cesium扩散圆，圆形波纹扩散效果

/* 圆形扩散波纹材质 color 颜色 duration 持续时间 毫秒 count 数量 gradient 渐变 */ import * as Cesium from 'cesium/Cesium'; class CircleWaveMaterialProperty { constructor(options) { let optionsD = Cesium.defaultValue(options, Cesium.defaultValue.EMPTY_OBJECT); this._definitionChanged = new Cesium.Event(); this._color = undefined; this._colorSubscription = undefined; this.color = optionsD.color; this.duration = Cesium.defaultValue(optionsD.duration, 1e3); this.count = Cesium.defaultValue(optionsD.count, 2); if (this.count <= 0) this.count = 1; this.gradient = Cesium.defaultValue(optionsD.gradient, 0.1); if (this.gradient < 0) this.gradient = 0; else if (this.gradient > 1) this.gradient = 1; this._time = performance.now(); } get isConstant () { return false; } get definitionChanged () { return this._definitionChanged; } getType (time) { return Cesium.Material.CircleWaveMaterialType; } getValue (time, result) { if (!Cesium.defined(result)) { result = {}; } result.color = Cesium.Property.getValueOrClonedDefault(this._color, time, Cesium.Color.WHITE, result.color); result.time = (performance.now() - this._time) / this.duration; result.count = this.count; result.gradient = 1 + 10 * (1 - this.gradient); return result; } equals (other) { return this === other || (other instanceof CircleWaveMaterialProperty && Cesium.Property.equals(this._color, other._color)) } } Object.defineProperties(CircleWaveMaterialProperty.prototype, { isConstant: { get: function () { return false; } }, definitionChanged: { get: function () { return this._definitionChanged; } }, color: Cesium.createPropertyDescriptor('color') }); Cesium.CircleWaveMaterialProperty = CircleWaveMaterialProperty; Cesium.Material.CircleWaveMaterialProperty = 'CircleWaveMaterialProperty'; Cesium.Material.CircleWaveMaterialType = 'waveType' + parseInt(Math.random() * 1000); Cesium.Material.CircleWaveMaterialSource = ` uniform float time; uniform float count; uniform float gradient; uniform vec4 color; czm_material czm_getMaterial(czm_materialInput materialInput) { czm_material material = czm_getDefaultMaterial(materialInput); material.diffuse = 1.5 * color.rgb; vec2 st = materialInput.st; vec3 str = materialInput.str; float dis = distance(st, vec2(0.5, 0.5)); float per = fract(time); if (abs(str.z) > 0.001) { discard; } if (dis > 0.5) { discard; } else { float perDis = 0.5 / count; float disNum; float bl = .0; for (int i = 0; i <= 999; i++) { if (float(i) <= count) { disNum = perDis * float(i) - dis + per / count; if (disNum > 0.0) { if (disNum < perDis) { bl = 1.0 - disNum / perDis; } else if (disNum - perDis < perDis) { bl = 1.0 - abs(1.0 - disNum / perDis); } material.alpha = pow(bl, gradient); } } } } return material; } ` Cesium.Material._materialCache.addMaterial(Cesium.Material.CircleWaveMaterialType, { fabric: { type: Cesium.Material.CircleWaveMaterialType, uniforms: { color: new Cesium.Color(1.0, 0.0, 0.0, 1.0), time: 1, count: 1, gradient: 0.1 }, source: Cesium.Material.CircleWaveMaterialSource }, translucent: function (material) { return !0; } }); export default CircleWaveMaterialProperty