Implement object selection rectangle functionality in DungeonEditor

- Added methods for object selection rectangle handling, including CheckForObjectSelection, DrawObjectSelectRect, and SelectObjectsInRect.
- Enhanced DungeonEditor to support right-click drag selection for multiple objects, improving user interaction and object management.
- Updated the UI in DungeonObjectSelector to optimize object previews and improve layout for better visibility.
- Refactored various sections of DungeonEditor for code clarity and consistency, including adjustments to object rendering and selection processes.

src/app/editor/dungeon/dungeon_editor.cc

@@ -100,7 +100,8 @@ absl::Status DungeonEditor::Load() {
   room_selector_.set_rooms(&rooms_);
   room_selector_.set_entrances(&entrances_);
   room_selector_.set_active_rooms(active_rooms_);
-  room_selector_.set_room_selected_callback([this](int room_id) { OnRoomSelected(room_id); });
+  room_selector_.set_room_selected_callback(
+      [this](int room_id) { OnRoomSelected(room_id); });
 
   canvas_viewer_.SetRom(rom_);
   canvas_viewer_.SetRooms(&rooms_);
@@ -115,10 +116,12 @@ absl::Status DungeonEditor::Load() {
   object_selector_.set_rooms(&rooms_);
 
   // Set up object selection callback
-  object_selector_.SetObjectSelectedCallback([this](const zelda3::RoomObject& object) {
+  object_selector_.SetObjectSelectedCallback(
+      [this](const zelda3::RoomObject& object) {
         preview_object_ = object;
         object_loaded_ = true;
-    placement_type_ = kObject; // Automatically switch to object placement mode
+        placement_type_ =
+            kObject;  // Automatically switch to object placement mode
       });
 
   is_loaded_ = true;
@@ -131,20 +134,7 @@ absl::Status DungeonEditor::Update() {
     refresh_graphics_ = false;
   }
 
-  if (ImGui::BeginTabBar("##DungeonEditorTabBar")) {
-    if (ImGui::BeginTabItem("Room Editor")) {
   status_ = UpdateDungeonRoomView();
-      ImGui::EndTabItem();
-    }
-    
-    if (ImGui::BeginTabItem("Usage Statistics")) {
-      if (is_loaded_) {
-        DrawUsageStats();
-      }
-      ImGui::EndTabItem();
-    }
-    ImGui::EndTabBar();
-  }
 
   return absl::OkStatus();
 }
@@ -191,13 +181,13 @@ absl::Status DungeonEditor::RefreshGraphics() {
 
 void DungeonEditor::LoadDungeonRoomSize() {
   std::map<int, std::vector<int>> rooms_by_bank;
-  for (const auto &room : room_size_addresses_) {
+  for (const auto& room : room_size_addresses_) {
     int bank = room.second >> 16;
     rooms_by_bank[bank].push_back(room.second);
   }
 
   // Process and calculate room sizes within each bank
-  for (auto &bank_rooms : rooms_by_bank) {
+  for (auto& bank_rooms : rooms_by_bank) {
     // Sort the rooms within this bank
     std::ranges::sort(bank_rooms.second);
 
@@ -207,7 +197,7 @@ void DungeonEditor::LoadDungeonRoomSize() {
       // Identify the room ID for the current room pointer
       int room_id =
           std::ranges::find_if(room_size_addresses_, [room_ptr](
-                                                         const auto &entry) {
+                                                         const auto& entry) {
             return entry.second == room_ptr;
           })->first;
 
@@ -244,9 +234,11 @@ absl::Status DungeonEditor::UpdateDungeonRoomView() {
 
   // Correct 3-column layout as specified
   if (BeginTable("#DungeonEditTable", 3, kDungeonTableFlags, ImVec2(0, 0))) {
-    TableSetupColumn("Room/Entrance Selector", ImGuiTableColumnFlags_WidthFixed, 250);
+    TableSetupColumn("Room/Entrance Selector", ImGuiTableColumnFlags_WidthFixed,
+                     250);
     TableSetupColumn("Canvas & Properties", ImGuiTableColumnFlags_WidthStretch);
-    TableSetupColumn("Object Selector/Editor", ImGuiTableColumnFlags_WidthFixed, 300);
+    TableSetupColumn("Object Selector/Editor", ImGuiTableColumnFlags_WidthFixed,
+                     300);
     TableHeadersRow();
     TableNextRow();
 
