| WORD GetDisplayUpd(lpPntStruc, wParam, lParam) | |||
| LPEXTPAINTSTRUC lpPntStruc; | |||
| WORD wParam; | |||
| DWORD lParam; |
The GetDisplayUpd function calls the virtual-display device (VDD) to get a display update (if any) and stores it in the PAINT structure.
It prevents any further changes from occurring in or to the application. The application restarts after a call to one of the following functions: UpdateScreen, PaintScreen, or GrbUnLockApp.
lpPntStruc
Points to an EXTPAINTSTRUC structure.
wParam
Specifies the 16-bit message parameter. It is -1 if WINOLDAP origin.
lParam
Specifies the 32-bit message parameter. It is 0 if WINOLDAP origin.
The return value is a display update flag. It can be a combination of the following values.
| Value | Meaning |
| fDisp_Ctlr (8) | Indicates controller-state change. |
| fDisp_VRAM (16) | Indicates video RAM change. |
| fDisp_Curs (32) | Indicates cursor change. |
| fDisp_HCurTrack (128) | Horizontal cursor track is required. |
The export ordinal for this function is 18.
This function “locks” the application (prevents further changes from occurring). The application can be started again by calling the UpdateScreen, PaintScreen, or GrbUnLockApp functions.