Initial commit

engines/mutationofjb/commands/randomcommand.cpp

@@ -0,0 +1,114 @@
+/* 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/>.
+ *
+ */
+
+#include "mutationofjb/commands/randomcommand.h"
+
+#include "mutationofjb/game.h"
+#include "mutationofjb/script.h"
+#include "common/debug.h"
+#include "common/random.h"
+
+/** @file
+ * "RANDOM " <numChoices>
+ *
+ * RANDOM command randomly picks one of the command blocks that
+ * follow it and jumps to its start.
+ *
+ * These blocks start with "/" and end with "\". The end of a random
+ * block also ends the current section. The number of blocks must
+ * match numChoices.
+ */
+
+namespace MutationOfJB {
+
+bool RandomCommandParser::parse(const Common::String &line, ScriptParseContext &parseCtx, Command *&command) {
+	if (line.size() < 8 || !line.hasPrefix("RANDOM")) {
+		return false;
+	}
+
+	int numChoices = atoi(line.c_str() + 7);
+	if (parseCtx._pendingRandomCommand) {
+		// Nested RANDOM commands are unused and not properly supported by the original game.
+		warning("Ignoring nested RANDOM command.");
+	} else if (numChoices >= 1) {
+		RandomCommand *randomCommand = new RandomCommand(static_cast<uint>(numChoices));
+		parseCtx._pendingRandomCommand = randomCommand;
+		command = randomCommand;
+	} else {
+		warning("Ignoring malformed RANDOM command with %d choices.", numChoices);
+	}
+
+	return true;
+}
+
+
+bool RandomBlockStartParser::parse(const Common::String &line, ScriptParseContext &parseCtx, Command *&) {
+	if (line != "/") {
+		return false;
+	}
+
+	if (!parseCtx._pendingRandomCommand) {
+		warning("Unexpected start of RANDOM block");
+	}
+
+	return true;
+}
+
+void RandomBlockStartParser::transition(ScriptParseContext &parseCtx, Command *, Command *newCommand, CommandParser *) {
+	RandomCommand *randomCommand = parseCtx._pendingRandomCommand;
+	if (newCommand && randomCommand) {
+		randomCommand->_choices.push_back(newCommand);
+
+		if (randomCommand->_choices.size() == randomCommand->_numChoices) {
+			parseCtx._pendingRandomCommand = nullptr;
+		}
+	}
+}
+
+
+RandomCommand::RandomCommand(uint numChoices)
+	: _numChoices(numChoices),
+	  _chosenNext(nullptr) {
+	_choices.reserve(numChoices);
+}
+
+Command::ExecuteResult RandomCommand::execute(ScriptExecutionContext &scriptExecCtx) {
+	assert(!_choices.empty());
+
+	Common::RandomSource &rng = scriptExecCtx.getGame().getRandomSource();
+	uint choice = rng.getRandomNumber(_choices.size() - 1);
+	_chosenNext = _choices[choice];
+	return Finished;
+}
+
+Command *RandomCommand::next() const {
+	return _chosenNext;
+}
+
+Common::String RandomCommand::debugString() const {
+	return Common::String::format("RANDOM %u", _numChoices);
+}
+
+const RandomCommand::Choices &RandomCommand::getChoices() const {
+	return _choices;
+}
+
+}