分类： iOS平台
2014-01-27 10:44:13
用到了非常好的协同机制实现鼠标2D统制，OnMouseDown事件表示鼠标已作了射线判断得到了对象。
拖拽时保持z轴不变，因为屏幕是xy二维的，空间是三维的。
IEnumerator OnMouseDown ()
{
var camera = Camera.mainCamera;
if (camera) {
//转换对象到当前屏幕位置
Vector3 screenPosition = camera.WorldToScreenPoint (transform.position);
//鼠标屏幕坐标
Vector3 mScreenPosition=new Vector3 (Input.mousePosition.x, Input.mousePosition.y, screenPosition.z);
//获得鼠标和对象之间的偏移量,拖拽时相机应该保持不动
Vector3 offset = transform.position - camera.ScreenToWorldPoint( mScreenPosition);
print ("drag starting:"+transform.name);
//若鼠标左键一直按着则循环继续
while (Input.GetMouseButton (0)) {
//鼠标屏幕上新位置
mScreenPosition = new Vector3 (Input.mousePosition.x, Input.mousePosition.y, screenPosition.z);
// 对象新坐标
transform.position=offset + camera.ScreenToWorldPoint (mScreenPosition);
//协同，等待下一帧继续
yield return new WaitForEndOfFrame ();
}
print ("drag compeleted");
}
}
///
/// 跟随鼠标旋转物体，并判断手势滑动离开时的旋转方向顺时针还是逆时针，可作些模拟拖拽完成时减速度效果
///
///
/// A
///
IEnumerator OnMouseDown ()
{
Camera camera = Camera.mainCamera;
if (camera) {
//一般指旋转物体的中心点或鼠标围绕某个旋转的中心
Vector3 relativePoint = camera.WorldToScreenPoint (transform.position);
//鼠标操作时只用x,y轴,计算时必须忽略z轴
relativePoint.z = 0;
//鼠标按下时的方向向量，作为拖拽起始参考向量
Vector3 relativeDirection = Input.mousePosition - relativePoint;
//手势滑动时旋转方向，1：顺时针，-1：逆时针
int flingDir = 1;
//最后倒数第二个方向的角度，用于比较最后旋转方向
float last2Angle =0;
print ("rotation starting:" + transform.name);
//对象原始角度
Vector3 originAngles = transform.eulerAngles;
Quaternion originRotation=transform.rotation;
//旋转总角度
float sumAngle = 0;
while (Input.GetMouseButton (0)) {
#region 当前旋转角度
Vector3 currentDirection = Input.mousePosition - relativePoint;
//0-180正角度，不适合拖拽旋转
//float currentAngle = Vector3.Angle (relativeDirection, currentDirection);
//有正负角度，可做鼠标跟随旋转角度
float currentSignAngle = SignAngle (relativeDirection, currentDirection);
#endregion
//离上次角度偏移量
float offsetAngle = currentSignAngle - last2Angle;
#region 判断方向
flingDir = currentSignAngle - last2Angle >= 0 ? 1 : -1;
#endregion
#region 总计正方向旋转角度
if (offsetAngle > 0) {
sumAngle += offsetAngle;
}
#endregion
last2Angle = currentSignAngle;
//print(offsetAngle+","+sumAngle);
print ("angle:" + currentSignAngle + ",fling:" + flingDir + ",sum:" + sumAngle);
//设置新的角度
transform.eulerAngles=originAngles+ originRotation*direction*currentSignAngle;
yield return new WaitForEndOfFrame ();
}
print ("rotation compeleted");
}
}
///
/// Math.atan2(y2-y1,x2-x1)
///
///
/// A
///
///
/// A
///
///
/// A
///
float SignAngle (Vector2 start, Vector2 end)
{
float num1 = (end.x * start.y)-(start.x * end.y);
float num2 = (start.x * end.x) + (start.y * end.y);
return (Mathf.Atan2 (num1, num2) * Mathf.Rad2Deg);
}
