当我们做洋流或者风场 可视化时候 echart 虽然也能用 但是数据量过大会很卡
数据调用是这个样子
样例数据
链接:https://pan.baidu.com/s/1yQrIMBMJdSPwnnI8YOC1_Q提取码: tnhc
最终调用
import {VectorField} from './VectorField';
// this.map 为arcgis Map对象实例
let vectorField = new VectorField(this.map);
const options = {
url: "./static/data/2020081106.json",
displayOptions: {
minVelocity: 0, // 最小速度
maxVelocity: 10, // 最大速度
velocityScale: 0.005, // 速度
particleAge: 90, // 粒子生存的帧数
lineWidth: 0.5, // 线宽
frameRate: 15, // 运动帧率
particleDensity: 10, // 每50x50像素块的粒子数
colorScale: ["#ffffff", "#e9ecfb", "#d3d9f7", "#bdc6f3", "#a7b3ef", "#91a0eb", "#7b8de7", "#657ae3", "#4f67df", "#3954db"]
}
}
vectorField.start(options);
我们需要两个类
AnimatedEnvironmentLayer 类
```javascript
import esriLoader from 'esri-loader';
export const AnimatedEnvironmentLayer = {}
AnimatedEnvironmentLayer.create = function () {
let a = null;
return new Promise(async (resolve, reject) => {
const [asd, MapView, Map, Point, GraphicsLayer, SpatialReference, Basemap, esriRequest, on, dom, BaseLayerView2D, watchUtils, webMercatorUtils] = await (esriLoader.loadModules([
"esri/core/accessorSupport/decorators",
"esri/views/MapView",
"esri/Map",
"esri/geometry/Point",
"esri/layers/GraphicsLayer",
"esri/geometry/SpatialReference",
"esri/Basemap",
"esri/request",
"dojo/on",
"dojo/dom",
"esri/views/2d/layers/BaseLayerView2D",
"esri/core/watchUtils",
"esri/geometry/support/webMercatorUtils",
]));
class AnimatedEnvironmentLayerView2D extends BaseLayerView2D {
constructor(props) {
super();
this.view = props.view;
this.layer = props.layer;
this.view.on("resize", () => {
if (!this.context) return;
// resize the canvas
this.context.canvas.width = this.view.width;
this.context.canvas.height = this.view.height;
});
watchUtils.watch(this.layer, "visible", (nv, olv, pn, ta) => {
if (!nv) {
this.clear();
} else {
this.prepDraw();
}
});
}
render(renderParameters) {
this.viewState = renderParameters.state;
if (!renderParameters.stationary) {
// not stationary so clear if drawn and set to prep again
if (this.drawing) {
this.clear();
this.drawing = false;
}
this.drawPrepping = false;
this.drawReady = false;
return;
}
if (!this.drawPrepping && !this.drawReady) {
// prep the draw
this.drawPrepping = true;
if (this.windy && this.windy.gridData) {
this.prepDraw();
}
return;
}
if (this.drawReady) {
if (!this.drawing) {
// this.animationLoop(); // haven't started drawing so kick off our animation loop
this.startWindy();
}
// draw the custom context into this layers context
renderParameters.context.drawImage(this.context.canvas, 0, 0);
this.drawing = true;
// call request render so we copy the draw again
this.requestRender();
}
}
startWindy() {
setTimeout(() => {
this.windy.start(
[[0, 0], [this.context.canvas.width, this.context.canvas.height]],
this.context.canvas.width,
this.context.canvas.height,
[[this.southWest.x, this.southWest.y], [this.northEast.x, this.northEast.y]]
);
this.setDate();
}, 500);
}
attach() {
// use attach to initilaize a custom canvas to draw on
// create the canvas, set some properties.
const canvas = document.createElement("canvas");
canvas.id = "ael-" + Date.now();
canvas.style.position = "absolute";
canvas.style.top = "0";
canvas.style.left = "0";
canvas.width = this.view.width;
canvas.height = this.view.height;
const context = canvas.getContext("2d");
this.context = context;
this.initWindy();
}
initWindy(data) {
this.windy = new Windy(
this.context.canvas,
this.layer.displayOptions,
undefined
);
}
clear(stopDraw = true) {
if (stopDraw) {
this.stopDraw();
}
if (this.context) {
this.context.clearRect(0, 0, this.view.width, this.view.height);
}
}
stopDraw() {
this.windy.stop();
this.drawing = false;
}
prepDraw(data) {
if (data) this.windy.setData(data);
this.setParticleDensity();
this.startDraw();
this.drawPrepping = false;
this.drawReady = true;
this.requestRender();
}
startDraw() {
// use the extent of the view, and not the extent passed into fetchImage...it was slightly off when it crossed IDL.
