NAME

       atan - return the arc-tangent of the parameters

DECLARATION

       genType atan(genType y, genType x);

       genType atan(genType y_over_x);

PARAMETERS

       y
           Specify the numerator of the fraction whose arctangent to return.

       x
           Specify the denominator of the fraction whose arctangent to return.

       y_over_x
           Specify the fraction whose arctangent to return.

DESCRIPTION

       atan returns the angle whose trigonometric arctangent is y x or y_over_x, depending on
       which overload is invoked. In the first overload, the signs of y and x are used to
       determine the quadrant that the angle lies in. The values returned by atan in this case
       are in the range −. Results are undefined if x is zero.

       For the second overload, atan returns the angle whose tangent is y_over_x. Values returned
       in this case are in the range − 2 2.

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     │      │      │      │      │      │      │      │      │      │      │      │      │
       ├─────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │atan     │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       └─────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘

SEE ALSO

       sin(), cos(), tan()

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]                             07/22/2015                                   ATAN(3G)