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engines/illusions/scriptstack.cpp

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+/* 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 "illusions/illusions.h"
+#include "illusions/scriptstack.h"
+
+namespace Illusions {
+
+// ScriptStack
+
+ScriptStack::ScriptStack() {
+	clear();
+}
+
+void ScriptStack::clear() {
+	for (uint i = 0; i < 256; ++i) {
+		_stack[i] = (int16)0xEEEE;
+	}
+	_stackPos = 256;
+}
+
+void ScriptStack::push(int16 value) {
+	--_stackPos;
+	if (_stackPos > 0)
+		_stack[_stackPos] = value;
+}
+
+int16 ScriptStack::pop() {
+	int16 value = 0;
+	if (_stackPos < 256) {
+		value = _stack[_stackPos];
+		_stack[_stackPos] = (int16)0xEEEE;
+		++_stackPos;
+	}
+	return value;
+}
+
+int16 ScriptStack::peek() {
+	int16 value = 0;
+	if (_stackPos < 256)
+		value = _stack[_stackPos];
+	return value;
+}
+
+int16 *ScriptStack::topPtr() {
+	return &_stack[_stackPos];
+}
+
+} // End of namespace Illusions