IDirectDrawSurface2::UpdateOverlay

HRESULT UpdateOverlay(LPRECT lpSrcRect,

LPDIRECTDRAWSURFACE2 lpDDDestSurface,

LPRECT lpDestRect, DWORD dwFlags,

LPDDOVERLAYFX lpDDOverlayFx);

Repositions or modifies the visual attributes of an overlay surface. These surfaces must have the DDSCAPS_OVERLAY value set.

·Returns DD_OK if successful, or one of the following error values otherwise:

DDERR_GENERIC

DDERR_HEIGHTALIGN

DDERR_INVALIDOBJECT

DDERR_INVALIDPARAMS

DDERR_INVALIDRECT

DDERR_INVALIDSURFACETYPE

DDERR_NOSTRETCHHW

DDERR_NOTAOVERLAYSURFACE

DDERR_SURFACELOST

DDERR_UNSUPPORTED

DDERR_XALIGN

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.

lpDDDestSurface

Address of the DirectDraw 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.

dwFlags

DDOVER_ADDDIRTYRECT

Adds a dirty rectangle to an emulated overlaid 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_DDFX

Uses the overlay FX flags to define special overlay effects.

DDOVER_HIDE

Turns this overlay off.

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_SHOW

Turns this overlay on.

DDOVER_ZORDER

Uses the dwZOrderFlags member of the DDOVERLAYFX structure as the z-order for the display of this overlay. The lpDDSRelative member is used if the dwZOrderFlags member is set to either DDOVERZ_INSERTINBACKOF or DDOVERZ_INSERTINFRONTOF.

lpDDOverlayFx

See the DDOVERLAYFX structure.