Question

我正在尝试使用捏合手势旋转演员。演员实际上在旋转，但有时旋转被“卡住”。我记录了deltaRotDeg（以度为单位的增量旋转），有时值会跳转。例如，它在-42.25918度旋转，然后它将跳到317.7408度。我在这里跟着轮换数学http://www.codeproject.com/Articles/319401/Simple-Gestures-on-Android

这是我的代码。我的数学错了或代码中有什么问题吗？

public ActorGestureListener gestureListener = new ActorGestureListener() {
 @Override
    public void pinch(InputEvent event, Vector2 initialPointer1, Vector2 initialPointer2, Vector2 pointer1, Vector2 pointer2)  {
        Actor actor = event.getListenerActor();
        if(actor.getName().equals("valve")){
            Vector2 a = initialPointer2.sub(initialPointer1);
            Vector2 b = pointer2.sub(pointer1);
            a = a.nor();
            b = b.nor();
            float deltaRot = (float)(Math.atan2(b.y,b.x) - Math.atan2(a.y,a.x));
            float deltaRotDeg = (float)((deltaRot*180)/Math.PI);
            world.getValve().rotate(deltaRotDeg);
        }
    }

Answer 1

替换

float deltaRotDeg = (float)((deltaRot*180)/Math.PI);

与

float deltaRotDeg = (float)(((deltaRot*180)/Math.PI + 360) % 360);

如何用捏手势旋转Actor

1 个答案: