54     vec_flip_ = Vec2( 1.f, -1.f );  in TapCamera()
58     vec_ball_center_ = Vec2( 0, 0 );  in TapCamera()
59     vec_ball_now_ = Vec2( 0, 0 );  in TapCamera()
60     vec_ball_down_ = Vec2( 0, 0 );  in TapCamera()
62     vec_pinch_start_ = Vec2( 0, 0 );  in TapCamera()
63     vec_pinch_start_center_ = Vec2( 0, 0 );  in TapCamera()
65     vec_flip_ = Vec2( 0, 0 );  in TapCamera()
80     vec_drag_delta_ = Vec2();  in InitParameters()
101         Vec2 v = vec_drag_delta_;  in Update()
102         BeginDrag( Vec2() ); //NOTE:This call reset _VDragDelta  in Update()
157 void TapCamera::BeginDrag( const Vec2& v )  in BeginDrag()
165     Vec2 vec = v * vec_flip_;  in BeginDrag()
172     vec_drag_delta_ = Vec2();  in BeginDrag()
185 void TapCamera::Drag( const Vec2& v )  in Drag()
190     Vec2 vec = v * vec_flip_;  in Drag()
200 void TapCamera::BeginPinch( const Vec2& v1, const Vec2& v2 )  in BeginPinch()
208     BeginDrag( Vec2() );  in BeginPinch()
212     Vec2 vec = v1 - v2;  in BeginPinch()
242 void TapCamera::Pinch( const Vec2& v1, const Vec2& v2 )  in Pinch()
251     Vec2 vec = v1 - v2;  in Pinch()
301 Vec3 TapCamera::PointOnSphere( Vec2& point )  in PointOnSphere()
305     Vec2 vec = (point - vec_ball_center_) / ball_radius_;  in PointOnSphere()