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178 | 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 | 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}; |
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16 | |||
17 | |||
18 | //----------------------------------------------- |
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180 | Nick666 | 19 | // Fast arctan2 with max error of .01 rads |
178 | Nick666 | 20 | // http://www.dspguru.com/comp.dsp/tricks/alg/fxdatan2.htm |
21 | //----------------------------------------------- |
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22 | signed int arctan_i(signed int x, signed int y) |
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23 | { |
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24 | float rad,r; |
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25 | signed int angle; |
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179 | Nick666 | 26 | short int m; |
178 | Nick666 | 27 | |
179 | Nick666 | 28 | if (!x && !y) return 0; |
178 | Nick666 | 29 | |
179 | Nick666 | 30 | if (y < 0) |
31 | { |
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32 | y = abs(y); |
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33 | m = -1; // neg. für Quadrant III + IV |
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34 | } |
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35 | else m = 1; |
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178 | Nick666 | 36 | |
37 | if (x>=0) |
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38 | { |
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39 | r = (x - y) / (x + y); |
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40 | rad = 0.1963*r*r*r - 0.9817*r + 0.7854; |
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41 | } |
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42 | else |
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43 | { |
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44 | r = (x + y) / (y - x); |
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45 | rad = 0.1963*r*r*r - 0.9817*r + 2.3562; |
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46 | } |
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47 | |||
48 | angle = (360 * rad) / 6.2832; |
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179 | Nick666 | 49 | |
50 | return(angle*m); |
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178 | Nick666 | 51 | } |
52 | |||
53 | // cosinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =cos(winkel)*1000 |
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54 | signed int cos_i(signed int winkel) |
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55 | { |
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56 | winkel = sin_i(90-winkel); |
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57 | return winkel; |
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58 | } |
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59 | |||
60 | |||
61 | // sinus Funktion: Eingabewert Winkel in Grad, Rueckgabe =sin(winkel)*1000 |
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62 | signed int sin_i(signed int winkel) |
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63 | { |
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64 | short int m; |
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65 | winkel = winkel % 360; |
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66 | |||
67 | if (winkel < 0) |
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68 | { |
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69 | m = -1; |
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70 | winkel = abs(winkel); |
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71 | } |
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72 | else m = +1; |
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73 | |||
74 | // Quadranten auswerten |
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75 | if ((winkel > 90 ) && (winkel <= 180)) winkel = winkel - 90; |
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76 | else if ((winkel > 180 ) && (winkel <= 270)) winkel = winkel - 180; |
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77 | else if ((winkel > 270) && (winkel <= 360)) winkel = winkel - 270; |
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78 | // else //0 - 90 Grad |
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79 | |||
80 | winkel = pgm_read_word(&pgm_sinus[winkel]); |
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81 | |||
82 | return (winkel*m); |
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83 | |||
84 | } |
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85 | |||
86 |