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GLGETUNIFORMLOCATION(3G)                         OpenGL 3.3                         GLGETUNIFORMLOCATION(3G)



NAME
       glGetUniformLocation - Returns the location of a uniform variable

C SPECIFICATION
       GLint glGetUniformLocation(GLuint program, const GLchar *name);

PARAMETERS
       program
           Specifies the program object to be queried.

       name
           Points to a null terminated string containing the name of the uniform variable whose location is
           to be queried.

DESCRIPTION
       glGetUniformLocation returns an integer that represents the location of a specific uniform variable
       within a program object.  name must be a null terminated string that contains no white space.  name
       must be an active uniform variable name in program that is not a structure, an array of structures,
       or a subcomponent of a vector or a matrix. This function returns -1 if name does not correspond to an
       active uniform variable in program or if name starts with the reserved prefix "gl_".

       Uniform variables that are structures or arrays of structures may be queried by calling
       glGetUniformLocation for each field within the structure. The array element operator "[]" and the
       structure field operator "." may be used in name in order to select elements within an array or
       fields within a structure. The result of using these operators is not allowed to be another
       structure, an array of structures, or a subcomponent of a vector or a matrix. Except if the last part
       of name indicates a uniform variable array, the location of the first element of an array can be
       retrieved by using the name of the array, or by using the name appended by "[0]".

       The actual locations assigned to uniform variables are not known until the program object is linked
       successfully. After linking has occurred, the command glGetUniformLocation can be used to obtain the
       location of a uniform variable. This location value can then be passed to glUniform() to set the
       value of the uniform variable or to glGetUniform() in order to query the current value of the uniform
       variable. After a program object has been linked successfully, the index values for uniform variables
       remain fixed until the next link command occurs. Uniform variable locations and values can only be
       queried after a link if the link was successful.

ERRORS
       GL_INVALID_VALUE is generated if program is not a value generated by OpenGL.

       GL_INVALID_OPERATION is generated if program is not a program object.

       GL_INVALID_OPERATION is generated if program has not been successfully linked.

ASSOCIATED GETS
       glGetActiveUniform() with arguments program and the index of an active uniform variable

       glGetProgram() with arguments program and GL_ACTIVE_UNIFORMS or GL_ACTIVE_UNIFORM_MAX_LENGTH

       glGetUniform() with arguments program and the name of a uniform variable

       glIsProgram()

SEE ALSO
       glLinkProgram(), glUniform()


COPYRIGHT
       Copyright (C) 2003-2005 3Dlabs Inc. Ltd. 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/.



OpenGL 3.3                                       03/08/2011                         GLGETUNIFORMLOCATION(3G)