2010-2013
Khronos Group.
glGetActiveSubroutineUniform
3G
glGetActiveSubroutineUniform
query a property of an active shader subroutine uniform
C Specification
void glGetActiveSubroutineUniformiv
GLuint program
GLenum shadertype
GLuint index
GLenum pname
GLint *values
Parameters
program
Specifies the name of the program containing the subroutine.
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.
index
Specifies the index of the shader subroutine uniform.
pname
Specifies the parameter of the shader subroutine uniform to query. pname
must be GL_NUM_COMPATIBLE_SUBROUTINES, GL_COMPATIBLE_SUBROUTINES,
GL_UNIFORM_SIZE or GL_UNIFORM_NAME_LENGTH.
values
Specifies the address of a into which the queried value or values will be placed.
Description
glGetActiveSubroutineUniform queries a parameter of an active shader subroutine uniform.
program contains the name of the program containing the uniform. shadertype
specifies the stage which which the uniform location, given by index, is valid. index
must be between zero and the value of GL_ACTIVE_SUBROUTINE_UNIFORMS minus one for the
shader stage.
If pname is GL_NUM_COMPATIBLE_SUBROUTINES, a single integer indicating the number
of subroutines that can be assigned to the uniform is returned in values.
If pname is GL_COMPATIBLE_SUBROUTINES, an array of integers is returned in
values, with each integer specifying the index of an active subroutine that can be assigned to
the selected subroutine uniform. The number of integers returned is the same as the value returned for
GL_NUM_COMPATIBLE_SUBROUTINES.
If pname is GL_UNIFORM_SIZE, a single integer is returned in values.
If the selected subroutine uniform is an array, the declared size of the array is returned; otherwise, one is returned.
If pname is GL_UNIFORM_NAME_LENGTH, a single integer specifying the length of
the subroutine uniform name (including the terminating null character) is returned in values.
Errors
GL_INVALID_ENUM is generated if shadertype or pname
is not one of the accepted values.
GL_INVALID_VALUE is generated if index is greater than or equal to
the value of GL_ACTIVE_SUBROUTINES.
GL_INVALID_VALUE is generated if program is not the name of an
existing program object.
Associated Gets
glGetProgramStage with argument GL_ACTIVE_SUBROUTINE_UNIFORMS
See Also
glGetSubroutineIndex,
glGetActiveSubroutineUniformName,
glGetProgramStage
Copyright
Copyright 2010-2013 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/.