28 lines
646 B
C

#include <complex.h>
#include <math.h>
double complex complex_approx_turn(double turn)
{
const static double a = 8 * M_SQRT2 / 3 - 3;
const static double b = 4 - 8 * M_SQRT2 / 3;
double p = turn * (b * turn * turn + a);
double q = p * p;
double r = 1 + q;
double c = (1 - q) / r, s = 2 * p / r;
return (c * c - s * s) + I * (2 * c * s);
}
double complex complex_turn(double turn) { return cexp(I * M_PI * turn); }
void turn_update(double turn, double complex* result)
{
*result = complex_turn(turn);
}
void approx_turn_update(double turn, double complex* result)
{
*result = complex_approx_turn(turn);
}