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engines/stark/movement/shortestpath.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 STARK_MOVEMENT_SHORTEST_PATH_H
+#define STARK_MOVEMENT_SHORTEST_PATH_H
+
+#include "common/list.h"
+#include "common/hashmap.h"
+
+namespace Stark {
+
+namespace Resources {
+class FloorEdge;
+}
+
+/**
+ * Find the shortest path between two nodes in a graph
+ *
+ * This is an implementation of Dijsktra's search algorithm
+ */
+class ShortestPath {
+public:
+	typedef Common::List<const Resources::FloorEdge *> NodeList;
+
+	/** Computes the shortest path between the start and the goal graph nodes */
+	NodeList search(const Resources::FloorEdge *start, const Resources::FloorEdge *goal);
+
+private:
+	typedef Common::HashMap<const Resources::FloorEdge *, const Resources::FloorEdge *> NodePrecedenceMap;
+	typedef Common::HashMap<const Resources::FloorEdge *, float> NodeCostMap;
+
+	const Resources::FloorEdge *popEdgeWithLowestCost(NodeList &frontier, const NodeCostMap &costSoFar) const;
+
+	NodeList rebuildPath(const Resources::FloorEdge *start, const Resources::FloorEdge *goal,
+	                                    const NodePrecedenceMap &cameFrom) const;
+};
+
+} // End of namespace Stark
+
+#endif // STARK_MOVEMENT_SHORTEST_PATH_H