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.

SEE ALSO

glGetProgram(), glGetActiveSubroutineUniform(), glGetActiveSubroutineUniformName()

COPYRIGHT

Copyright © 2010 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/.

AUTHORS

opengl.org