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 Name

1.10

1.20

1.30

1.40

1.50

3.30

4.00

4.10

4.20

4.30

4.40

4.50

atan

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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. https://opencontent.org/openpub/.