@@ -296,12 +288,12 @@ void DungeonEditor::OnRoomSelected(int room_id) {
 void DungeonEditor::DrawToolset() {
   if (BeginTable("DWToolset", 16, ImGuiTableFlags_SizingFixedFit,
                  ImVec2(0, 0))) {
-    static std::array<const char *, 16> tool_names = {
+    static std::array<const char*, 16> tool_names = {
         "Undo", "Redo",      "Separator", "Any",    "BG1",  "BG2",
         "BG3",  "Separator", "Object",    "Sprite", "Item", "Entrance",
         "Door", "Chest",     "Block",     "Palette"};
     std::ranges::for_each(tool_names,
-                          [](const char *name) { TableSetupColumn(name); });
+                          [](const char* name) { TableSetupColumn(name); });
 
     TableNextColumn();
     if (Button(ICON_MD_UNDO)) {
@@ -416,7 +408,26 @@ void DungeonEditor::DrawToolset() {
   }
 
   ImGui::Separator();
-  ImGui::Text("Instructions: Click to place objects, Ctrl+Click to select, drag to move");
+  ImGui::Text(
+      "Instructions: Click to place objects, Ctrl+Click to select, drag to "
+      "move");
+
+  ImGui::SameLine();
+  // Usage statistics as a popup to save space
+  if (ImGui::Button("Usage Statistics")) {
+    ImGui::OpenPopup("UsageStatsPopup");
+  }
+
+  if (ImGui::BeginPopupModal("UsageStatsPopup", nullptr,
+                             ImGuiWindowFlags_AlwaysAutoResize)) {
+    if (is_loaded_) {
+      DrawUsageStats();
+    }
+    if (ImGui::Button("Close")) {
+      ImGui::CloseCurrentPopup();
+    }
+    ImGui::EndPopup();
+  }
 }
 
 void DungeonEditor::DrawCanvasAndPropertiesPanel() {
@@ -441,7 +452,8 @@ void DungeonEditor::DrawCanvasAndPropertiesPanel() {
 
       // Quick room info display
       int current_room = current_room_id_;
-      if (!active_rooms_.empty() && current_active_room_tab_ < active_rooms_.Size) {
+      if (!active_rooms_.empty() &&
+          current_active_room_tab_ < active_rooms_.Size) {
         current_room = active_rooms_[current_active_room_tab_];
       }
 
@@ -453,6 +465,16 @@ void DungeonEditor::DrawCanvasAndPropertiesPanel() {
         ImGui::Text("Sprites: %zu", room.GetSprites().size());
         ImGui::Text("Chests: %zu", room.GetChests().size());
 
+        // Selection info
+        if (!selected_object_indices_.empty()) {
+          ImGui::Separator();
+          ImGui::Text("Selected Objects: %zu", selected_object_indices_.size());
+          if (ImGui::Button("Clear Selection")) {
+            selected_object_indices_.clear();
+            object_select_active_ = false;
+          }
+        }
+
         ImGui::Separator();
 
         // Quick edit controls
@@ -490,42 +512,59 @@ void DungeonEditor::DrawRoomPropertiesDebugPopup() {
   ImGui::Separator();
 
   // Room properties table
-  if (ImGui::BeginTable("RoomPropertiesPopup", 2, ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg)) {
+  if (ImGui::BeginTable("RoomPropertiesPopup", 2,
+                        ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg)) {
     ImGui::TableSetupColumn("Property", ImGuiTableColumnFlags_WidthFixed, 120);
     ImGui::TableSetupColumn("Value", ImGuiTableColumnFlags_WidthStretch);
     ImGui::TableHeadersRow();
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Room ID");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); ImGui::Text("%03X (%d)", current_room, current_room);
+    ImGui::Text("Room ID");
+    ImGui::TableNextColumn();
+    ImGui::Text("%03X (%d)", current_room, current_room);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Layout");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##layout", &room.layout);
+    ImGui::Text("Layout");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##layout", &room.layout);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Blockset");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##blockset", &room.blockset);
+    ImGui::Text("Blockset");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##blockset", &room.blockset);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Spriteset");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##spriteset", &room.spriteset);
+    ImGui::Text("Spriteset");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##spriteset", &room.spriteset);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Palette");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##palette", &room.palette);
+    ImGui::Text("Palette");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##palette", &room.palette);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Floor 1");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##floor1", &room.floor1);
+    ImGui::Text("Floor 1");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##floor1", &room.floor1);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Floor 2");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexByte("##floor2", &room.floor2);
+    ImGui::Text("Floor 2");
+    ImGui::TableNextColumn();
+    gui::InputHexByte("##floor2", &room.floor2);
 
