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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /xpcom/ds/nsMathUtils.h | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/ds/nsMathUtils.h')
-rw-r--r-- | xpcom/ds/nsMathUtils.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/xpcom/ds/nsMathUtils.h b/xpcom/ds/nsMathUtils.h new file mode 100644 index 000000000..b10b8144e --- /dev/null +++ b/xpcom/ds/nsMathUtils.h @@ -0,0 +1,127 @@ +/* -*- 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 |