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DDOVERLAYFX

  • Article

This structure passes override information to the IDirectDrawSurface5::UpdateOverlay method.

typedef struct _DDOVERLAYFX{ 
  DWORD dwSize; 
  DWORD dwAlphaEdgeBlendBitDepth; 
  DWORD dwAlphaEdgeBlend; 
  DWORD dwReserved; 
  DWORD dwAlphaDestConstBitDepth; 
  union 
  { 
    DWORD dwAlphaDestConst; 
    LPDIRECTDRAWSURFACE lpDDSAlphaDest; 
  } DUMMYUNIONNAMEN(1);
  DWORD dwAlphaSrcConstBitDepth; 
  union 
  { 
    DWORD dwAlphaSrcConst; 
    LPDIRECTDRAWSURFACE lpDDSAlphaSrc; 
  } DUMMYUNIONNAMEN(2);
  DDCOLORKEY dckDestColorkey; 
  DDCOLORKEY dckSrcColorkey; 
  DWORD dwDDFX; 
  DWORD dwFlags; 
} DDOVERLAYFX,FAR *LPDDOVERLAYFX;

Members

  • dwSize
    Size of the structure, in bytes. This member must be initialized before the structure is used.
  • dwAlphaEdgeBlendBitDepth
    Bit depth used to specify the constant for an alpha edge blend.
  • dwAlphaEdgeBlend
    Constant to use as the alpha for an edge blend.
  • dwReserved
    Reserved for future use.
  • dwAlphaDestConstBitDepth
    Bit depth used to specify the alpha constant for a destination.
  • dwAlphaDestConst
    Constant to use as the alpha channel for a destination.
  • lpDDSAlphaDest
    Address of a surface to use as the alpha channel for a destination.
  • dwAlphaSrcConstBitDepth
    Bit depth used to specify the alpha constant for a source.
  • dwAlphaSrcConst
    Constant to use as the alpha channel for a source.
  • lpDDSAlphaSrc
    Address of a surface to use as the alpha channel for a source.
  • dckDestColorkey
    Destination color key override.
  • dckSrcColorkey
    Source color key override.
  • dwDDFX
    Overlay FX flags. The following table shows the possible flags.
    Flag Description
    DDOVERFX_ARITHSTRETCHY If stretching, use arithmetic stretching along the y-axis for this overlay.
    DDOVERFX_MIRRORLEFTRIGHT Mirror the overlay around the vertical axis.
    DDOVERFX_MIRRORUPDOWN Mirror the overlay around the horizontal axis.
  • dwFlags
    This member is currently not used and must be set to zero.

Remarks

The unions in this structure 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

OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
Header: Ddraw.h.

 Last updated on Thursday, April 08, 2004

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