Hide connection tiles that cant be seen from current map

include/editor.h

@@ -64,6 +64,7 @@ public:
     void displayMapBorder();
     void displayMapGrid();
     void displayWildMonTables();
+    void maskNonVisibleConnectionTiles();
 
     void updateMapBorder();
     void updateMapConnections();
@@ -109,6 +110,7 @@ public:
     ConnectionPixmapItem* selected_connection_item = nullptr;
     QList<QGraphicsPixmapItem*> connection_items;
     QList<ConnectionPixmapItem*> connection_edit_items;
+    QGraphicsPathItem *connection_mask = nullptr;
     CollisionPixmapItem *collision_item = nullptr;
     QGraphicsItemGroup *events_group = nullptr;
     QList<QGraphicsPixmapItem*> borderItems;

src/editor.cpp

@@ -759,11 +759,13 @@ void Editor::updateCurrentConnectionDirection(QString curDirection) {
     QString originalDirection = selected_connection_item->connection->direction;
     setCurrentConnectionDirection(curDirection);
     updateMirroredConnectionDirection(selected_connection_item->connection, originalDirection);
+    maskNonVisibleConnectionTiles();
 }
 
 void Editor::onConnectionMoved(MapConnection* connection) {
     updateMirroredConnectionOffset(connection);
     onConnectionOffsetChanged(connection->offset.toInt());
+    maskNonVisibleConnectionTiles();
 }
 
 void Editor::onConnectionOffsetChanged(int newOffset) {
@@ -1458,6 +1460,8 @@ void Editor::displayMapConnections() {
     if (!connection_edit_items.empty()) {
         onConnectionItemSelected(connection_edit_items.first());
     }
+
+    maskNonVisibleConnectionTiles();
 }
 
 void Editor::createConnectionItem(MapConnection* connection, bool hide) {
@@ -1502,6 +1506,31 @@ void Editor::createConnectionItem(MapConnection* connection, bool hide) {
     connection_edit_items.append(connection_edit_item);
 }
 
+// Hides connected map tiles that cannot be seen from the current map (beyond BORDER_DISTANCE).
+void Editor::maskNonVisibleConnectionTiles() {
+    if (connection_mask) {
+        if (connection_mask->scene()) {
+            connection_mask->scene()->removeItem(connection_mask);
+        }
+        delete connection_mask;
+    }
+
+    QPainterPath mask;
+    mask.addRect(scene->itemsBoundingRect().toRect());
+    mask.addRect(
+        -BORDER_DISTANCE * 16,
+        -BORDER_DISTANCE * 16,
+        (map->getWidth() + BORDER_DISTANCE * 2) * 16,
+        (map->getHeight() + BORDER_DISTANCE * 2) * 16
+    );
+
+    // Mask the tiles with the current theme's background color.
+    QPen pen(ui->graphicsView_Map->palette().color(QPalette::Base));
+    QBrush brush(ui->graphicsView_Map->palette().color(QPalette::Base));
+
+    connection_mask = scene->addPath(mask, pen, brush);
+}
+
 void Editor::displayMapBorder() {
     for (QGraphicsPixmapItem* item : borderItems) {
         if (item->scene()) {
@@ -1548,6 +1577,8 @@ void Editor::updateMapConnections() {
         connection_edit_items[i]->basePixmap = pixmap;
         connection_edit_items[i]->setPixmap(pixmap);
     }
+
+    maskNonVisibleConnectionTiles();
 }
 
 int Editor::getBorderDrawDistance(int dimension) {
@@ -1604,6 +1635,7 @@ void Editor::updateConnectionOffset(int offset) {
     }
     selected_connection_item->blockSignals(false);
     updateMirroredConnectionOffset(selected_connection_item->connection);
+    maskNonVisibleConnectionTiles();
 }
 
 void Editor::setConnectionMap(QString mapName) {
@@ -1624,6 +1656,7 @@ void Editor::setConnectionMap(QString mapName) {
     selected_connection_item->connection->map_name = mapName;
     setCurrentConnectionDirection(selected_connection_item->connection->direction);
     updateMirroredConnectionMap(selected_connection_item->connection, originalMapName);
+    maskNonVisibleConnectionTiles();
 }
 
 void Editor::addNewConnection() {

src/mainwindow.cpp

@@ -2536,6 +2536,7 @@ void MainWindow::on_actionThemes_triggered()
             QString theme = themeSelector->currentText();
             porymapConfig.setTheme(theme);
             this->setTheme(theme);
+            editor->maskNonVisibleConnectionTiles();
         }
     });
     connect(&buttonBox, SIGNAL(rejected()), &themeSelectorWindow, SLOT(reject()));