scummvm/common/xpfloat.h

63 lines
2.1 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef COMMON_XPFLOAT_H
#define COMMON_XPFLOAT_H
// 80-bit extended precision floating point
// Mostly encountered stored as data on Apple systems
#include "common/scummsys.h"
namespace Common {
struct XPFloat {
uint16 signAndExponent;
uint64 mantissa;
enum Semantics {
kSemanticsMC68881,
kSemanticsSANE = kSemanticsMC68881,
// Could add Intel 8087 and derivatives here since they're mostly compatible,
// but have different NaN/INF flag cases.
};
XPFloat();
XPFloat(uint16 signAndExponent, uint64 mantissa);
static XPFloat fromDouble(double value, Semantics semantics = kSemanticsMC68881);
static XPFloat fromDoubleBits(uint64 value, Semantics semantics = kSemanticsMC68881);
void toDoubleSafe(double &result, bool &outOverflowed, Semantics semantics = kSemanticsMC68881) const;
void toDoubleBitsSafe(uint64 &result, bool &outOverflowed, Semantics semantics = kSemanticsMC68881) const;
// Simple version that clamps to infinity and warns on overflow
double toDouble(Semantics semantics = kSemanticsMC68881) const;
};
inline XPFloat::XPFloat() : signAndExponent(0), mantissa(0) {}
inline XPFloat::XPFloat(uint16 fSignAndExponent, uint64 fMantissa) : signAndExponent(fSignAndExponent), mantissa(fMantissa) {}
}
#endif