glGetActiveSubroutineUniform.3G man page

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()

Info

02/04/2016 [FIXME: source] [FIXME: manual]