6.28. OpenGL Interoperability

impl_private

This section describes the OpenGL interoperability functions of the CUDA runtime application programming interface. Note that mapping of OpenGL resources is performed with the graphics API agnostic, resource mapping interface described in Graphics Interopability.

Enumerations

cudaGLDeviceList

CUDA devices corresponding to the current OpenGL context.

Functions

__host__ cudaError_t cudaGLGetDevices(unsigned int *pCudaDeviceCount, int *pCudaDevices, unsigned int cudaDeviceCount, enum cudaGLDeviceList deviceList)

Gets the CUDA devices associated with the current OpenGL context.

__host__ cudaError_t cudaGraphicsGLRegisterBuffer(struct cudaGraphicsResource **resource, GLuint buffer, unsigned int flags)

Registers an OpenGL buffer object.

__host__ cudaError_t cudaGraphicsGLRegisterImage(struct cudaGraphicsResource **resource, GLuint image, GLenum target, unsigned int flags)

Register an OpenGL texture or renderbuffer object.

__host__ cudaError_t cudaWGLGetDevice(int *device, HGPUNV hGpu)

Gets the CUDA device associated with hGpu.

Typedefs

HGPUNV

6.28.1. Enumerations

enum cudaGLDeviceList

CUDA devices corresponding to the current OpenGL context.

Values:

enumerator cudaGLDeviceListAll

The CUDA devices for all GPUs used by the current OpenGL context.

enumerator cudaGLDeviceListCurrentFrame

The CUDA devices for the GPUs used by the current OpenGL context in its currently rendering frame.

enumerator cudaGLDeviceListNextFrame

The CUDA devices for the GPUs to be used by the current OpenGL context in the next frame

6.28.2. Functions

__host__ cudaError_t cudaGLGetDevices(unsigned int *pCudaDeviceCount, int *pCudaDevices, unsigned int cudaDeviceCount, enum cudaGLDeviceList deviceList)

Gets the CUDA devices associated with the current OpenGL context.

Returns in *pCudaDeviceCount the number of CUDA-compatible devices corresponding to the current OpenGL context. Also returns in *pCudaDevices at most cudaDeviceCount of the CUDA-compatible devices corresponding to the current OpenGL context. If any of the GPUs being used by the current OpenGL context are not CUDA capable then the call will return cudaErrorNoDevice.

See also

cudaGraphicsUnregisterResource, cudaGraphicsMapResources, cudaGraphicsSubResourceGetMappedArray, cudaGraphicsResourceGetMappedPointer, ::cuGLGetDevices

Note

This function is not supported on Mac OS X.

Note

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

Parameters

• pCudaDeviceCount – - Returned number of CUDA devices corresponding to the current OpenGL context

• pCudaDevices – - Returned CUDA devices corresponding to the current OpenGL context

• cudaDeviceCount – - The size of the output device array pCudaDevices

• deviceList – - The set of devices to return. This set may be cudaGLDeviceListAll for all devices, cudaGLDeviceListCurrentFrame for the devices used to render the current frame (in SLI), or cudaGLDeviceListNextFrame for the devices used to render the next frame (in SLI).

Returns

cudaSuccess, cudaErrorNoDevice, cudaErrorInvalidGraphicsContext, cudaErrorOperatingSystem, cudaErrorUnknown

__host__ cudaError_t cudaGraphicsGLRegisterBuffer(struct cudaGraphicsResource **resource, GLuint buffer, unsigned int flags)

Registers an OpenGL buffer object.

Registers the buffer object specified by buffer for access by CUDA. A handle to the registered object is returned as resource. The register flags flags specify the intended usage, as follows:

• cudaGraphicsRegisterFlagsNone: Specifies no hints about how this resource will be used. It is therefore assumed that this resource will be read from and written to by CUDA. This is the default value.

• cudaGraphicsRegisterFlagsReadOnly: Specifies that CUDA will not write to this resource.

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

See also

cudaGraphicsUnregisterResource, cudaGraphicsMapResources, cudaGraphicsResourceGetMappedPointer, ::cuGraphicsGLRegisterBuffer

Note

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

Parameters

• resource – - Pointer to the returned object handle

• buffer – - name of buffer object to be registered

• flags – - Register flags

Returns

cudaSuccess, cudaErrorInvalidDevice, cudaErrorInvalidValue, cudaErrorInvalidResourceHandle, cudaErrorOperatingSystem, cudaErrorUnknown

__host__ cudaError_t cudaGraphicsGLRegisterImage(struct cudaGraphicsResource **resource, GLuint image, GLenum target, unsigned int flags)

Register an OpenGL texture or renderbuffer object.

Registers the texture or renderbuffer object specified by image for access by CUDA. A handle to the registered object is returned as resource.

target must match the type of the object, and must be one of ::GL_TEXTURE_2D, ::GL_TEXTURE_RECTANGLE, ::GL_TEXTURE_CUBE_MAP, ::GL_TEXTURE_3D, ::GL_TEXTURE_2D_ARRAY, or ::GL_RENDERBUFFER.

The register flags flags specify the intended usage, as follows:

• cudaGraphicsRegisterFlagsNone: Specifies no hints about how this resource will be used. It is therefore assumed that this resource will be read from and written to by CUDA. This is the default value.

• cudaGraphicsRegisterFlagsReadOnly: Specifies that CUDA will not write to this resource.

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

• cudaGraphicsRegisterFlagsSurfaceLoadStore: Specifies that CUDA will bind this resource to a surface reference.

• cudaGraphicsRegisterFlagsTextureGather: Specifies that CUDA will perform texture gather operations on this resource.

The following image formats are supported. For brevity’s sake, the list is abbreviated. For ex., {GL_R, GL_RG} X {8, 16} would expand to the following 4 formats {GL_R8, GL_R16, GL_RG8, GL_RG16} :

• GL_RED, GL_RG, GL_RGBA, GL_LUMINANCE, GL_ALPHA, GL_LUMINANCE_ALPHA, GL_INTENSITY

• {GL_R, GL_RG, GL_RGBA} X {8, 16, 16F, 32F, 8UI, 16UI, 32UI, 8I, 16I, 32I}

• {GL_LUMINANCE, GL_ALPHA, GL_LUMINANCE_ALPHA, GL_INTENSITY} X {8, 16, 16F_ARB, 32F_ARB, 8UI_EXT, 16UI_EXT, 32UI_EXT, 8I_EXT, 16I_EXT, 32I_EXT}

The following image classes are currently disallowed:

• Textures with borders

• Multisampled renderbuffers

See also

cudaGraphicsUnregisterResource, cudaGraphicsMapResources, cudaGraphicsSubResourceGetMappedArray, ::cuGraphicsGLRegisterImage

Note

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

Parameters

• resource – - Pointer to the returned object handle

• image – - name of texture or renderbuffer object to be registered

• target – - Identifies the type of object specified by image

• flags – - Register flags

Returns

cudaSuccess, cudaErrorInvalidDevice, cudaErrorInvalidValue, cudaErrorInvalidResourceHandle, cudaErrorOperatingSystem, cudaErrorUnknown

__host__ cudaError_t cudaWGLGetDevice(int *device, HGPUNV hGpu)

Gets the CUDA device associated with hGpu.

Returns the CUDA device associated with a hGpu, if applicable.

See also

::WGL_NV_gpu_affinity, ::cuWGLGetDevice

Note

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

Parameters

• device – - Returns the device associated with hGpu, or -1 if hGpu is not a compute device.

• hGpu – - Handle to a GPU, as queried via WGL_NV_gpu_affinity

Returns

cudaSuccess

6.28.3. Typedefs

typedef void *HGPUNV