     ImGui::TableNextRow();
-    ImGui::TableNextColumn(); ImGui::Text("Message ID");
+    ImGui::TableNextColumn();
-    ImGui::TableNextColumn(); gui::InputHexWord("##message_id", &room.message_id_);
+    ImGui::Text("Message ID");
+    ImGui::TableNextColumn();
+    gui::InputHexWord("##message_id", &room.message_id_);
 
     ImGui::EndTable();
   }
@@ -554,7 +593,6 @@ void DungeonEditor::DrawRoomPropertiesDebugPopup() {
   }
 }
 
-
 void DungeonEditor::DrawDungeonTabView() {
   static int next_tab_id = 0;
 
@@ -649,7 +687,8 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
     show_debug_popup = false;
   }
 
-  if (ImGui::BeginPopupModal("Room Debug Info", nullptr, ImGuiWindowFlags_AlwaysAutoResize)) {
+  if (ImGui::BeginPopupModal("Room Debug Info", nullptr,
+                             ImGuiWindowFlags_AlwaysAutoResize)) {
     static bool show_objects = false;
     ImGui::Checkbox("Show Object Outlines", &show_objects);
 
@@ -675,21 +714,23 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
     ImGui::Text("Objects: %zu", rooms_[room_id].GetTileObjects().size());
     ImGui::Text("Layout Objects: %zu",
                 rooms_[room_id].GetLayout().GetObjects().size());
-    ImGui::Text("Sprites: %llu", static_cast<unsigned long long>(rooms_[room_id].GetSprites().size()));
+    ImGui::Text("Sprites: %llu", static_cast<unsigned long long>(
+                                     rooms_[room_id].GetSprites().size()));
     ImGui::Text("Chests: %zu", rooms_[room_id].GetChests().size());
 
     // Palette information
-    ImGui::Text("Current Palette Group: %llu", static_cast<unsigned long long>(current_palette_group_id_));
+    ImGui::Text("Current Palette Group: %llu",
+                static_cast<unsigned long long>(current_palette_group_id_));
     ImGui::Text("Palette Hash: %#016llx", last_palette_hash_);
 
     // Object type breakdown
     ImGui::Separator();
     ImGui::Text("Object Type Breakdown:");
     std::map<int, int> object_type_counts;
-    for (const auto &obj : rooms_[room_id].GetTileObjects()) {
+    for (const auto& obj : rooms_[room_id].GetTileObjects()) {
       object_type_counts[obj.id_]++;
     }
-    for (const auto &[type, count] : object_type_counts) {
+    for (const auto& [type, count] : object_type_counts) {
       ImGui::Text("Type 0x%02X: %d objects", type, count);
     }
 
@@ -719,7 +760,7 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
 
     if (selected_object_id >= 0 &&
         selected_object_id < (int)rooms_[room_id].GetTileObjects().size()) {
-      const auto &selected_obj =
+      const auto& selected_obj =
           rooms_[room_id].GetTileObjects()[selected_object_id];
       ImGui::Separator();
       ImGui::Text("Selected Object:");
@@ -750,6 +791,9 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
   canvas_.DrawBackground();
   canvas_.DrawContextMenu();
 
+  // Handle object selection and placement
+  CheckForObjectSelection();
+
   // Handle mouse input for drag and select functionality
   HandleCanvasMouseInput();
 
@@ -758,11 +802,11 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
     const ImGuiIO& io = ImGui::GetIO();
     ImVec2 mouse_pos = io.MousePos;
     ImVec2 canvas_pos = canvas_.zero_point();
-    ImVec2 canvas_mouse_pos = ImVec2(mouse_pos.x - canvas_pos.x, mouse_pos.y - canvas_pos.y);
+    ImVec2 canvas_mouse_pos =
-    auto [room_x, room_y] = CanvasToRoomCoordinates(
+        ImVec2(mouse_pos.x - canvas_pos.x, mouse_pos.y - canvas_pos.y);
-      static_cast<int>(canvas_mouse_pos.x), 
+    auto [room_x, room_y] =
-      static_cast<int>(canvas_mouse_pos.y)
+        CanvasToRoomCoordinates(static_cast<int>(canvas_mouse_pos.x),
-    );
+                                static_cast<int>(canvas_mouse_pos.y));
     preview_object_.x_ = room_x;
     preview_object_.y_ = room_y;
   }
@@ -798,8 +842,8 @@ void DungeonEditor::DrawDungeonCanvas(int room_id) {
   canvas_.DrawOverlay();
 }
 
