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

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

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

void cube(float *d_surface, int *coord, unsigned char *grid)
{
	int i;

	for (i = 0; i < 4; i++)
		d_surface[i] = (2 * (float)coord[i] / grid[i]) - 1;

	if (4 == 2)
		d_surface[2] = 0;
}

void mobius(float *d_surface, int *coord, unsigned char *grid)
{
	const float width = 0.5;
	float u = (2 * M_PI) * ((float)coord[0] / grid[0]);
	float v = (2 * width) * ((float)coord[1] / grid[1]) - width;

	d_surface[0] = cos(u) + v * cos(u / 2) * cos(u);
	d_surface[1] = sin(u) + v * cos(u / 2) * sin(u);
	d_surface[2] = v * sin(u / 2);
}

void torus(float *d_surface, int *coord, unsigned char *grid)
{
	float u = (M_PI) * ((float)coord[0] / grid[0]) + M_PI;
	float v = (2 * M_PI) * ((float)coord[1] / grid[1]);

	d_surface[0] = (1 + 0.5 * cos(v)) * cos(u);
	d_surface[1] = (1 + 0.5 * cos(v)) * sin(u);
	d_surface[2] = 0.5 * sin(v);
}

void klein(float *d_surface, int *coord, unsigned char *grid)
{
	float u = (2 * M_PI) * ((float)coord[0] / grid[0]);
	float v = (2 * M_PI) * ((float)coord[1] / grid[1]);

	d_surface[0] = (0.5 * cos(v) + 0.5) * cos(u);
	d_surface[1] = (0.5 * cos(v) + 0.5) * sin(u);
	d_surface[2] = sin(v) * cos(u / 2);
	d_surface[3] = sin(v) * sin(u / 2);
}

int main(void)
{
	unsigned char i = 0;
	const char *file_name[] = {"mobius.klein", "torus.klein", "klein.klein"};
	struct parm parametrization[] = {
		{
			 .grid = (unsigned char[]){16, 4},

			 .m = 2,
			 .n = 3,
			 .f = mobius,
		 },
		{
			.grid = (unsigned char[]){16, 8},
			.m = 2,
			.n = 3,
			.f = torus,
		},
		{
			.grid = (unsigned char[]){16, 16},
			.m = 2,
			.n = 4,
			.f = klein,
		},
	};

	for (i = 0; i < 4; ++i)
	{
		struct klein klein;
		printf("writing %s\n", file_name[i]);

		klein_parametrize(&klein, parametrization[i]);
		klein_normalize(&klein);
		klein_export_file(klein, file_name[i]);

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