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Retrieve the location of a subroutine uniform of a given shader stage within a program.

C Specification[edit]

GLint glGetSubroutineUniformLocation( GLuint program, GLenum shadertype, const GLchar * name );


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.


 glGetSubroutineUniformLocation returns the location of the subroutine uniform variable name in the shader stage of type shadertype attached to program , with behavior otherwise identical to glGetUniformLocation .

If name is not the name of a subroutine uniform in the shader stage, -1 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_SUBROUTINE_LOCATIONS minus one will be returned. Subroutine locations are assigned using consecutive integers in the range from zero to the value of GL_ACTIVE_SUBROUTINE_LOCATIONS minus one for the shader stage. For active subroutine uniforms declared as arrays, the declared array elements are assigned consecutive locations.


 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[edit]

 glGetSubroutineUniformLocation  4.0+

See Also[edit]

 glGetProgram , glGetActiveSubroutineUniform , glGetActiveSubroutineUniformName , glGetUniformLocation 


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.