gboolean gdk_events_get_angle ( GdkEvent* event1, GdkEvent* event2, double* angle )
Returns the relative angle from
The relative angle is the angle between the X axis and the line through both events’ positions. The rotation direction for positive angles is from the positive X axis towards the positive Y axis.
This assumes that both events have X/Y information.
If not, this function returns
The data is owned by the caller of the function.
Return location for the relative angle between both events.
The argument will be set by the function.