GLAPI/glGetActiveSubroutineUniform

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glGetActiveSubroutineUniform
Core in version 4.4
Core since version 4.0
Core ARB extension ARB_shader_subroutine

glGetActiveSubroutineUniform: query a property of an active shader subroutine uniform

Function Definition

 void glGetActiveSubroutineUniformiv(GLuint program​, GLenum shadertype​, GLuint index​, GLenum pname​, GLint *values​);
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​, GL_FRAGMENT_SHADER​, or GL_COMPUTE_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​

glGetProgramInterface with the interface set to GL_VERTEX_SUBROUTINE_UNIFORM​, ​GL_TESS_CONTROL_SUBROUTINE_UNIFORM​, GL_TESS_EVALUATION_SUBROUTINE​_UNIFORM​, GL_GEOMETRY_SUBROUTINE_UNIFORM​, ​GL_FRAGMENT_SUBROUTINE_UNIFORM​​, or GL_COMPUTE_SUBROUTINE​_UNIFORM​ as appropriate, and with GL_ACTIVE_RESOURCES​

glGetSubroutineIndex

glGetProgramResourceIndex with the interface set to GL_VERTEX_SUBROUTINE_UNIFORM​, ​GL_TESS_CONTROL_SUBROUTINE_UNIFORM​, GL_TESS_EVALUATION_SUBROUTINE​_UNIFORM​, GL_GEOMETRY_SUBROUTINE_UNIFORM​, ​GL_FRAGMENT_SUBROUTINE_UNIFORM​​, or GL_COMPUTE_SUBROUTINE​_UNIFORM​ as appropriate

See Also

glGetActiveSubroutineUniformName, glGetProgramResource, glGetProgramResourceName

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/.