PDD_SURFCB_BLT callback function (ddrawint.h)
The DdBlt callback function performs a bit-block transfer.
Syntax
PDD_SURFCB_BLT PddSurfcbBlt;
DWORD PddSurfcbBlt(
PDD_BLTDATA unnamedParam1
)
{...}
Parameters
unnamedParam1
Points to the DD_BLTDATA structure that contains the information required for the driver to perform the blit.
Return value
DdBlt returns one of the following callback codes:
Remarks
DdBlt can be optionally implemented in DirectDraw drivers.
Before performing the bit block transfer, the driver should ensure that a flip involving the destination surface is not in progress. If the destination surface is involved in a flip, the driver should set the ddRVal member of the DD_BLTDATA structure at lpBlt to DDERR_WASSTILLDRAWING and return DDHAL_DRIVER_HANDLED.
The driver should check dwFlags to determine the type of blit operation to perform. The driver should not check for flags that are undocumented.
When performing transparent (color keyed) blts, drivers should ignore any unused pixel bits in their comparisons. (For instance in 32bpp modes, the high byte is typically unused. This byte should not be used in the color key comparison.)
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | ddrawint.h (include Winddi.h) |