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engines/glk/quest/limit_stack.h

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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/>.
+ *
+ */
+
+#ifndef GLK_QUEST_LIMIT_STACK
+#define GLK_QUEST_LIMIT_STACK
+
+namespace Glk {
+namespace Quest {
+
+template <class T> class LimitStack {
+	uint stack_size, cur_ptr, end_ptr;
+	Common::Array<T> data;
+	//bool last_push;
+
+
+	uint dofwd(uint i) const {
+		i ++;
+		return i == stack_size ? 0 : i;
+	}
+	uint dobwd(uint i) const {
+		return (i == 0 ? stack_size : i) - 1;
+	}
+	void fwd(uint &i) const {
+		i = dofwd(i);
+	}
+	void bwd(uint &i) const {
+		i = dobwd(i);
+	}
+
+	/*
+	void fwd (uint &i) { i ++; if (i == stack_size) i = 0; }
+	void bwd (uint &i) { i = (i == 0 ? stack_size : i) - 1; }
+	uint dofwd (uint i) { uint rv = i; fwd(rv); return rv; }
+	uint dobwd (uint i) { uint rv = i; bwd(rv); return rv; }
+	*/
+
+public:
+	LimitStack(uint maxSize) : stack_size(maxSize), cur_ptr(0), end_ptr(maxSize - 1), data(Common::Array<T> (maxSize)) { }
+
+	void push(T &item) {
+		if (cur_ptr == end_ptr)
+			fwd(end_ptr);
+		data[cur_ptr] = item;
+		fwd(cur_ptr);
+	}
+
+	T &pop() {
+		assert(!is_empty());
+		bwd(cur_ptr);
+		return data[cur_ptr];
+	}
+
+	bool is_empty() {
+		return dobwd(cur_ptr) == end_ptr;
+	}
+
+	uint size() {
+		if (cur_ptr > end_ptr)
+			return cur_ptr - end_ptr - 1;
+		else
+			return (cur_ptr + stack_size) - end_ptr - 1;
+	}
+
+	void dump(Common::WriteStream &o) {
+		o << size() << ": < ";
+		for (uint i = dobwd(cur_ptr); i != end_ptr; bwd(i))
+			o << data[i] << " ";
+		o << ">";
+	}
+
+	T &peek() {
+		return data[dobwd(cur_ptr)];
+	}
+};
+
+template<class T> Common::WriteStream &operator<< (Common::WriteStream &o, LimitStack<T> st) {
+	st.dump(o);
+	return o;
+}
+
+} // End of namespace Quest
+} // End of namespace Glk
+
+#endif