Surfaces

A surface represents a linear area of display memory. A surface usually resides in the display memory of the display card, although surfaces can exist in system memory. Surface objects are contained within the IDirect3DSurface9 interface.

An IDirect3DSurface9 interface is obtained by calling one of the following methods.

• IDirect3DCubeTexture9::GetCubeMapSurface
• IDirect3DDevice9::CreateDepthStencilSurface
• IDirect3DDevice9::CreateRenderTarget
• IDirect3DDevice9::GetBackBuffer
• IDirect3DDevice9::GetDepthStencilSurface
• IDirect3DDevice9::GetFrontBufferData
• IDirect3DDevice9::GetRenderTarget
• IDirect3DSwapChain9::GetBackBuffer
• IDirect3DTexture9::GetSurfaceLevel

The IDirect3DSurface9 interface enables you to indirectly access memory through the IDirect3DDevice9::UpdateSurface method. This method allows you to copy a rectangular region of pixels from one IDirect3DSurface9 interface to another IDirect3DSurface9 interface. The surface interface also has methods to directly access display memory. For example, you can use the IDirect3DSurface9::LockRect method to lock a rectangular region of display memory. It is important to call IDirect3DSurface9::UnlockRect after you are done working with the locked rectangular region on the surface.

Surface formats dictate how data for each pixel in surface memory is interpreted. Microsoft?Direct3D?uses the D3DFORMAT member of the D3DSURFACE_DESC structure to describe the surface format. You can retrieve the format of an existing surface by calling the IDirect3DSurface9::GetDesc method.

Additional information can be found in the following topics.

• Width vs. Pitch
• Flipping Surfaces
• Page Flipping and Back Buffering
• Copying to Surfaces
• Copying Surfaces
• Accessing Surface Memory Directly
• Private Surface Data
• Gamma Controls