GLGETPROGRAM(3G)

NAME
glGetProgramiv - Returns a parameter from a program object

C SPECIFICATION

void glGetProgramiv(GLuint program, GLenum pname, GLint *params);

PARAMETERS

program
    Specifies the program object to be queried.

pname
    Specifies the object parameter. Accepted symbolic names are GL_DELETE_STATUS, GL_LINK_STATUS, GL_VALIDATE_STATUS, GL_INFO_LOG_LENGTH, GL_ATTACHED_SHADERS, GL_ACTIVE_ATOMIC_COUNTER_BUFFERS, GL_ACTIVE_ATTRIBUTES, GL_ACTIVE_ATTRIBUTE_MAX_LENGTH, GL_ACTIVE_UNIFORMS, GL_ACTIVE_UNIFORM_BLOCKS, GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH, GL_ACTIVE_UNIFORM_MAX_LENGTH, GL_COMPUTE_WORK_GROUP_SIZEGL_PROGRAM_BINARY_LENGTH, GL_TRANSFORM_FEEDBACK_BUFFER_MODE, GL_TRANSFORM_FEEDBACK_VARYINGS, GL_TRANSFORM_FEEDBACK_VARYING_MAX_LENGTH, GL_GEOMETRY_VERTICES_OUT, GL_GEOMETRY_INPUT_TYPE, and GL_GEOMETRY_OUTPUT_TYPE.

params
    Returns the requested object parameter.

DESCRIPTION

glGetProgram returns in params the value of a parameter for a specific program object. The following parameters are defined:

GL_DELETE_STATUS

    params returns GL_TRUE if program is currently flagged for deletion, and GL_FALSE otherwise.

GL_LINK_STATUS

    params returns GL_TRUE if the last link operation on program was successful, and GL_FALSE otherwise.

GL_VALIDATE_STATUS

    params returns GL_TRUE or if the last validation operation on program was successful, and GL_FALSE otherwise.

GL_INFO_LOG_LENGTH

    params returns the number of characters in the information log for program including the null termination character (i.e., the size of the character buffer required to store the information log). If program has no information log, a value of 0 is returned.

GL_ATTACHED_SHADERS

    params returns the number of shader objects attached to program.

GL_ACTIVE_ATOMIC_COUNTER_BUFFERS

    params returns the number of active attribute atomic counter buffers used by program.

GL_ACTIVE_ATTRIBUTES

    params returns the number of active attribute variables for program.

GL_ACTIVE_ATTRIBUTE_MAX_LENGTH

    params returns the length of the longest active attribute name for program, including the null termination character (i.e., the size of the character buffer required to store the longest attribute name). If no active attributes exist, 0 is returned.

GL_ACTIVE_UNIFORMS

    params returns the number of active uniform variables for program.

GL_ACTIVE_UNIFORM_MAX_LENGTH

    params returns the length of the longest active uniform variable name for program, including the null termination character (i.e., the size of the character buffer required to store the longest uniform variable name). If no active uniform variables exist, 0 is returned.

GL_PROGRAM_BINARY_LENGTH

    params returns the length of the program binary, in bytes that will be returned by a call to glGetProgramBinary(). When a progam's GL_LINK_STATUS is GL_FALSE, its program binary length is zero.

GL_COMPUTE_WORK_GROUP_SIZE

    params returns an array of three integers containing the local work group size of the compute program as specified by its input layout qualifier(s). program must be the name of a program object that has been previously linked successfully and contains a binary for the compute shader stage.

GL_TRANSFORM_FEEDBACK_BUFFER_MODE

    params returns a symbolic constant indicating the buffer mode used when transform feedback is active. This may be GL_SEPARATE_ATTRIBS or GL_INTERLEAVED_ATTRIBS.

GL_TRANSFORM_FEEDBACK_VARYINGS

    params returns the number of varying variables to capture in transform feedback mode for the program.

GL_TRANSFORM_FEEDBACK_VARYING_MAX_LENGTH

    params returns the length of the longest variable name to be used for transform feedback, including the null-terminator.

GL_GEOMETRY_VERTICES_OUT

    params returns the maximum number of vertices that the geometry shader in program will output.

GL_GEOMETRY_INPUT_TYPE

    params returns a symbolic constant indicating the primitive type accepted as input to the geometry shader contained in program.

GL_GEOMETRY_OUTPUT_TYPE

    params returns a symbolic constant indicating the primitive type that will be output by the geometry shader contained in program.

NOTES

GL_ACTIVE_UNIFORM_BLOCKS and GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH are available only if the GL version 3.1 or greater.

GL_GEOMETRY_VERTICES_OUT, GL_GEOMETRY_INPUT_TYPE and GL_GEOMETRY_OUTPUT_TYPE are accepted only if the GL version is 3.2 or greater.

GL_COMPUTE_WORK_GROUP_SIZE is accepted only if the GL version is 4.3 or greater.

If an error is generated, no change is made to the contents of params.

ERRORS

GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if program does not refer to a program object.

GL_INVALID_OPERATION is generated if pname is GL_GEOMETRY_VERTICES_OUT, GL_GEOMETRY_INPUT_TYPE, or GL_GEOMETRY_OUTPUT_TYPE, and program does not contain a geometry shader.

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_OPERATION is generated if pname is GL_COMPUTE_WORK_GROUP_SIZE and program does not contain a binary for the compute shader stage.

ASSOCIATED GETS

glGetActiveAttrib() with argument program

glGetActiveUniform() with argument program

glGetAttachedShaders() with argument program

glGetProgramInfoLog() with argument program

glIsProgram()

SEE ALSO

glAttachShader(), glCreateProgram(), glDeleteProgram(), glGetShader(), glLinkProgram(), glValidateProgram()

COPYRIGHT

Copyright © 2003-2005 3Dlabs Inc. Ltd. Copyright © 2010-2011 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.