C - Equivalent of Lua's math.rad

Question

I'm currently working on convertering some Lua script to C, and I've struggled upon some code:

markerCoords.x = playerCoords.x - ( sin(math.rad(camRot.z)) * 20 );
markerCoords.y = playerCoords.y + ( cos(math.rad(camRot.z)) * 20 );

I've looked online but I can't seem to find an equivalent of Lua's math.rad in C.

The description of this math function is as follows:

math.rad (x)

Returns the angle x (given in degrees) in radians.

What is the equivalent of Lua's math.rad in C?

Answer 1

There isn't a standard function to do that in C, but as shown in this Q&A

Is there a function in C language to calculate degrees/radians?

It can be done with an user defined function

// Make sure to have the (non standard) M_PI defined
#define _USE_MATH_DEFINES
#include <math.h>

#ifndef M_PI
#define M_PI 3.14159265358979323846264338327950288
#endif

// Apply basic trigonometry
inline double rad_from_deg(double degrees)
{
    return degrees * M_PI / 180.0;
}

inline double deg_from_rad(double radians)
{
    return radians * 180.0 / M_PI;
}