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/* arithmetic.h
Copyright 2009 Taco Hoekwater <taco@luatex.org>
This file is part of LuaTeX.
LuaTeX is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.
LuaTeX is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU General Public License along
with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */
#ifndef ARITHMETIC_H
# define ARITHMETIC_H
/* |incr| and |decr| are in texmfmp.h */
/* #define incr(A) (A)++ *//* increase a variable by unity */
/* #define decr(A) (A)-- *//* decrease a variable by unity */
# define negate(A) (A)=-(A) /* change the sign of a variable */
# undef half
extern int half(int x);
/*
Fixed-point arithmetic is done on {\sl scaled integers\/} that are multiples
of $2^{-16}$. In other words, a binary point is assumed to be sixteen bit
positions from the right end of a binary computer word.
*/
# define unity 0200000 /* $2^{16}$, represents 1.00000 */
# define two 0400000 /* $2^{17}$, represents 2.00000 */
typedef unsigned int nonnegative_integer; /* $0\L x<2^{31}$ */
extern scaled round_decimals(int k);
extern void print_scaled(scaled s);
extern boolean arith_error;
extern scaled tex_remainder;
extern scaled mult_and_add(int n, scaled x, scaled y, scaled max_answer);
# define nx_plus_y(A,B,C) mult_and_add((A),(B),(C),07777777777)
# define mult_integers(A,B) mult_and_add((A),(B),0,017777777777)
extern scaled x_over_n(scaled x, int n);
extern scaled xn_over_d(scaled x, int n, int d);
# define inf_bad 10000 /* infinitely bad value */
extern halfword badness(scaled t, scaled s);
# define set_glue_ratio_zero(A) (A)=0.0 /* store the representation of zero ratio */
# define set_glue_ratio_one(A) (A)=1.0 /* store the representation of unit ratio */
# define float_cast(A) (float)(A) /* convert from |glue_ratio| to type |real| */
# define unfloat(A) (glue_ratio)(A) /* convert from |real| to type |glue_ratio| */
# define float_constant(A) (float)A /* convert |integer| constant to |real| */
# define float_round round
extern void initialize_arithmetic(void);
extern scaled random_seed; /* the default random seed */
extern void init_randoms(int seed);
extern int unif_rand(int x);
extern int norm_rand(void);
extern int fix_int(int val, int min, int max);
#endif
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