tile16_editor.cc

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#include "tile16_editor.h"
 
#include <array>
#include <memory>
 
#include "absl/status/status.h"
#include "absl/strings/str_format.h"
#include "app/editor/overworld/tile16_editor_action_state.h"
#include "app/editor/overworld/tile16_editor_shortcuts.h"
#include "app/editor/overworld/tile8_source_interaction.h"
#include "app/gfx/backend/irenderer.h"
#include "app/gfx/core/bitmap.h"
#include "app/gfx/debug/performance/performance_profiler.h"
#include "app/gfx/resource/arena.h"
#include "app/gfx/types/snes_palette.h"
#include "app/gui/canvas/canvas.h"
#include "app/gui/core/input.h"
#include "app/gui/core/style.h"
#include "app/gui/core/style_guard.h"
#include "app/gui/widgets/themed_widgets.h"
#include "imgui/imgui.h"
#include "rom/rom.h"
#include "util/hex.h"
#include "util/log.h"
#include "util/macro.h"
#include "zelda3/game_data.h"
#include "zelda3/overworld/overworld.h"
#include "zelda3/overworld/tile16_metadata.h"
#include "zelda3/overworld/tile16_renderer.h"
#include "zelda3/overworld/tile16_stamp.h"
#include "zelda3/overworld/tile16_usage_index.h"
 
namespace yaze {
namespace editor {
 
using namespace ImGui;
 
// Display scales used for the tile8 source/preview rendering.
constexpr float kTile8DisplayScale = 4.0f;
 
namespace {
 
constexpr int kTile16Count = zelda3::kNumTile16Individual;
 
gfx::SnesPalette BuildFallbackDisplayPalette() {
  std::vector<gfx::SnesColor> grayscale;
  grayscale.reserve(gfx::SnesPalette::kMaxColors);
  for (int i = 0; i < static_cast<int>(gfx::SnesPalette::kMaxColors); ++i) {
    const float value = static_cast<float>(i) / 255.0f;
    grayscale.emplace_back(ImVec4(value, value, value, 1.0f));
  }
  if (!grayscale.empty()) {
    grayscale[0].set_transparent(true);
  }
  return gfx::SnesPalette(grayscale);
}
 
gfx::TileInfo& TileInfoForQuadrant(gfx::Tile16* tile, int quadrant) {
  return zelda3::MutableTile16QuadrantInfo(*tile, quadrant);
}
 
const gfx::TileInfo& TileInfoForQuadrant(const gfx::Tile16& tile,
                                         int quadrant) {
  return zelda3::Tile16QuadrantInfo(tile, quadrant);
}
 
void SyncTilesInfoArray(gfx::Tile16* tile) {
  zelda3::SyncTile16TilesInfo(tile);
}
 
const char* EditModeLabel(Tile16EditMode mode) {
  switch (mode) {
    case Tile16EditMode::kPaint:
      return "Paint";
    case Tile16EditMode::kPick:
      return "Pick";
    case Tile16EditMode::kUsageProbe:
      return "Usage Probe";
    default:
      return "Paint";
  }
}
 
}  // namespace
 
absl::Status Tile16Editor::Initialize(
    gfx::Bitmap& tile16_blockset_bmp, gfx::Bitmap& current_gfx_bmp,
    std::array<uint8_t, 0x200>& all_tiles_types) {
  all_tiles_types_ = all_tiles_types;
  tile16_blockset_bmp_ = &tile16_blockset_bmp;
  current_gfx_bmp_ = &current_gfx_bmp;
 
  // Note: LoadTile8() will be called after palette is set by overworld editor
  // This ensures proper palette coordination from the start
 
  // Initialize current tile16 bitmap - this will be set by SetCurrentTile
  current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8,
                             std::vector<uint8_t>(kTile16PixelCount, 0));
  current_tile16_bmp_.SetPalette(tile16_blockset_bmp.palette());
  // Queue texture for later rendering.
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::CREATE,
                                        &current_tile16_bmp_);
 
  // Initialize enhanced canvas features with proper sizing
  tile16_edit_canvas_.InitializeDefaults();
  tile8_source_canvas_.InitializeDefaults();
 
  // Attach blockset canvas to the selector widget
  blockset_selector_.AttachCanvas(&blockset_canvas_);
  blockset_selector_.SetTileCount(kTile16Count);
 
