Initial commit

engines/ultima/nuvie/pathfinder/astar_path.h

@@ -0,0 +1,82 @@
+/* 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 NUVIE_PATHFINDER_ASTAR_PATH_H
+#define NUVIE_PATHFINDER_ASTAR_PATH_H
+
+#include "ultima/nuvie/core/map.h"
+#include "ultima/nuvie/pathfinder/path.h"
+
+namespace Ultima {
+namespace Nuvie {
+
+typedef struct astar_node_s {
+	MapCoord loc; // location
+	uint32 to_start; // costs from this node to start and to goal
+	uint32 to_goal;
+	uint32 score; // node score
+	uint32 len; // number of nodes before this one, regardless of score
+	struct astar_node_s *parent;
+	astar_node_s() : loc(0, 0, 0), to_start(0), to_goal(0), score(0), len(0),
+		parent(nullptr) { }
+} astar_node;
+/* Provides A* search and cost methods for PathFinder and subclasses.
+ */class AStarPath: public Path {
+protected:
+	Std::list<astar_node *> open_nodes, closed_nodes; // nodes seen
+	astar_node *final_node; // last node in path search, used by create_path()
+	/* Forms a usable path from results of a search. */
+	void create_path();
+	/* Search routine. */
+	bool search_node_neighbors(astar_node *nnode, const MapCoord &goal, const uint32 max_score);
+	bool compare_neighbors(astar_node *nnode, astar_node *neighbor,
+	                       sint32 nnode_to_neighbor, astar_node *in_open,
+	                       astar_node *in_closed);
+	bool score_to_neighbor(sint8 dir, astar_node *nnode, astar_node *neighbor,
+	                       sint32 &nnode_to_neighbor);
+public:
+	AStarPath();
+	~AStarPath() override { }
+	bool path_search(const MapCoord &start, const MapCoord &goal) override;
+	uint32 path_cost_est(const MapCoord &s, const MapCoord &g) override  {
+		return Path::path_cost_est(s, g);
+	}
+	uint32 get_max_score(uint32 cost) override {
+		return Path::get_max_score(cost);
+	}
+	uint32 path_cost_est(const astar_node &n1, const astar_node &n2) {
+		return Path::path_cost_est(n1.loc, n2.loc);
+	}
+	sint32 step_cost(const MapCoord &c1, const MapCoord &c2) override;
+protected:
+	/* FIXME: These node functions can be replaced with a priority_queue and a list. */
+	astar_node *find_open_node(astar_node *ncmp);
+	void push_open_node(astar_node *node);
+	astar_node *pop_open_node();
+	astar_node *find_closed_node(astar_node *ncmp);
+	void remove_closed_node(astar_node *ncmp);
+	void delete_nodes();
+};
+
+} // End of namespace Nuvie
+} // End of namespace Ultima
+
+#endif