scummvm/engines/mutationofjb/commands/ifcommand.cpp
2018-08-25 23:12:01 +02:00

111 lines
3.2 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 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 "mutationofjb/commands/ifcommand.h"
#include "mutationofjb/gamedata.h"
#include "mutationofjb/script.h"
#include "common/str.h"
#include "common/translation.h"
/** @file
* "IF" <tag> <sceneId> <objectId> <value> ["!"]
*
* IF command compares the value of the WX pseudo-register of the object in the specified scene.
* If the values match, execution continues to the next line.
* Otherwise execution continues after first "#ELSE" or "=ELSE" with the same <tag>.
* The logic can be reversed with exclamation mark at the end.
*
* <tag> is always 1 character long, <sceneId> and <objectId> 2 characters long.
*
* Please note that this does not work like you are used to from saner languages.
* IF does not have any blocks. It only searches for first #ELSE, so you can have stuff like:
* IF something
* IF something else
* #ELSE
* ...
* This is effectively logical AND.
*/
namespace MutationOfJB {
bool IfCommandParser::parse(const Common::String &line, ScriptParseContext &, Command *&command) {
// IFtss oo val!
// <t> 1B Tag.
// <ss> 2B Scene.
// <oo> 2B Object ID.
// <val> VL Value.
// ! 1B Negation (optional).
if (line.size() < 10) {
return false;
}
if (!line.hasPrefix("IF")) {
return false;
}
const char *const cstr = line.c_str();
const char tag = cstr[2] == ' ' ? 0 : cstr[2];
const uint8 sceneId = atoi(cstr + 3);
const uint8 objectId = atoi(cstr + 6);
const uint8 value = atoi(cstr + 9);
const bool negative = (line.lastChar() == '!');
_lastTag = tag;
command = new IfCommand(sceneId, objectId, value, negative);
return true;
}
IfCommand::IfCommand(uint8 sceneId, uint8 objectId, uint16 value, bool negative) :
_sceneId(sceneId),
_objectId(objectId),
_value(value),
_negative(negative)
{}
Command::ExecuteResult IfCommand::execute(ScriptExecutionContext &scriptExecCtx) {
Scene *const scene = scriptExecCtx.getGameData().getScene(_sceneId);
if (!scene) {
return Finished;
}
Object *const object = scene->getObject(_objectId);
if (!object) {
return Finished;
}
_cachedResult = (object->_WX == _value);
if (_negative) {
_cachedResult = !_cachedResult;
}
return Finished;
}
Common::String IfCommand::debugString() const {
return Common::String::format("IF scene%d.object%d.WX %s %d", _sceneId, _objectId, _negative ? "!=" : "==", _value);
}
}