1 /* LIBGIMP - The GIMP Library 2 * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball 3 * 4 * gimpmath.h 5 * 6 * This library is free software: you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 3 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library. If not, see 18 * <https://www.gnu.org/licenses/>. 19 */ 20 21 #ifndef __GIMP_MATH_H__ 22 #define __GIMP_MATH_H__ 23 24 25 #include <math.h> 26 27 #ifdef HAVE_IEEEFP_H 28 #include <ieeefp.h> 29 #endif 30 31 #ifdef G_OS_WIN32 32 #include <float.h> 33 #endif 34 35 #define __GIMP_MATH_H_INSIDE__ 36 37 #include <libgimpmath/gimpmathtypes.h> 38 39 #include <libgimpmath/gimpmatrix.h> 40 #include <libgimpmath/gimpmd5.h> 41 #include <libgimpmath/gimpvector.h> 42 43 #undef __GIMP_MATH_H_INSIDE__ 44 45 46 G_BEGIN_DECLS 47 48 49 /** 50 * SECTION: gimpmath 51 * @title: GimpMath 52 * @short_description: Mathematical definitions and macros. 53 * 54 * Mathematical definitions and macros for use both by the GIMP 55 * application and plug-ins. These macros should be used rather than 56 * the ones from <math.h> for enhanced portability. 57 **/ 58 59 60 /** 61 * RINT: 62 * @x: the value to be rounded 63 * 64 * This macro rounds its argument @x to an integer value in floating 65 * point format. Use RINT() instead of rint(). 66 **/ 67 #if defined (HAVE_RINT) && 0 68 /* note: rint() depends on the current floating-point rounding mode. when the 69 * rounding mode is FE_TONEAREST, it, in parctice, breaks ties to even. this 70 * is different from 'floor (x + 0.5)', which breaks ties up. in other words 71 * 'rint (2.5) == 2.0', while 'floor (2.5 + 0.5) == 3.0'. this is asking for 72 * trouble, so let's just use the latter. 73 */ 74 #define RINT(x) rint(x) 75 #else 76 #define RINT(x) floor ((x) + 0.5) 77 #endif 78 79 /** 80 * ROUND: 81 * @x: the value to be rounded. 82 * 83 * This macro rounds its positive argument @x to the nearest integer. 84 **/ 85 #define ROUND(x) ((int) ((x) + 0.5)) 86 87 /** 88 * SIGNED_ROUND: 89 * @x: the value to be rounded. 90 * 91 * This macro rounds its argument @x to the nearest integer. 92 **/ 93 #define SIGNED_ROUND(x) ((int) RINT (x)) 94 95 /** 96 * SQR: 97 * @x: the value to be squared. 98 * 99 * This macro squares its argument @x. 100 **/ 101 #define SQR(x) ((x) * (x)) 102 103 /** 104 * MAX255: 105 * @a: the value to be limited. 106 * 107 * This macro limits it argument @a, an (0-511) int, to 255. 108 **/ 109 #define MAX255(a) ((a) | (((a) & 256) - (((a) & 256) >> 8))) 110 111 /** 112 * CLAMP0255: 113 * @a: the value to be clamped. 114 * 115 * This macro clamps its argument @a, an int32-range int, between 0 116 * and 255 inclusive. 117 **/ 118 #define CLAMP0255(a) CLAMP(a,0,255) 119 120 /** 121 * SAFE_CLAMP: 122 * @x: the value to be limited. 123 * @low: the lower limit. 124 * @high: the upper limit. 125 * 126 * Ensures that @x is between the limits set by @low and @high, 127 * even if @x is NaN. If @low is greater than @high, or if either 128 * of them is NaN, the result is undefined. 129 * 130 * Since: 2.10 131 **/ 132 #define SAFE_CLAMP(x, low, high) ((x) > (low) ? (x) < (high) ? (x) : (high) : (low)) 133 134 /** 135 * gimp_deg_to_rad: 136 * @angle: the angle to be converted. 137 * 138 * This macro converts its argument @angle from degree to radian. 139 **/ 140 #define gimp_deg_to_rad(angle) ((angle) * (2.0 * G_PI) / 360.0) 141 142 /** 143 * gimp_rad_to_deg: 144 * @angle: the angle to be converted. 145 * 146 * This macro converts its argument @angle from radian to degree. 147 **/ 148 #define gimp_rad_to_deg(angle) ((angle) * 360.0 / (2.0 * G_PI)) 149 150 151 G_END_DECLS 152 153 #endif /* __GIMP_MATH_H__ */ 154