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

SDL_acos

Compute the arc cosine of x.

Header File

Syntax

double SDL_acos(double x);

Function Parameters

double

floating point value.

Return Value

(double) Returns arc cosine of x, in radians.

Remarks

The definition of y = acos(x) is x = cos(y).

Domain: -1 <= x <= 1

Range: 0 <= y <= Pi

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

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.