GLPROVOKINGVERTEX(3G)           [FIXME: manual]          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:

       +-------------------+--------------+---------------------+
       | Primitive Type of |  First       |  Last Vertex        |
       |Polygon i          | Vertex       | Convention          |
       |                   | Convention   |                     |
       +-------------------+--------------+---------------------+
       |point              | i            | i                   |
       +-------------------+--------------+---------------------+
       |independent line   | 2i - 1       | 2i                  |
       +-------------------+--------------+---------------------+
       |line loop          | i            |  i + 1, if i < n    |
       |                   |              | .PP 1, if i = n     |
       +-------------------+--------------+---------------------+
       |line strip         | i            | i + 1               |
       +-------------------+--------------+---------------------+
       |independent        | 3i - 2       | 3i                  |
       |triangle           |              |                     |
       +-------------------+--------------+---------------------+
       |triangle strip     | i            | i + 2               |
       +-------------------+--------------+---------------------+
       |triangle fan       | i + 1        | i + 2               |
       +-------------------+--------------+---------------------+
       |line adjacency     | 4i - 2       | 4i - 1              |
       +-------------------+--------------+---------------------+
       |line strip         | i + 1        | i + 2               |
       |adjacency          |              |                     |
       +-------------------+--------------+---------------------+
       |triangle adjacency | 6i - 5       | 6i - 1              |
       +-------------------+--------------+---------------------+
       |triangle strip     | 2i - 1       | 2i + 3              |
       |adjacency          |              |                     |
       +-------------------+--------------+---------------------+

       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.

VERSION SUPPORT

       +------------------+-----------------------------------------------------------------------+
       |                  |                            OpenGL Version                             |
       +------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
       |Function /        | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
       |Feature Name      |     |     |     |     |     |     |     |     |     |     |     |     |
       +------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
       |glProvokingVertex |  -  |  -  |  -  |  -  | <?> | <?> | <?> | <?> | <?> | <?> | <?> | <?> |
       +------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+

SEE ALSO
COPYRIGHT
       Copyright (C) 2010-2014 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/.

COPYRIGHT
       Copyright (C) 2010-2014 Khronos Group

[FIXME: source]                   05/21/2022             GLPROVOKINGVERTEX(3G)