IDirectDrawSurface7::Blt method (ddraw.h)

Article
11/01/2022

Performs a bit block transfer (bitblt). This method does not support z-buffering or alpha blending during bitblt operations.

Syntax

HRESULT Blt(
  [in] LPRECT               unnamedParam1,
  [in] LPDIRECTDRAWSURFACE7 unnamedParam2,
  [in] LPRECT               unnamedParam3,
  [in] DWORD                unnamedParam4,
  [in] LPDDBLTFX            unnamedParam5
);

Parameters

[in] unnamedParam1

A pointer to a RECT structure that defines the upper-left and lower-right points of the rectangle to bitblt to on the destination surface. If this parameter is NULL, the entire destination surface is used.

[in] unnamedParam2

A pointer to the IDirectDrawSurface7 interface for the DirectDrawSurface object that is the source of the bitblt.

[in] unnamedParam3

A pointer to a RECT structure that defines the upper-left and lower-right points of the rectangle to bitblt from on the source surface. If this parameter is NULL, the entire source surface is used.

[in] unnamedParam4

A combination of flags that determine the valid members of the associated DDBLTFX structure, specify color-key information, or request special behavior from the method. The following flags are defined:

Validation flags

DDBLT_COLORFILL

Uses the dwFillColor member of the DDBLTFX structure as the RGB color that fills the destination rectangle on the destination surface.

DDBLT_DDFX

Uses the dwDDFX member of the DDBLTFX structure to specify the effects to use for this bitblt.

DDBLT_DDROPS

Uses the dwDDROP member of the DDBLTFX structure to specify the raster operations (ROPS) that are not part of the Win32 API.

DDBLT_DEPTHFILL

Uses the dwFillDepth member of the DDBLTFX structure as the depth value with which to fill the destination rectangle on the destination z-buffer surface.

DDBLT_KEYDESTOVERRIDE

Uses the ddckDestColorkey member of the DDBLTFX structure as the color key for the destination surface.

DDBLT_KEYSRCOVERRIDE

Uses the ddckSrcColorkey member of the DDBLTFX structure as the color key for the source surface.

DDBLT_ROP

Uses the dwROP member of the DDBLTFX structure for the ROP for this bitblt. These ROPs are the same as those defined in the Win32 API.

DDBLT_ROTATIONANGLE

Uses the dwRotationAngle member of the DDBLTFX structure as the rotation angle (specified in 1/100s of a degree) for the surface.

Color key flags

DDBLT_KEYDEST

Uses the color key that is associated with the destination surface.

DDBLT_KEYSRC

Uses the color key that is associated with the source surface.

Behavior flags

DDBLT_ASYNC

Performs this bitblt asynchronously through the first in, first out (FIFO) hardware in the order received. If no room is available in the FIFO hardware, the call fails.

DDBLT_DONOTWAIT

Returns without bitbltting and also returns DDERR_WASSTILLDRAWING if the bitbltter is busy.

DDBLT_WAIT

Postpones the DDERR_WASSTILLDRAWING return value if the bitbltter is busy, and returns as soon as the bitblt can be set up or another error occurs.

Obsolete and unsupported flags

All DDBLT_ALPHA flag values

Not currently implemented.

All DDBLT_ZBUFFER flag values

This method does not currently support z-aware bitblt operations. None of the flags beginning with "DDBLT_ZBUFFER" are supported.

[in] unnamedParam5

A pointer to the DDBLTFX structure for the bitblt.

Return value

If the method succeeds, the return value is DD_OK.

If it fails, the method can return one of the following error values:

DDERR_GENERIC
DDERR_INVALIDCLIPLIST
DDERR_INVALIDOBJECT
DDERR_INVALIDPARAMS
DDERR_INVALIDRECT
DDERR_NOALPHAHW
DDERR_NOBLTHW
DDERR_NOCLIPLIST
DDERR_NODDROPSHW
DDERR_NOMIRRORHW
DDERR_NORASTEROPHW
DDERR_NOROTATIONHW
DDERR_NOSTRETCHHW
DDERR_NOZBUFFERHW
DDERR_SURFACEBUSY
DDERR_SURFACELOST
DDERR_UNSUPPORTED
DDERR_WASSTILLDRAWING

Remarks

Blt can perform synchronous or asynchronous bitblts (the latter is the default behavior). These bitblts can occur from display memory to display memory, from display memory to system memory, from system memory to display memory, or from system memory to system memory. The bitblts can be performed by using source color keys and destination color keys. Arbitrary stretching or shrinking is performed if the source and destination rectangles are not the same size.

Typically, Blt returns immediately with an error if the bitbltter is busy and the bitblt could not be set up. Specify the DDBLT_WAIT flag to request a synchronous bitblt. When you include the DDBLT_WAIT flag, Blt waits until the bitblt can be set up or another error occurs before it returns.

RECT structures are defined so that the right and bottom members are exclusive—therefore, right minus left equals the width of the rectangle, not 1 less than the width.

Requirements

Requirement	Value
Target Platform	Windows
Header	ddraw.h
Library	Ddraw.lib
DLL	Ddraw.dll

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