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engines/ags/engine/ac/route_finder_jps.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/>.
+ *
+ */
+
+#include "common/std/queue.h"
+#include "common/std/vector.h"
+#include "common/std/algorithm.h"
+#include "common/std/functional.h"
+#include "common/std/xutility.h"
+
+// Not all platforms define INFINITY
+#ifndef INFINITY
+#define INFINITY   ((float)(1e+300 * 1e+300)) // This must overflow
+#endif
+
+namespace AGS3 {
+
+// TODO: this could be cleaned up/simplified ...
+
+// further optimizations possible:
+//    - forward refinement should use binary search
+
+class Navigation {
+public:
+	Navigation();
+
+	void Resize(int width, int height);
+
+	enum NavResult {
+		// unreachable
+		NAV_UNREACHABLE,
+		// straight line exists
+		NAV_STRAIGHT,
+		// path used
+		NAV_PATH
+	};
+
+	// ncpath = navpoint-compressed path
+	// opath = path composed of individual grid elements
+	NavResult NavigateRefined(int sx, int sy, int ex, int ey, std::vector<int> &opath,
+	                          std::vector<int> &ncpath);
+
+	NavResult Navigate(int sx, int sy, int ex, int ey, std::vector<int> &opath);
+
+	bool TraceLine(int srcx, int srcy, int targx, int targy, int &lastValidX, int &lastValidY) const;
+	bool TraceLine(int srcx, int srcy, int targx, int targy, std::vector<int> *rpath = nullptr) const;
+
+	inline void SetMapRow(int y, const unsigned char *row) {
+		map[y] = row;
+	}
+
+	static int PackSquare(int x, int y);
+	static void UnpackSquare(int sq, int &x, int &y);
+
+private:
+	// priority queue entry
+	struct Entry {
+		float cost;
+		int index;
+
+		inline Entry() {}
+
+		inline Entry(float ncost, int nindex)
+			: cost(ncost)
+			, index(nindex) {
+		}
+
+		inline bool operator <(const Entry &b) const {
+			return cost < b.cost;
+		}
+
+		inline bool operator >(const Entry &b) const {
+			return cost > b.cost;
+		}
+	};
+
+	int mapWidth;
+	int mapHeight;
+	std::vector<const unsigned char *> map;
+
+	typedef unsigned short tFrameId;
+	typedef int tPrev;
+
+	struct NodeInfo {
+		// quantized min distance from origin
+		unsigned short dist;
+		// frame id (counter to detect new search)
+		tFrameId frameId;
+		// previous node index (packed, relative to current node)
+		tPrev prev;
+
+		inline NodeInfo()
+			: dist(0)
+			, frameId(0)
+			, prev(-1) {
+		}
+	};
+
+	static const float DIST_SCALE_PACK;
+	static const float DIST_SCALE_UNPACK;
+
+	std::vector<NodeInfo> mapNodes;
+	tFrameId frameId;
+
+	std::priority_queue<Entry, std::vector<Entry>, Common::Greater<Entry> > pq;
+
+	// temporary buffers:
+	mutable std::vector<int> fpath;
+	std::vector<int> ncpathIndex;
+	std::vector<int> rayPath, orayPath;
+
+	// temps for routing towards unreachable areas
+	int cnode;
+	int closest;
+
+	// orthogonal only (this should correspond to what AGS is doing)
+	bool nodiag;
+
+	bool navLock;
+
+	void IncFrameId();
+
+	// outside map test
+	inline bool Outside(int x, int y) const;
+	// stronger inside test
+	bool Passable(int x, int y) const;
+	// plain access, unchecked
+	inline bool Walkable(int x, int y) const;
+
+	void AddPruned(int *buf, int &bcount, int x, int y) const;
+	bool HasForcedNeighbor(int x, int y, int dx, int dy) const;
+	int FindJump(int x, int y, int dx, int dy, int ex, int ey);
+	int FindOrthoJump(int x, int y, int dx, int dy, int ex, int ey);
+
+	// neighbor reachable (nodiag only)
+	bool Reachable(int x0, int y0, int x1, int y1) const;
+
+	static inline int sign(int n) {
+		return n < 0 ? -1 : (n > 0 ? 1 : 0);
+	}
+
+	static inline int iabs(int n) {
+		return n < 0 ? -n : n;
+	}
+
+	static inline int iclamp(int v, int min, int max) {
+		return v < min ? min : (v > max ? max : v);
+	}
+
+	static inline int ClosestDist(int dx, int dy) {
+		return dx * dx + dy * dy;
+		// Manhattan?
+		//return iabs(dx) + iabs(dy);
+	}
+};
+
+inline int Navigation::PackSquare(int x, int y) {
+	return (y << 16) + x;
+}
+
+inline void Navigation::UnpackSquare(int sq, int &x, int &y) {
+	y = sq >> 16;
+	x = sq & ((1 << 16) - 1);
+}
+
+inline bool Navigation::Outside(int x, int y) const {
+	return
+	    (unsigned)x >= (unsigned)mapWidth ||
+	    (unsigned)y >= (unsigned)mapHeight;
+}
+
+inline bool Navigation::Walkable(int x, int y) const {
+	// invert condition because of AGS
+	return map[y][x] != 0;
+}
+
+} // namespace AGS3