optar/optar.300dpi.h

   1 /* (c) GPL 2007 Karel 'Clock' Kulhavy, Twibright Labs */
   2
   3 #define MIN(x,y) ((x)<(y)?(x):(y))
   4 #define MAX(x,y) ((x)>(y)?(x):(y))
   5
   6 #define BORDER 2 /* In pixels. Thickness of the border */
   7 #define CHALF 3 /* Size of the cross half. Size of the cross is CHALF*2 x CHALF*2.
   8                    */
   9 #define CPITCH 24 /* Distance between cross centers */
  10
  11 /* XCROSSES A4 65, US Letter 67. */
  12 #define XCROSSES 32 /* Number of crosses horizontally */
  13 /* YCROSSES A4 93, US Letter 87. */
  14 #define YCROSSES 46 /* Number of crosses vertically */
  15
  16 #define DATA_WIDTH (CPITCH*(XCROSSES-1)+2*CHALF) /* The rectangle occupied by
  17                                                     the data and crosses */
  18 #define DATA_HEIGHT (CPITCH*(YCROSSES-1)+2*CHALF)
  19 #define WIDTH (2*BORDER+DATA_WIDTH) /* In pixels, including the border */
  20 /* In pixels, including the border and the label */
  21
  22 #define TEXT_WIDTH 13 /* Width of a single letter */
  23
  24 /* Definitions for seq2xy */
  25
  26 /* Properties of the narrow horizontal strip, with crosses */
  27 #define NARROWHEIGHT (2*CHALF)
  28 #define GAPWIDTH (CPITCH-2*CHALF)
  29 #define NARROWWIDTH (GAPWIDTH*(XCROSSES-1)) /* Useful width */
  30 #define NARROWPIXELS (NARROWHEIGHT*NARROWWIDTH) /* Useful pixels */
  31
  32 /* Properties of the wide horizontal strip, without crosses */
  33 #define WIDEHEIGHT GAPWIDTH
  34 #define WIDEWIDTH (WIDTH-2*BORDER)
  35 #define WIDEPIXELS (WIDEHEIGHT*WIDEWIDTH)
  36
  37 /* Amount of raw payload pixels in one narrow-wide strip pair */
  38 #define REPHEIGHT (NARROWHEIGHT+WIDEHEIGHT)
  39 #define REPPIXELS (WIDEPIXELS+NARROWPIXELS)
  40
  41 /* Total bits before hamming including the unused */
  42 #define TOTALBITS ((long)REPPIXELS*(YCROSSES-1)+NARROWPIXELS)
  43
  44 /* Hamming codes with parity */
  45 #define FEC_ORDER 1 /* Can be 2 to 5 inclusive.
  46                            5 is 26/32,
  47                            4 is 11/16,
  48                            3 is 4/8,
  49                            2 is 4/1
  50                            1 is golay codes */
  51 #if FEC_ORDER==1
  52 /* Golay */
  53 #define FEC_LARGEBITS 24
  54 #define FEC_SMALLBITS 12
  55 #else
  56 /* Hamming */
  57 #define FEC_LARGEBITS (1<<FEC_ORDER)
  58 #define FEC_SMALLBITS (FEC_LARGEBITS-1-FEC_ORDER)
  59 #endif
  60
  61 /* Hamming net channel capacity */
  62 #define FEC_SYMS (TOTALBITS/FEC_LARGEBITS)
  63 #define NETBITS (FEC_SYMS*FEC_SMALLBITS) /* Net payload bits */
  64 #define USEDBITS (FEC_SYMS*FEC_LARGEBITS) /* Used raw bits to store
  65                                                      Hamming symbols */
  66
  67 /* Functions from common.c */
  68 extern unsigned long parity(unsigned long in);
  69 extern int is_cross(unsigned x, unsigned y);
  70 extern void seq2xy(int *x, int *y, unsigned seq);
  71
  72 /* Counts number of '1' bits */
  73 unsigned ones(unsigned long in);
  74
  75 /* Golay codes */
  76 unsigned long golay(unsigned long in);
  77 extern unsigned long golay_codes[4096];