  // Configure canvases with proper initialization
  tile16_edit_canvas_.SetAutoResize(false);
  tile8_source_canvas_.SetAutoResize(false);
 
  // Initialize enhanced palette editors if ROM is available
  if (rom_) {
    tile16_edit_canvas_.InitializePaletteEditor(rom_);
    tile8_source_canvas_.InitializePaletteEditor(rom_);
  }
 
  // Initialize the current tile16 properly from the blockset
  if (tile16_blockset_) {
    RETURN_IF_ERROR(SetCurrentTile(0));  // Start with tile 0
  }
 
  map_blockset_loaded_ = true;
 
  // Setup collision type labels for tile8 canvas
  ImVector<std::string> tile16_names;
  for (int i = 0; i < 0x200; ++i) {
    std::string str = util::HexByte(all_tiles_types_[i]);
    tile16_names.push_back(str);
  }
  *tile8_source_canvas_.mutable_labels(0) = tile16_names;
  *tile8_source_canvas_.custom_labels_enabled() = true;
 
  // Setup tile info table
  gui::AddTableColumn(tile_edit_table_, "##tile16ID",
                      [&]() { Text("Tile16: %02X", current_tile16_); });
  gui::AddTableColumn(tile_edit_table_, "##tile8ID",
                      [&]() { Text("Tile8: %02X", current_tile8_); });
  gui::AddTableColumn(tile_edit_table_, "##tile16Flip", [&]() {
    Checkbox("X Flip", &x_flip);
    Checkbox("Y Flip", &y_flip);
    Checkbox("Priority", &priority_tile);
  });
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::Update() {
  if (!map_blockset_loaded_) {
    return absl::InvalidArgumentError("Blockset not initialized, open a ROM.");
  }
 
  if (BeginMenuBar()) {
    if (BeginMenu("View")) {
      Checkbox("Show Collision Types",
               tile8_source_canvas_.custom_labels_enabled());
      EndMenu();
    }
 
    if (BeginMenu("Edit")) {
      if (MenuItem("Copy Current Tile16", "Ctrl+C")) {
        RETURN_IF_ERROR(CopyTile16ToClipboard(current_tile16_));
      }
      if (MenuItem("Paste to Current Tile16", "Ctrl+V")) {
        RETURN_IF_ERROR(PasteTile16FromClipboard());
      }
      EndMenu();
    }
 
    if (BeginMenu("File")) {
      if (MenuItem("Write Pending to ROM", "Ctrl+S")) {
        status_ = CommitAllChanges();
      }
      if (MenuItem("Refresh Blockset Preview", "Ctrl+Shift+S")) {
        status_ = CommitChangesToBlockset();
      }
      Separator();
      bool live_preview = live_preview_enabled_;
      if (MenuItem("Live Preview", nullptr, &live_preview)) {
        EnableLivePreview(live_preview);
      }
      EndMenu();
    }
 
    if (BeginMenu("Scratch Space")) {
      for (int i = 0; i < 4; i++) {
        std::string slot_name = "Slot " + std::to_string(i + 1);
        if (scratch_space_[i].has_data) {
          if (MenuItem((slot_name + " (Load)").c_str())) {
            RETURN_IF_ERROR(LoadTile16FromScratchSpace(i));
          }
          if (MenuItem((slot_name + " (Save)").c_str())) {
            RETURN_IF_ERROR(SaveTile16ToScratchSpace(i));
          }
          if (MenuItem((slot_name + " (Clear)").c_str())) {
            RETURN_IF_ERROR(ClearScratchSpace(i));
          }
        } else {
          if (MenuItem((slot_name + " (Save)").c_str())) {
            RETURN_IF_ERROR(SaveTile16ToScratchSpace(i));
          }
        }
        if (i < 3)
          Separator();
      }
      EndMenu();
    }
 
    EndMenuBar();
  }
 
  // About popup
  if (BeginPopupModal("About Tile16 Editor", NULL,
                      ImGuiWindowFlags_AlwaysAutoResize)) {
    Text("Tile16 Editor for Link to the Past");
    Text("This editor allows you to edit 16x16 tiles used in the game.");
    Text("Features:");
    BulletText("Edit Tile16 graphics by placing 8x8 tiles in the quadrants");
    BulletText("Copy and paste Tile16 graphics");
    BulletText("Save and load Tile16 graphics to/from scratch space");
    BulletText("Preview Tile16 graphics at a larger size");
    Separator();
    if (Button("Close")) {
      CloseCurrentPopup();
    }
    EndPopup();
  }
 