let extent = this.view.extent;
if (extent.spatialReference.isWebMercator) {
extent = webMercatorUtils.webMercatorToGeographic(extent);
}
this.northEast = new Point({x: extent.xmax, y: extent.ymax});
this.southWest = new Point({x: extent.xmin, y: extent.ymin});
// resize the canvas
this.context.canvas.width = this.view.width;
this.context.canvas.height = this.view.height;
// cater for the extent crossing the IDL
if (this.southWest.x > this.northEast.x && this.northEast.x < 0) {
this.northEast.x = 360 + this.northEast.x;
}
}
setParticleDensity() {
if (!Array.isArray(this.layer.displayOptions.particleDensity)) {
return; // not an array, so must be a number, exit out here as there's no calc to do
}
const stops = this.layer.displayOptions.particleDensity;
const currentZoom = Math.round(this.view.zoom);
let density = -1;
const zoomMap = stops.map((stop) => {
return stop.zoom;
});
console.log("zoomMap", zoomMap);
// loop the zooms
for (let i = 0; i < stops.length; i++) {
const stop = stops[i];
if (stop.zoom === currentZoom) {
density = stop.density;
break;
}
const nextStop = i + 1 < stops.length ? stops[i + 1] : undefined;
if (!nextStop) {
// this is the last one, so just set to this value
density = stop.density;
break;
}
if (nextStop.zoom > currentZoom) {
density = stop.density;
break;
}
}
// if density still not found, set it to the last value in the stops array
if (density === -1) {
density = stops[stops.length - 1].density;
}
this.windy.calculatedDensity = density;
}
setDate() {
if (this.windy) {
if (this.windy.refTime && this.windy.forecastTime) {
// assume the ref time is an iso string, or some other equivalent that javascript Date object can parse.
const d = new Date(this.windy.refTime);
// add the forecast time as hours to the refTime;
d.setHours(d.getHours() + this.windy.forecastTime);
this.date = d;
return;
}
}
this.date = undefined;
}
}
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({__proto__: []} instanceof Array && function (d, b) {
d.__proto__ = b;
}) ||
function (d, b) {
for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
};
return extendStatics(d, b);
};
return function (d, b) {
extendStatics(d, b);
function __() {
this.constructor = d;
}
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
var c = arguments.length,
r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
if (typeof Reflect === "object" && typeof Reflect.decorate === "function") {
r = Reflect.decorate(decorators, target, key, desc);
} else {
for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
}
return c > 3 && r && Object.defineProperty(target, key, r), r;
};
var __metadata = (this && this.__metadata) || function (k, v) {
if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
var AnimatedEnvironmentLayer = /** @class */ (function (_super) {
__extends(AnimatedEnvironmentLayer, _super);
function AnimatedEnvironmentLayer(properties) {
var _this = _super.call(this, properties) || this;
// If the active view is set in properties, then set it here.
_this.url = properties.url;
_this.displayOptions = properties.displayOptions || {};
if (Array.isArray(_this.displayOptions.particleDensity)) {
// make sure the particle density stops array is is order by zoom level lowest zooms first
_this.displayOptions.particleDensity.sort(function (a, b) {
return a.zoom - b.zoom;
});
}
_this.reportValues = properties.reportValues === false ? false : true; // default to true
// watch url prop so a fetch of data and redraw will occur.
watchUtils.watch(_this, "url", function (a, b, c, d) {
return _this._urlChanged(a, b, c, d);
});
// watch visible so a fetch of data and redraw will occur.
watchUtils.watch(_this, "visible", function (a, b, c, d) {
return _this._visibleChanged(a, b, c, d);
});
// watch display options so to redraw when changed.
watchUtils.watch(_this, "displayOptions", function (a, b, c, d) {
return _this._displayOptionsChanged(a, b, c, d);
});
_this.dataFetchRequired = true;
return _this;
}
AnimatedEnvironmentLayer.prototype.createLayerView = function (view) {
var _this = this;
// only supports 2d right now.
