DXGI_USAGE
Flags for surface and resource creation options.
| Constant/value | Description |
|---|---|
|
The surface or resource is used as a back buffer. You don’t need to pass DXGI_USAGE_BACK_BUFFER when you create a swap chain. But you can determine whether a resource belongs to a swap chain when you call IDXGIResource::GetUsage and get DXGI_USAGE_BACK_BUFFER. |
|
This flag is for internal use only. |
|
Use the surface or resource for reading only. |
|
Use the surface or resource as an output render target. |
|
Use the surface or resource as an input to a shader. |
|
Share the surface or resource. |
|
Use the surface or resource for unordered access. |
Remarks
Each flag is defined as an unsigned integer.
#define DXGI_CPU_ACCESS_NONE ( 0 )
#define DXGI_CPU_ACCESS_DYNAMIC ( 1 )
#define DXGI_CPU_ACCESS_READ_WRITE ( 2 )
#define DXGI_CPU_ACCESS_SCRATCH ( 3 )
#define DXGI_CPU_ACCESS_FIELD 15
#define DXGI_USAGE_SHADER_INPUT ( 1L << (0 + 4) )
#define DXGI_USAGE_RENDER_TARGET_OUTPUT ( 1L << (1 + 4) )
#define DXGI_USAGE_BACK_BUFFER ( 1L << (2 + 4) )
#define DXGI_USAGE_SHARED ( 1L << (3 + 4) )
#define DXGI_USAGE_READ_ONLY ( 1L << (4 + 4) )
#define DXGI_USAGE_DISCARD_ON_PRESENT ( 1L << (5 + 4) )
#define DXGI_USAGE_UNORDERED_ACCESS ( 1L << (6 + 4) )
typedef UINT DXGI_USAGE;
These flag options are used in a call to the IDXGIFactory::CreateSwapChain, IDXGIFactory2::CreateSwapChainForHwnd, IDXGIFactory2::CreateSwapChainForCoreWindow, or IDXGIFactory2::CreateSwapChainForComposition method to describe the surface usage and CPU access options for the back buffer of a swap chain. You can't use the DXGI_USAGE_SHARED, DXGI_USAGE_DISCARD_ON_PRESENT, and DXGI_USAGE_READ_ONLY values as input to create a swap chain. However, DXGI can set DXGI_USAGE_DISCARD_ON_PRESENT and DXGI_USAGE_READ_ONLY for some of the swap chain's back buffers on the application's behalf. You can call the IDXGIResource::GetUsage method to retrieve the usage of these back buffers. Swap chain's only support the DXGI_CPU_ACCESS_NONE value in the DXGI_CPU_ACCESS_FIELD part of DXGI_USAGE.
These flag options are also used by the IDXGIDevice::CreateSurface method.
Requirements
| Requirement | Value |
|---|---|
| Header |
|
See also