ID3D10Buffer::Map method (d3d10.h)

Get a pointer to the data contained in the resource and deny GPU access to the resource.

Syntax

HRESULT Map(
  [in]  D3D10_MAP MapType,
  [in]  UINT      MapFlags,
  [out] void      **ppData
);

Parameters

[in] MapType

Type: D3D10_MAP

Flag that specifies the CPU's permissions for the reading and writing of a resource. For possible values, see D3D10_MAP.

[in] MapFlags

Type: UINT

Flag that specifies what the CPU should do when the GPU is busy (see D3D10_MAP_FLAG). This flag is optional.

[out] ppData

Type: void**

Pointer to the buffer resource data.

Return value

Type: HRESULT

If this function succeeds, it returns S_OK. The following list contains some of the reasons that Map can fail:

• If MapFlags specifies D3D10_MAP_FLAG_DO_NOT_WAIT and the GPU is not yet finished with the resource, ID3D10Buffer::Map returns DXGI_ERROR_WAS_STILL_DRAWING.
• ID3D10Buffer::Map returns DXGI_ERROR_DEVICE_REMOVED if MapType includes any flags that permit reading and the hardware device (that is, the video card) has been removed.

Remarks

For the CPU to write the contents of a resource, the resource must be created with the dynamic usage flag, D3D10_USAGE_DYNAMIC. To both read and write those contents, the resource must be created with the staging usage flag, D3D10_USAGE_STAGING. (For more information about these flags, see D3D10_USAGE.) ID3D10Buffer::Map will retrieve a pointer to the resource data. For a discussion on how to access resources efficiently, see Copying and Accessing Resource Data (Direct3D 10).

Call ID3D10Buffer::Unmap to signify that the application has finished accessing the resource.

ID3D10Buffer::Map has a few other restrictions. For example:

• The same buffer cannot be mapped multiple times; in other words, do not call ID3D10Buffer::Map on a buffer that is already mapped.
• Any buffer that is bound to the pipeline must be unmapped before any rendering operation (that is, ID3D10Device::Draw) can be executed.

Requirements

See also

ID3D10Buffer Interface