mdw@git.distorted.org.uk Git - mup/blob - mup/mup/rational.h

   1 /* Copyright (c) 1995, 1996, 1997, 2001 by Arkkra Enterprises */
   2 /* All rights reserved */
   3 /*
   4  *      rational.h      definitions for using rational numbers
   5  */
   6 #ifndef _RATIONAL
   7 #define _RATIONAL
   8
   9
  10 /*
  11  * The code in rational.h/rational.c is written in a way that depends on
  12  * certain variables being 32-bit numbers stored in two's complement form.  For
  13  * most compilers, "long" works for this, but for some compilers, "long" is
  14  * 64 bits, or maybe something else.  C standards after (and not including) the
  15  * 1994 version guarantee the existence of a header file stdint.h which defines
  16  * typedefs int32_t and uint32_t.  So for those standards we will use those
  17  * typedefs from that header when defining our INT32B and UINT32B.  Otherwise
  18  * we will just use long and unsigned long.  If these aren't 32-bit, two's
  19  * complement, you will have to change this code.
  20  */
  21 #if __STDC_VERSION__ > 199409L
  22 #include <stdint.h>
  23 #define INT32B  int32_t
  24 #define UINT32B uint32_t
  25 #else
  26 #define INT32B  long
  27 #define UINT32B unsigned long
  28 #endif
  29
  30 /*
  31  * Define the structure that represents a rational number.  The number
  32  * should be kept in standard form; that is, in lowest terms with a positive
  33  * denominator.  Zero should be stored as 0/1.
  34  */
  35 struct rational {
  36         INT32B n;       /* numerator */
  37         INT32B d;       /* denominator */
  38 };
  39
  40 typedef struct rational RATIONAL;
  41
  42
  43 /* macros for comparing rational numbers */
  44 /* numbers must be in standard form */
  45
  46 #define EQ(a, b)        ((a).n == (b).n && (a).d == (b).d)
  47 #define NE(a, b)        ((a).n != (b).n || (a).d != (b).d)
  48
  49 /* must call function for inequalities, because overflow possibilities */
  50
  51 #define GT(a, b)        gtrat(a, b)
  52 #define LT(a, b)        gtrat(b, a)
  53 #define GE(a, b)        ( ! gtrat(b, a) )
  54 #define LE(a, b)        ( ! gtrat(a, b) )
  55
  56
  57 /* macros for testing a rational number */
  58 /* numbers must be in standard form, or at least have positive denominator */
  59
  60 #define ZE(a)           ((a).n == 0)
  61 #define PL(a)           ((a).n >  0)
  62 #define MI(a)           ((a).n <  0)
  63 #define NZ(a)           ((a).n != 0)
  64 #define NM(a)           ((a).n >= 0)
  65 #define NP(a)           ((a).n <= 0)
  66
  67
  68 /* definitions for error handling */
  69
  70 #define RATNOERR        0
  71 #define RATOVER         1
  72 #define RATDIV0         2
  73 #define RATPARM         3
  74
  75 #ifndef MAXLONG
  76 #define MAXLONG         0x7fffffff
  77 #endif
  78
  79 extern int raterrno;                    /* holds error code */
  80 #ifdef __STDC__
  81 extern void (*raterrfuncp)(int);        /* pointer to user error handler */
  82 #else
  83 extern void (*raterrfuncp)();           /* pointer to user error handler */
  84 #endif
  85
  86
  87 /* functions to do operations on rational numbers */
  88
  89 #ifdef __STDC__
  90 extern RATIONAL radd(RATIONAL x, RATIONAL y);
  91 extern RATIONAL rsub(RATIONAL x, RATIONAL y);
  92 extern RATIONAL rmul(RATIONAL x, RATIONAL y);
  93 extern RATIONAL rdiv(RATIONAL x, RATIONAL y);
  94 extern RATIONAL rneg(RATIONAL x);
  95 extern RATIONAL rinv(RATIONAL x);
  96 extern RATIONAL rrai(RATIONAL x, int n);
  97 extern void rred(RATIONAL *ap);
  98 extern char *ator(RATIONAL *rp, char s[]);
  99 extern char *rtoa(char s[], RATIONAL *rp);
 100 extern int gtrat(RATIONAL x, RATIONAL y);
 101 #else
 102 extern RATIONAL radd(), rsub(), rmul(), rdiv(), rneg(), rinv(), rrai();
 103 extern void rred();
 104 extern char *ator(), *rtoa();
 105 extern int gtrat();
 106 #endif
 107
 108 #endif