#include <complex.h>
#include <math.h>
#include <stdio.h>

#define KLEIN_IMPLEMENT
#include <klein/klein.h>
#include <klein/norm.h>
#include <klein/parm.h>

#ifndef CMPLX
#define CMPLX(a, b) (a + I * b)
#endif

complex float f(complex float z) { return csqrt(z); }

void riemman(float *d_surface, int *coords, unsigned char *grid)
{
	complex float eq;
	float u = 2 * ((float)coords[0] / grid[0]) - 1;
	float v = 2 * ((float)coords[1] / grid[1]) - 1;

	eq = f(CMPLX(u, v));

	d_surface[0] = u;
	d_surface[1] = v;
	d_surface[2] = creal(eq);
	d_surface[3] = cimag(eq);
}

int main(void)
{
	const char *file_name = "riemman.klein";
	struct klein klein;
	struct parm parametrization = {
		.grid = (unsigned char[]){16, 4},
		.m = 2,
		.n = 4,
		.f = riemman,
	};

	printf("writing %s\n", file_name);

	klein_parametrize(&klein, parametrization);
	klein_normalize(&klein);
	klein_export_file(klein, file_name);

	free(klein.vertex);
	free(klein.normals);
	return 0;
}