add options to count metatiles to tileset editor

- count the total number of usages across all maps of specific metatiles
- display the count and/or display unused metatiles
- this does not account for metatiles used in code (most of these are labeled)

include/ui/tileseteditor.h

@@ -75,6 +75,9 @@ private slots:
 
     void on_actionChange_Palettes_triggered();
 
+    void on_actionShow_Unused_toggled(bool checked);
+    void on_actionShow_Counts_toggled(bool checked);
+
     void on_actionUndo_triggered();
 
     void on_actionRedo_triggered();
@@ -119,6 +122,7 @@ private:
     void refresh();
     void saveMetatileLabel();
     void closeEvent(QCloseEvent*);
+    void countMetatileUsage();
 
     Ui::TilesetEditor *ui;
     History<MetatileHistoryItem*> metatileHistory;

include/ui/tileseteditormetatileselector.h

@@ -8,21 +8,20 @@
 class TilesetEditorMetatileSelector: public SelectablePixmapItem {
     Q_OBJECT
 public:
-    TilesetEditorMetatileSelector(Tileset *primaryTileset, Tileset *secondaryTileset, Map *map): SelectablePixmapItem(32, 32, 1, 1) {
-        this->primaryTileset = primaryTileset;
-        this->secondaryTileset = secondaryTileset;
-        this->numMetatilesWide = 8;
-        this->map = map;
-        setAcceptHoverEvents(true);
-    }
+    TilesetEditorMetatileSelector(Tileset *primaryTileset, Tileset *secondaryTileset, Map *map);
     Map *map = nullptr;
     void draw();
     bool select(uint16_t metatileId);
-    void setTilesets(Tileset*, Tileset*);
+    void setTilesets(Tileset*, Tileset*, bool draw = true);
     uint16_t getSelectedMetatile();
     void updateSelectedMetatile();
     QPoint getMetatileIdCoordsOnWidget(uint16_t metatileId);
 
+    // 
+    QVector<uint16_t> usedMetatiles;
+    bool selectorShowUnused = false;
+    bool selectorShowCounts = false;
+
 protected:
     void mousePressEvent(QGraphicsSceneMouseEvent*);
     void mouseMoveEvent(QGraphicsSceneMouseEvent*);
@@ -39,6 +38,10 @@ private:
     QPoint getMetatileIdCoords(uint16_t);
     bool shouldAcceptEvent(QGraphicsSceneMouseEvent*);
 
+    void drawFilters();
+    void drawUnused();
+    void drawCounts();
+
 signals:
     void hoveredMetatileChanged(uint16_t);
     void hoveredMetatileCleared();