NAME

       glGetProgramStage - retrieve properties of a program object corresponding to a specified
       shader stage

C SPECIFICATION

       void glGetProgramStageiv(GLuint program, GLenum shadertype, GLenum pname, GLint *values);

PARAMETERS

       program
           Specifies the name of the program containing shader stage.

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

       pname
           Specifies the parameter of the shader to query.  pname must be
           GL_ACTIVE_SUBROUTINE_UNIFORMS, GL_ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS,
           GL_ACTIVE_SUBROUTINES, GL_ACTIVE_SUBROUTINE_UNIFORM_MAX_LENGTH, or
           GL_ACTIVE_SUBROUTINE_MAX_LENGTH.

       values
           Specifies the address of a variable into which the queried value or values will be
           placed.

DESCRIPTION

       glGetProgramStage queries a parameter of 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 the parameter.  pname specifies which parameter
       should be queried. The value or values of the parameter to be queried is returned in the
       variable whose address is given in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORMS, the number of active subroutine variables in
       the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS, the number of active subroutine
       variable locations in the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINES, the number of active subroutines in the stage is
       returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORM_MAX_LENGTH, the length of the longest subroutine
       uniform for the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_MAX_LENGTH, the length of the longest subroutine name for
       the stage is returned in values. The returned name length includes space for the
       null-terminator.

       If there is no shader present of type shadertype, the returned value will be consistent
       with a shader containing no subroutines or subroutine uniforms.

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            │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │
       │/                   │     │     │     │     │     │     │     │     │     │     │     │     │
       │Feature             │     │     │     │     │     │     │     │     │     │     │     │     │
       │Name                │     │     │     │     │     │     │     │     │     │     │     │     │
       ├────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │glGetProgramStageiv │  -  │  -  │  -  │  -  │  -  │  -  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │
       └────────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘

SEE ALSO

       glGetProgram()

COPYRIGHT

       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/.

COPYRIGHT

       Copyright © 2010-2014 Khronos Group.

[FIXME: source]                             07/22/2015                      GLGETPROGRAMSTAGE(3G)