  // Unsaved changes confirmation dialog
  if (show_unsaved_changes_dialog_) {
    OpenPopup("Unsaved Changes##Tile16Editor");
  }
  if (BeginPopupModal("Unsaved Changes##Tile16Editor", NULL,
                      ImGuiWindowFlags_AlwaysAutoResize)) {
    Text("Tile %d has staged changes.", current_tile16_);
    Text("What would you like to do?");
    Separator();
 
    if (Button("Keep Staged & Continue", ImVec2(220, 0))) {
      if (IsItemHovered()) {
        SetTooltip(
            "Switch to the requested tile now. Other tiles with staged edits "
            "stay in the write queue until you use Write Pending or Discard.");
      }
      if (pending_tile_switch_target_ >= 0) {
        auto status = SetCurrentTile(pending_tile_switch_target_);
        if (!status.ok()) {
          util::logf("Failed to switch to tile %d: %s",
                     pending_tile_switch_target_, status.message().data());
        }
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (gui::SuccessButton("Write Pending & Continue", ImVec2(220, 0))) {
      auto status = CommitAllChanges();
      if (status.ok() && pending_tile_switch_target_ >= 0) {
        status = SetCurrentTile(pending_tile_switch_target_);
      }
      if (!status.ok()) {
        util::logf("Failed to write/switch pending changes: %s",
                   status.message().data());
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (gui::DangerButton("Discard Current & Continue", ImVec2(220, 0))) {
      pending_tile16_changes_.erase(current_tile16_);
      pending_tile16_bitmaps_.erase(current_tile16_);
      if (pending_tile_switch_target_ >= 0) {
        auto status = SetCurrentTile(pending_tile_switch_target_);
        if (!status.ok()) {
          util::logf("Failed to switch to tile %d: %s",
                     pending_tile_switch_target_, status.message().data());
        }
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (Button("Cancel", ImVec2(220, 0))) {
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    EndPopup();
  }
 
  // Handle keyboard shortcuts (shared implementation)
  HandleKeyboardShortcuts();
 
  DrawTile16Editor();
 
  // Draw palette settings popup if enabled
  DrawPaletteSettings();
 
  // Update live preview if dirty
  RETURN_IF_ERROR(UpdateLivePreview());
 
  return absl::OkStatus();
}
 
void Tile16Editor::DrawTile16Editor() {
  // REFACTORED: Single unified table layout in UpdateTile16Edit
  status_ = UpdateTile16Edit();
}
 
absl::Status Tile16Editor::UpdateAsPanel() {
  if (!map_blockset_loaded_) {
    return absl::InvalidArgumentError("Blockset not initialized, open a ROM.");
  }
 
  // Menu button for context menu
  if (Button(ICON_MD_MENU " Menu")) {
    OpenPopup("##Tile16EditorContextMenu");
  }
  SameLine();
  TextDisabled("Right-click for more options");
 
  // Context menu
  DrawContextMenu();
 
  // About popup
  if (BeginPopupModal("About Tile16 Editor", NULL,
                      ImGuiWindowFlags_AlwaysAutoResize)) {
    Text("Tile16 Editor for Link to the Past");
    Text("This editor allows you to edit 16x16 tiles used in the game.");
    Text("Features:");
    BulletText("Edit Tile16 graphics by placing 8x8 tiles in the quadrants");
    BulletText("Copy and paste Tile16 graphics");
    BulletText("Save and load Tile16 graphics to/from scratch space");
    BulletText("Preview Tile16 graphics at a larger size");
    Separator();
    if (Button("Close")) {
      CloseCurrentPopup();
    }
    EndPopup();
  }
 
