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You can also create complex surfaces. A complex surface is a set of surfaces created with a single call to the IDirectDraw4::CreateSurfacemethod. If the DDSCAPS_COMPLEX flag is set when you call CreateSurfacecall, DirectDraw implicitly creates one or more surfaces in addition to the surface explicitly specified. You manage complex surfaces just like a single surfacea single call to the IDirectDraw::Releasemethod releases all surfaces, and a single call to the IDirectDrawSurface5::Restoremethod restores them all. However, implicitly created surfaces cannot be detached. For more information, see IDirectDrawSurface5::DeleteAttachedSurface.
One of the most useful complex surfaces you can create is a flipping chain. Usually, a flipping chain is made of a primary surface and one or more back buffers. The DDSCAPS_FLIP flag indicates that a surface is part of a flipping chain. Creating a flipping chain this way requires that you also include the DDSCAPS_COMPLEX flag.
The following example shows how to prepare for creating a primary surface flipping chain.
DDSURFACEDESC2 ddsd2; ddsd2.dwSize = sizeof(ddsd2); // Tell DirectDraw which members are valid. ddsd2.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT; // Request a primary surface with a single // back buffer ddsd2.ddsCaps.dwCaps = DDSCAPS_COMPLEX | DDSCAPS_FLIP | DDSCAPS_PRIMARYSURFACE; ddsd2.dwBackBufferCount = 1;
The previous example constructs a double-buffered flipping environmenta single call to the IDirectDrawSurface5::Flipmethod exchanges the surface memory of the primary surface and the back buffer. If you specify 2 for the value of the dwBackBufferCountmember of the DDSURFACEDESC2structure, two back buffers are created, and each call to Fliprotates the surfaces in a circular pattern, providing a triple-buffered flipping environment. For more information, see Flipping Surfaces.
Note To create a flipping chain that comprises surfaces that will be used as 3-D render targets, be sure to include the DDSCAPS_3DDEVICE capability flag in the surface description, as well as the DDSCAPS_COMPLEX and DDSCAPS_FLIP flags.
Unlike the CreateSurfacemethod exposed by the IDirectDraw3and earlier interfaces, you cannot use IDirectDraw4::CreateSurfaceto implicitly create a flipping chain of render target surfaces with an attached depth-buffer. The DDSURFACEDESC2structure that the IDirectDraw4::CreateSurfacemethod accepts doesn't contain a field to specify a depth-buffer bit depth. As a result, applications must create a depth-buffer surface explicitly, then attach it to the back-buffer render target surface.
Last updated on Tuesday, May 18, 2004