1 files changed, 125 insertions, 0 deletions
diff --git a/libtiled/gidmapper.cpp b/libtiled/gidmapper.cpp
new file mode 100644
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+++ b/libtiled/gidmapper.cpp
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+/*
+ * gidmapper.cpp
+ * Copyright 2011, Thorbjørn Lindeijer <thorbjorn@lindeijer.nl>
+ *
+ * This file is part of libtiled.
+ *
+ * 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 2 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 "gidmapper.h"
+
+#include "tile.h"
+#include "tileset.h"
+#include "map.h"
+
+using namespace Tiled;
+
+// Bits on the far end of the 32-bit global tile ID are used for tile flags
+const int FlippedHorizontallyFlag   = 0x80000000;
+const int FlippedVerticallyFlag     = 0x40000000;
+const int FlippedAntiDiagonallyFlag = 0x20000000;
+
+GidMapper::GidMapper()
+{
+}
+
+GidMapper::GidMapper(const QList<Tileset *> &tilesets)
+{
+    uint firstGid = 1;
+    foreach (Tileset *tileset, tilesets) {
+        insert(firstGid, tileset);
+        firstGid += tileset->tileCount();
+    }
+}
+
+Cell GidMapper::gidToCell(uint gid, bool &ok) const
+{
+    Cell result;
+
+    // Read out the flags
+    result.flippedHorizontally = (gid & FlippedHorizontallyFlag);
+    result.flippedVertically = (gid & FlippedVerticallyFlag);
+    result.flippedAntiDiagonally = (gid & FlippedAntiDiagonallyFlag);
+
+    // Clear the flags
+    gid &= ~(FlippedHorizontallyFlag |
+             FlippedVerticallyFlag |
+             FlippedAntiDiagonallyFlag);
+
+    if (gid == 0) {
+        ok = true;
+    } else if (isEmpty()) {
+        ok = false;
+    } else {
+        // Find the tileset containing this tile
+        QMap<uint, Tileset*>::const_iterator i = mFirstGidToTileset.upperBound(gid);
+        --i; // Navigate one tileset back since upper bound finds the next
+        int tileId = gid - i.key();
+        const Tileset *tileset = i.value();
+
+        if (tileset) {
+            const int columnCount = mTilesetColumnCounts.value(tileset);
+            if (columnCount > 0 && columnCount != tileset->columnCount()) {
+                // Correct tile index for changes in image width
+                const int row = tileId / columnCount;
+                const int column = tileId % columnCount;
+                tileId = row * tileset->columnCount() + column;
+            }
+
+            result.tile = tileset->tileAt(tileId);
+        } else {
+            result.tile = 0;
+        }
+
+        ok = true;
+    }
+
+    return result;
+}
+
+uint GidMapper::cellToGid(const Cell &cell) const
+{
+    if (cell.isEmpty())
+        return 0;
+
+    const Tileset *tileset = cell.tile->tileset();
+
+    // Find the first GID for the tileset
+    QMap<uint, Tileset*>::const_iterator i = mFirstGidToTileset.begin();
+    QMap<uint, Tileset*>::const_iterator i_end = mFirstGidToTileset.end();
+    while (i != i_end && i.value() != tileset)
+        ++i;
+
+    if (i == i_end) // tileset not found
+        return 0;
+
+    uint gid = i.key() + cell.tile->id();
+    if (cell.flippedHorizontally)
+        gid |= FlippedHorizontallyFlag;
+    if (cell.flippedVertically)
+        gid |= FlippedVerticallyFlag;
+    if (cell.flippedAntiDiagonally)
+        gid |= FlippedAntiDiagonallyFlag;
+
+    return gid;
+}
+
+void GidMapper::setTilesetWidth(const Tileset *tileset, int width)
+{
+    if (tileset->tileWidth() == 0)
+        return;
+
+    mTilesetColumnCounts.insert(tileset, tileset->columnCountForWidth(width));
+}