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/*
This program (files math.c and math.h) 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 3 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, see <http://www.gnu.org/licenses/>.
Please note: All the other files for the project "Mikrokopter" by H.Buss are under the license (license_buss.txt) published by www.mikrokopter.de
*/
#include "main.h"
const unsigned int pgm_sinus
[91] PROGMEM
= {0,17,35,52,70,87,105,122,139,156,174,191,208,225,242,259,276,292,309,326,342,358,375,391,407,423,438,454,469,485,500,515,530,545,559,574,588,602,616,629,643,656,669,682,695,707,719,731,743,755,766,777,788,799,809,819,829,839,848,857,866,875,883,891,899,906,914,921,927,934,940,946,951,956,961,966,970,974,978,982,985,988,990,993,995,996,998,999,999,1000,1000};
//-----------------------------------------------
// Fast arctan2
// http://www.dspguru.com/comp.dsp/tricks/alg/fxdatan2.htm
//-----------------------------------------------
signed int arctan_i
(signed int x
, signed int y
)
{
float rad
,r
;
signed int angle
;
if ( !x
&& !y
) return 0;
y
= abs(y
);
if (x
>=0)
{
r
= (x
- y
) / (x
+ y
);
rad
= 0.1963*r
*r
*r
- 0.9817*r
+ 0.7854;
}
else
{
r
= (x
+ y
) / (y
- x
);
rad
= 0.1963*r
*r
*r
- 0.9817*r
+ 2.3562;
}
angle
= (360 * rad
) / 6.2832;
if (y
< 0) return(-angle
); // negate if in quad III or IV
else return(angle
);
}
// cosinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =cos(winkel)*1000
signed int cos_i
(signed int winkel
)
{
winkel
= sin_i
(90-winkel
);
return winkel
;
}
// sinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =sin(winkel)*1000
signed int sin_i
(signed int winkel
)
{
short int m
;
winkel
= winkel
% 360;
if (winkel
< 0)
{
m
= -1;
winkel
= abs(winkel
);
}
else m
= +1;
// Quadranten auswerten
if ((winkel
> 90 ) && (winkel
<= 180)) winkel
= winkel
- 90;
else if ((winkel
> 180 ) && (winkel
<= 270)) winkel
= winkel
- 180;
else if ((winkel
> 270) && (winkel
<= 360)) winkel
= winkel
- 270;
// else //0 - 90 Grad
winkel
= pgm_read_word
(&pgm_sinus
[winkel
]);
return (winkel
*m
);
}