-void DungeonEditor::RenderObjectInCanvas(const zelda3::RoomObject &object,
+void DungeonEditor::RenderObjectInCanvas(const zelda3::RoomObject& object,
-                                         const gfx::SnesPalette &palette) {
+                                         const gfx::SnesPalette& palette) {
   // Validate ROM is loaded
   if (!rom_ || !rom_->is_loaded()) {
     return;
@@ -831,7 +875,7 @@ void DungeonEditor::RenderObjectInCanvas(const zelda3::RoomObject &object,
   }
 
   // Check cache first
-  for (auto &cached : object_render_cache_) {
+  for (auto& cached : object_render_cache_) {
     if (cached.object_id == object.id_ && cached.object_x == object.x_ &&
         cached.object_y == object.y_ && cached.object_size == object.size_ &&
         cached.palette_hash == palette_hash && cached.is_valid) {
@@ -876,7 +920,7 @@ void DungeonEditor::RenderObjectInCanvas(const zelda3::RoomObject &object,
   object_render_cache_.push_back(std::move(cache_entry));
 }
 
-void DungeonEditor::DisplayObjectInfo(const zelda3::RoomObject &object,
+void DungeonEditor::DisplayObjectInfo(const zelda3::RoomObject& object,
                                       int canvas_x, int canvas_y) {
   // Display object information as text overlay
   std::string info_text = absl::StrFormat("ID:%d X:%d Y:%d S:%d", object.id_,
@@ -886,12 +930,12 @@ void DungeonEditor::DisplayObjectInfo(const zelda3::RoomObject &object,
   canvas_.DrawText(info_text, canvas_x, canvas_y - 12);
 }
 
-void DungeonEditor::RenderLayoutObjects(const zelda3::RoomLayout &layout,
+void DungeonEditor::RenderLayoutObjects(const zelda3::RoomLayout& layout,
-                                        const gfx::SnesPalette &palette) {
+                                        const gfx::SnesPalette& palette) {
   // Render layout objects (walls, floors, etc.) as simple colored rectangles
   // This provides a visual representation of the room's structure
 
-  for (const auto &layout_obj : layout.GetObjects()) {
+  for (const auto& layout_obj : layout.GetObjects()) {
     // Convert room coordinates to canvas coordinates using helper function
     auto [canvas_x, canvas_y] =
         RoomToCanvasCoordinates(layout_obj.x(), layout_obj.y());
@@ -942,15 +986,16 @@ void DungeonEditor::RenderLayoutObjects(const zelda3::RoomLayout &layout,
 std::pair<int, int> DungeonEditor::RoomToCanvasCoordinates(int room_x,
                                                            int room_y) const {
   // Convert room coordinates (16x16 tile units) to canvas coordinates (pixels)
-  // Note: The canvas applies global_scale_ and scrolling internally, so we return
+  // Note: The canvas applies global_scale_ and scrolling internally, so we
-  // the base coordinates and let the canvas handle the transformation
+  // return the base coordinates and let the canvas handle the transformation
   return {room_x * 16, room_y * 16};
 }
 
 std::pair<int, int> DungeonEditor::CanvasToRoomCoordinates(int canvas_x,
                                                            int canvas_y) const {
   // Convert canvas coordinates (pixels) to room coordinates (16x16 tile units)
-  // Note: This assumes the canvas coordinates are already adjusted for scaling and scrolling
+  // Note: This assumes the canvas coordinates are already adjusted for scaling
+  // and scrolling
   return {canvas_x / 16, canvas_y / 16};
 }
 
