功能:触摸缩放在双指中心缩放

src/Editor/CameraControls.ts

@@ -116,6 +116,7 @@ export class CameraControls
     };
 
     //触屏开始事件(点击操作区和点击虚拟鼠标中间时可触发)
+    private _TouchScaleCenter = new Vector3;
     onTouchStart = (event: Touch_Event) =>
     {
         this.Viewer.UpdateLockTarget();
@@ -128,6 +129,10 @@ export class CameraControls
                 let dy = event.touches[0].pageY - event.touches[1].pageY;
                 let distance = Math.sqrt(dx * dx + dy * dy);
                 this.DollyStart.set(0, distance);
+
+                let rect = (event.target as HTMLElement).getBoundingClientRect();
+                this._TouchScaleCenter.set((event.touches[0].clientX + event.touches[1].clientX) * 0.5 - rect.left, (event.touches[0].clientY + event.touches[1].clientY) * 0.5 - rect.top, 0);
+                this.Viewer.ScreenToWorld(this._TouchScaleCenter);
             }
 
             this.State_Touch = this.TouchTypeList[event.touches.length - 1];
@@ -166,13 +171,9 @@ export class CameraControls
                     let distance = Math.sqrt(dx * dx + dy * dy);
                     this.DollyEnd.set(0, distance);
                     if (distance > this.DollyStart.y)
-                    {
-                        this.Viewer.Zoom(0.95);
-                    }
+                        this.Viewer.Zoom(0.95, this._TouchScaleCenter);
                     else
-                    {
-                        this.Viewer.Zoom(1.05);
-                    }
+                        this.Viewer.Zoom(1.05, this._TouchScaleCenter);
                     this.DollyStart.copy(this.DollyEnd);
                     break;
                 }