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 ES Shading Language Version
Function Name 1.00 3.00
atan✔✔

See Also

sin, cos, tan, asin, acos

Copyright

Copyright © 2011-2013 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.