Describes the state of a mouse device that has up to four buttons, or another device that is being accessed as if it were a mouse device. This structure is used with the IDirectInputDevice8::GetDeviceState method.
typedef struct DIMOUSESTATE { LONG lX; LONG lY; LONG lZ; BYTE rgbButtons[4]; } DIMOUSESTATE, *LPDIMOUSESTATE;
You must prepare the device for mouse-style access by calling the IDirectInputDevice8::SetDataFormat method, passing the c_dfDIMouse global data format variable.
The mouse is a relative-axis device, so the absolute axis positions for mouse axes are accumulated relative motion. Therefore, the value of the absolute axis position is not meaningful except in comparison with other absolute axis positions.
If an axis is in relative mode, the appropriate member contains the change in position. If it is in absolute mode, the member contains the absolute axis position.