3.19. Graphics Interoperability

This section describes the graphics interoperability functions of the CUDA runtime application programming interface.

Functions

cudaError_t cudaGraphicsMapResources ( int  count, cudaGraphicsResource_t* resources, cudaStream_t stream = 0 )
Map graphics resources for access by CUDA.
cudaError_t cudaGraphicsResourceGetMappedMipmappedArray ( cudaMipmappedArray_t* mipmappedArray, cudaGraphicsResource_t resource )
Get a mipmapped array through which to access a mapped graphics resource.
cudaError_t cudaGraphicsResourceGetMappedPointer ( void** devPtr, size_t* size, cudaGraphicsResource_t resource )
Get an device pointer through which to access a mapped graphics resource.
cudaError_t cudaGraphicsResourceSetMapFlags ( cudaGraphicsResource_t resource, unsigned int  flags )
Set usage flags for mapping a graphics resource.
cudaError_t cudaGraphicsSubResourceGetMappedArray ( cudaArray_t* array, cudaGraphicsResource_t resource, unsigned int  arrayIndex, unsigned int  mipLevel )
Get an array through which to access a subresource of a mapped graphics resource.
cudaError_t cudaGraphicsUnmapResources ( int  count, cudaGraphicsResource_t* resources, cudaStream_t stream = 0 )
Unmap graphics resources.
cudaError_t cudaGraphicsUnregisterResource ( cudaGraphicsResource_t resource )
Unregisters a graphics resource for access by CUDA.

Functions

cudaError_t cudaGraphicsMapResources ( int  count, cudaGraphicsResource_t* resources, cudaStream_t stream = 0 )
Map graphics resources for access by CUDA.
Parameters
count
- Number of resources to map
resources
- Resources to map for CUDA
stream
- Stream for synchronization
Description

Maps the count graphics resources in resources for access by CUDA.

The resources in resources may be accessed by CUDA until they are unmapped. The graphics API from which resources were registered should not access any resources while they are mapped by CUDA. If an application does so, the results are undefined.

This function provides the synchronization guarantee that any graphics calls issued before cudaGraphicsMapResources() will complete before any subsequent CUDA work issued in stream begins.

If resources contains any duplicate entries then cudaErrorInvalidResourceHandle is returned. If any of resources are presently mapped for access by CUDA then cudaErrorUnknown is returned.

Note:
  • This function uses standard NULL stream semantics.

  • Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsResourceGetMappedPointer, cudaGraphicsSubResourceGetMappedArray, cudaGraphicsUnmapResources

cudaError_t cudaGraphicsResourceGetMappedMipmappedArray ( cudaMipmappedArray_t* mipmappedArray, cudaGraphicsResource_t resource )
Get a mipmapped array through which to access a mapped graphics resource.
Parameters
mipmappedArray
- Returned mipmapped array through which resource may be accessed
resource
- Mapped resource to access
Description

Returns in *mipmappedArray a mipmapped array through which the mapped graphics resource resource may be accessed. The value set in mipmappedArray may change every time that resource is mapped.

If resource is not a texture then it cannot be accessed via an array and cudaErrorUnknown is returned. If resource is not mapped then cudaErrorUnknown is returned.

Note:

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsResourceGetMappedPointer

cudaError_t cudaGraphicsResourceGetMappedPointer ( void** devPtr, size_t* size, cudaGraphicsResource_t resource )
Get an device pointer through which to access a mapped graphics resource.
Parameters
devPtr
- Returned pointer through which resource may be accessed
size
- Returned size of the buffer accessible starting at *devPtr
resource
- Mapped resource to access
Description

Returns in *devPtr a pointer through which the mapped graphics resource resource may be accessed. Returns in *size the size of the memory in bytes which may be accessed from that pointer. The value set in devPtr may change every time that resource is mapped.

If resource is not a buffer then it cannot be accessed via a pointer and cudaErrorUnknown is returned. If resource is not mapped then cudaErrorUnknown is returned. *

Note:

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsMapResources, cudaGraphicsSubResourceGetMappedArray

cudaError_t cudaGraphicsResourceSetMapFlags ( cudaGraphicsResource_t resource, unsigned int  flags )
Set usage flags for mapping a graphics resource.
Parameters
resource
- Registered resource to set flags for
flags
- Parameters for resource mapping
Description

Set flags for mapping the graphics resource resource.

Changes to flags will take effect the next time resource is mapped. The flags argument may be any of the following:

  • cudaGraphicsMapFlagsNone: Specifies no hints about how resource will be used. It is therefore assumed that CUDA may read from or write to resource.

  • cudaGraphicsMapFlagsReadOnly: Specifies that CUDA will not write to resource.

  • cudaGraphicsMapFlagsWriteDiscard: Specifies CUDA will not read from resource and will write over the entire contents of resource, so none of the data previously stored in resource will be preserved.

If resource is presently mapped for access by CUDA then cudaErrorUnknown is returned. If flags is not one of the above values then cudaErrorInvalidValue is returned.

Note:

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsMapResources

cudaError_t cudaGraphicsSubResourceGetMappedArray ( cudaArray_t* array, cudaGraphicsResource_t resource, unsigned int  arrayIndex, unsigned int  mipLevel )
Get an array through which to access a subresource of a mapped graphics resource.
Parameters
array
- Returned array through which a subresource of resource may be accessed
resource
- Mapped resource to access
arrayIndex
- Array index for array textures or cubemap face index as defined by cudaGraphicsCubeFace for cubemap textures for the subresource to access
mipLevel
- Mipmap level for the subresource to access
Description

Returns in *array an array through which the subresource of the mapped graphics resource resource which corresponds to array index arrayIndex and mipmap level mipLevel may be accessed. The value set in array may change every time that resource is mapped.

If resource is not a texture then it cannot be accessed via an array and cudaErrorUnknown is returned. If arrayIndex is not a valid array index for resource then cudaErrorInvalidValue is returned. If mipLevel is not a valid mipmap level for resource then cudaErrorInvalidValue is returned. If resource is not mapped then cudaErrorUnknown is returned.

Note:

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsResourceGetMappedPointer

cudaError_t cudaGraphicsUnmapResources ( int  count, cudaGraphicsResource_t* resources, cudaStream_t stream = 0 )
Unmap graphics resources.
Parameters
count
- Number of resources to unmap
resources
- Resources to unmap
stream
- Stream for synchronization
Description

Unmaps the count graphics resources in resources.

Once unmapped, the resources in resources may not be accessed by CUDA until they are mapped again.

This function provides the synchronization guarantee that any CUDA work issued in stream before cudaGraphicsUnmapResources() will complete before any subsequently issued graphics work begins.

If resources contains any duplicate entries then cudaErrorInvalidResourceHandle is returned. If any of resources are not presently mapped for access by CUDA then cudaErrorUnknown is returned.

Note:
  • This function uses standard NULL stream semantics.

  • Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsMapResources

cudaError_t cudaGraphicsUnregisterResource ( cudaGraphicsResource_t resource )
Unregisters a graphics resource for access by CUDA.
Parameters
resource
- Resource to unregister
Description

Unregisters the graphics resource resource so it is not accessible by CUDA unless registered again.

If resource is invalid then cudaErrorInvalidResourceHandle is returned.

Note:

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cudaGraphicsD3D9RegisterResource, cudaGraphicsD3D10RegisterResource, cudaGraphicsD3D11RegisterResource, cudaGraphicsGLRegisterBuffer, cudaGraphicsGLRegisterImage