import * as Cesium from 'cesium'
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export const getLngLatDistance = (
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lat1: number,
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lng1: number,
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lat2: number,
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lng2: number,
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) => {
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const radLat1 = (lat1 * Math.PI) / 180.0
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const radLat2 = (lat2 * Math.PI) / 180.0
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const a = radLat1 - radLat2
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const b = (lng1 * Math.PI) / 180.0 - (lng2 * Math.PI) / 180.0
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let s =
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2 *
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Math.asin(
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Math.sqrt(
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Math.pow(Math.sin(a / 2), 2) +
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Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2),
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),
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)
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s = s * 6378.137 // EARTH_RADIUS;
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s = Math.round(s * 10000) / 10000
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return s * 1000
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}
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// 获取限polyline长度
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export const getPolylineLength = (entity: any) => {
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let length = 0
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// 获取Polyline的所有顶点位置
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const positions = entity.polyline.positions.getValue()
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for (let i = 0; i < positions.length - 1; ++i) {
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const startPosition = positions[i]
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const endPosition = positions[i + 1]
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// 使用Cesium提供的distanceBetween函数计算两个顶点之间的距离
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const distance = Cesium.Cartesian3.distance(startPosition, endPosition)
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// 将每个顶点之间的距离相加得到总长度
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length += distance
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}
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return length
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}
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// 创建三角广告牌
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export const createTriangleMarker = (title: string | number, color: string) => {
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// 创建canvas绘制广告牌
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const billboard = document.createElement('canvas')
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billboard.width = 30
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billboard.height = 30
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const ctx: HTMLCanvasElement | any = billboard.getContext('2d')
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ctx.beginPath()
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ctx.moveTo(0, 0)
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ctx.lineTo(30, 0)
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ctx.lineTo(15, 22)
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ctx.fillStyle = color
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ctx.fill()
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ctx.font = '18px serif'
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ctx.fillStyle = '#ffffff'
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ctx.fillText(title, 10, 15)
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ctx.closePath()
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return billboard
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}
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