ATAN(3G)                        [FIXME: manual]                       ATAN(3G)

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 either the angle whose trigonometric arctangent is $y
       \over x$ 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 value returned by atan in this
       case is in the range $[-\pi,\pi]$. The result is undefined if $x = 0$.

       For the second overload, atan returns the angle whose tangent is
       y_over_x. The value returned in this case is in the range $[-{\pi \over
       2 },{\pi \over 2}]$.

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 (C) 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 (C) 2011-2014 Khronos Group

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