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author | Willem Jan Palenstijn | 2015-07-22 22:37:40 +0200 |
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committer | Willem Jan Palenstijn | 2015-07-22 22:43:42 +0200 |
commit | 6ec9c81b575f13b2c4b30aeac592ebf2557b5890 (patch) | |
tree | 503d50902bad2d800165593039d08d5ccf0c98ab /engines/sword25/util/double_serialization.cpp | |
parent | 5ec05f6b647c5ea41418be7ed19ad381f97cabd8 (diff) | |
parent | 4e5c8d35f7e133e2e72a846fdbd54900c91eeb73 (diff) | |
download | scummvm-rg350-6ec9c81b575f13b2c4b30aeac592ebf2557b5890.tar.gz scummvm-rg350-6ec9c81b575f13b2c4b30aeac592ebf2557b5890.tar.bz2 scummvm-rg350-6ec9c81b575f13b2c4b30aeac592ebf2557b5890.zip |
Merge branch 'master' into mm
Conflicts:
engines/access/access.cpp
engines/access/asurface.h
engines/access/bubble_box.cpp
engines/access/bubble_box.h
engines/access/martian/martian_game.cpp
engines/access/player.cpp
engines/access/player.h
engines/access/resources.cpp
engines/access/screen.cpp
engines/access/screen.h
engines/access/sound.cpp
engines/access/sound.h
Diffstat (limited to 'engines/sword25/util/double_serialization.cpp')
-rw-r--r-- | engines/sword25/util/double_serialization.cpp | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/engines/sword25/util/double_serialization.cpp b/engines/sword25/util/double_serialization.cpp new file mode 100644 index 0000000000..13fa42b6be --- /dev/null +++ b/engines/sword25/util/double_serialization.cpp @@ -0,0 +1,68 @@ +/* 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 2 + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +#include "sword25/util/double_serialization.h" + +#include "common/scummsys.h" + + +namespace Util { + +SerializedDouble encodeDouble(double value) { + // Split the value into its significand and exponent + int exponent; + double significand = frexp(value, &exponent); + + // Shift the the first part of the significand into the integer range + double shiftedsignificandPart = ldexp(fabs(significand), 32); + uint32 significandOne = uint32(floor(shiftedsignificandPart)); + + // Shift the remainder of the significand into the integer range + shiftedsignificandPart -= significandOne; + uint32 significandTwo = (uint32)(ldexp(shiftedsignificandPart, 31)); + + SerializedDouble returnValue; + returnValue.significandOne = significandOne; // SignificandOne + returnValue.signAndSignificandTwo = ((uint32)(value < 0 ? 1 : 0) << 31) | // Sign + significandTwo; // SignificandTwo + returnValue.exponent = (int16)exponent; + return returnValue; +} + +double decodeDouble(SerializedDouble value) { + // Expand the exponent and the parts of the significand + int exponent = (int)value.exponent; + double expandedsignificandOne = (double)value.significandOne; + double expandedsignificandTwo = (double)(value.signAndSignificandTwo & 0x7FFFFFFF); + + // Deflate the significand + double shiftedsignificand = ldexp(expandedsignificandTwo, -21); + double significand = ldexp(expandedsignificandOne + shiftedsignificand, -32); + + // Re-calculate the actual double + double returnValue = ldexp(significand, exponent); + + // Check the sign bit and return + return ((value.signAndSignificandTwo & 0x80000000) == 0x80000000) ? -returnValue : returnValue; +} + +} // End of namespace Sword25 |