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/*

Copyright 2007, Niklas Nold

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 Lesser 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser 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 uint8_t pgm_atan[270] PROGMEM = {0,1,2,3,5,6,7,8,9,10,11,12,13,15,16,17,18,19,20,21,22,23,24,25,26,27,27,28,29,30,31,32,33,33,34,35,36,37,37,38,39,39,40,41,41,42,43,43,44,44,45,46,46,47,47,48,48,49,49,50,50,51,51,52,52,52,53,53,54,54,54,55,55,56,56,56,57,57,57,58,58,58,59,59,59,60,60,60,60,61,61,61,61,62,62,62,62,63,63,63,63,64,64,64,64,65,65,65,65,65,66,66,66,66,66,67,67,67,67,67,67,68,68,68,68,68,68,69,69,69,69,69,69,69,70,70,70,70,70,70,70,70,71,71,71,71,71,71,71,71,72,72,72,72,72,72,72,72,72,73,73,73,73,73,73,73,73,73,73,74,74,74,74,74,74,74,74,74,74,74,74,75,75,75,75,75,75,75,75,75,75,75,75,75,76,76,76,76,76,76,76,76,76,76,76,76,76,76,76,77,77,77,77,77,77,77,77,77,77,77,77,77,77,77,77,77,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79,79};

//############################################################################
// Arkustangens2 im Gradmaß
signed int atan2_i(signed int x,  signed int y)
//############################################################################
{
        int i,angle;
        int8_t m;
       
        if (!x && !y) return 0;         //atan2 = 0 für x und y = 0
       
        if (y < 0) m=-1;
        else m=1;
       
        if (x==0) return (90*m);                // atan2 = 90° für x = 0
       
        i = abs(((long)y*50) / x);              // Berechne i für die Lookup table (Schrittweite atan(x) ist 0.02 -> *50)

        if (i<270) angle = pgm_read_byte(&pgm_atan[i]); // Lookup für 1° bis 79°
        else if (i>5750) angle = 90;                                            // Grenzwert ist 90°
        else if (i>=1910) angle = 89;                                           // 89° bis 80° über Wertebereiche
        else if (i>=1150) angle = 88;
        else if (i>=820) angle = 87;
        else if (i>=640) angle = 86;
        else if (i>=520) angle = 85;
        else if (i>=440) angle = 84;
        else if (i>=380) angle = 83;
        else if (i>=335) angle = 82;
        else if (i>=299) angle = 81;
        else angle = 80; // (i>=270)
       
        if (x > 0) return (angle*m);    // Quadrant I und IV
        else if ((x < 0) && (m > 0)) return (-angle + 180);     // Quadrant II
        else return (angle - 180); // x < 0 && y < 0    Quadrant III
}


const float pgm_sinus_f[91] PROGMEM = {0.0,0.0174524,0.0348995,0.0523360,0.0697565,0.0871557,0.1045285,0.1218693,0.1391731,0.1564345,0.1736482,0.1908090,0.2079117,0.2249510,0.2419219,0.2588190,0.2756373,0.2923717,0.3090170,0.3255681,0.3420201,0.3583679,0.3746066,0.3907311,0.4067366,0.4226182,0.4383711,0.4539905,0.4694715,0.4848096,0.5000000,0.5150381,0.5299193,0.5446390,0.5591929,0.5735764,0.5877852,0.6018150,0.6156615,0.6293204,0.6427876,0.6560590,0.6691306,0.6819983,0.6946584,0.7071068,0.7193398,0.7313537,0.7431448,0.7547096,0.7660444,0.7771459,0.7880107,0.7986355,0.8090170,0.8191520,0.8290376,0.8386706,0.8480481,0.8571673,0.8660254,0.8746197,0.8829476,0.8910065,0.8987940,0.9063078,0.9135454,0.9205048,0.9271838,0.9335804,0.9396926,0.9455186,0.9510565,0.9563047,0.9612617,0.9659258,0.9702957,0.9743701,0.9781476,0.9816272,0.9848077,0.9876883,0.9902681,0.9925461,0.9945219,0.9961947,0.9975640,0.9986295,0.9993908,0.9998477,1.0};

inline float pgm_read_float(const float *addr)
{      
        union
        {
                uint16_t i[2];  // 2 16-bit-Worte
                float f;
        } u;
       
        u.i[0]=pgm_read_word((PGM_P)addr);
        u.i[1]=pgm_read_word((PGM_P)addr+2);
       
        return u.f;
}

//############################################################################
// Kosinusfunktion im Gradmaß
float cos_f(signed int winkel)
//############################################################################
{
 return (sin_f(90-winkel));
}

//############################################################################
// Sinusfunktion im Gradmaß
float sin_f(signed int winkel)
//############################################################################
{
 short int m,n;
 float sinus;
 
 //winkel = winkel % 360;
 
 if (winkel < 0)
 {
        m = -1;
        winkel = abs(winkel);
 }
 else m = +1;
 
 // Quadranten auswerten
 if (winkel <= 90) n=1;
 else if ((winkel > 90 ) && (winkel <= 180)) {winkel = 180 - winkel; n = 1;}
 else if ((winkel > 180 ) && (winkel <= 270)) {winkel = winkel - 180; n = -1;}
 else {winkel = 360 - winkel; n = -1;}  //if ((winkel > 270) && (winkel <= 360))

 sinus = pgm_read_float(&pgm_sinus_f[winkel]);

return (sinus*m*n);
}

/*
const uint8_t pgm_asin[201] PROGMEM = {0,0,1,1,1,1,2,2,2,3,3,3,3,4,4,4,5,5,5,5,6,6,6,7,7,7,7,8,8,8,9,9,9,9,10,10,10,11,11,11,12,12,12,12,13,13,13,14,14,14,14,15,15,15,16,16,16,17,17,17,17,18,18,18,19,19,19,20,20,20,20,21,21,21,22,22,22,23,23,23,24,24,24,25,25,25,25,26,26,26,27,27,27,28,28,28,29,29,29,30,30,30,31,31,31,32,32,32,33,33,33,34,34,34,35,35,35,36,36,37,37,37,38,38,38,39,39,39,40,40,41,41,41,42,42,42,43,43,44,44,44,45,45,46,46,46,47,47,48,48,49,49,49,50,50,51,51,52,52,53,53,54,54,55,55,56,56,57,57,58,58,59,59,60,60,61,62,62,63,64,64,65,66,66,67,68,68,69,70,71,72,73,74,75,76,77,79,80,82,84,90};

//############################################################################
// Akurssinusfunktion im Gradmaß
int8_t asin_i(signed int i)
//############################################################################
{
        signed char m;
       
        if (i < 0) {m=-1;i=abs(i);}
        else m=1;
       
        i = i % 200;
       
        return (pgm_read_byte(&pgm_asin[i]) * m);
}
*/