NAME

SDL_atan2 - Compute the arc tangent of y/x , using the signs of x and y to adjust the result's quadrant.

HEADER FILE

Defined in SDL3/SDL_stdinc.h

SYNOPSIS

#include "SDL3/SDL.h"

double SDL_atan2(double y, double x);

DESCRIPTION

The definition of z=atan2(x,y) is y=xtan(z) , where the quadrant of z is determined based on the signs of x and y.

Domain: -INF<=x<=INF , -INF<=y<=INF Range: -Pi/2<=y<=Pi/2 This function operates on double-precision floating point values, use

SDL_atan2f
for single-precision floats.

To calculate the arc tangent of a single value, use SDL_atan .

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

FUNCTION PARAMETERS

y

floating point value of the numerator (y coordinate).

x

floating point value of the denominator (x coordinate).

RETURN VALUE

Returns arc tangent of of y/x in radians, or, if x=0 , either -Pi/2 , 0 , or Pi/2 , depending on the value of y .

THREAD SAFETY

It is safe to call this function from any thread.

AVAILABILITY

This function is available since SDL 3.2.0.

SEE ALSO

•(3), SDL_atan2f(3), •(3), SDL_atan(3), •(3), SDL_tan(3)