| 1 | /* useful.h |
|---|
| 2 | * Lots of oddments that come in handy generally |
|---|
| 3 | * Copyright (C) 1993-2003,2004,2010,2011,2014,2025 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 <stdio.h> |
|---|
| 29 | #include <math.h> |
|---|
| 30 | |
|---|
| 31 | /* M_PI, etc may be defined in math.h */ |
|---|
| 32 | #ifndef M_PI |
|---|
| 33 | # define M_PI 3.14159265358979323846264338327950288419716939937510582097494459 |
|---|
| 34 | #endif |
|---|
| 35 | #ifndef M_PI_2 |
|---|
| 36 | # define M_PI_2 (M_PI / 2.0) |
|---|
| 37 | #endif |
|---|
| 38 | #ifndef M_PI_4 |
|---|
| 39 | # define M_PI_4 (M_PI / 4.0) |
|---|
| 40 | #endif |
|---|
| 41 | |
|---|
| 42 | #define MM_PER_INCH 25.4 /* exact value */ |
|---|
| 43 | #define METRES_PER_FOOT 0.3048 /* exact value */ |
|---|
| 44 | #define POINTS_PER_INCH 72.0 |
|---|
| 45 | #define POINTS_PER_MM (POINTS_PER_INCH / MM_PER_INCH) |
|---|
| 46 | |
|---|
| 47 | // Write a newline char. |
|---|
| 48 | #define putnl() putchar('\n') |
|---|
| 49 | |
|---|
| 50 | // Write a newline char to a file. |
|---|
| 51 | #define fputnl(FH) PUTC('\n', (FH)) |
|---|
| 52 | |
|---|
| 53 | // Square X. |
|---|
| 54 | #define sqrd(X) ((X) * (X)) |
|---|
| 55 | |
|---|
| 56 | /* 2D Euclidean distance */ |
|---|
| 57 | #ifndef HAVE_HYPOT |
|---|
| 58 | # define hypot(X, Y) sqrt(sqrd((double)(X)) + sqrd((double)(Y))) |
|---|
| 59 | #endif |
|---|
| 60 | #define rad(X) ((M_PI / 180.0) * (X)) /* convert from degrees to radians */ |
|---|
| 61 | #define deg(X) ((180.0 / M_PI) * (X)) /* convert from radians to degrees */ |
|---|
| 62 | |
|---|
| 63 | /* macro to convert argument to a string literal */ |
|---|
| 64 | #define STRING(X) STRING_(X) |
|---|
| 65 | #define STRING_(X) #X |
|---|
| 66 | |
|---|
| 67 | #endif /* !USEFUL_H */ |
|---|
