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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) && (y >= 0)) return ((angle*-1) + 180);        // Quadrant II

        else return (angle - 180); // x < 0 && y < 0    Quadrant III

}

const float pgm_sinus_f [91] PROGMEM = {0.000,0.017,0.035,0.052,0.070,0.087,0.105,0.122,0.139,0.156,0.174,0.191,0.208,0.225,0.242,0.259,0.276,0.292,0.309,0.326,0.342,0.358,0.375,0.391,0.407,0.423,0.438,0.454,0.469,0.485,0.500,0.515,0.530,0.545,0.559,0.574,0.588,0.602,0.616,0.629,0.643,0.656,0.669,0.682,0.695,0.707,0.719,0.731,0.743,0.755,0.766,0.777,0.788,0.799,0.809,0.819,0.829,0.839,0.848,0.857,0.866,0.875,0.883,0.891,0.899,0.906,0.914,0.921,0.927,0.934,0.940,0.946,0.951,0.956,0.961,0.966,0.970,0.974,0.978,0.982,0.985,0.988,0.990,0.993,0.995,0.996,0.998,0.999,0.999,1.000,1.000};

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 ) && (winkel <= 180)) {winkel = 180 - winkel; n = 1;}

 else if ((winkel > 180 ) && (winkel <= 270)) {winkel = winkel - 180; n = -1;}

 else if ((winkel > 270) && (winkel <= 360)) {winkel = 360 - winkel; n = -1;}

 else n = 1; //0 - 90 Grad

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;

        return (pgm_read_byte(&pgm_asin[i]) * m);

}