SDL_atan2 - Man Page
Compute the arc tangent of y / x, using the signs of x and y to adjust the result's quadrant.
Synopsis
#include <SDL3/SDL_stdinc.h> double SDL_atan2(double y, double x);
Description
The definition of z = atan2(x, y) is y = x tan(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 <= y <= Pi
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
Referenced By
SDL_atan(3), SDL_atan2f(3), SDL_tan(3).