NAME

       faceforward - return a vector pointing in the same direction as another

DECLARATION

       genType faceforward(genType N, genType I, genType Nref);

       genDType faceforward(genDType N, genDType I, genDType Nref);

PARAMETERS

       N
           Specifies the vector to orient.

       I
           Specifies the incident vector.

       Nref
           Specifies the reference vector.

DESCRIPTION

       faceforward orients a vector to point away from a surface as defined by its normal. If
       dot()(Nref, I) < 0 faceforward returns N, otherwise it returns -N.

VERSION SUPPORT

       ┌────────────┬───────────────────────────────────────────────────────────────────────────────────┐
       │            │        OpenGL Shading Language Version                                            │
       ├────────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
       │Function    │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
       │Name        │      │      │      │      │      │      │      │      │      │      │      │      │
       ├────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │faceforward │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       │(genType)   │      │      │      │      │      │      │      │      │      │      │      │      │
       ├────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │faceforward │  -   │  -   │  -   │  -   │  -   │  -   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       │(genDType)  │      │      │      │      │      │      │      │      │      │      │      │      │
       └────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘

SEE ALSO

       reflect(), refract()

COPYRIGHT

       Copyright © 2011-2014 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 © 2011-2014 Khronos Group

[FIXME: source]                             01/03/2018                            FACEFORWARD(3G)