root/modules/cordic_math.h

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INCLUDED FROM

   1 /*
   2 CORDIC LIBRARY
   3 integer based trigonometric mathematics
   4 all values scaled by 100000 (CORDIC_SCALE)
   5 
   6 based on http://www.andreadrian.de/c-workshop/index.html
   7 
   8 (c)2012/2013 rudi from CHDK[-DE] forum
   9 License GPL 2.0
  10 
  11 trigonometric functions
  12     angle as DEG:
  13     sind, cosd, tand, asind, acosd, atand, recd, pold
  14     angle as RAD:
  15     sinr, cosr, tanr, asinr, acosr, atanr, recr, polr
  16 
  17 additional functions
  18     integer calculation (a * b / c):
  19     fixed muldivScaled(fixed a , fixed b, fixed c)
  20 
  21 additional math functions
  22     fixed fint(a)   get integer
  23     fixed fceil(a)  get largest previous integer
  24     fixed ffloor(a) get smallest following integer
  25     fixed fround(a) get nearest integer
  26 
  27 all values in CORDIC routines are from type 'fixed' (4 byte integer)
  28     makros to convert values:
  29     FIXED(X) ...... convert double to cordic fixed
  30     FLOAT(X) ...... convert cordic fixed to double
  31     INT2FIXED(X) .. convert integer (value *1000) to cordic fixed
  32     INT2FIXEDR(X) . equal to INT2FIXED(X) with round
  33     FIXED2INT(X) .. convert cordic fixed to integer (value * 1000)
  34     FIXED2INTR(X) . equal to FIXED2INT(X) with round
  35 */
  36 
  37 typedef long fixed;
  38 typedef int int4b; //4 byte integer
  39 
  40 enum {ROTATE, VECTOR};
  41 typedef int fcordic;
  42 enum {RAD, DEG};
  43 typedef int tangle;
  44 
  45 enum {
  46     FRACTIONBITS = 17,
  47     N = 17,
  48     M = 9,
  49     CORDIC_SCALE = 1 << FRACTIONBITS,
  50     CORDIC_INTEGER = ~(CORDIC_SCALE - 1),
  51     INT_SCALE = 1000,
  52 };
  53 
  54 #include "limits.h"
  55 
  56 #define FIXED(X)        (floatToFixed((X)))
  57 #define FLOAT(X)        ((X) / (double)CORDIC_SCALE)
  58 #define INT2FIXED(X)    (intToFixed((X), 0))
  59 #define INT2FIXEDR(X)   (intToFixed((X), 1))
  60 #define FIXED2INT(X)    (fixedToInt((X), 0))
  61 #define FIXED2INTR(X)   (fixedToInt((X), 1))
  62 
  63 // extern
  64 // PI/2, PI, 2*PI
  65 LUAI_DATA fixed FULL_CIRCLE[];
  66 LUAI_DATA fixed HALF_CIRCLE[];
  67 LUAI_DATA fixed QUART_CIRCLE[];
  68 //used by macro
  69 LUALIB_API fixed floatToFixed(double a);
  70 LUALIB_API fixed intToFixed(int4b a, int round);
  71 LUALIB_API int4b fixedToInt(fixed a, int round);
  72 //additional
  73 LUALIB_API fixed muldivScaled(fixed a, fixed b, fixed c);
  74 // DEG
  75 LUALIB_API fixed sind(fixed phi);
  76 LUALIB_API fixed cosd(fixed phi);
  77 LUALIB_API fixed tand(fixed phi);
  78 LUALIB_API void recd(fixed r, fixed theta, fixed *px, fixed *py);
  79 LUALIB_API fixed asind(fixed x);
  80 LUALIB_API fixed acosd(fixed x);
  81 LUALIB_API fixed atand(fixed x);
  82 LUALIB_API void pold(fixed px, fixed py, fixed *r, fixed *theta);
  83 // RAD
  84 LUALIB_API fixed sinr(fixed phi);
  85 LUALIB_API fixed cosr(fixed phi);
  86 LUALIB_API fixed tanr(fixed phi);
  87 LUALIB_API void recr(fixed r, fixed theta, fixed *px, fixed *py);
  88 LUALIB_API fixed asinr(fixed x);
  89 LUALIB_API fixed acosr(fixed x);
  90 LUALIB_API fixed atanr(fixed x);
  91 LUALIB_API void polr(fixed px, fixed py, fixed *r, fixed *theta);
  92 //additional math
  93 LUALIB_API fixed fint(fixed a);
  94 LUALIB_API fixed fceil(fixed a);
  95 LUALIB_API fixed ffloor(fixed a);
  96 LUALIB_API fixed fround(fixed a);
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