osx man page for glprovokingvertex

GLPROVOKINGVERTEX(3G)						    OpenGL 3.3						     GLPROVOKINGVERTEX(3G)

NAME
       glProvokingVertex - specifiy the vertex to be used as the source of data for flat shaded varyings

C SPECIFICATION
       void glProvokingVertex(GLenum provokeMode);

PARAMETERS
       provokeMode
	   Specifies the vertex to be used as the source of data for flat shaded varyings.

DESCRIPTION
       Flatshading a vertex shader varying output means to assign all vetices of the primitive the same value for that output. The vertex from
       which these values is derived is known as the provoking vertex and glProvokingVertex specifies which vertex is to be used as the source of
       data for flat shaded varyings.

       provokeMode must be either GL_FIRST_VERTEX_CONVENTION or GL_LAST_VERTEX_CONVENTION, and controls the selection of the vertex whose values
       are assigned to flatshaded varying outputs. The interpretation of these values for the supported primitive types is:

       If a vertex or geometry shader is active, user-defined varying outputs may be flatshaded by using the flat qualifier when declaring the
       output.

NOTES
       glProvokingVertex is available only if the GL version is 3.2 or greater.

ERRORS
       GL_INVALID_ENUM is generated if provokeMode is not an accepted value.

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/.

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