glGetProgram

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Returns a parameter from a program object.

C Specification[edit]

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


Parameters[edit]

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_SIZE  GL_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[edit]

 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[edit]

 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[edit]

 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[edit]

 glGetActiveAttrib with argument program 

 glGetActiveUniform with argument program 

 glGetAttachedShaders with argument program 

 glGetProgramInfoLog with argument program 

 glIsProgram   


Version Support[edit]

 glGetProgramiv  2.0+

See Also[edit]

 glAttachShader , glCreateProgram , glDeleteProgram , glGetShader , glLinkProgram , glValidateProgram 


Copyright[edit]

Copyright© 2003-2005 3Dlabs Inc. Ltd. Copyright© 2010-2014 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/.