view sankaku.c @ 0:01387a2e419e

initial version
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Tue, 07 Dec 2010 15:39:45 +0900
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#include <math.h>
#include "sankaku.h"

#define SANKAKU 100000

int mysin[181];
int mycos[181];

void sankakuf()
{
    int i;
    for (i = 0; i < 181; i++) {
	mysin[i] = sin(i / 360.0 * pi2) * SANKAKU;
    }
    for (i = 0; i < 181; i++) {
	mycos[i] = cos(i / 360.0 * pi2) * SANKAKU;
    }
}

int Mycos(int c)
{
    c %= 360;
    if (c < 0)
	c += 360;
    if ((c <= 180))
	return (mycos[c]);
    if (c > 180)
	return (mycos[180 - (c - 180)]);
    return (0);
}

int Mysin(int c)
{
    c %= 360;
    if (c < 0)
	c += 360;
    if (c <= 180)
	return (mysin[c]);
    if (c > 180)
	return (mysin[180 - (c - 180)] * -1);
    return (0);
}