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| 205 | Nick666 | 1 | /* |
| 2 | This program (files math.c and math.h) is free software; you can redistribute it and/or modify |
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| 3 | it under the terms of the GNU General Public License as published by the Free Software Foundation; |
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| 4 | either version 3 of the License, or (at your option) any later version. |
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| 5 | This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; |
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| 6 | without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 7 | GNU General Public License for more details. You should have received a copy of the GNU General Public License |
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| 8 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
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| 9 | |||
| 10 | 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 |
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| 11 | */ |
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| 12 | |||
| 13 | #include "main.h" |
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| 14 | |||
| 15 | //----------------------------------------------- |
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| 16 | // Fast arctan2 with max error of .01 rads |
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| 17 | // http://www.dspguru.com/comp.dsp/tricks/alg/fxdatan2.htm |
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| 18 | //----------------------------------------------- |
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| 214 | Nick666 | 19 | float arctan_f(signed int x, signed int y) |
| 205 | Nick666 | 20 | { |
| 21 | float rad,r; |
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| 22 | signed int angle; |
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| 23 | short int m; |
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| 24 | |||
| 25 | if (!x && !y) return 0; |
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| 26 | |||
| 27 | if (y < 0) {y = abs(y); m = -1;} |
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| 28 | else m = 1; |
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| 29 | |||
| 30 | if (x>=0) |
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| 31 | { |
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| 32 | r = (x - y) / (x + y); |
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| 33 | rad = 0.1963*r*r*r - 0.9817*r + 0.7854; |
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| 34 | } |
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| 35 | else |
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| 36 | { |
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| 37 | r = (x + y) / (y - x); |
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| 38 | rad = 0.1963*r*r*r - 0.9817*r + 2.3562; |
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| 39 | } |
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| 40 | |||
| 214 | Nick666 | 41 | return(rad*m); |
| 205 | Nick666 | 42 | } |
| 43 | |||
| 214 | Nick666 | 44 | /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| 45 | Peter Muehlenbrock |
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| 46 | arctan in brute-force Art |
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| 47 | Stand 1.10.2007 |
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| 48 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
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| 49 | */ |
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| 50 | |||
| 51 | // arctan Funktion: Eingabewert x,y Rueckgabe =arctan(x,y) in grad |
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| 52 | int8_t arctan_i( signed int x, signed int y) |
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| 53 | { |
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| 54 | short int change_xy = 0; |
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| 55 | signed int i; |
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| 56 | long signed int wert; |
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| 57 | int return_value; |
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| 58 | |||
| 59 | if ((abs(x)) > (abs(y))) // x,y Werte vertauschen damit arctan <45 grad bleibt |
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| 60 | { |
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| 61 | change_xy = 1; |
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| 62 | i = x; |
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| 63 | x = y; |
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| 64 | y = i; |
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| 65 | } |
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| 66 | |||
| 67 | // Quadranten ermitteln |
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| 68 | |||
| 69 | // Wert durch lineare Interpolation ermitteln |
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| 70 | if ((y == 0) && (x == 0)) wert =1; // Division durch 0 nicht erlaubt |
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| 71 | else wert= abs((x*1000)/y); |
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| 72 | |||
| 73 | if (wert <=268) //0...0.0,268 entsprechend 0..15 Grad |
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| 74 | { |
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| 75 | return_value = (signed int)((wert*100)/(268-0)*(15-0)/100) +0; |
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| 76 | } |
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| 77 | else if (wert <=578) //0,268...0.0,568 entsprechend 15..30 Grad |
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| 78 | { |
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| 79 | return_value = (signed int)((((wert-268)*100)/(578-268)*(30-15))/100) +15; |
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| 80 | } |
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| 81 | else //0,568...1 entsprechend 30..45 Grad |
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| 82 | { |
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| 83 | return_value = (signed int)((((wert-578)*50)/(1000-578)*(45-30))/50) +30; |
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| 84 | } |
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| 85 | |||
| 86 | if (change_xy == 0) return_value = 90-return_value; //Quadrant 45..90 Grad |
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| 87 | if ((x >= 0) && (y <0)) return_value = - return_value; |
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| 88 | else if ((x < 0) && (y >= 0)) return_value = - return_value; |
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| 89 | |||
| 90 | return return_value; |
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| 91 | } |
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| 92 | |||
| 205 | Nick666 | 93 | // cosinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =cos(winkel)*1000 |
| 94 | signed int cos_i(signed int winkel) |
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| 95 | { |
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| 96 | winkel = sin_i(90-winkel); |
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| 97 | return winkel; |
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| 98 | } |
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| 99 | |||
| 100 | |||
| 214 | Nick666 | 101 | 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}; |
| 205 | Nick666 | 102 | |
| 103 | // sinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =sin(winkel)*1000 |
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| 104 | signed int sin_i(signed int winkel) |
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| 105 | { |
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| 106 | short int m,n; |
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| 107 | |||
| 108 | //winkel = winkel % 360; |
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| 109 | |||
| 110 | if (winkel < 0) |
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| 111 | { |
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| 112 | m = -1; |
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| 113 | winkel = abs(winkel); |
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| 114 | } |
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| 115 | else m = +1; |
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| 116 | |||
| 117 | // Quadranten auswerten |
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| 118 | if ((winkel > 90 ) && (winkel <= 180)) {winkel = 180 - winkel; n = 1;} |
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| 119 | else if ((winkel > 180 ) && (winkel <= 270)) {winkel = winkel - 180; n = -1;} |
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| 120 | else if ((winkel > 270) && (winkel <= 360)) {winkel = 360 - winkel; n = -1;} |
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| 121 | else n = 1; //0 - 90 Grad |
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| 122 | |||
| 123 | winkel = pgm_read_word(&pgm_sinus[winkel]); |
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| 124 | |||
| 125 | return (winkel*m*n); |
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| 126 | } |
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| 127 | |||
| 128 |