clGetGLContextInfoKHR

Get OpenGL context information

cl_int clGetGLContextInfoKHR ( const cl_context_properties *properties,
  cl_gl_context_info param_name,
  size_t param_value_size,
  void *param_value,
  size_t *param_value_size_ret)

Parameters

properties

Points to an attribute list whose format and valid contents are identical to the properties argument of clCreateContext. properties must identify a single valid GL context or GL share group object.

param_name

A constant that specifies the GL context information to query, and must be one of:

  • CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR: (Return type: cl_device_id) - Return the CL device currently associated with the specified OpenGL context.
  • CL_DEVICES_FOR_GL_CONTEXT_KHR: (Return type: cl_device_id[]) - List of all CL devices which may be associated with the specified OpenGL context.
param_value_size

Returns the actual size in bytes of data being queried by param_value. If param_value_size_ret is NULL, it is ignored

param_value

A pointer to memory where the appropriate result is returned. If param_value is NULL, it is ignored.

param_value_size_ret

Returns the actual size in bytes of data being queried to param_value. If param_value_size_ret is NULL, it is ignored.

Notes

This extension defines optional attributes to OpenCL context creation routines which associate a GL context or share group object with a newly created OpenCL context. If this extension is supported by an implementation, the string cl_khr_gl_sharing will be present in the CL_PLATFORM_EXTENSIONS or CL_DEVICE_EXTENSIONS string.

Errors

Returns CL_SUCCESS if the function is executed successfully. If no device(s) exist corresponding to param_name, the call will not fail, but the value of param_value_size_ret will be zero. Otherwise returns one of the following:

  • Returns CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR if a context was specified by any of the following means:

    • A context was specified for an EGL-based OpenGL ES or OpenGL implementation by setting the attributes CL_GL_CONTEXT_KHR and CL_EGL_DISPLAY_KHR..
    • A context was specified for a GLX-based OpenGL implementation by setting the attributes CL_GL_CONTEXT_KHR and CL_GLX_DISPLAY_KHR.
    • A context was specified for a WGL-based OpenGL implementation by setting the attributes CL_GL_CONTEXT_KHR and CL_WGL_HDC_KHR.

    and any of the following conditions hold:

    • The specified display and context attributes do not identify a valid OpenGL or OpenGL ES context.
    • The specified context does not support buffer and renderbuffer objects.
    • The specified context is not compatible with the OpenCL context being created (for example, it exists in a physically distinct address space, such as another hardware device; or it does not support sharing data with OpenCL due to implementation restrictions).
  • Returns CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR if a share group was specified for a CGL-based OpenGL implementation by setting the attribute CL_CGL_SHAREGROUP_KHR, and the specified share group does not identify a valid CGL share group object.
  • Returns CL_INVALID_OPERATION if a context was specified as described above and any of the following conditions hold:

    • A context or share group object was specified for one of CGL, EGL, GLX, or WGL and the OpenGL implementation does not support that window-system binding API.
    • More than one of the attributes CL_CGL_SHAREGROUP_KHR, CL_EGL_DISPLAY_KHR, CL_GLX_DISPLAY_KHR, and CL_WGL_HDC_KHR is set to a non-default value.
    • Both of the attributes CL_CGL_SHAREGROUP_KHR and CL_GL_CONTEXT_KHR are set to non-default values.
    • Any of the devices specified in the devices argument cannot support OpenCL objects which share the data store of an OpenGL object.
  • Returns CL_INVALID_VALUE if an attribute name other than one of the following is specified in properties: CL_GL_CONTEXT_KHR, CL_CGL_SHAREGROUP_KHR, CL_EGL_DISPLAY_KHR, CL_GLX_DISPLAY_KHR, CL_WGL_HDC_KHR.
  • Returns CL_INVALID_VALUE if param_name is not CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR or CL_DEVICES_FOR_GL_CONTEXT_KHR; or if the size in bytes specified by param_value_size is less than the size of CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR or CL_DEVICES_FOR_GL_CONTEXT_KHR; and param_value is not a NULL value.
  • Returns CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation on the device
  • Returns CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the OpenCL implementation on the host.

Specification

OpenCL Specification

Also see

clCreateContext cl_khr_gl_sharing

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