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/* useful.h
* Lots of oddments that come in handy generally
* Copyright (C) 1993-2003,2004,2010,2011,2014,2025 Olly Betts
*
* This program 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.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* only include once */
#ifndef USEFUL_H
#define USEFUL_H
#ifndef PACKAGE
# error config.h must be included first in each C/C++ source file
#endif
#include <stdio.h>
#include <math.h>
/* M_PI, etc may be defined in math.h */
#ifndef M_PI
# define M_PI 3.14159265358979323846264338327950288419716939937510582097494459
#endif
#ifndef M_PI_2
# define M_PI_2 (M_PI / 2.0)
#endif
#ifndef M_PI_4
# define M_PI_4 (M_PI / 4.0)
#endif
#define MM_PER_INCH 25.4 /* exact value */
#define METRES_PER_FOOT 0.3048 /* exact value */
#define POINTS_PER_INCH 72.0
#define POINTS_PER_MM (POINTS_PER_INCH / MM_PER_INCH)
// Write a newline char.
#define putnl() PUTCHAR('\n')
// Write a newline char to a file.
#define fputnl(FH) PUTC('\n', (FH))
// Square X.
#define sqrd(X) ((X) * (X))
/* 2D Euclidean distance */
#ifndef HAVE_HYPOT
# define hypot(X, Y) sqrt(sqrd((double)(X)) + sqrd((double)(Y)))
#endif
#define rad(X) ((M_PI / 180.0) * (X)) /* convert from degrees to radians */
#define deg(X) ((180.0 / M_PI) * (X)) /* convert from radians to degrees */
/* macro to convert argument to a string literal */
#define STRING(X) STRING_(X)
#define STRING_(X) #X
#endif /* !USEFUL_H */
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