  // Unsaved changes confirmation dialog
  if (show_unsaved_changes_dialog_) {
    OpenPopup("Unsaved Changes##Tile16Editor");
  }
  if (BeginPopupModal("Unsaved Changes##Tile16Editor", NULL,
                      ImGuiWindowFlags_AlwaysAutoResize)) {
    Text("Tile %d has staged changes.", current_tile16_);
    Text("What would you like to do?");
    Separator();
 
    if (Button("Keep Staged & Continue", ImVec2(220, 0))) {
      if (IsItemHovered()) {
        SetTooltip(
            "Switch to the requested tile now. Other tiles with staged edits "
            "stay in the write queue until you use Write Pending or Discard.");
      }
      if (pending_tile_switch_target_ >= 0) {
        auto status = SetCurrentTile(pending_tile_switch_target_);
        if (!status.ok()) {
          util::logf("Failed to switch to tile %d: %s",
                     pending_tile_switch_target_, status.message().data());
        }
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (gui::SuccessButton("Write Pending & Continue", ImVec2(220, 0))) {
      auto status = CommitAllChanges();
      if (status.ok() && pending_tile_switch_target_ >= 0) {
        status = SetCurrentTile(pending_tile_switch_target_);
      }
      if (!status.ok()) {
        util::logf("Failed to write/switch pending changes: %s",
                   status.message().data());
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (gui::DangerButton("Discard Current & Continue", ImVec2(220, 0))) {
      pending_tile16_changes_.erase(current_tile16_);
      pending_tile16_bitmaps_.erase(current_tile16_);
      if (pending_tile_switch_target_ >= 0) {
        auto status = SetCurrentTile(pending_tile_switch_target_);
        if (!status.ok()) {
          util::logf("Failed to switch to tile %d: %s",
                     pending_tile_switch_target_, status.message().data());
        }
      }
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    if (Button("Cancel", ImVec2(220, 0))) {
      pending_tile_switch_target_ = -1;
      show_unsaved_changes_dialog_ = false;
      CloseCurrentPopup();
    }
 
    EndPopup();
  }
 
  // Handle keyboard shortcuts (shared implementation)
  HandleKeyboardShortcuts();
 
  DrawTile16Editor();
  DrawPaletteSettings();
  RETURN_IF_ERROR(UpdateLivePreview());
 
  return absl::OkStatus();
}
 
void Tile16Editor::DrawContextMenu() {
  if (BeginPopup("##Tile16EditorContextMenu")) {
    if (BeginMenu("View")) {
      Checkbox("Show Collision Types",
               tile8_source_canvas_.custom_labels_enabled());
      EndMenu();
    }
 
    if (BeginMenu("Edit")) {
      if (MenuItem("Copy Current Tile16", "Ctrl+C")) {
        status_ = CopyTile16ToClipboard(current_tile16_);
      }
      if (MenuItem("Paste to Current Tile16", "Ctrl+V")) {
        status_ = PasteTile16FromClipboard();
      }
      Separator();
      if (MenuItem("Flip Horizontal", "H")) {
        status_ = FlipTile16Horizontal();
      }
      if (MenuItem("Flip Vertical", "V")) {
        status_ = FlipTile16Vertical();
      }
      if (MenuItem("Rotate", "R")) {
        status_ = RotateTile16();
      }
      if (MenuItem("Clear", "Delete")) {
        status_ = ClearTile16();
      }
      EndMenu();
    }
 
    if (BeginMenu("File")) {
      if (MenuItem("Write Pending to ROM", "Ctrl+S")) {
        status_ = CommitAllChanges();
      }
      if (MenuItem("Refresh Blockset Preview", "Ctrl+Shift+S")) {
        status_ = CommitChangesToBlockset();
      }
      Separator();
      bool live_preview = live_preview_enabled_;
      if (MenuItem("Live Preview", nullptr, &live_preview)) {
        EnableLivePreview(live_preview);
      }
      EndMenu();
    }
 
    if (BeginMenu("Scratch Space")) {
      for (int i = 0; i < 4; i++) {
        std::string slot_name = "Slot " + std::to_string(i + 1);
        if (scratch_space_[i].has_data) {
          if (MenuItem((slot_name + " (Load)").c_str())) {
            status_ = LoadTile16FromScratchSpace(i);
          }
          if (MenuItem((slot_name + " (Save)").c_str())) {
            status_ = SaveTile16ToScratchSpace(i);
          }
          if (MenuItem((slot_name + " (Clear)").c_str())) {
            status_ = ClearScratchSpace(i);
          }
        } else {
          if (MenuItem((slot_name + " (Save)").c_str())) {
            status_ = SaveTile16ToScratchSpace(i);
          }
        }
        if (i < 3)
          Separator();
      }
      EndMenu();
    }
 
    EndPopup();
  }
}
 
absl::Status Tile16Editor::UpdateBlockset() {
  gui::BeginPadding(2);
  gui::BeginChildWithScrollbar("##Tile16EditorBlocksetScrollRegion");
 
