VisRegionNotify: Difference between revisions
Created page with "VisRegionNotify recalculates the visible region and validates the DC region. == Syntax == VisRegionNotify(hdc); == Parameters == ; hdc (ULONG) - input : Device context han..." |
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VisRegionNotify recalculates the visible region and validates the DC region. | VisRegionNotify recalculates the visible region and validates the DC region. | ||
== Syntax == | |||
== Syntax == | |||
VisRegionNotify(hdc); | VisRegionNotify(hdc); | ||
== Parameters == | == Parameters == | ||
; hdc (ULONG) - input : Device context handle. | ; hdc (ULONG) - input : Device context handle. | ||
== Returns == | == Returns == | ||
; fSuccess (BOOL) - returns : Return codes. | ; fSuccess (BOOL) - returns : Return codes. | ||
: This function returns BOOLEAN (fSuccess). | : This function returns BOOLEAN (fSuccess). | ||
* TRUE Successful | * TRUE Successful | ||
* FALSE Error | * FALSE Error | ||
== Sample == | == Sample == | ||
| Line 20: | Line 21: | ||
fSuccess = VisRegionNotify(hdc); | fSuccess = VisRegionNotify(hdc); | ||
</pre> | </pre> | ||
== Remarks == | == Remarks == | ||
The handling routine in the graphics engine does the necessary calculations and calls the GreNotifyClipChange routine in the presentation driver so that the driver can receive the new clip regions. | The handling routine in the graphics engine does the necessary calculations and calls the GreNotifyClipChange routine in the presentation driver so that the driver can receive the new clip regions. | ||
VisRegionNotify is used only by display drivers. These drivers maintain an HDC_IS_DIRTY flag that is set ON by GreDeviceInvalidateClipRegion and cleared by GreNotifyClipChange. In the display driver, the handling routines for all drawing functions should check the HDC_IS_DIRTY flag, and if it is set, call VisRegionNotify before drawing. | VisRegionNotify is used only by display drivers. These drivers maintain an HDC_IS_DIRTY flag that is set ON by GreDeviceInvalidateClipRegion and cleared by GreNotifyClipChange. In the display driver, the handling routines for all drawing functions should check the HDC_IS_DIRTY flag, and if it is set, call VisRegionNotify before drawing. | ||
VisRegionNotify is available across the system at Ring 3. Presentation drivers do not need to import this function through the module definition file. | VisRegionNotify is available across the system at Ring 3. Presentation drivers do not need to import this function through the module definition file. | ||
[[Category:Spl]] | [[Category:Spl]] | ||
Latest revision as of 21:47, 2 July 2023
VisRegionNotify recalculates the visible region and validates the DC region.
Syntax
VisRegionNotify(hdc);
Parameters
- hdc (ULONG) - input
- Device context handle.
Returns
- fSuccess (BOOL) - returns
- Return codes.
- This function returns BOOLEAN (fSuccess).
- TRUE Successful
- FALSE Error
Sample
#include <os2.h> ULONG hdc; /* Device context handle. */ BOOL fSuccess; /* Return codes. */ fSuccess = VisRegionNotify(hdc);
Remarks
The handling routine in the graphics engine does the necessary calculations and calls the GreNotifyClipChange routine in the presentation driver so that the driver can receive the new clip regions.
VisRegionNotify is used only by display drivers. These drivers maintain an HDC_IS_DIRTY flag that is set ON by GreDeviceInvalidateClipRegion and cleared by GreNotifyClipChange. In the display driver, the handling routines for all drawing functions should check the HDC_IS_DIRTY flag, and if it is set, call VisRegionNotify before drawing.
VisRegionNotify is available across the system at Ring 3. Presentation drivers do not need to import this function through the module definition file.