2010 Khronos Group glGetFragDataIndex 3G glGetFragDataIndex query the bindings of color indices to user-defined varying out variables GLint glGetFragDataIndex GLuint program const char * name program The name of the program containing varying out variable whose binding to query name The name of the user-defined varying out variable whose index to query glGetFragDataIndex returns the index of the fragment color to which the variable name was bound when the program object program was last linked. If name is not a varying out variable of program, or if an error occurs, -1 will be returned. glGetFragDataIndex is available only if the GL version is 3.3 or greater. GL_INVALID_OPERATION is generated if program is not the name of a program object. glCreateProgram, glBindFragDataLocation, glBindFragDataLocationIndexed, glGetFragDataLocation 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/.