source/texk/web2c/luatexdir/tex/arithmetic.h

   1 /* arithmetic.h
   2
   3    Copyright 2009 Taco Hoekwater <taco@luatex.org>
   4
   5    This file is part of LuaTeX.
   6
   7    LuaTeX is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2 of the License, or (at your
  10    option) any later version.
  11
  12    LuaTeX is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */
  19
  20
  21 #ifndef ARITHMETIC_H
  22 #  define ARITHMETIC_H
  23
  24 /* |incr| and |decr| are in texmfmp.h */
  25
  26                                                                                                                                                                    /* #define incr(A) (A)++ *//* increase a variable by unity */
  27                                                                                                                                                                    /* #define decr(A) (A)-- *//* decrease a variable by unity */
  28
  29 #  define negate(A) (A)=-(A)    /* change the sign of a variable */
  30
  31 #  undef half
  32 extern int half(int x);
  33
  34 /*
  35 Fixed-point arithmetic is done on {\sl scaled integers\/} that are multiples
  36 of $2^{-16}$. In other words, a binary point is assumed to be sixteen bit
  37 positions from the right end of a binary computer word.
  38 */
  39
  40 #  define unity 0200000         /* $2^{16}$, represents 1.00000 */
  41 #  define two   0400000         /* $2^{17}$, represents 2.00000 */
  42
  43 typedef unsigned int nonnegative_integer;       /* $0\L x<2^{31}$ */
  44
  45 extern scaled round_decimals(int k);
  46 extern void print_scaled(scaled s);
  47
  48 extern boolean arith_error;
  49 extern scaled tex_remainder;
  50
  51 extern scaled mult_and_add(int n, scaled x, scaled y, scaled max_answer);
  52
  53 #  define nx_plus_y(A,B,C) mult_and_add((A),(B),(C),07777777777)
  54 #  define mult_integers(A,B) mult_and_add((A),(B),0,017777777777)
  55
  56 extern scaled x_over_n(scaled x, int n);
  57 extern scaled xn_over_d(scaled x, int n, int d);
  58
  59 #  define inf_bad 10000         /* infinitely bad value */
  60
  61 extern halfword badness(scaled t, scaled s);
  62
  63 #  define set_glue_ratio_zero(A) (A)=0.0        /* store the representation of zero ratio */
  64 #  define set_glue_ratio_one(A) (A)=1.0 /* store the representation of unit ratio */
  65 #  define float_cast(A) (float)(A)      /* convert from |glue_ratio| to type |real| */
  66 #  define unfloat(A) (glue_ratio)(A)    /* convert from |real| to type |glue_ratio| */
  67 #  define float_constant(A) (float)A    /* convert |integer| constant to |real| */
  68 #  define float_round round
  69
  70 extern void initialize_arithmetic(void);
  71
  72 extern scaled random_seed;      /* the default random seed */
  73
  74 extern void init_randoms(int seed);
  75 extern int unif_rand(int x);
  76 extern int norm_rand(void);
  77
  78 extern int fix_int(int val, int min, int max);
  79
  80 #endif