Codechange: Make a k-d tree index of stations

1 files changed, 42 insertions, 0 deletions

diff --git a/src/station_kdtree.h b/src/station_kdtree.h
new file mode 100644
index 000000000..321bbacc6
--- /dev/null
+++ b/src/station_kdtree.h
@@ -0,0 +1,42 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD 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, version 2.
+ * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file station_kdtree.h Declarations for accessing the k-d tree of stations */
+
+#ifndef STATION_KDTREE_H
+#define STATION_KDTREE_H
+
+#include "core/kdtree.hpp"
+#include "core/math_func.hpp"
+#include "station_base.h"
+#include "map_func.h"
+
+inline uint16 Kdtree_StationXYFunc(StationID stid, int dim) { return (dim == 0) ? TileX(BaseStation::Get(stid)->xy) : TileY(BaseStation::Get(stid)->xy); }
+typedef Kdtree<StationID, decltype(&Kdtree_StationXYFunc), uint16, int> StationKdtree;
+extern StationKdtree _station_kdtree;
+
+/**
+ * Call a function on all stations whose sign is within a radius of a center tile.
+ * @param center  Central tile to search around.
+ * @param radius  Distance in both X and Y to search within.
+ * @param func    The function to call, must take a single parameter which is Station*.
+ */
+template <typename Func>
+void ForAllStationsRadius(TileIndex center, uint radius, Func func)
+{
+	uint16 x1, y1, x2, y2;
+	x1 = (uint16)max<int>(0, TileX(center) - radius);
+	x2 = (uint16)min<int>(TileX(center) + radius + 1, MapSizeX());
+	y1 = (uint16)max<int>(0, TileY(center) - radius);
+	y2 = (uint16)min<int>(TileY(center) + radius + 1, MapSizeY());
+
+	_station_kdtree.FindContained(x1, y1, x2, y2, [&](StationID id) {
+		func(Station::Get(id));
+	});
+}
+
+#endif