原理就是不断改变地图中心点,改变相机角度方向,明白这一点,其他地图引擎譬如cesium都可效仿,本人就是通过cesium的漫游实现四维图新的漫游,唯一不足的是转弯的时候不能丝滑转向,尝试过应该是四维图新引擎的问题
export default function flyView (map, roadLine,nextIndex){let index = 1;let ding;let currentCenter;if(nextIndex){index = nextIndex;}const flyTime = 12000; function setExtentTime(time) {const startTime = new Date().getTime();const stopTime = startTime + time;return {stopTime,startTime };}function bearings(startLat, startLng, destLat, destLng) {const y = Math.sin(destLng - startLng) * Math.cos(destLat);const x = Math.cos(startLat) * Math.sin(destLat) - Math.sin(startLat) * Math.cos(destLat) * Math.cos(destLng - startLng);const brng = Math.atan2(y, x);const brngDgr = brng * 180 / Math.PI;return brngDgr;}function flyExtent() {if(index>=roadLine.length-1){index = 1;}const time = setExtentTime(flyTime);const bearing = Math.abs(bearings(roadLine[index - 1].lat, roadLine[index - 1].lng, roadLine[index].lat, roadLine[index].lng));map.setCenter([roadLine[index - 1].lng,roadLine[index - 1].lat])map.setBearing(Math.abs(bearing));const loop = function () {const delTime = new Date().getTime() - time.startTime;const stepLng = (roadLine[index].lng - roadLine[index - 1].lng) / flyTime * delTime;const stepLat = (roadLine[index].lat - roadLine[index - 1].lat) / flyTime * delTime;const currentBearing = map.getBearing();if (delTime > 0) {const endPosition = [roadLine[index - 1].lng + stepLng,roadLine[index - 1].lat + stepLat];map.setCenter([endPosition[0], endPosition[1]]);} };ding = setInterval(() => {loop();if (new Date().getTime() - time.stopTime >= 0) {console.log(111);clearInterval(ding);index = ++index >= roadLine.length ? 0 : index;if (index != 0) {console.log(index);flyExtent();}}}, 100);function stopFlyExtent() {clearInterval(ding);currentCenter = map.getCenter();}function startFlyExtent() {roadLine[index-1].lng = currentCenter.lngroadLine[index-1].lat = currentCenter.latflyExtent(index);}return {stopFlyExtent,startFlyExtent,index};}const control = flyExtent();return control;}const roadLine = [{lng: 118.30918373160092,lat: 33.8934430266404},{lng: 118.317598598913,lat: 33.89589007385073},{lng: 118.32260700135133,lat: 33.897263166704974},{lng: 118.32527174444655,lat: 33.897387332495924},
]
使用
this.control = flyView(map, roadLine);
this.control.startFlyExtent();
this.control.stopFlyExtent();