IDirectDrawSurface4::BltFast

The IDirectDrawSurface4::BltFast method performs a source copy blit or transparent blit by using a source color key or destination color key.

HRESULT BltFast(
  DWORD dwX,                            
  DWORD dwY,                            
  LPDIRECTDRAWSURFACE4 lpDDSrcSurface,  
  LPRECT lpSrcRect,                     
  DWORD dwTrans                         
);
 

Parameters

dwX and dwY

The x- and y-coordinates to blit to on the destination surface.

lpDDSrcSurface

Address of an IDirectDrawSurface4 interface for the DirectDrawSurface object that is the source of the blit.

lpSrcRect

Address of a RECT structure that defines the upper-left and lower-right points of the rectangle to blit from on the source surface.

dwTrans

Type of transfer.

DDBLTFAST_DESTCOLORKEY

Specifies a transparent blit that uses the destination's color key.

DDBLTFAST_NOCOLORKEY

Specifies a normal copy blit with no transparency.

DDBLTFAST_SRCCOLORKEY

Specifies a transparent blit that uses the source's color key.

DDBLTFAST_WAIT

Postpones the DDERR_WASSTILLDRAWING message if the blitter is busy, and returns as soon as the blit can be set up or another error occurs.

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:

Remarks

This method always attempts an asynchronous blit if it is supported by the hardware.

This method works only on display memory surfaces and cannot clip when blitting. If you use this method on a surface with an attached clipper, the call will fail and the method will return DDERR_UNSUPPORTED.

The software implementation of IDirectDrawSurface4::BltFast is 10 percent faster than the IDirectDrawSurface4::Blt method. However, there is no speed difference between the two if display hardware is being used.

Typically, IDirectDrawSurface4::BltFast returns immediately with an error if the blitter is busy and the blit cannot be set up. You can use the DDBLTFAST_WAIT flag, however, if you want this method to not return until either the blit can be set up or another error occurs.

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.