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/* cos_check.c */
/* asserv - Position & speed motor control on a ATmega128. {{{
 *
 * Copyright (C) 2004 Nicolas Schodet
 *
 * Robot APB Team/Efrei 2005.
 *        Web: http://assos.efrei.fr/robot/
 *      Email: robot AT efrei DOT fr
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * }}} */
#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include <stdlib.h>

/* +AutoDec */
/* -AutoDec */

static int
cos_dli (int a, int prec)
{
    static const int f[] = {
	(1 << 24) * -26.42625678337439745096,
	(1 << 24) * 60.24464137187666035919,
	(1 << 24) * -85.45681720669372773226,
	(1 << 24) * 64.93939402266829148905,
	(1 << 24) * -19.73920880217871723738,
	(1 << 24) * 1,
	0
    };
    int r;
    int a2 = (a * a) >> 8;
    int i;
    r = 0;
    for (i = 0; f[i] != 0; i++)
      {
	if (prec)
	    prec--;
	else
	    r = (((long long)r * a2) >> 24) + (f[i] << 0);
      }
    return r; //(r >> 8) + ((r >> 7) & 1);
}

static int
cos_tbl (int a)
{
    /* Bof, il faudrait augmenter la pr�cicion et donc la taille des
     * tables. */
    static int tcosc[257];
    static int tcosf[257];
    static int tsinf[257];
    static int inited = 0;
    if (!inited)
      {
	double x;
	int i;
	for (i = 0; i <= 0x100; i++)
	  {
	    x = (double) i * 2.0 * M_PI / 0x100;
	    tcosc[i] = cos (x) * (1 << 16);
	    x /= 0x100;
	    tcosf[i] = cos (x) * (1 << 16);
	    tsinf[i] = sin (x) * (1 << 16);
	  }
      }
    return (tcosc[(a >> 8) & 0xff] * tcosf[a & 0xff]
	- tcosc[0x100 - ((a >> 8) & 0xff)] * tsinf[a & 0xff]) >> 16;
}

static float
cos_dlf (float a)
{
    static const float f[] = {
	-26.42625678337439745096f,
	60.24464137187666035919f,
	-85.45681720669372773226f,
	64.93939402266829148905f,
	-19.73920880217871723738f,
	1.0f,
	0
    };
    float r;
    float a2 = a * a;
    int i;
    r = 0.0f;
    for (i = 0; f[i] != 0; i++)
      {
	r = r * a2 + f[i];
      }
    return r;
}

static double
cos_dl (double a)
{
    static const double f[] = {
	-26.42625678337439745096,
	60.24464137187666035919,
	-85.45681720669372773226,
	64.93939402266829148905,
	-19.73920880217871723738,
	1,
	0
    };
    double r;
    double a2 = a * a;
    int i;
    r = 0.0;
    for (i = 0; f[i] != 0; i++)
      {
	r = r * a2 + f[i];
      }
    return r;
}

int
main (int argc, char **argv)
{
    double a, c;
    int i, ci;
    int prec = 0;
    if (argc >= 2)
	prec = atoi (argv[1]);
    /*for (i = 0; i < 1024; i++)
      {
	f = ((double) i) / 1024.0 / 4.0;
	printf ("%f %f\n", f * 2.0 * M_PI, cos_dl (f));
      }*/
    /*for (i = 0; i < 1024; i++)
      {
	a = ((float) i) / 1024.0 / 4.0;
	printf ("%f %f\n", a * 2.0 * M_PI, cos_dlf (a));
      }*/
    for (i = 0; i < (1 << 14); i++)
      {
	a = ((double) i) * 2.0 * M_PI / (1 << 16);
	ci = cos_dli (i, prec);
	c = ((double) ci) / (1 << 24);
	printf ("%f %f %i\n", a, c, ci);
      }
    return 0;
}