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engines/ultima/nuvie/pathfinder/seek_path.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 NUVIE_PATHFINDER_SEEK_PATH_H
+#define NUVIE_PATHFINDER_SEEK_PATH_H
+
+#include "ultima/shared/std/containers.h"
+#include "ultima/nuvie/pathfinder/path.h"
+
+namespace Ultima {
+namespace Nuvie {
+
+/* Provides routines for building short paths around obstacles and seeking a
+ * target. Much of the work doesn't involve finding a path at all, but instead
+ * finding the direction closest to the target.
+ */
+class SeekPath: public Path {
+protected:
+	Std::vector<MapCoord> A_scan, B_scan; // nodes of a line scanned by trace_obstacle()
+
+	void create_path(const MapCoord &start, const MapCoord &goal);
+	Std::vector<MapCoord> *get_best_scan(const MapCoord &start, const MapCoord &goal);
+	void delete_nodes();
+	bool trace_check_obstacle(bool &turned, MapCoord &line, sint32 &deltax, sint32 &deltay, sint32 &xdir, sint32 &ydir, Std::vector<MapCoord> *scan);
+	void trace_around_corner(MapCoord &line, sint32 &deltax, sint32 &deltay, sint32 &xdir, sint32 &ydir, Std::vector<MapCoord> *scan);
+
+public:
+	SeekPath();
+	~SeekPath() override;
+	sint32 step_cost(const MapCoord &c1, const MapCoord &c2) override {
+		return -1;
+	}
+	bool path_search(const MapCoord &start, const MapCoord &goal) override;
+	void delete_path() {
+		Path::delete_path();
+		delete_nodes();
+	}
+
+	/* Trace obstacle towards xdir,ydir for a possible opening. */
+	bool trace_obstacle(MapCoord line, sint32 deltax, sint32 deltay, sint32 xdir, sint32 ydir, Std::vector<MapCoord> *scan);
+	/* Get two relative directions that a line can travel to trace around an
+	   obstacle towards `xdir',`ydir'. */
+	bool get_obstacle_tracer(const MapCoord &start, sint32 xdir, sint32 ydir,
+	                         sint32 &Axdir, sint32 &Aydir,
+	                         sint32 &Bxdir, sint32 &Bydir);
+};
+
+} // End of namespace Nuvie
+} // End of namespace Ultima
+
+#endif