Creating Complex Surfaces and Flipping Chains

You can also create complex surfaces. A complex surface is a set of surfaces created with a single call to the IDirectDraw2::CreateSurface method. If the DDSCAPS_COMPLEX flag is set when you call CreateSurface call, DirectDraw implicitly creates one or more surfaces in addition to the surface explicitly specified. You manage complex surfaces just like a single surface¾a single call to the IDirectDraw::Release method releases all surfaces, and a single call to the IDirectDrawSurface3::Restore method restores them all. However, implicitly created surfaces cannot be detached. For more information, see IDirectDrawSurface3::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.

DDSURFACEDESC ddsd;

ddsd.dwSize = sizeof(ddsd);

// Tell DirectDraw which members are valid.

ddsd.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT;

// Request a primary surface with a single

// back buffer

ddsd.ddsCaps.dwCaps = DDSCAPS_COMPLEX | DDSCAPS_FLIP |

DDSCAPS_PRIMARYSURFACE;

ddsd.dwBackBufferCount = 1;

The previous example constructs a double-buffered flipping environment¾a single call to the IDirectDrawSurface3::Flip method exchanges the surface memory of the primary surface and the back buffer. If you specify 2 for the value of the dwBackBufferCount member of the DDSURFACEDESC structure, two back buffers are created, and each call to Flip rotates the surfaces in a circular pattern, providing a triple-buffered flipping environment.