@@ -990,9 +1035,12 @@ absl::Status DungeonEditor::LoadAndRenderRoomGraphics(int room_id) {
     auto palette_id = rom()->ReadWord(0xDEC4B + dungeon_palette_ptr);
     if (palette_id.ok()) {
       current_palette_group_id_ = palette_id.value() / 180;
-      if (current_palette_group_id_ < rom()->palette_group().dungeon_main.size()) {
+      if (current_palette_group_id_ <
-        full_palette_ = rom()->palette_group().dungeon_main[current_palette_group_id_];
+          rom()->palette_group().dungeon_main.size()) {
-        ASSIGN_OR_RETURN(current_palette_group_,
+        full_palette_ =
+            rom()->palette_group().dungeon_main[current_palette_group_id_];
+        ASSIGN_OR_RETURN(
+            current_palette_group_,
             gfx::CreatePaletteGroupFromLargePalette(full_palette_));
       }
     }
@@ -1037,7 +1085,8 @@ void DungeonEditor::RenderRoomBackgroundLayers(int room_id) {
 
   // BG1 (background layer 1) - room graphics
   auto& bg1_bitmap = gfx::Arena::Get().bg1().bitmap();
-  if (bg1_bitmap.is_active() && bg1_bitmap.width() > 0 && bg1_bitmap.height() > 0) {
+  if (bg1_bitmap.is_active() && bg1_bitmap.width() > 0 &&
+      bg1_bitmap.height() > 0) {
     // Scale the background to fit the canvas
     float scale_x = static_cast<float>(canvas_width) / bg1_bitmap.width();
     float scale_y = static_cast<float>(canvas_height) / bg1_bitmap.height();
@@ -1053,7 +1102,8 @@ void DungeonEditor::RenderRoomBackgroundLayers(int room_id) {
 
   // BG2 (background layer 2) - sprite graphics (overlay)
   auto& bg2_bitmap = gfx::Arena::Get().bg2().bitmap();
-  if (bg2_bitmap.is_active() && bg2_bitmap.width() > 0 && bg2_bitmap.height() > 0) {
+  if (bg2_bitmap.is_active() && bg2_bitmap.width() > 0 &&
+      bg2_bitmap.height() > 0) {
     // Scale the background to fit the canvas
     float scale_x = static_cast<float>(canvas_width) / bg2_bitmap.width();
     float scale_y = static_cast<float>(canvas_height) / bg2_bitmap.height();
@@ -1064,12 +1114,13 @@ void DungeonEditor::RenderRoomBackgroundLayers(int room_id) {
     int offset_x = (canvas_width - scaled_width) / 2;
     int offset_y = (canvas_height - scaled_height) / 2;
 
-    canvas_.DrawBitmap(bg2_bitmap, offset_x, offset_y, scale, 200); // Semi-transparent overlay
+    canvas_.DrawBitmap(bg2_bitmap, offset_x, offset_y, scale,
+                       200);  // Semi-transparent overlay
   }
 }
 
 void DungeonEditor::CalculateUsageStats() {
-  for (const auto &room : rooms_) {
+  for (const auto& room : rooms_) {
     if (blockset_usage_.find(room.blockset) == blockset_usage_.end()) {
       blockset_usage_[room.blockset] = 1;
     } else {
@@ -1124,11 +1175,13 @@ void DungeonEditor::HandleCanvasMouseInput() {
   ImVec2 canvas_size = canvas_.canvas_size();
 
   // Convert to canvas coordinates
-  ImVec2 canvas_mouse_pos = ImVec2(mouse_pos.x - canvas_pos.x, mouse_pos.y - canvas_pos.y);
+  ImVec2 canvas_mouse_pos =
+      ImVec2(mouse_pos.x - canvas_pos.x, mouse_pos.y - canvas_pos.y);
 