if (view.type !== "2d") {
console.error("不支持3D(only supports 2d right now)", view.type)
return;
}
// hook up the AnimatedEnvironmentLayerView2D as the layer view
this.layerView = new AnimatedEnvironmentLayerView2D({
view: view,
layer: this
});
this.layerView.view.on("pointer-move", function (evt) {
return _this.viewPointerMove(evt);
});
this.draw(true);
return this.layerView;
};
AnimatedEnvironmentLayer.prototype.draw = function (forceDataRefetch) {
var _this = this;
if (forceDataRefetch != null) {
this.dataFetchRequired = forceDataRefetch;
}
if (!this.url || !this.visible) {
return;
} // no url set, not visible or is currently drawing, exit here.
// if data should be fetched, go get it now.
if (this.dataFetchRequired) {
this.isErrored = false;
this.dataLoading = true;
esriRequest(this.url, {
responseType: "json"
})
.then(function (response) {
_this.dataFetchRequired = false;
_this.doDraw(response.data); // all sorted draw now.
_this.dataLoading = false;
})
.otherwise(function (err) {
console.error("Error occurred retrieving data. " + err);
_this.dataLoading = false;
_this.isErrored = true;
});
}
else {
// no need for data, just draw. no need for data, just draw.
this.doDraw();
}
};
AnimatedEnvironmentLayer.prototype.stop = function () {
if (this.layerView) {
this.layerView.stopDraw();
}
};
AnimatedEnvironmentLayer.prototype.start = function () {
this.doDraw();
};
AnimatedEnvironmentLayer.prototype.doDraw = function (data) {
this.layerView.prepDraw(data);
};
AnimatedEnvironmentLayer.prototype.viewPointerMove = function (evt) {
if (!this.layerView.windy || !this.visible) {
return;
}
var mousePos = this._getMousePos(evt);
var point = this.layerView.view.toMap({x: mousePos.x, y: mousePos.y});
if (point.spatialReference.isWebMercator) {
point = webMercatorUtils.webMercatorToGeographic(point);
}
var grid = this.layerView.windy.interpolate(point.x, point.y);
var result = {
point: point,
target: this
};
if (!grid || (isNaN(grid[0]) || isNaN(grid[1]) || !grid[2])) {
// the current point contains no data in the windy grid, so emit an object with no speed or direction object
//当前点在风网格中不包含任何数据，所以发射一个没有速度或方向的对象
this.emit("point-report", result);
return;
}
// get the speed and direction and emit the result 获得速度和方向，并发出结果
result.velocity = this._vectorToSpeed(grid[0], grid[1]);
result.degree = this._vectorToDegrees(grid[0], grid[1]);
this.emit("point-report", result);
};
AnimatedEnvironmentLayer.prototype._vectorToSpeed = function (uMs, vMs) {
var speedAbs = Math.sqrt(Math.pow(uMs, 2) + Math.pow(vMs, 2));
return speedAbs;
};
AnimatedEnvironmentLayer.prototype._vectorToDegrees = function (uMs, vMs) {
var abs = Math.sqrt(Math.pow(uMs, 2) + Math.pow(vMs, 2));
var direction = Math.atan2(uMs / abs, vMs / abs);
var directionToDegrees = direction * 180 / Math.PI + 180;
directionToDegrees += 180;
if (directionToDegrees >= 360) {
directionToDegrees -= 360;
}
return directionToDegrees;
};
AnimatedEnvironmentLayer.prototype._getMousePos = function (evt) {
// container on the view is actually a html element at this point, not a string as the typings suggest.
