Add: BitmapTileArea and Iterator to handle sparse tile areas.

1 files changed, 120 insertions, 0 deletions

diff --git a/src/bitmap_type.h b/src/bitmap_type.h
new file mode 100644
index 000000000..11a419093
--- /dev/null
+++ b/src/bitmap_type.h
@@ -0,0 +1,120 @@
+/* $Id$ */
+
+/*
+ * 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 bitmap_type.hpp Bitmap functions. */
+
+#ifndef BITMAP_TYPE_HPP
+#define BITMAP_TYPE_HPP
+
+#include <vector>
+
+/** Represents a tile area containing containing individually set tiles.
+ * Each tile must be contained within the preallocated area.
+ * A std::vector<bool> is used to mark which tiles are contained.
+ */
+class BitmapTileArea : public TileArea {
+protected:
+	std::vector<bool> data;
+
+	inline uint Index(uint x, uint y) const { return y * this->w + x; }
+
+	inline uint Index(TileIndex tile) const { return Index(TileX(tile) - TileX(this->tile), TileY(tile) - TileY(this->tile)); }
+
+public:
+	BitmapTileArea()
+	{
+		this->tile = INVALID_TILE;
+		this->w = 0;
+		this->h = 0;
+	}
+
+	/**
+	 * Reset and clear the BitmapTileArea.
+	 */
+	void Reset()
+	{
+		this->tile = INVALID_TILE;
+		this->w = 0;
+		this->h = 0;
+		this->data.clear();
+	}
+
+	/**
+	 * Initialize the BitmapTileArea with the specified Rect.
+	 * @param rect Rect to use.
+	 */
+	void Initialize(Rect r)
+	{
+		this->tile = TileXY(r.left, r.top);
+		this->w = r.right - r.left + 1;
+		this->h = r.bottom - r.top + 1;
+		this->data.clear();
+		this->data.resize(Index(w, h));
+	}
+
+	/**
+	 * Add a tile as part of the tile area.
+	 * @param tile Tile to add.
+	 */
+	inline void SetTile(TileIndex tile)
+	{
+		assert(this->Contains(tile));
+		this->data[Index(tile)] = true;
+	}
+
+	/**
+	 * Clear a tile from the tile area.
+	 * @param tile Tile to clear
+	 */
+	inline void ClrTile(TileIndex tile)
+	{
+		assert(this->Contains(tile));
+		this->data[Index(tile)] = false;
+	}
+
+	/**
+	 * Test if a tile is part of the tile area.
+	 * @param tile Tile to check
+	 */
+	inline bool HasTile(TileIndex tile) const
+	{
+		return this->Contains(tile) && this->data[Index(tile)];
+	}
+};
+
+/** Iterator to iterate over all tiles belonging to a bitmaptilearea. */
+class BitmapTileIterator : public OrthogonalTileIterator {
+protected:
+	const BitmapTileArea *bitmap;
+public:
+	/**
+	 * Construct the iterator.
+	 * @param bitmap BitmapTileArea to iterate.
+	 */
+	BitmapTileIterator(const BitmapTileArea &bitmap) : OrthogonalTileIterator(bitmap), bitmap(&bitmap)
+	{
+		if (!this->bitmap->HasTile(TileIndex(this->tile))) ++(*this);
+	}
+
+	inline TileIterator& operator ++()
+	{
+		(*this).OrthogonalTileIterator::operator++();
+		while (this->tile != INVALID_TILE && !this->bitmap->HasTile(TileIndex(this->tile))) {
+			(*this).OrthogonalTileIterator::operator++();
+		}
+		return *this;
+	}
+
+	virtual TileIterator *Clone() const
+	{
+		return new BitmapTileIterator(*this);
+	}
+};
+
+#endif /* BITMAP_TYPE_HPP */