Provided by: opencl-1.2-man-doc_1.0~svn22836-1.1_all 
NAME
clCreateFromGLRenderbuffer - Creates an OpenCL 2D image object from an OpenGL renderbuffer
object.
cl_mem clCreateFromGLRenderbuffer(cl_context context, cl_mem_flags flags,
GLuint renderbuffer, cl_int * errcode_ret);
PARAMETERS
context
A valid OpenCL context created from an OpenGL context.
flags
A bit-field that is used to specify usage information. Refer to the table at
clCreateBuffer(3clc) for a description of flags. Only CL_MEM_READ_ONLY,
CL_MEM_WRITE_ONLY, and CL_MEM_READ_WRITE values specified in the table at
clCreateBuffer(3clc) can be used.
renderbuffer
The name of a GL renderbuffer object. The renderbuffer storage must be specified
before the image object can be created. The renderbuffer format and dimensions defined
by OpenGL will be used to create the 2D image object. Only GL renderbuffers with
internal formats that map to appropriate image channel order and data type specified
in the table of supported Image Channel Order Values and the table of supported Image
Channel Data Types for cl_image_format(3clc) can be used to create the 2D image
object.
errcode_ret
Returns an appropriate error code as described below. If errcode_ret is NULL, no error
code is returned.
DESCRIPTION
If the state of a GL renderbuffer object is modified through the GL API (i.e. changes to
the dimensions or format used to represent pixels of the GL renderbuffer using appropriate
GL API calls such as glRenderbufferStorage) while there exists a corresponding CL image
object, subsequent use of the CL image object will result in undefined behavior.
The clRetainMemObject(3clc) and clReleaseMemObject(3clc) functions can be used to retain
and release the image objects.
The table below (Table 9.4) describes the list of GL texture internal formats and the
corresponding CL image formats. If a GL texture object with an internal format from the
table below is successfully created by OpenGL, then there is guaranteed to be a mapping to
one of the corresponding CL image format(s) in that table. Texture objects created with
other OpenGL internal formats may (but are not guaranteed to) have a mapping to a CL image
format; if such mappings exist, they are guaranteed to preserve all color components, data
types, and at least the number of bits/component actually allocated by OpenGL for that
format.
┌─────────────────────────────┬─────────────────────────────────┐
│ GL internal format │ CL image format (channel order, │
│ │ channel data type) │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA8 │ CL_RGBA, CL_UNORM_INT8 or │
│ │ CL_BGRA, CL_UNORM_INT8 │
├─────────────────────────────┼─────────────────────────────────┤
│GL_RGBA, │ CL_RGBA, CL_UNORM_INT8 │
│GL_UNSIGNED_INT_8_8_8_8_REV │ │
├─────────────────────────────┼─────────────────────────────────┤
│GL_BGRA, │ CL_BGRA, CL_UNORM_INT8 │
│GL_UNSIGNED_INT_8_8_8_8_REV │ │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA16 │ CL_RGBA, CL_UNORM_INT16 │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA8I, GL_RGBA8I_EXT │ CL_RGBA, CL_SIGNED_INT8 │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA16I, GL_RGBA16I_EXT │ CL_RGBA, CL_SIGNED_INT16 │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA32I, GL_RGBA32I_EXT │ CL_RGBA, CL_SIGNED_INT32 │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA8UI, GL_RGBA8UI_EXT │ CL_RGBA, CL_UNSIGNED_INT8 │
├─────────────────────────────┼─────────────────────────────────┤
│GL_RGBA16UI, GL_RGBA16UI_EXT │ CL_RGBA, CL_UNSIGNED_INT16 │
├─────────────────────────────┼─────────────────────────────────┤
│GL_RGBA32UI, GL_RGBA32UI_EXT │ CL_RGBA, CL_UNSIGNED_INT32 │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA16F, GL_RGBA16F_ARB │ CL_RGBA, CL_HALF_FLOAT │
├─────────────────────────────┼─────────────────────────────────┤
│ GL_RGBA32F, GL_RGBA32F_ARB │ CL_RGBA, CL_FLOAT │
└─────────────────────────────┴─────────────────────────────────┘
ERRORS
Returns a valid non-zero OpenCL image object and errcode_ret is set to CL_SUCCESS if the
image object is created successfully. Otherwise, it returns a NULL value with one of the
following error values returned in errcode_ret:
· CL_INVALID_CONTEXT if context is not a valid context or was not created from a GL
context.
· CL_INVALID_VALUE if values specified in flags are not valid.
· CL_INVALID_GL_OBJECT if renderbuffer is not a GL renderbuffer object or if the width
or height of renderbuffer is zero.
· CL_INVALID_IMAGE_FORMAT_DESCRIPTOR if the OpenGL renderbuffer internal format does not
map to a supported OpenCL image format.
· CL_INVALID_OPERATION if renderbuffer is a multi-sample GL renderbuffer object.
· CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL
implementation on the device.
· CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the
OpenCL implementation on the host.
SPECIFICATION
OpenCL Specification[1]
SEE ALSO
cl_khr_gl_sharing(3clc), clCreateBuffer(3clc), cl_image_format(3clc),
clRetainMemObject(3clc), clReleaseMemObject(3clc)
AUTHORS
The Khronos Group
COPYRIGHT
Copyright © 2007-2011 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and/or associated documentation files (the "Materials"), to deal in the Materials
without restriction, including without limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of the Materials, and to permit
persons to whom the Materials are furnished to do so, subject to the condition that this
copyright notice and permission notice shall be included in all copies or substantial
portions of the Materials.
NOTES
1. OpenCL Specification
page 53, section 9.7.4 - CL Image Objects -> GL Renderbuffers