(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_atan

Compute the arc tangent of x.

Header File

Syntax

double SDL_atan(double x);

Function Parameters

double

floating point value.

Return Value

(double) Returns arc tangent of of x in radians, or 0 if x = 0.

Remarks

The definition of y = atan(x) is x = tan(y).

Domain: -INF <= x <= INF

Range: -Pi/2 <= y <= Pi/2

This function operates on double-precision floating point values, use SDL_atanf for single-precision floats.

To calculate the arc tangent of y / x, use SDL_atan2.

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.

Thread Safety

It is safe to call this function from any thread.

Version

This function is available since SDL 3.1.3.