cesium 实现鼠标中键拖动地图

cesium默认左键拖动地图，中键旋转，再绘图时带来诸多不便。所以改成鼠标中键按下拖动地图，鼠标左键选点。代码如下：【感谢chatGPT】

  //改为中建拖动// 假设 viewer 是你的 Cesium Viewer 实例const cameraController = viewer.scene.screenSpaceCameraController;// 关闭默认的左键旋转操作cameraController.enableRotate = false;// 禁用中键的默认倾斜操作cameraController.enableTilt = false;// 创建一个新的事件处理器const handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);let isMiddleDown = false;let lastPosition;let scale = 0;handler.setInputAction((movement) => {isMiddleDown = true;lastPosition = Cesium.Cartesian3.clone(movement.position);const height = viewer.camera.positionCartographic.height;const canvas = viewer.scene.canvas;// 使用经验公式获取米/(像素值*每米弧度值)scale = (height * 0.5) / (canvas.clientHeight * 6371000);}, Cesium.ScreenSpaceEventType.MIDDLE_DOWN);handler.setInputAction((movement) => {isMiddleDown = false;}, Cesium.ScreenSpaceEventType.MIDDLE_UP);handler.setInputAction((movement) => {if (isMiddleDown) {const dx = movement.endPosition.x - lastPosition.x;const dy = movement.endPosition.y - lastPosition.y;const deltaPhi = dx * scale;const deltaTheta = dy * scale;console.log(`dx:${dx};dy${dy};scale:${scale};deltaPhi:${deltaPhi};deltaTheta:${deltaTheta}`)viewer.camera.rotateRight(-deltaPhi);viewer.camera.rotateUp(-deltaTheta);lastPosition = Cesium.Cartesian3.clone(movement.endPosition);}}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);