  // Tile ID search/jump bar
  if (blockset_selector_.DrawFilterBar()) {
    RequestTileSwitch(blockset_selector_.GetSelectedTileID());
  }
 
  // Configure canvas frame options for blockset view
  gui::CanvasFrameOptions frame_opts;
  frame_opts.draw_grid = true;
  frame_opts.grid_step = 32.0f;  // Tile16 grid
  frame_opts.draw_context_menu = true;
  frame_opts.draw_overlay = true;
  frame_opts.render_popups = true;
  frame_opts.use_child_window = false;
 
  auto canvas_rt = gui::BeginCanvas(blockset_canvas_, frame_opts);
  gui::EndPadding();
 
  // Ensure selector is synced with current selection
  if (blockset_selector_.GetSelectedTileID() != current_tile16_) {
    blockset_selector_.SetSelectedTile(current_tile16_);
  }
 
  if (tile16_blockset_bmp_ == nullptr) {
    return absl::FailedPreconditionError(
        "Tile16 blockset bitmap not initialized");
  }
 
  // Render the selector widget (handles bitmap, grid, highlights, interaction)
  auto result = blockset_selector_.Render(*tile16_blockset_bmp_, true);
 
  if (result.selection_changed) {
    // Use RequestTileSwitch to handle pending changes confirmation
    RequestTileSwitch(result.selected_tile);
    util::logf("Selected Tile16 from blockset: %d", result.selected_tile);
  }
 
  gui::EndCanvas(blockset_canvas_, canvas_rt, frame_opts);
  EndChild();
 
  return absl::OkStatus();
}
 
// ROM data access methods
gfx::Tile16* Tile16Editor::GetCurrentTile16Data() {
  if (!rom_ || current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return nullptr;
  }
  return &current_tile16_data_;
}
 
absl::Status Tile16Editor::UpdateROMTile16Data() {
  auto* tile_data = GetCurrentTile16Data();
  if (!tile_data) {
    return absl::FailedPreconditionError("Cannot access current tile16 data");
  }
 
  // Write the modified tile16 data back to ROM
  RETURN_IF_ERROR(
      rom_->WriteTile16(current_tile16_, zelda3::kTile16Ptr, *tile_data));
 
  util::logf("ROM Tile16 data written for tile %d", current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::RefreshTile16Blockset() {
  if (!tile16_blockset_) {
    return absl::FailedPreconditionError("Tile16 blockset not available");
  }
 
  // CRITICAL FIX: Force regeneration without using problematic tile cache
  // Directly mark atlas as modified to trigger regeneration from ROM data
 
  // Mark atlas as modified to trigger regeneration
  tile16_blockset_->atlas.set_modified(true);
 
  // Queue texture update via Arena's deferred system
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &tile16_blockset_->atlas);
 
  util::logf("Tile16 blockset refreshed and regenerated");
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::BuildTile16BitmapFromData(
    const gfx::Tile16& tile_data, gfx::Bitmap* output_bitmap) const {
  return zelda3::RenderTile16BitmapFromMetadata(
      tile_data, current_gfx_individual_, output_bitmap);
}
 
void Tile16Editor::CopyTileBitmapToBlockset(int tile_id,
                                            const gfx::Bitmap& tile_bitmap) {
  if (!tile_bitmap.is_active()) {
    return;
  }
 
  if (tile16_blockset_bmp_ != nullptr) {
    zelda3::BlitTile16BitmapToAtlas(tile16_blockset_bmp_, tile_id, tile_bitmap);
  }
  if (HasTile16BlocksetBitmap()) {
    tile16_blockset_bmp_->set_modified(true);
  }
 
  if (tile16_blockset_ && tile16_blockset_->atlas.is_active()) {
    zelda3::BlitTile16BitmapToAtlas(&tile16_blockset_->atlas, tile_id,
                                    tile_bitmap);
    tile16_blockset_->atlas.set_modified(true);
  }
}
 
absl::Status Tile16Editor::UpdateBlocksetBitmap() {
  gfx::ScopedTimer timer("tile16_blockset_update");
 
  if (!tile16_blockset_) {
    return absl::FailedPreconditionError("Tile16 blockset not initialized");
  }
 
  if (current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return absl::OutOfRangeError("Current tile16 ID out of range");
  }
 
