height / rect.height,
};
}
function pickCountry(event) {
// exit if we have not loaded the data yet
if (!countryInfos) {
return;
}
const position = getCanvasRelativePosition(event);
const id = pickHelper.pick(position, pickingScene, camera);
if (id > 0) {
// we clicked a country. Toggle its 'selected' property
const countryInfo = countryInfos[id - 1];
const selected = !countryInfo.selected;
// if we're selecting this country and modifiers are not
// pressed unselect everything else.
if (selected && !event.shiftKey && !event.ctrlKey && !event.metaKey) {
unselectAllCountries();
}
numCountriesSelected += selected ? 1 : -1;
countryInfo.selected = selected;
} else if (numCountriesSelected) {
unselectAllCountries();
}
requestRenderIfNotRequested();
}
function unselectAllCountries() {
numCountriesSelected = 0;
countryInfos.forEach((countryInfo) => {
countryInfo.selected = false;
});
}
canvas.addEventListener('pointerup', pickCountry);
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;
}
let renderRequested = false;
function render() {
renderRequested = undefined;
if (resizeRendererToDisplaySize(renderer)) {
const canvas = renderer.domElement;
camera.aspect = canvas.clientWidth / canvas.clientHeight;
camera.updateProjectionMatrix();
}
controls.update();
updateLabels();
renderer.render(scene, camera);
}
render();
function requestRenderIfNotRequested() {
if (!renderRequested) {
renderRequested = true;
requestAnimationFrame(render);
}
}
controls.addEventListener('change', requestRenderIfNotRequested);
window.addEventListener('resize', requestRenderIfNotRequested);
}
main();
</script>
</html>