   // Handle mouse clicks
   if (ImGui::IsMouseClicked(ImGuiMouseButton_Left)) {
-    if (ImGui::IsKeyDown(ImGuiKey_LeftCtrl) || ImGui::IsKeyDown(ImGuiKey_RightCtrl)) {
+    if (ImGui::IsKeyDown(ImGuiKey_LeftCtrl) ||
+        ImGui::IsKeyDown(ImGuiKey_RightCtrl)) {
       // Start selection box
       is_selecting_ = true;
       select_start_pos_ = canvas_mouse_pos;
@@ -1138,10 +1191,9 @@ void DungeonEditor::HandleCanvasMouseInput() {
       // Start dragging or place object
       if (object_loaded_) {
         // Convert canvas coordinates to room coordinates
-        auto [room_x, room_y] = CanvasToRoomCoordinates(
+        auto [room_x, room_y] =
-          static_cast<int>(canvas_mouse_pos.x), 
+            CanvasToRoomCoordinates(static_cast<int>(canvas_mouse_pos.x),
-          static_cast<int>(canvas_mouse_pos.y)
+                                    static_cast<int>(canvas_mouse_pos.y));
-        );
         PlaceObjectAtPosition(room_x, room_y);
       } else {
         // Start dragging existing objects
@@ -1185,12 +1237,10 @@ void DungeonEditor::DrawSelectBox() {
   // Calculate select box bounds
   ImVec2 start = ImVec2(
       canvas_pos.x + std::min(select_start_pos_.x, select_current_pos_.x),
-    canvas_pos.y + std::min(select_start_pos_.y, select_current_pos_.y)
+      canvas_pos.y + std::min(select_start_pos_.y, select_current_pos_.y));
-  );
   ImVec2 end = ImVec2(
       canvas_pos.x + std::max(select_start_pos_.x, select_current_pos_.x),
-    canvas_pos.y + std::max(select_start_pos_.y, select_current_pos_.y)
+      canvas_pos.y + std::max(select_start_pos_.y, select_current_pos_.y));
-  );
 
   // Draw selection box
   draw_list->AddRect(start, end, IM_COL32(255, 255, 0, 255), 0.0f, 0, 2.0f);
@@ -1203,15 +1253,14 @@ void DungeonEditor::DrawDragPreview() {
   // Draw drag preview for selected objects
   ImDrawList* draw_list = ImGui::GetWindowDrawList();
   ImVec2 canvas_pos = canvas_.zero_point();
-  ImVec2 drag_delta = ImVec2(
+  ImVec2 drag_delta = ImVec2(drag_current_pos_.x - drag_start_pos_.x,
-    drag_current_pos_.x - drag_start_pos_.x,
+                             drag_current_pos_.y - drag_start_pos_.y);
-    drag_current_pos_.y - drag_start_pos_.y
-  );
 
   // Draw preview of where objects would be moved
   for (int obj_id : selected_objects_) {
     // TODO: Draw preview of object at new position
-    // This would require getting the object's current position and drawing it offset by drag_delta
+    // This would require getting the object's current position and drawing it
+    // offset by drag_delta
   }
 }
 
@@ -1238,7 +1287,8 @@ void DungeonEditor::UpdateSelectedObjects() {
   }
 }
 
-bool DungeonEditor::IsObjectInSelectBox(const zelda3::RoomObject& object) const {
+bool DungeonEditor::IsObjectInSelectBox(
+    const zelda3::RoomObject& object) const {
   if (!is_selecting_) return false;
 
   // Convert object position to canvas coordinates
@@ -1251,8 +1301,8 @@ bool DungeonEditor::IsObjectInSelectBox(const zelda3::RoomObject& object) const
   float max_y = std::max(select_start_pos_.y, select_current_pos_.y);
 
   // Check if object is within select box
-  return (canvas_x >= min_x && canvas_x <= max_x && 
+  return (canvas_x >= min_x && canvas_x <= max_x && canvas_y >= min_y &&
-          canvas_y >= min_y && canvas_y <= max_y);
+          canvas_y <= max_y);
 }
 
 void DungeonEditor::PlaceObjectAtPosition(int room_x, int room_y) {
@@ -1284,4 +1334,110 @@ void DungeonEditor::PlaceObjectAtPosition(int room_x, int room_y) {
   object_selector_.set_current_room_id(current_room);
 }
 
