DDPIXELFORMAT structure (ddraw.h)
The DDPIXELFORMAT structure describes the pixel format of a DirectDrawSurface object for the IDirectDrawSurface7::GetPixelFormat method.
Syntax
typedef struct _DDPIXELFORMAT {
DWORD dwSize;
DWORD dwFlags;
DWORD dwFourCC;
#if ...
union {
DWORD dwRGBBitCount;
DWORD dwYUVBitCount;
DWORD dwZBufferBitDepth;
DWORD dwAlphaBitDepth;
DWORD dwLuminanceBitCount;
DWORD dwBumpBitCount;
DWORD dwPrivateFormatBitCount;
} DUMMYUNIONNAMEN;
#elif
union {
DWORD dwRBitMask;
DWORD dwYBitMask;
DWORD dwStencilBitDepth;
DWORD dwLuminanceBitMask;
DWORD dwBumpDuBitMask;
DWORD dwOperations;
} DUMMYUNIONNAMEN;
#elif
union {
DWORD dwGBitMask;
DWORD dwUBitMask;
DWORD dwZBitMask;
DWORD dwBumpDvBitMask;
struct {
WORD wFlipMSTypes;
WORD wBltMSTypes;
} MultiSampleCaps;
} DUMMYUNIONNAMEN;
#elif
union {
DWORD dwBBitMask;
DWORD dwVBitMask;
DWORD dwStencilBitMask;
DWORD dwBumpLuminanceBitMask;
} DUMMYUNIONNAMEN;
#else
union {
DWORD dwRGBAlphaBitMask;
DWORD dwYUVAlphaBitMask;
DWORD dwLuminanceAlphaBitMask;
DWORD dwRGBZBitMask;
DWORD dwYUVZBitMask;
} DUMMYUNIONNAMEN;
#endif
} DDPIXELFORMAT;
Members
dwSize
Size of the structure, in bytes. This member must be initialized before the structure is used.
dwFlags
The following flags to describe optional controls for this structure.
DDPF_ALPHA
The pixel format describes an alpha-only surface.
DDPF_ALPHAPIXELS
The surface has alpha channel information in the pixel format.
DDPF_ALPHAPREMULT
The surface uses the premultiplied alpha format. That is, the color components in each pixel are premultiplied by the alpha component.
DDPF_BUMPLUMINANCE
The luminance data in the pixel format is valid, and the dwLuminanceBitMask member describes valid luminance bits for a luminance-only or luminance-alpha surface.
DDPF_BUMPDUDV
Bump-map data in the pixel format is valid. Bump-map information is in the dwBumpBitCount, dwBumpDuBitMask, dwBumpDvBitMask, and dwBumpLuminanceBitMask members.
DDPF_COMPRESSED
The surface accepts pixel data in the specified format and compress it during the write operation.
DDPF_D3DFORMAT
Indicates a DirectX 8.0 and later format capability entry in the texture format list. This flag is not exposed to applications and is defined in Ddrawi.h.
DDPF_FOURCC
The dwFourCC member is valid and contains a FOURCC code that describes a non-RGB pixel format.
DDPF_LUMINANCE
The pixel format describes a luminance-only or luminance-alpha surface.
DDPF_PALETTEINDEXED1
The surface is 1-bit color-indexed.
DDPF_PALETTEINDEXED2
The surface is 2-bit color-indexed.
DDPF_PALETTEINDEXED4
The surface is 4-bit color-indexed.
DDPF_PALETTEINDEXED8
The surface is 8-bit color-indexed.
DDPF_PALETTEINDEXEDTO8
The surface is 1-, 2-, or 4-bit color-indexed to an 8-bit palette.
DDPF_RGB
The RGB data in the pixel format structure is valid.
DDPF_RGBTOYUV
The surface accepts RGB data and translates it during the write operation to YUV data. The format of the data to be written is contained in the pixel format structure. The DDPF_RGB flag is set.
DDPF_STENCILBUFFER
The surface encodes stencil and depth information in each pixel of the z-buffer. This flag can be used only if the DDPF_ZBUFFER flag is also specified.
DDPF_YUV
The YUV data in the pixel format structure is valid.
DDPF_ZBUFFER
The pixel format describes a z-buffer surface.
DDPF_ZPIXELS
The surface contains z information in the pixels.
dwFourCC
A FourCC code.
DUMMYUNIONNAMEN
DUMMYUNIONNAMEN.dwRGBBitCount
RGB bits per pixel (4, 8, 16, 24, or 32).
DUMMYUNIONNAMEN.dwYUVBitCount
YUV bits per pixel (4, 8, 16, 24, or 32).