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("Current tile16 bitmap is not active");
  }
 
  CopyTileBitmapToBlockset(current_tile16_, current_tile16_bmp_);
 
  if (HasTile16BlocksetBitmap()) {
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, tile16_blockset_bmp_);
  }
  if (tile16_blockset_ && tile16_blockset_->atlas.is_active()) {
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, &tile16_blockset_->atlas);
  }
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::RegenerateTile16BitmapFromROM() {
  // Rebuild preview from `current_tile16_data_` (SetCurrentTile prefers pending
  // maps over ROM). Name is historical.
  auto* tile_data = GetCurrentTile16Data();
  if (!tile_data) {
    return absl::FailedPreconditionError("Cannot access current tile16 data");
  }
 
  // Tests and some initialization paths reach regeneration before tile8 previews
  // are built; lazily populate them so metadata->bitmap rendering can proceed.
  if (current_gfx_individual_.empty()) {
    if (!HasCurrentGfxBitmap()) {
      return absl::FailedPreconditionError("Tile8 source bitmap not active");
    }
    RETURN_IF_ERROR(LoadTile8());
  }
 
  // Shared render path used by regeneration, stamping, and multi-tile updates.
  RETURN_IF_ERROR(BuildTile16BitmapFromData(*tile_data, &current_tile16_bmp_));
 
  // Set the appropriate palette using the same system as overworld
  ApplyPaletteToCurrentTile16Bitmap();
 
  // Queue texture creation via Arena's deferred system
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::CREATE,
                                        &current_tile16_bmp_);
 
  util::logf("Regenerated Tile16 bitmap for tile %d from ROM data",
             current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::DrawToCurrentTile16(ImVec2 pos,
                                               const gfx::Bitmap* source_tile) {
  constexpr int kTile8Size = 8;
  (void)source_tile;
 
  // Save undo state before making changes
  auto now = std::chrono::steady_clock::now();
  auto time_since_last_edit =
      std::chrono::duration_cast<std::chrono::milliseconds>(now -
                                                            last_edit_time_)
          .count();
 
  if (time_since_last_edit > 100) {  // 100ms threshold
    SaveUndoState();
    last_edit_time_ = now;
  }
 
  // Validate inputs
  if (current_tile8_ < 0 ||
      current_tile8_ >= static_cast<int>(current_gfx_individual_.size())) {
    return absl::OutOfRangeError(
        absl::StrFormat("Invalid tile8 index: %d", current_tile8_));
  }
 
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("Target tile16 bitmap not active");
  }
 
  const int tile8_count =
      static_cast<int>(std::min<size_t>(current_gfx_individual_.size(), 1024));
  const int max_tile8_id = std::max(0, tile8_count - 1);
  const int tile8_row_stride =
      std::max(1, current_gfx_bmp_->width() / kTile8Size);
  const int quadrant_x = (pos.x >= kTile8Size) ? 1 : 0;
  const int quadrant_y = (pos.y >= kTile8Size) ? 1 : 0;
  const int quadrant_index = quadrant_x + (quadrant_y * 2);
  active_quadrant_ = std::clamp(quadrant_index, 0, 3);
 
  zelda3::Tile16StampRequest stamp_request;
  stamp_request.current_tile16 = current_tile16_data_;
  stamp_request.current_tile16_id = current_tile16_;
  stamp_request.selected_tile8_id = current_tile8_;
  stamp_request.stamp_size = tile8_stamp_size_;
  stamp_request.quadrant_index = quadrant_index;
  stamp_request.palette_id = current_palette_;
  stamp_request.x_flip = x_flip;
  stamp_request.y_flip = y_flip;
  stamp_request.priority = priority_tile;
  stamp_request.tile8_row_stride = tile8_row_stride;
  stamp_request.tile16_row_stride = kTilesPerRow;
  stamp_request.max_tile8_id = max_tile8_id;
  stamp_request.max_tile16_id = kTile16Count - 1;
 
