GLGETPROGRAMSTAGE(3G)						   OpenGL Manual					     GLGETPROGRAMSTAGE(3G)

NAME

       glGetProgramStage - retrieve properties of a program object corresponding to a specified shader stage

C SPECIFICATION

       void glGetProgramStageiv(GLuint program, GLenum shadertype, GLenum pname, GLint *values);

PARAMETERS

       program
	   Specifies the name of the program containing shader stage.

       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.

       pname
	   Specifies the parameter of the shader to query.  pname must be GL_ACTIVE_SUBROUTINE_UNIFORMS, GL_ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS,
	   GL_ACTIVE_SUBROUTINES, GL_ACTIVE_SUBROUTINE_UNIFORM_MAX_LENGTH, or GL_ACTIVE_SUBROUTINE_MAX_LENGTH.

       values
	   Specifies the address of a variable into which the queried value or values will be placed.

DESCRIPTION

       glGetProgramStage queries a parameter of 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 the parameter.  pname specifies which parameter should be
       queried. The value or values of the parameter to be queried is returned in the variable whose address is given in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORMS, the number of active subroutine variables in the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS, the number of active subroutine variable locations in the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINES, the number of active subroutines in the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_UNIFORM_MAX_LENGTH, the length of the longest subroutine uniform for the stage is returned in values.

       If pname is GL_ACTIVE_SUBROUTINE_MAX_LENGTH, the length of the longest subroutine name for the stage is returned in values. The returned
       name length includes space for the null-terminator.

       If there is no shader present of type shadertype, the returned value will be consistent with a shader containing no subroutines or
       subroutine uniforms.

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()

COPYRIGHT

       Copyright (C) 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

opengl.org							    06/10/2014						     GLGETPROGRAMSTAGE(3G)