var container = this.layerView.view.container;
var rect = container.getBoundingClientRect();
return {
x: evt.x - rect.left,
y: evt.y - rect.top
};
};
AnimatedEnvironmentLayer.prototype._urlChanged = function (a, b, c, d) {
this.stop();
this.dataFetchRequired = true;
this.draw();
};
AnimatedEnvironmentLayer.prototype._visibleChanged = function (visible, b, c, d) {
if (!visible) {
this.stop();
}
else {
this.draw();
}
};
AnimatedEnvironmentLayer.prototype._displayOptionsChanged = function (newOptions, b, c, d) {
if (!this.layerView.windy) {
return;
}
this.layerView.windy.stop();
this.layerView.windy.setDisplayOptions(newOptions);
this.draw();
};
__decorate([
asd.property(),
__metadata("design:type", String)
], AnimatedEnvironmentLayer.prototype, "url", void 0);
__decorate([
asd.property(),
__metadata("design:type", Object)
], AnimatedEnvironmentLayer.prototype, "displayOptions", void 0);
__decorate([
asd.property(),
__metadata("design:type", Boolean)
], AnimatedEnvironmentLayer.prototype, "reportValues", void 0);
__decorate([
asd.property(),
__metadata("design:type", Boolean)
], AnimatedEnvironmentLayer.prototype, "dataLoading", void 0);
__decorate([
asd.property(),
__metadata("design:type", Boolean)
], AnimatedEnvironmentLayer.prototype, "isErrored", void 0);
AnimatedEnvironmentLayer = __decorate([
asd.subclass("AnimatedEnvironmentLayer"),
__metadata("design:paramtypes", [Object])
], AnimatedEnvironmentLayer);
return AnimatedEnvironmentLayer;
}(asd.declared(GraphicsLayer)));
var Windy = /** @class */ (function () {
function Windy(canvas, options, data) {
this.NULL_WIND_VECTOR = [NaN, NaN, null]; // singleton for no wind in the form: [u, v, magnitude]
this.canvas = canvas;
this.setDisplayOptions(options);
this.gridData = data;
}
Windy.prototype.setData = function (data) {
this.gridData = data;
};
Windy.prototype.setDisplayOptions = function (options) {
this.displayOptions = options;
// setup some defaults
this.displayOptions.minVelocity = this.displayOptions.minVelocity || 0;
this.displayOptions.maxVelocity = this.displayOptions.maxVelocity || 10;
this.displayOptions.particleDensity = this.displayOptions.particleDensity || 10;
this.calculatedDensity = Array.isArray(this.displayOptions.particleDensity) ? 10 : this.displayOptions.particleDensity;
this.displayOptions.velocityScale = (this.displayOptions.velocityScale || 0.005) * (Math.pow(window.devicePixelRatio, 1 / 3) || 1); // scale for velocity (completely arbitrary -- this value looks nice)
this.displayOptions.particleAge = this.displayOptions.particleAge || 90;
this.displayOptions.lineWidth = this.displayOptions.lineWidth || 1;
this.displayOptions.particleReduction = this.displayOptions.particleReduction || (Math.pow(window.devicePixelRatio, 1 / 3) || 1.6); // multiply particle count for mobiles by this amount
this.displayOptions.frameRate = this.displayOptions.frameRate || 15;
var defaultColorScale = ["rgb(61,160,247)", "rgb(99,164,217)", "rgb(138,168,188)", "rgb(177,173,158)", "rgb(216,177,129)", "rgb(255,182,100)", "rgb(240,145,87)", "rgb(225,109,74)", "rgb(210,72,61)", "rgb(195,36,48)", "rgb(180,0,35)"];
this.colorScale = this.displayOptions.colorScale || defaultColorScale;
this.FRAME_TIME = 1000 / this.displayOptions.frameRate; // desired frames per second
};
Windy.prototype.start = function (bounds, width, height, extent) {
var _this = this;
var mapBounds = {
south: this.deg2rad(extent[0][1]),
north: this.deg2rad(extent[1][1]),
east: this.deg2rad(extent[1][0]),
west: this.deg2rad(extent[0][0]),
width: width,
height: height
};
this.stop();
// build grid
this.buildGrid(this.gridData, function (gridResult) {
var builtBounds = _this.buildBounds(bounds, width, height);
_this.interpolateField(gridResult, builtBounds, mapBounds, function (bounds, field) {
// animate the canvas with random points
Windy.field = field;
_this.animate(bounds, Windy.field);
});
});
};
Windy.prototype.stop = function () {
if (Windy.field) {
Windy.field.release();
}
if (Windy.animationLoop) {
cancelAnimationFrame(Windy.animationLoop);
}
};
/**
* Get interpolated grid value from Lon/Lat position
* @param lon {Float} Longitude
更多消息参考https://xiaozhuanlan.com/topic/2178340659
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