  ASSIGN_OR_RETURN(auto staged_tiles,
                   zelda3::BuildTile16StampMutations(stamp_request));
 
  for (const auto& mutation : staged_tiles) {
    const int tile16_id = mutation.tile16_id;
    const gfx::Tile16& tile_data = mutation.tile_data;
    gfx::Bitmap staged_bitmap;
    RETURN_IF_ERROR(BuildTile16BitmapFromData(tile_data, &staged_bitmap));
    if (current_tile16_bmp_.palette().size() > 0) {
      staged_bitmap.SetPalette(current_tile16_bmp_.palette());
    }
 
    if (tile16_id == current_tile16_) {
      current_tile16_data_ = tile_data;
      SyncTilesInfoArray(&current_tile16_data_);
      current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8,
                                 staged_bitmap.vector());
      ApplyPaletteToCurrentTile16Bitmap();
      current_tile16_bmp_.set_modified(true);
      gfx::Arena::Get().QueueTextureCommand(
          gfx::Arena::TextureCommandType::UPDATE, &current_tile16_bmp_);
      MarkCurrentTileModified();
    } else {
      pending_tile16_changes_[tile16_id] = tile_data;
      pending_tile16_bitmaps_[tile16_id] = staged_bitmap;
      preview_dirty_ = true;
    }
 
    CopyTileBitmapToBlockset(tile16_id, staged_bitmap);
  }
 
  if (HasTile16BlocksetBitmap()) {
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, tile16_blockset_bmp_);
  }
  if (tile16_blockset_ && tile16_blockset_->atlas.is_active()) {
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, &tile16_blockset_->atlas);
  }
 
  tile8_usage_cache_dirty_ = true;
 
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  util::logf(
      "Local tile16 stamp staged (size=%dx, tiles=%zu). Use 'Write Pending' to "
      "commit.",
      tile8_stamp_size_, staged_tiles.size());
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::HandleTile16CanvasClick(const ImVec2& tile_position,
                                                   bool left_click,
                                                   bool right_click) {
  if (!left_click && !right_click) {
    return absl::OkStatus();
  }
 
  if (right_click) {
    RETURN_IF_ERROR(PickTile8FromTile16(tile_position));
    util::logf("Picked tile8 from tile16 at (%d, %d)",
               static_cast<int>(tile_position.x),
               static_cast<int>(tile_position.y));
    return absl::OkStatus();
  }
 
  switch (edit_mode_) {
    case Tile16EditMode::kPaint:
      // Pass nullptr to let DrawToCurrentTile16 handle flipping and store
      // correct TileInfo metadata. The preview bitmap is pre-flipped for
      // display only.
      RETURN_IF_ERROR(DrawToCurrentTile16(tile_position, nullptr));
      break;
    case Tile16EditMode::kPick:
    case Tile16EditMode::kUsageProbe:
      RETURN_IF_ERROR(PickTile8FromTile16(tile_position));
      break;
  }
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::UpdateTile16Edit() {
  static bool show_advanced_controls = false;
  static bool show_debug_info = false;
 
  // Modern header with improved styling
  gui::StyleVarGuard header_var_guard(
      {{ImGuiStyleVar_FramePadding, ImVec2(8, 4)},
       {ImGuiStyleVar_ItemSpacing, ImVec2(8, 4)}});
 
  const bool has_pending = has_pending_changes();
  const bool current_tile_pending = is_tile_modified(current_tile16_);
  const int pending_count = pending_changes_count();
 
  DrawEditorHeader(show_debug_info);
  DrawEditorHeaderToggles(&show_debug_info, &show_advanced_controls);
  DrawStagedStateBar(has_pending, current_tile_pending, pending_count);
 
  ImGui::Separator();
 
  // REFACTORED: Improved 3-column layout with better space utilization
  if (ImGui::BeginTable("##Tile16EditLayout", 3,
                        ImGuiTableFlags_Resizable |
                            ImGuiTableFlags_BordersInnerV |
                            ImGuiTableFlags_SizingStretchProp)) {
    ImGui::TableSetupColumn("Tile16 Blockset",
                            ImGuiTableColumnFlags_WidthStretch, 0.35f);
    ImGui::TableSetupColumn("Tile8 Source", ImGuiTableColumnFlags_WidthStretch,
                            0.35f);
    ImGui::TableSetupColumn("Editor & Controls",
                            ImGuiTableColumnFlags_WidthStretch, 0.30f);
 
    ImGui::TableHeadersRow();
    ImGui::TableNextRow();
 
    // ========== COLUMN 1: Tile16 Blockset ==========
    ImGui::TableNextColumn();
    ImGui::BeginGroup();
 
    // Navigation header with tile info
    ImGui::TextColored(ImVec4(0.9f, 0.9f, 0.9f, 1.0f), "Tile16 Blockset");
    ImGui::SameLine();
 