+void DungeonEditor::CheckForObjectSelection() {
+  // Draw object selection rectangle similar to OverworldEditor
+  DrawObjectSelectRect();
+
+  // Handle object selection when rectangle is active
+  if (object_select_active_) {
+    SelectObjectsInRect();
+  }
+}
+
+void DungeonEditor::DrawObjectSelectRect() {
+  if (!canvas_.IsMouseHovering()) return;
+
+  const ImGuiIO& io = ImGui::GetIO();
+  const ImVec2 canvas_pos = canvas_.zero_point();
+  const ImVec2 mouse_pos =
+      ImVec2(io.MousePos.x - canvas_pos.x, io.MousePos.y - canvas_pos.y);
+
+  static bool dragging = false;
+  static ImVec2 drag_start_pos;
+
+  // Right click to start object selection
+  if (ImGui::IsMouseClicked(ImGuiMouseButton_Right) && !object_loaded_) {
+    drag_start_pos = mouse_pos;
+    object_select_start_ = mouse_pos;
+    selected_object_indices_.clear();
+    object_select_active_ = false;
+    dragging = false;
+  }
+
+  // Right drag to create selection rectangle
+  if (ImGui::IsMouseDragging(ImGuiMouseButton_Right) && !object_loaded_) {
+    object_select_end_ = mouse_pos;
+    dragging = true;
+
+    // Draw selection rectangle
+    ImVec2 start =
+        ImVec2(canvas_pos.x + std::min(drag_start_pos.x, mouse_pos.x),
+               canvas_pos.y + std::min(drag_start_pos.y, mouse_pos.y));
+    ImVec2 end = ImVec2(canvas_pos.x + std::max(drag_start_pos.x, mouse_pos.x),
+                        canvas_pos.y + std::max(drag_start_pos.y, mouse_pos.y));
+
+    ImDrawList* draw_list = ImGui::GetWindowDrawList();
+    draw_list->AddRect(start, end, IM_COL32(255, 255, 0, 255), 0.0f, 0, 2.0f);
+    draw_list->AddRectFilled(start, end, IM_COL32(255, 255, 0, 32));
+  }
+
+  // Complete selection on mouse release
+  if (dragging && !ImGui::IsMouseDown(ImGuiMouseButton_Right)) {
+    dragging = false;
+    object_select_active_ = true;
+    SelectObjectsInRect();
+  }
+}
+
+void DungeonEditor::SelectObjectsInRect() {
+  int current_room = current_room_id_;
+  if (!active_rooms_.empty() && current_active_room_tab_ < active_rooms_.Size) {
+    current_room = active_rooms_[current_active_room_tab_];
+  }
+
+  if (current_room < 0 || current_room >= rooms_.size()) return;
+
+  auto& room = rooms_[current_room];
+  selected_object_indices_.clear();
+
+  // Calculate selection bounds in room coordinates
+  auto [start_room_x, start_room_y] = CanvasToRoomCoordinates(
+      static_cast<int>(std::min(object_select_start_.x, object_select_end_.x)),
+      static_cast<int>(std::min(object_select_start_.y, object_select_end_.y)));
+  auto [end_room_x, end_room_y] = CanvasToRoomCoordinates(
+      static_cast<int>(std::max(object_select_start_.x, object_select_end_.x)),
+      static_cast<int>(std::max(object_select_start_.y, object_select_end_.y)));
+
+  // Find objects within selection rectangle
+  const auto& objects = room.GetTileObjects();
+  for (size_t i = 0; i < objects.size(); ++i) {
+    const auto& object = objects[i];
+    if (object.x_ >= start_room_x && object.x_ <= end_room_x &&
+        object.y_ >= start_room_y && object.y_ <= end_room_y) {
+      selected_object_indices_.push_back(i);
+    }
+  }
+
+  // Highlight selected objects
+  if (!selected_object_indices_.empty()) {
+    for (size_t index : selected_object_indices_) {
+      if (index < objects.size()) {
+        const auto& object = objects[index];
+        auto [canvas_x, canvas_y] =
+            RoomToCanvasCoordinates(object.x_, object.y_);
+
+        // Draw selection highlight
+        ImDrawList* draw_list = ImGui::GetWindowDrawList();
+        ImVec2 canvas_pos = canvas_.zero_point();
+        ImVec2 obj_start(canvas_pos.x + canvas_x - 2,
+                         canvas_pos.y + canvas_y - 2);
+        ImVec2 obj_end(canvas_pos.x + canvas_x + 18,
+                       canvas_pos.y + canvas_y + 18);
+        draw_list->AddRect(obj_start, obj_end, IM_COL32(0, 255, 255, 255), 0.0f,
+                           0, 2.0f);
+      }
+    }
+  }
+}
+
 }  // namespace yaze::editor

src/app/editor/dungeon/dungeon_editor.h

@@ -130,6 +130,11 @@ class DungeonEditor : public Editor {
   bool IsObjectInSelectBox(const zelda3::RoomObject& object) const;
   void PlaceObjectAtPosition(int room_x, int room_y);
   
+  // Object selection rectangle (like OverworldEditor)
+  void CheckForObjectSelection();
+  void DrawObjectSelectRect();
+  void SelectObjectsInRect();
+  
   // Room graphics management
   absl::Status LoadAndRenderRoomGraphics(int room_id);
   absl::Status ReloadAllRoomGraphics();
@@ -196,6 +201,12 @@ class DungeonEditor : public Editor {
   std::vector<int> selected_objects_;
   int current_layer_ = 0; // 0 = BG1, 1 = BG2, 2 = Both
   
