IDirectDrawSurface4::UpdateOverlay

The IDirectDrawSurface4::UpdateOverlay method repositions or modifies the visual attributes of an overlay surface. These surfaces must have the DDSCAPS_OVERLAY flag set.

HRESULT UpdateOverlay(
  LPRECT lpSrcRect,                      
  LPDIRECTDRAWSURFACE4 lpDDDestSurface,  
  LPRECT lpDestRect,                     
  DWORD dwFlags,                         
  LPDDOVERLAYFX lpDDOverlayFx            
);
 

Parameters

lpSrcRect

Address of a RECT structure that defines the x, y, width, and height of the region on the source surface being used as the overlay. This parameter can be NULL when hiding an overlay or to indicate that the entire overlay surface is to be used and that the overlay surface conforms to any boundary and size alignment restrictions imposed by the device driver.

lpDDDestSurface

Address of the IDirectDrawSurface4 interface for the surface that is being overlaid.

lpDestRect

Address of a RECT structure that defines the x, y, width, and height of the region on the destination surface that the overlay should be moved to. This parameter can be NULL when hiding the overlay.

dwFlags

DDOVER_ADDDIRTYRECT

Adds a dirty rectangle to an emulated overlay surface.

DDOVER_ALPHADEST

Uses either the alpha information in pixel format or the alpha channel surface attached to the destination surface as the alpha channel for this overlay.

DDOVER_ALPHADESTCONSTOVERRIDE

Uses the dwAlphaDestConst member of the DDOVERLAYFX structure as the destination alpha channel for this overlay.

DDOVER_ALPHADESTNEG

Indicates that the destination surface becomes more transparent as the alpha value increases (0 is opaque).

DDOVER_ALPHADESTSURFACEOVERRIDE

Uses the lpDDSAlphaDest member of the DDOVERLAYFX structure as the alpha channel destination for this overlay.

DDOVER_ALPHAEDGEBLEND

Uses the dwAlphaEdgeBlend member of the DDOVERLAYFX structure as the alpha channel for the edges of the image that border the color key colors.

DDOVER_ALPHASRC

Uses either the alpha information in pixel format or the alpha channel surface attached to the source surface as the source alpha channel for this overlay.

DDOVER_ALPHASRCCONSTOVERRIDE

Uses the dwAlphaSrcConst member of the DDOVERLAYFX structure as the source alpha channel for this overlay.

DDOVER_ALPHASRCNEG

Indicates that the source surface becomes more transparent as the alpha value increases (0 is opaque).

DDOVER_ALPHASRCSURFACEOVERRIDE

Uses the lpDDSAlphaSrc member of the DDOVERLAYFX structure as the alpha channel source for this overlay.

DDOVER_AUTOFLIP

Automatically flip to the next surface in the flip chain each time a video port VSYNC occurs.

DDOVER_BOB

Display each field individually of the interlaced video stream without causing any artifacts.

DDOVER_BOBHARDWARE

Indicates that bob operations will be performed using hardware rather than software or emulated. This flag must be used with the DDOVER_BOB flag.

DDOVER_DDFX

Uses the overlay FX flags in the lpDDOverlayFx parameter to define special overlay effects.

DDOVER_HIDE

Turns off this overlay.

DDOVER_KEYDEST

Uses the color key associated with the destination surface.

DDOVER_KEYDESTOVERRIDE

Uses the dckDestColorkey member of the DDOVERLAYFX structure as the color key for the destination surface.

DDOVER_KEYSRC

Uses the color key associated with the source surface.

DDOVER_KEYSRCOVERRIDE

Uses the dckSrcColorkey member of the DDOVERLAYFX structure as the color key for the source surface.

DDOVER_OVERRIDEBOBWEAVE

Indicates that bob/weave decisions should not be overridden by other interfaces.

DDOVER_INTERLEAVED

Indicates that the surface memory is composed of interleaved fields.

DDOVER_SHOW

Turns on this overlay.

lpDDOverlayFx

Address of a DDOVERLAYFX structure that describes the effects to be used. This parameter can be NULL if the DDOVER_DDFX flag is not specified.

Return Values

If the method succeeds, the return value is DD_OK.

If the method fails, the return value may be one of the following error values:

QuickInfo

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in ddraw.h.
  Import Library: Use ddraw.lib.