/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=8 sts=2 et sw=2 tw=80: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef nsMathUtils_h__ #define nsMathUtils_h__ #include "nscore.h" #include <cmath> #include <float.h> #ifdef SOLARIS #include <ieeefp.h> #endif /* * round */ inline double NS_round(double aNum) { return aNum >= 0.0 ? floor(aNum + 0.5) : ceil(aNum - 0.5); } inline float NS_roundf(float aNum) { return aNum >= 0.0f ? floorf(aNum + 0.5f) : ceilf(aNum - 0.5f); } inline int32_t NS_lround(double aNum) { return aNum >= 0.0 ? int32_t(aNum + 0.5) : int32_t(aNum - 0.5); } /* NS_roundup30 rounds towards infinity for positive and */ /* negative numbers. */ #if defined(XP_WIN32) && defined(_M_IX86) && !defined(__GNUC__) && !defined(__clang__) inline int32_t NS_lroundup30(float x) { /* Code derived from Laurent de Soras' paper at */ /* http://ldesoras.free.fr/doc/articles/rounding_en.pdf */ /* Rounding up on Windows is expensive using the float to */ /* int conversion and the floor function. A faster */ /* approach is to use f87 rounding while assuming the */ /* default rounding mode of rounding to the nearest */ /* integer. This rounding mode, however, actually rounds */ /* to the nearest integer so we add the floating point */ /* number to itself and add our rounding factor before */ /* doing the conversion to an integer. We then do a right */ /* shift of one bit on the integer to divide by two. */ /* This routine doesn't handle numbers larger in magnitude */ /* than 2^30 but this is fine for NSToCoordRound because */ /* Coords are limited to 2^30 in magnitude. */ static const double round_to_nearest = 0.5f; int i; __asm { fld x ; load fp argument fadd st, st(0) ; double it fadd round_to_nearest ; add the rounding factor fistp dword ptr i ; convert the result to int } return i >> 1; /* divide by 2 */ } #endif /* XP_WIN32 && _M_IX86 && !__GNUC__ */ inline int32_t NS_lroundf(float aNum) { return aNum >= 0.0f ? int32_t(aNum + 0.5f) : int32_t(aNum - 0.5f); } /* * hypot. We don't need a super accurate version of this, if a platform * turns up with none of the possibilities below it would be okay to fall * back to sqrt(x*x + y*y). */ inline double NS_hypot(double aNum1, double aNum2) { #ifdef __GNUC__ return __builtin_hypot(aNum1, aNum2); #elif defined _WIN32 return _hypot(aNum1, aNum2); #else return hypot(aNum1, aNum2); #endif } /** * Check whether a floating point number is finite (not +/-infinity and not a * NaN value). */ inline bool NS_finite(double aNum) { #ifdef WIN32 // NOTE: '!!' casts an int to bool without spamming MSVC warning C4800. return !!_finite(aNum); #elif defined(XP_DARWIN) // Darwin has deprecated |finite| and recommends |isfinite|. The former is // not present in the iOS SDK. return std::isfinite(aNum); #else return finite(aNum); #endif } /** * Returns the result of the modulo of x by y using a floored division. * fmod(x, y) is using a truncated division. * The main difference is that the result of this method will have the sign of * y while the result of fmod(x, y) will have the sign of x. */ inline double NS_floorModulo(double aNum1, double aNum2) { return (aNum1 - aNum2 * floor(aNum1 / aNum2)); } #endif