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The DdGetScanLine callback function returns the number of the current physical scan line.
Syntax
PDD_GETSCANLINE PddGetscanline;
DWORD PddGetscanline(
PDD_GETSCANLINEDATA unnamedParam1
)
{...}
Parameters
unnamedParam1
Points to a DD_GETSCANLINEDATA structure in which the driver returns the number of the current scan line.
Return value
DdGetScanLine returns one of the following callback codes:
Remarks
If the monitor is not in vertical blank, the driver should write the scan line value in the dwScanLine member of the DD_GETSCANLINEDATA structure at pGetScanLine. The number must be in the range [0, n], where scan line 0 is the first visible scan line and scan line n is the last visible scan line on the screen. The driver should then set DD_OK in the ddRVal member of DD_GETSCANLINEDATA and return DDHAL_DRIVER_HANDLED.
The scan line is indeterminate if a vertical blank is in progress. In this situation, the driver should set ddRVal to DDERR_VERTICALBLANKINPROGRESS and return DDHAL_DRIVER_HANDLED.
Requirements
Requirement | Value |
---|---|
Target Platform | Desktop |
Header | ddrawint.h (include Winddi.h) |