GLGETSUBROUTINEINDEX(3G)        [FIXME: manual]       GLGETSUBROUTINEINDEX(3G)

NAME
       glGetSubroutineIndex - retrieve the index of a subroutine uniform of a
       given shader stage within a program

C SPECIFICATION
       GLuint glGetSubroutineIndex(GLuint program, GLenum shadertype,
                                   const GLchar *name);

PARAMETERS
       program
           Specifies the name of the program containing shader stage.

       shadertype
           Specifies the shader stage from which to query for subroutine
           uniform index.  shadertype must be one of GL_VERTEX_SHADER,
           GL_TESS_CONTROL_SHADER, GL_TESS_EVALUATION_SHADER,
           GL_GEOMETRY_SHADER or GL_FRAGMENT_SHADER.

       name
           Specifies the name of the subroutine uniform whose index to query.

DESCRIPTION
       glGetSubroutineIndex returns the index of a subroutine uniform within a
       shader stage attached to a program object.  program contains the name
       of the program to which the shader is attached.  shadertype specifies
       the stage from which to query shader subroutine index.  name contains
       the null-terminated name of the subroutine uniform whose name to query.

       If name is not the name of a subroutine uniform in the shader stage,
       GL_INVALID_INDEX is returned, but no error is generated. If name is the
       name of a subroutine uniform in the shader stage, a value between zero
       and the value of GL_ACTIVE_SUBROUTINES minus one will be returned.
       Subroutine indices are assigned using consecutive integers in the range
       from zero to the value of GL_ACTIVE_SUBROUTINES minus one for the
       shader stage.

ERRORS
       GL_INVALID_ENUM is generated if shadertype or pname is not one of the
       accepted values.

       GL_INVALID_VALUE is generated if program is not the name of an existing
       program object.

VERSION SUPPORT

       +---------------------+-----------------------------------------------------------------------+
       |                     |                            OpenGL Version                             |
       +---------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
       |Function / Feature   | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
       |Name                 |     |     |     |     |     |     |     |     |     |     |     |     |
       +---------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
       |glGetSubroutineIndex |  -  |  -  |  -  |  -  |  -  |  -  | <?> | <?> | <?> | <?> | <?> | <?> |
       +---------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+

SEE ALSO
       glGetProgram(), glGetActiveSubroutineUniform(),
       glGetActiveSubroutineUniformName()

COPYRIGHT
       Copyright (C) 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/.

COPYRIGHT
       Copyright (C) 2010-2014 Khronos Group.

[FIXME: source]                   05/21/2022          GLGETSUBROUTINEINDEX(3G)