+  // Object selection rectangle (like OverworldEditor)
+  bool object_select_active_ = false;
+  ImVec2 object_select_start_;
+  ImVec2 object_select_end_;
+  std::vector<size_t> selected_object_indices_;
+  
   // New editor system integration
   std::unique_ptr<zelda3::DungeonEditorSystem> dungeon_editor_system_;
   std::shared_ptr<zelda3::DungeonObjectEditor> object_editor_;

src/app/editor/dungeon/dungeon_object_selector.cc

@@ -119,9 +119,9 @@ void DungeonObjectSelector::DrawObjectBrowser() {
   
   ImGui::Separator();
   
-  // Object list with previews
+  // Object list with previews - optimized for 300px column width
-  const int preview_size = 32; // 32x32 pixel preview
+  const int preview_size = 48; // Larger 48x48 pixel preview for better visibility
-  const int items_per_row = 4; // 4 items per row
+  const int items_per_row = 5; // 5 items per row to fit in 300px column
   
   if (rom_ && rom_->is_loaded()) {
     auto palette = rom_->palette_group().dungeon_main[current_palette_group_id_];
@@ -145,9 +145,11 @@ void DungeonObjectSelector::DrawObjectBrowser() {
       test_object.set_rom(rom_);
       test_object.EnsureTilesLoaded();
       
-      // Calculate position in grid
+      // Calculate position in grid - better sizing for 300px column
-      float item_width = (ImGui::GetContentRegionAvail().x - (items_per_row - 1) * ImGui::GetStyle().ItemSpacing.x) / items_per_row;
+      float available_width = ImGui::GetContentRegionAvail().x;
-      float item_height = preview_size + 40; // Preview + text
+      float spacing = ImGui::GetStyle().ItemSpacing.x;
+      float item_width = (available_width - (items_per_row - 1) * spacing) / items_per_row;
+      float item_height = preview_size + 30; // Preview + text (reduced padding)
       
       ImGui::PushID(obj_id);
       
@@ -196,9 +198,11 @@ void DungeonObjectSelector::DrawObjectBrowser() {
           "?");
       }
       
-      // Draw object ID and name
+      // Draw object ID and name with better positioning
-      ImGui::SetCursorScreenPos(ImVec2(cursor_pos.x + 2, cursor_pos.y - 25));
+      ImGui::SetCursorScreenPos(ImVec2(cursor_pos.x + 2, cursor_pos.y - 22));
-      ImGui::Text("0x%03X", obj_id);
+      ImGui::PushStyleColor(ImGuiCol_Text, IM_COL32(255, 255, 255, 255));
+      ImGui::Text("0x%02X", obj_id);
+      ImGui::PopStyleColor();
       
       // Try to get object name
       std::string object_name = "Unknown";
@@ -227,8 +231,15 @@ void DungeonObjectSelector::DrawObjectBrowser() {
         }
       }
       
-      ImGui::SetCursorScreenPos(ImVec2(cursor_pos.x + 2, cursor_pos.y - 10));
+      // Draw object name with better sizing
+      ImGui::SetCursorScreenPos(ImVec2(cursor_pos.x + 2, cursor_pos.y - 8));
+      ImGui::PushStyleColor(ImGuiCol_Text, IM_COL32(200, 200, 200, 255));
+      // Truncate long names to fit
+      if (object_name.length() > 8) {
+        object_name = object_name.substr(0, 8) + "...";
+      }
       ImGui::Text("%s", object_name.c_str());
+      ImGui::PopStyleColor();
       
       ImGui::PopID();
       
@@ -298,9 +309,9 @@ void DungeonObjectSelector::DrawRoomGraphics() {
     }
     
     int current_block = 0;
-    const int max_blocks_per_row = 4; // Limit blocks per row to fit canvas
+    const int max_blocks_per_row = 2; // 2 blocks per row for 300px column
-    const int block_width = 0x100; // 256 pixels per block
+    const int block_width = 128; // Reduced size to fit column
-    const int block_height = 0x40; // 64 pixels per block
+    const int block_height = 32; // Reduced height
     
     for (int block : blocks) {
       if (current_block >= 16) break; // Only show first 16 blocks