34935-vm/assets/js/wind.js
2025-10-17 01:31:35 +00:00

312 lines
11 KiB
JavaScript

/*
* Original code from https://github.com/RaymanNg/3D-Wind-Field
* under the MIT license.
*
* MIT License
*
* Copyright (c) 2019 Rayman Ng
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OF OTHER DEALINGS IN THE
* SOFTWARE.
*/
class WindLayer {
constructor(viewer, options = {}) {
this.viewer = viewer;
this.scene = viewer.scene;
this.camera = viewer.camera;
this.ellipsoid = viewer.scene.globe.ellipsoid;
this.options = options;
this.windData = null;
this.particleSystem = null;
this.visible = false;
// A promise that resolves when the layer is ready
this.readyPromise = this.init();
}
init() {
return this.loadWindData().then(() => {
if (this.windData) {
this.particleSystem = new ParticleSystem(this.scene, {
windData: this.windData,
...this.options.particleSystem
});
// Apply the stored visibility state once ready
this.particleSystem.polylines.show = this.visible;
}
}).catch(error => {
console.error("Error initializing WindLayer:", error);
// Propagate error to allow for further handling
throw error;
});
}
async loadWindData() {
try {
const response = await fetch(this.options.windDataUrl || 'api/wind.php');
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
const data = await response.json();
this.windData = this.processWindData(data);
} catch (error) {
console.error('Error loading or processing wind data:', error);
throw error; // Re-throw to be caught by the init promise chain
}
}
processWindData(data) {
let uComponent = null, vComponent = null;
data.forEach(record => {
const type = record.header.parameterCategory + ',' + record.header.parameterNumber;
if (type === '2,2') uComponent = record;
if (type === '2,3') vComponent = record;
});
if (!uComponent || !vComponent) {
console.error("Wind data components not found.");
return null;
}
const header = uComponent.header;
return {
nx: header.nx,
ny: header.ny,
lo1: header.lo1,
la1: header.la1,
dx: header.dx,
dy: header.dy,
u: uComponent.data,
v: vComponent.data
};
}
setVisible(visible) {
this.visible = visible;
// Use the promise to safely apply visibility
this.readyPromise.then(() => {
if (this.particleSystem) {
this.particleSystem.polylines.show = this.visible;
}
});
}
setOptions(options) {
this.readyPromise.then(() => {
if (this.particleSystem) {
this.particleSystem.applyOptions(options);
}
});
}
pause() {
this.readyPromise.then(() => {
if (this.particleSystem) {
this.particleSystem.pause();
}
});
}
play() {
this.readyPromise.then(() => {
if (this.particleSystem) {
this.particleSystem.play();
}
});
}
isPlaying() {
return this.particleSystem && this.particleSystem.isPlaying;
}
setParticleDensity(density) {
this.readyPromise.then(() => {
if (this.particleSystem) {
this.particleSystem.setParticleCount(density);
}
});
}
}
class ParticleSystem {
constructor(scene, options) {
this.scene = scene;
this.options = options;
this.windData = options.windData;
// Use a polyline collection instead of a point collection
this.polylines = this.scene.primitives.add(new Cesium.PolylineCollection());
this.particles = [];
this.isPlaying = true;
this.createParticles();
this.scene.preRender.addEventListener(this.update, this);
}
createParticles() {
const particleCount = this.options.particleCount || 10000;
for (let i = 0; i < particleCount; i++) {
const p = this.createParticle();
this.particles.push(p);
// Create a polyline for each particle. It will be updated in the update loop.
this.polylines.add({
positions: [p.position, p.position], // Start with a zero-length line
width: this.options.lineWidth || 1.0,
material: new Cesium.Material({
fabric: {
type: 'Color',
uniforms: {
color: Cesium.Color.WHITE.withAlpha(0.0) // Initially transparent
}
}
})
});
}
}
createParticle() {
const lon = Math.random() * 360 - 180;
const lat = Math.random() * 180 - 90;
const altitude = this.options.particleHeight || 10000;
const position = Cesium.Cartesian3.fromDegrees(lon, lat, altitude);
return {
position: position,
previousPosition: position, // Store previous position for the tail of the line
age: Math.floor(Math.random() * (this.options.maxAge || 120)),
maxAge: this.options.maxAge || 120,
speed: Math.random() * (this.options.particleSpeed || 5)
};
}
getWind(position) {
const cartographic = Cesium.Cartographic.fromCartesian(position);
const lon = Cesium.Math.toDegrees(cartographic.longitude);
const lat = Cesium.Math.toDegrees(cartographic.latitude);
const { nx, ny, lo1, la1, dx, dy, u, v } = this.windData;
const i = Math.floor((lon - lo1) / dx);
const j = Math.floor((la1 - lat) / dy);
if (i >= 0 && i < nx && j >= 0 && j < ny) {
const index = j * nx + i;
return { u: u[index], v: v[index] };
}
return { u: 0, v: 0 };
}
update() {
if (this.polylines.length === 0 || !this.polylines.show) return;
for (let i = 0; i < this.particles.length; i++) {
const particle = this.particles[i];
const polyline = this.polylines.get(i);
if (particle.age >= particle.maxAge) {
Object.assign(particle, this.createParticle());
// Reset polyline to a zero-length, transparent line
polyline.positions = [particle.position, particle.position];
if (polyline.material && polyline.material.uniforms) {
polyline.material.uniforms.color = Cesium.Color.WHITE.withAlpha(0.0);
}
continue; // Skip to next particle
}
const wind = this.getWind(particle.position);
const speed = particle.speed;
const metersPerDegree = 111320;
const vx = wind.u * speed / metersPerDegree;
const vy = wind.v * speed / metersPerDegree;
// Store current position as the previous one
particle.previousPosition = particle.position;
const cartographic = Cesium.Cartographic.fromCartesian(particle.position);
cartographic.longitude += Cesium.Math.toRadians(vx);
cartographic.latitude += Cesium.Math.toRadians(vy);
particle.position = Cesium.Cartesian3.fromRadians(
cartographic.longitude,
cartographic.latitude,
cartographic.height
);
particle.age++;
// Update polyline positions to create a line segment
polyline.positions = [particle.previousPosition, particle.position];
// Fade the line based on age
if (polyline.material && polyline.material.uniforms) {
polyline.material.uniforms.color = Cesium.Color.WHITE.withAlpha(1 - (particle.age / particle.maxAge));
}
}
}
applyOptions(options) {
this.options = Object.assign(this.options, options);
// Apply new options to existing polylines
for (let i = 0; i < this.polylines.length; i++) {
const polyline = this.polylines.get(i);
if (options.lineWidth) {
polyline.width = options.lineWidth;
}
}
}
setParticleCount(density) {
const maxParticles = this.options.maxParticles || this.options.particleCount || 10000;
if (!this.options.maxParticles) {
this.options.maxParticles = maxParticles;
}
const newParticleCount = Math.floor(maxParticles * density);
this.polylines.removeAll();
this.particles = [];
for (let i = 0; i < newParticleCount; i++) {
const p = this.createParticle();
this.particles.push(p);
this.polylines.add({
positions: [p.position, p.position],
width: this.options.lineWidth || 1.0,
material: new Cesium.Material({
fabric: {
type: 'Color',
uniforms: {
color: Cesium.Color.WHITE.withAlpha(0.0)
}
}
})
});
}
}
pause() {
this.isPlaying = false;
this.scene.preRender.removeEventListener(this.update, this);
}
play() {
this.isPlaying = true;
this.scene.preRender.addEventListener(this.update, this);
}
}