DUMMYUNIONNAMEN.dwZBufferBitDepth
Z-buffer bit depth (8, 16, 24, or 32).
DUMMYUNIONNAMEN.dwAlphaBitDepth
Alpha channel bit depth (1, 2, 4, or 8) for an alpha-only surface (DDPF_ALPHA). For pixel formats that contain alpha information interleaved with color data (DDPF_ALPHAPIXELS), count the bits in the dwRGBAlphaBitMask member to obtain the bit depth of the alpha component. For more information about how to determine alpha bit depth, see Remarks.
DUMMYUNIONNAMEN.dwLuminanceBitCount
Total luminance bits per pixel. This member applies only to luminance-only and luminance-alpha surfaces.
DUMMYUNIONNAMEN.dwBumpBitCount
Total bump-map bits per pixel in a bump-map surface.
DUMMYUNIONNAMEN.dwPrivateFormatBitCount
Bits per pixel of private driver formats. Only valid in texture format list and if DDPF_D3DFORMAT is set.
DUMMYUNIONNAMEN.dwRBitMask
Mask for red bits.
DUMMYUNIONNAMEN.dwYBitMask
Mask for Y bits.
DUMMYUNIONNAMEN.dwStencilBitDepth
Bit depth of the stencil buffer. This member specifies how many bits are reserved within each pixel of the z-buffer for stencil information (the total number of z-bits is equal to dwZBufferBitDepth minus dwStencilBitDepth).
DUMMYUNIONNAMEN.dwLuminanceBitMask
Mask for luminance bits.
DUMMYUNIONNAMEN.dwBumpDuBitMask
Mask for bump-map U-delta bits.
DUMMYUNIONNAMEN.dwOperations
Flags that specify the operations that can be performed on surfaces with the DDPF_D3DFORMAT pixel format. The flags are defined in Ddrawi.h.
DUMMYUNIONNAMEN.dwGBitMask
Mask for green bits.
DUMMYUNIONNAMEN.dwUBitMask
Mask for U bits.
DUMMYUNIONNAMEN.dwZBitMask
Mask for z bits.
DUMMYUNIONNAMEN.dwBumpDvBitMask
Mask for bump-map V-delta bits.
DUMMYUNIONNAMEN.MultiSampleCaps
A structure that contains the following two members. This structure is used to specify surfaces that can be used when performing multisample rendering. Each bit in the 16-bit masks indicates support of multisampling with a specific number of samples. For example, bit 0 indicates support of multisampling with only a single sample, bit 1 indicates the support of multisampling with two samples, and so on. The driver can indicate more than one supported level by combining the bits by using a bitwise OR.
DUMMYUNIONNAMEN.MultiSampleCaps.wFlipMSTypes
A 16-bit mask for full-screen (flip) mode multisampling.
DUMMYUNIONNAMEN.MultiSampleCaps.wBltMSTypes
A 16-bit mask for windowed (bit-block transfer) mode multisampling.
DUMMYUNIONNAMEN.dwBBitMask
Mask for blue bits.
DUMMYUNIONNAMEN.dwVBitMask
Mask for V bits.
DUMMYUNIONNAMEN.dwStencilBitMask
Mask for stencil bits within each z-buffer pixel.
DUMMYUNIONNAMEN.dwBumpLuminanceBitMask
Mask for luminance in a bump-map pixel.
DUMMYUNIONNAMEN.dwRGBAlphaBitMask
RGB mask for the alpha channel.
DUMMYUNIONNAMEN.dwYUVAlphaBitMask
YUV mask for the alpha channel.
DUMMYUNIONNAMEN.dwLuminanceAlphaBitMask
Luminance mask for the alpha channel.
DUMMYUNIONNAMEN.dwRGBZBitMask
RGB mask for the z channel.
DUMMYUNIONNAMEN.dwYUVZBitMask
YUV mask for the z channel.
Remarks
The dwAlphaBitDepth member reflects the bit depth of an alpha-only pixel format (DDPF_ALPHA). For pixel formats that include the alpha component with color components (DDPF_ALPHAPIXELS), the alpha bit depth is obtained by counting the bits in the various mask members. The following code example returns the number of bits set in a given bitmask.
WORD GetNumberOfBits( DWORD dwMask )
{
WORD wBits = 0;
while( dwMask )
{
dwMask = dwMask & ( dwMask - 1 );
wBits++;
}
return wBits;
}
The unions in DDPIXELFORMAT have been updated to work with compilers that do not support nameless unions. If your compiler does not support nameless unions, define the NONAMELESSUNION token before including the Ddraw.h header file.
Requirements
| Requirement | Value |
|---|---|
| Header | ddraw.h |
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