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 #ifndef PACKAGE
  25 # error config.h must be included first in each C/C++ source file
  26 #endif
  27
  28 #include <stdint.h>
  29 #include <stdlib.h> /* for Borland C which #defines max() & min() there */
  30 #include <stdio.h>
  31 #include <math.h>
  32
  33 /* Macro to allow easy building of macros contain multiple statements, such
  34  * that the likes of “if (x == y) macro1(x); else x = 2;” works properly  */
  35 #define BLK(X) do {X} while(0)
  36
  37 /* Macro to do nothing, but avoid compiler warnings about empty if bodies &c */
  38 #define NOP (void)0
  39
  40 /* In C++ code, #include<algorithm> and use std::max and std::min instead. */
  41 #ifndef __cplusplus
  42 /* Return max/min of two numbers. */
  43 /* May be defined already (e.g. by Borland C in stdlib.h) */
  44 /* NB Bad news if X or Y has side-effects... */
  45 # ifndef max
  46 #  define max(X, Y) ((X) > (Y) ? (X) : (Y))
  47 # endif
  48 # ifndef min
  49 #  define min(X, Y) ((X) < (Y) ? (X) : (Y))
  50 # endif
  51 #endif
  52
  53 /* M_PI, etc may be defined in math.h */
  54 #ifndef M_PI
  55 # ifdef PI /* MSVC defines PI IIRC */
  56 #  define M_PI PI
  57 # else
  58 #  define M_PI 3.14159265358979323846264338327950288419716939937510582097494459
  59 # endif
  60 #endif
  61 #ifndef M_PI_2
  62 # define M_PI_2 (M_PI / 2.0)
  63 #endif
  64 #ifndef M_PI_4
  65 # define M_PI_4 (M_PI / 4.0)
  66 #endif
  67
  68 #define MM_PER_INCH 25.4 /* exact value */
  69 #define METRES_PER_FOOT 0.3048 /* exact value */
  70
  71 #define putnl() putchar('\n')    /* print a newline char */
  72 #define fputnl(FH) PUTC('\n', (FH)) /* print a newline char to a file */
  73 /* print a line followed by a newline char to a file */
  74 #define fputsnl(SZ, FH) BLK(fputs((SZ), (FH)); PUTC('\n', (FH));)
  75 #define sqrd(X) ((X) * (X))        /* macro to square things */
  76
  77 /* 2D Euclidean distance */
  78 #ifndef HAVE_HYPOT
  79 # define hypot(X, Y) sqrt(sqrd((double)(X)) + sqrd((double)(Y)))
  80 #endif
  81 #define rad(X) ((M_PI / 180.0) * (X))  /* convert from degrees to radians */
  82 #define deg(X) ((180.0 / M_PI) * (X))  /* convert from radians to degrees */
  83
  84 /* macro to convert argument to a string literal */
  85 #define STRING(X) STRING_(X)
  86 #define STRING_(X) #X
  87
  88 #ifndef WORDS_BIGENDIAN
  89 # define put16(W, FH) BLK(int16_t w = (W); fwrite(&w, 2, 1, (FH));)
  90 # define put32(W, FH) BLK(int32_t w = (W); fwrite(&w, 4, 1, (FH));)
  91
  92 # ifdef __GNUC__
  93 __attribute__((unused))
  94 # endif
  95 static inline int16_t get16(FILE *fh) {
  96     int16_t w;
  97     if (fread(&w, 2, 1, fh) == 0) {
  98         /* We check feof() and ferror() afterwards, so checking the return
  99          * value achieves nothing, but we get a warning from glibc's
 100          * _FORTIFY_SOURCE if we don't pretend to. */
 101     }
 102     return w;
 103 }
 104
 105 # ifdef __GNUC__
 106 __attribute__((unused))
 107 # endif
 108 static inline int32_t get32(FILE *fh) {
 109     int32_t w;
 110     if (fread(&w, 4, 1, fh) == 0) {
 111         /* We check feof() and ferror() afterwards, so checking the return
 112          * value achieves nothing, but we get a warning from glibc's
 113          * _FORTIFY_SOURCE if we don't pretend to. */
 114     }
 115     return w;
 116 }
 117 #else
 118 void useful_put16(int16_t, FILE *);
 119 void useful_put32(int32_t, FILE *);
 120 int16_t useful_get16(FILE *);
 121 int32_t useful_get32(FILE *);
 122
 123 # define put16(W, FH) useful_put16(W, FH)
 124 # define put32(W, FH) useful_put32(W, FH)
 125 # define get16(FH) useful_get16(FH)
 126 # define get32(FH) useful_get32(FH)
 127 #endif
 128
 129 #endif /* !USEFUL_H */