Creates an OpenCL image object, image array object, or image buffer object from an OpenGL texture object, texture array object, texture buffer object, or a single face of an OpenGL cubemap texture object.
cl_mem
clCreateFromGLTexture
(
| cl_context context, |
cl_mem_flags flags, | |
GLenum texture_target, | |
GLint miplevel, | |
GLuint texture, | |
cl_int * errcode_ret) |
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 for
clCreateBuffer
for a description of flags
. Only the values
CL_MEM_READ_ONLY
, CL_MEM_WRITE_ONLY
and CL_MEM_READ_WRITE
can be used.
texture_target
texture_target
This value must be one of GL_TEXTURE_1D
,
GL_TEXTURE_1D_ARRAY
,
GL_TEXTURE_BUFFER
, GL_TEXTURE_2D
,
GL_TEXTURE_2D_ARRAY
, GL_TEXTURE_3D
,
GL_TEXTURE_CUBE_MAP_POSITIVE_X
,
GL_TEXTURE_CUBE_MAP_POSITIVE_Y
,
GL_TEXTURE_CUBE_MAP_POSITIVE_Z
,
GL_TEXTURE_CUBE_MAP_NEGATIVE_X
,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y
,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
, or
GL_TEXTURE_RECTANGLE
. This requires OpenGL 3.1.
Alternatively, GL_TEXTURE_RECTANGLE_ARB
may be
specified if the OpenGL extension GL_ARB_texture_rectangle is supported.
texture_target
is used only to define the image type
of texture
. No reference to a bound GL texture object
is made or implied by this parameter.
miplevel
The mipmap level to be used. If
texture_target
is GL_TEXTURE_BUFFER
,
miplevel must be 0. Implementations may return
CL_INVALID_OPERATION
for miplevel values > 0
texture
The name of a GL 1D, 2D, 3D, 1D array,
2D array, cubemap, rectangle or buffer texture object. The texture object
must be a complete texture as per OpenGL rules on texture completeness. The
texture
format and dimensions defined by OpenGL for the
specified miplevel
of the texture will be used to create
the OpenCL image memory object. Only GL texture objects with an internal
format that maps to appropriate image channel order and data type specified
in tables 5.5 and 5.6 may be used to create the OpenCL image memory object.
errcode_ret
Returns an appropriate error code as described
below. If errcode_ret
is NULL, no error code is returned.
If the state of a GL texture object is modified through the GL API
(e.g. glTexImage2D
, glTexImage3D
or
the values of the texture parameters GL_TEXTURE_BASE_LEVEL
or GL_TEXTURE_MAX_LEVEL
are modified) while there exists a
corresponding CL image object, subsequent use of the CL image object will result in
undefined behavior.
The clRetainMemObject and clReleaseMemObject functions can be used to retain and release the image objects.
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
:
context
is not
a valid context or was not created from a GL context.
flags
are not valid or if value specified in
texture_target
is not one of the values specified in the
description of texture_target
.
miplevel
is less than the value of levelbase
(for OpenGL implementations) or zero (for OpenGL ES implementations); or
greater than the value of q
(for both OpenGL and OpenGL
ES). levelbase
and q
are defined for the texture in section 3.8.10 (Texture Completeness) of the OpenGL
2.1 specification and section 3.7.10 of the OpenGL ES 2.0.
miplevel
is
greater than zero and the OpenGL implementation does not support creating from
non-zero mipmap levels.
texture
is not
a GL texture object whose type matches texture_target
, if the
specified miplevel
of texture
is not defined,
or if the width or height of the specified miplevel
is zero.