src/useful.h

   1 /* useful.h
   2  * Lots of oddments that come in handy generally
   3  * Copyright (C) 1993-2003,2004,2010,2011,2014 Olly Betts
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 /* only include once */
  21 #ifndef USEFUL_H
  22 #define USEFUL_H
  23
  24 #include <config.h>
  25
  26 #if HAVE_STDINT_H
  27 # include <stdint.h>
  28 #endif
  29
  30 #include <stdlib.h> /* for Borland C which #defines max() & min() there */
  31 #include <stdio.h>
  32 #include <math.h>
  33 #include "osalloc.h"
  34
  35 /* Macro to allow easy building of macros contain multiple statements, such
  36  * that the likes of “if (x == y) macro1(x); else x = 2;” works properly  */
  37 #define BLK(X) do {X} while(0)
  38
  39 /* Macro to do nothing, but avoid compiler warnings about empty if bodies &c */
  40 #define NOP (void)0
  41
  42 /* In C++ code, #include<algorithm> and use std::max and std::min instead. */
  43 #ifndef __cplusplus
  44 /* Return max/min of two numbers. */
  45 /* May be defined already (e.g. by Borland C in stdlib.h) */
  46 /* NB Bad news if X or Y has side-effects... */
  47 # ifndef max
  48 #  define max(X, Y) ((X) > (Y) ? (X) : (Y))
  49 # endif
  50 # ifndef min
  51 #  define min(X, Y) ((X) < (Y) ? (X) : (Y))
  52 # endif
  53 #endif
  54
  55 /* M_PI, etc may be defined in math.h */
  56 #ifndef M_PI
  57 # ifdef PI /* MSVC defines PI IIRC */
  58 #  define M_PI PI
  59 # else
  60 #  define M_PI 3.14159265358979323846264338327950288419716939937510582097494459
  61 # endif
  62 #endif
  63 #ifndef M_PI_2
  64 # define M_PI_2 (M_PI / 2.0)
  65 #endif
  66 #ifndef M_PI_4
  67 # define M_PI_4 (M_PI / 4.0)
  68 #endif
  69
  70 #define MM_PER_INCH 25.4 /* exact value */
  71 #define METRES_PER_FOOT 0.3048 /* exact value */
  72
  73 /* DJGPP needs these: */
  74
  75 #ifndef EXIT_FAILURE
  76 # define EXIT_FAILURE 1
  77 #endif /* !EXIT_FAILURE */
  78
  79 #ifndef EXIT_SUCCESS
  80 # define EXIT_SUCCESS 0
  81 #endif /* !EXIT_SUCCESS */
  82
  83 #ifndef SEEK_SET
  84 # define SEEK_SET 0
  85 # define SEEK_CUR 1
  86 # define SEEK_END 2
  87 #endif /* !SEEK_SET */
  88
  89 /* Older UNIX libraries and DJGPP libraries have HUGE instead of HUGE_VAL */
  90 #ifndef HUGE_VAL
  91 # ifdef HUGE
  92 #  define HUGE_VAL HUGE
  93 # else
  94 #  error Neither HUGE_VAL nor HUGE is defined
  95 # endif
  96 #endif
  97
  98 #include "ostypes.h"
  99
 100 #define putnl() putchar('\n')    /* print a newline char */
 101 #define fputnl(FH) PUTC('\n', (FH)) /* print a newline char to a file */
 102 /* print a line followed by a newline char to a file */
 103 #define fputsnl(SZ, FH) BLK(fputs((SZ), (FH)); PUTC('\n', (FH));)
 104 #define sqrd(X) ((X) * (X))        /* macro to square things */
 105
 106 /* 2D Euclidean distance */
 107 #ifndef HAVE_HYPOT
 108 # define hypot(X, Y) sqrt(sqrd((double)(X)) + sqrd((double)(Y)))
 109 #endif
 110 #define rad(X) ((M_PI / 180.0) * (X))  /* convert from degrees to radians */
 111 #define deg(X) ((180.0 / M_PI) * (X))  /* convert from radians to degrees */
 112
 113 /* macro to convert argument to a string literal */
 114 #define STRING(X) STRING_(X)
 115 #define STRING_(X) #X
 116
 117 #include "osdepend.h"
 118
 119 #ifndef WORDS_BIGENDIAN
 120 # define put16(W, FH) BLK(int16_t w = (W); fwrite(&w, 2, 1, (FH));)
 121 # define put32(W, FH) BLK(int32_t w = (W); fwrite(&w, 4, 1, (FH));)
 122
 123 static inline int16_t get16(FILE *fh) {
 124     int16_t w;
 125     if (fread(&w, 2, 1, fh) == 0) {
 126         /* We check feof() and ferror() afterwards, so checking the return
 127          * value achieves nothing, but we get a warning from glibc's
 128          * _FORTIFY_SOURCE if we don't pretend to. */
 129     }
 130     return w;
 131 }
 132
 133 static inline int32_t get32(FILE *fh) {
 134     int32_t w;
 135     if (fread(&w, 4, 1, fh) == 0) {
 136         /* We check feof() and ferror() afterwards, so checking the return
 137          * value achieves nothing, but we get a warning from glibc's
 138          * _FORTIFY_SOURCE if we don't pretend to. */
 139     }
 140     return w;
 141 }
 142 #else
 143 void useful_put16(int16_t, FILE *);
 144 void useful_put32(int32_t, FILE *);
 145 int16_t useful_get16(FILE *);
 146 int32_t useful_get32(FILE *);
 147
 148 # define put16(W, FH) useful_put16(W, FH)
 149 # define put32(W, FH) useful_put32(W, FH)
 150 # define get16(FH) useful_get16(FH)
 151 # define get32(FH) useful_get32(FH)
 152 #endif
 153
 154 #endif /* !USEFUL_H */