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engines/ultima/nuvie/pathfinder/dir_finder.cpp

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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 "ultima/nuvie/core/nuvie_defs.h"
+#include "ultima/nuvie/misc/u6_misc.h"
+#include "ultima/nuvie/core/map.h"
+#include "ultima/nuvie/pathfinder/dir_finder.h"
+
+namespace Ultima {
+namespace Nuvie {
+
+/** STATIC FUNCTIONS **/
+
+/* From a normalized direction xdir,ydir as base, get the normalized direction
+ * towards one of the seven nearby tiles to the left or right of base.
+ * For rotate: -n = left n tiles, n = right n tiles
+ */
+void DirFinder::get_adjacent_dir(sint8 &xdir, sint8 &ydir, sint8 rotate) {
+	struct {
+		sint8 x, y;
+	} neighbors[8] = { { -1, -1}, { +0, -1}, { +1, -1},
+		{ +1, +0},/*ACTOR*/ { +1, +1},
+		{ +0, +1}, { -1, +1}, { -1, +0}
+	};
+
+	for (uint32 start = 0; start < 8; start++)
+		if (neighbors[start].x == xdir && neighbors[start].y == ydir) {
+			sint32 dest = start + rotate;
+			while (dest < 0 || dest > 7)
+				dest += (dest < 0) ? 8 : -8;
+			xdir = neighbors[dest].x;
+			ydir = neighbors[dest].y;
+			break;
+		}
+}
+
+NuvieDir DirFinder::get_nuvie_dir(sint16 xrel, sint16 yrel) {
+	NuvieDir direction = NUVIE_DIR_N; // default
+
+	if (xrel == 0 && yrel == 0) // nowhere
+		return direction;
+	if (xrel == 0) // up or down
+		direction = (yrel < 0) ? NUVIE_DIR_N : NUVIE_DIR_S;
+	else if (yrel == 0) // left or right
+		direction = (xrel < 0) ? NUVIE_DIR_W : NUVIE_DIR_E;
+	else if (xrel < 0 && yrel < 0)
+		direction = NUVIE_DIR_NW;
+	else if (xrel > 0 && yrel < 0)
+		direction = NUVIE_DIR_NE;
+	else if (xrel < 0 && yrel > 0)
+		direction = NUVIE_DIR_SW;
+	else if (xrel > 0 && yrel > 0)
+		direction = NUVIE_DIR_SE;
+	return direction;
+}
+
+NuvieDir DirFinder::get_nuvie_dir(uint16 sx, uint16 sy, uint16 tx, uint16 ty, uint8 z) {
+	return DirFinder::get_nuvie_dir(get_wrapped_rel_dir(tx, sx, z), get_wrapped_rel_dir(ty, sy, z));
+}
+
+// oxdir = original xdir, txdir = to xdir
+sint8 DirFinder::get_turn_towards_dir(sint16 oxdir, sint16 oydir, sint8 txdir, sint8 tydir) {
+	oxdir = clamp(oxdir, -1, 1);
+	oydir = clamp(oydir, -1, 1);
+	txdir = clamp(txdir, -1, 1);
+	tydir = clamp(tydir, -1, 1);
+	struct {
+		sint8 x, y;
+	} dirs[8] = {{ -1, -1}, { +0, -1}, { +1, -1}, { +1, +0}, { +1, +1}, { +0, +1}, { -1, +1}, { -1, +0}};
+	uint8 t = 0, o = 0;
+	for (uint8 d = 0; d < 8; d++) {
+		if (dirs[d].x == oxdir && dirs[d].y == oydir)
+			o = d;
+		if (dirs[d].x == txdir && dirs[d].y == tydir)
+			t = d;
+	}
+	sint8 turn = t - o;
+	if (turn > 4)
+		turn = -(8 - turn);
+	return clamp(turn, -1, 1);
+}
+
+// xdir,ydir = normal direction from->to (simple method)
+void DirFinder::get_normalized_dir(const MapCoord &from, const MapCoord &to, sint8 &xdir, sint8 &ydir) {
+	xdir = clamp(to.x - from.x, -1, 1);
+	ydir = clamp(to.y - from.y, -1, 1);
+
+	/*    uint16 dx = from.xdistance(to), dy = from.ydistance(to);
+	    if(dx > 0 && dy > 0)
+	    {
+	        if(dx > dy) xdir = 0;
+	        else if(dx < dy) ydir = 0;
+	    }*/
+}
+
+} // End of namespace Nuvie
+} // End of namespace Ultima