 Important: |
|---|
| This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist. |
The DDPIXELFORMATstructure describes the pixel format of a DirectDrawSurface object for the IDirectDrawSurface5::GetPixelFormat method.
typedef struct _DDPIXELFORMAT{
DWORD
dwSize
;
DWORD
dwFlags
;
DWORD
dwFourCC
;
union
{
DWORD
dwRGBBitCount
;
DWORD
dwYUVBitCount
;
DWORD
dwZBufferBitDepth
;
DWORD
dwAlphaBitDepth
;
DWORD
dwLuminanceBitCount
;
DWORD
dwBumpBitCount
;
} DUMMYUNIONNAMEN(1);
union
{
DWORD
dwRBitMask
;
DWORD
dwYBitMask
;
DWORD
dwStencilBitDepth
;
DWORD
dwLuminanceBitMask
;
DWORD
dwBumpDuBitMask
;
} DUMMYUNIONNAMEN(2);
union
{
DWORD
dwGBitMask
;
DWORD
dwUBitMask
;
DWORD
dwZBitMask
;
DWORD
dwBumpDvBitMask
;
} DUMMYUNIONNAMEN(3);
union
{
DWORD
dwBBitMask
;
DWORD
dwVBitMask
;
DWORD
dwStencilBitMask
;
DWORD
dwBumpLuminanceBitMask
;
} DUMMYUNIONNAMEN(4);
union
{
DWORD
dwRGBAlphaBitMask
;
DWORD
dwYUVAlphaBitMask
;
DWORD
dwLuminanceAlphaBitMask
;
DWORD
dwRGBZBitMask
;
DWORD
dwYUVZBitMask
;
} DUMMYUNIONNAMEN(5);
} DDPIXELFORMAT, FAR* LPDDPIXELFORMAT;
Members
- dwSize
- Size of the structure, in bytes. This member must be initialized before the structure is used.
- dwFlags
- Optional control flags.
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 dwLuminanceBitMaskmember 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 dwBumpLuminanceBitMaskmembers. DDPF_COMPRESSED The surface will accept pixel data in the specified format and compress it during the write operation. DDPF_FOURCC The dwFourCCmember is valid and contains a FOURCC code describing a non-RGB pixel format. DDPF_LUMINANCE The pixel format describes a luminance-only or luminance-alpha surface. DDPF_PALETTEINDEXED1 DDPF_PALETTEINDEXED2 DDPF_PALETTEINDEXED4 DDPF_PALETTEINDEXED8 The surface is 1-, 2-, 4-, or 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 will accept RGB data and translate it during the write operation to YUV data. The format of the data to be written will be contained in the pixel format structure. The DDPF_RGB flag will be set. DDPF_STENCILBUFFER The surface encodes stencil and depth information in each pixel of the Z-buffer. This flag can only be used 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-buffer information in the pixels. - dwFourCC
- FourCC code. For more information see, Four Character Codes (FOURCC).
- dwRGBBitCount
- RGB bits per pixel (4, 8, 16, 24, or 32).
- dwYUVBitCount
- YUV bits per pixel (4, 8, 16, 24, or 32).
- dwZBufferBitDepth
- Z-buffer bit depth (8, 16, 24, or 32).
- 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), you must count the bits in the dwRGBAlphaBitMaskmember to obtain the bit-depth of the alpha component.
- dwLuminanceBitCount
- Total luminance bits per pixel. This member applies only to luminance-only and luminance-alpha surfaces.
- dwBumpBitCount
- Total bump-map bits per pixel in a bump-map surface.
- dwRBitMask
- Mask for red bits.
- dwYBitMask
- Mask for Y bits.
- 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 dwZBufferBitDepthminus dwStencilBitDepth).
- dwLuminanceBitMask
- Mask for luminance bits.
- dwBumpDuBitMask
- Mask for bump-map U delta bits.
- dwGBitMask
- Mask for green bits.
- dwUBitMask
- Mask for U bits.
- dwZBitMask
- Mask for Z bits.
- dwBumpDvBitMask
- Mask for bump-map V delta bits.
- dwBBitMask
- Mask for blue bits.
- dwVBitMask
- Mask for V bits.
- dwStencilBitMask
- Mask for stencil bits within each Z-buffer pixel.
- dwBumpLuminanceBitMask
- Mask for luminance in a bump-map pixel.
- dwRGBAlphaBitMaskand dwYUVAlphaBitMaskand dwLuminanceAlphaBitMask
- Masks for alpha channel.
- dwRGBZBitMaskand dwYUVZBitMask
- Masks for the Z channel.
Remarks
The dwAlphaBitDepthmember 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 example function 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 this structure have been updated to work with compilers that don't support nameless unions. If your compiler doesn't support nameless unions, define the NONAMELESSUNION token before including the Ddraw.h header file.
Requirements
Runs on Versions Declared in Windows CE OS 2.12 or later. Version 2.12 requires DXPAK 1.0 or later. ddraw.h See Also