| /*------------------------------------------------------------------------- |
| * drawElements Base Portability Library |
| * ------------------------------------- |
| * |
| * Copyright 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| *//*! |
| * \file |
| * \brief Basic mathematical operations. |
| *//*--------------------------------------------------------------------*/ |
| |
| #include "deMath.h" |
| |
| #if (DE_COMPILER == DE_COMPILER_MSC) |
| # include <float.h> |
| #endif |
| |
| #if (DE_COMPILER == DE_COMPILER_GCC) || (DE_COMPILER == DE_COMPILER_CLANG) |
| # include <fenv.h> |
| #endif |
| |
| deRoundingMode deGetRoundingMode (void) |
| { |
| #if (DE_COMPILER == DE_COMPILER_MSC) |
| unsigned int status = 0; |
| int ret; |
| |
| ret = _controlfp_s(&status, 0, 0); |
| DE_ASSERT(ret == 0); |
| |
| switch (status & _MCW_RC) |
| { |
| case _RC_CHOP: return DE_ROUNDINGMODE_TO_ZERO; |
| case _RC_UP: return DE_ROUNDINGMODE_TO_POSITIVE_INF; |
| case _RC_DOWN: return DE_ROUNDINGMODE_TO_NEGATIVE_INF; |
| case _RC_NEAR: return DE_ROUNDINGMODE_TO_NEAREST; |
| default: return DE_ROUNDINGMODE_LAST; |
| } |
| #elif (DE_COMPILER == DE_COMPILER_GCC) || (DE_COMPILER == DE_COMPILER_CLANG) |
| int mode = fegetround(); |
| switch (mode) |
| { |
| case FE_TOWARDZERO: return DE_ROUNDINGMODE_TO_ZERO; |
| case FE_UPWARD: return DE_ROUNDINGMODE_TO_POSITIVE_INF; |
| case FE_DOWNWARD: return DE_ROUNDINGMODE_TO_NEGATIVE_INF; |
| case FE_TONEAREST: return DE_ROUNDINGMODE_TO_NEAREST; |
| default: return DE_ROUNDINGMODE_LAST; |
| } |
| #else |
| # error Implement deGetRoundingMode(). |
| #endif |
| } |
| |
| deBool deSetRoundingMode (deRoundingMode mode) |
| { |
| #if (DE_COMPILER == DE_COMPILER_MSC) |
| unsigned int flag = 0; |
| unsigned int oldState; |
| int ret; |
| |
| switch (mode) |
| { |
| case DE_ROUNDINGMODE_TO_ZERO: flag = _RC_CHOP; break; |
| case DE_ROUNDINGMODE_TO_POSITIVE_INF: flag = _RC_UP; break; |
| case DE_ROUNDINGMODE_TO_NEGATIVE_INF: flag = _RC_DOWN; break; |
| case DE_ROUNDINGMODE_TO_NEAREST: flag = _RC_NEAR; break; |
| default: |
| DE_ASSERT(DE_FALSE); |
| } |
| |
| ret = _controlfp_s(&oldState, flag, _MCW_RC); |
| return ret == 0; |
| #elif (DE_COMPILER == DE_COMPILER_GCC) || (DE_COMPILER == DE_COMPILER_CLANG) |
| int flag = 0; |
| int ret; |
| |
| switch (mode) |
| { |
| case DE_ROUNDINGMODE_TO_ZERO: flag = FE_TOWARDZERO; break; |
| case DE_ROUNDINGMODE_TO_POSITIVE_INF: flag = FE_UPWARD; break; |
| case DE_ROUNDINGMODE_TO_NEGATIVE_INF: flag = FE_DOWNWARD; break; |
| case DE_ROUNDINGMODE_TO_NEAREST: flag = FE_TONEAREST; break; |
| default: |
| DE_ASSERT(DE_FALSE); |
| } |
| |
| ret = fesetround(flag); |
| return ret == 0; |
| #else |
| # error Implement deSetRoundingMode(). |
| #endif |
| } |
| |
| double deFractExp (double x, int* exponent) |
| { |
| if (deIsInf(x)) |
| { |
| *exponent = 0; |
| return x; |
| } |
| else |
| { |
| int tmpExp = 0; |
| double fract = frexp(x, &tmpExp); |
| *exponent = tmpExp - 1; |
| return fract * 2.0; |
| } |
| } |
| |
| /* We could use frexpf, if available. */ |
| float deFloatFractExp (float x, int* exponent) |
| { |
| return (float)deFractExp(x, exponent); |
| } |
| |
| double deRoundEven (double a) |
| { |
| double integer; |
| double fract = modf(a, &integer); |
| if (fabs(fract) == 0.5) |
| return 2.0 * deRound(a / 2.0); |
| return deRound(a); |
| } |