    // Show current tile and total tiles
    int total_tiles = zelda3::ComputeTile16Count(tile16_blockset_);
    ImGui::TextDisabled("(%d / %d)", current_tile16_, total_tiles);
 
    // Navigation controls row
    {
      gui::StyleVarGuard nav_spacing_guard(ImGuiStyleVar_ItemSpacing,
                                           ImVec2(4, 4));
 
      // Jump to Tile ID input - live navigation as user types
      ImGui::SetNextItemWidth(80);
      if (ImGui::InputInt("##JumpToTile", &jump_to_tile_id_, 0, 0)) {
        // Clamp to valid range
        jump_to_tile_id_ = std::clamp(jump_to_tile_id_, 0, total_tiles - 1);
        if (jump_to_tile_id_ != current_tile16_) {
          RequestTileSwitch(jump_to_tile_id_);
          scroll_to_current_ = true;
        }
      }
      if (ImGui::IsItemHovered()) {
        ImGui::SetTooltip("Tile ID (0-%d) - navigates as you type",
                          total_tiles - 1);
      }
 
      ImGui::SameLine();
      ImGui::TextDisabled("|");
      ImGui::SameLine();
 
      // Page navigation
      int total_pages = (total_tiles + kTilesPerPage - 1) / kTilesPerPage;
      current_page_ = current_tile16_ / kTilesPerPage;
 
      if (ImGui::Button("<<")) {
        RequestTileSwitch(0);
        scroll_to_current_ = true;
      }
      if (ImGui::IsItemHovered())
        ImGui::SetTooltip("First page");
 
      ImGui::SameLine();
      if (ImGui::Button("<")) {
        int new_tile = std::max(0, current_tile16_ - kTilesPerPage);
        RequestTileSwitch(new_tile);
        scroll_to_current_ = true;
      }
      if (ImGui::IsItemHovered())
        ImGui::SetTooltip("Previous page (PageUp)");
 
      ImGui::SameLine();
      ImGui::TextDisabled("Page %d/%d", current_page_ + 1, total_pages);
 
      ImGui::SameLine();
      if (ImGui::Button(">")) {
        int new_tile =
            std::min(total_tiles - 1, current_tile16_ + kTilesPerPage);
        RequestTileSwitch(new_tile);
        scroll_to_current_ = true;
      }
      if (ImGui::IsItemHovered())
        ImGui::SetTooltip("Next page (PageDown)");
 
      ImGui::SameLine();
      if (ImGui::Button(">>")) {
        RequestTileSwitch(total_tiles - 1);
        scroll_to_current_ = true;
      }
      if (ImGui::IsItemHovered())
        ImGui::SetTooltip("Last page");
 
      // Display current tile info (sheet and palette)
      ImGui::SameLine();
      ImGui::TextDisabled("|");
      ImGui::SameLine();
      int sheet_idx = GetSheetIndexForTile8(current_tile8_);
      ImGui::Text("Sheet: %d | Palette: %d", sheet_idx, current_palette_);
 
      // Handle keyboard shortcuts for page navigation
      if (ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows)) {
        if (ImGui::IsKeyPressed(ImGuiKey_PageUp)) {
          int new_tile = std::max(0, current_tile16_ - kTilesPerPage);
          RequestTileSwitch(new_tile);
          scroll_to_current_ = true;
        }
        if (ImGui::IsKeyPressed(ImGuiKey_PageDown)) {
          int new_tile =
              std::min(total_tiles - 1, current_tile16_ + kTilesPerPage);
          RequestTileSwitch(new_tile);
          scroll_to_current_ = true;
        }
        if (ImGui::IsKeyPressed(ImGuiKey_Home)) {
          RequestTileSwitch(0);
          scroll_to_current_ = true;
        }
        if (ImGui::IsKeyPressed(ImGuiKey_End)) {
          RequestTileSwitch(total_tiles - 1);
          scroll_to_current_ = true;
        }
 
        // Arrow keys for single-tile navigation (when Ctrl not held)
        if (!ImGui::GetIO().KeyCtrl) {
          if (ImGui::IsKeyPressed(ImGuiKey_LeftArrow)) {
            if (current_tile16_ > 0) {
              RequestTileSwitch(current_tile16_ - 1);
              scroll_to_current_ = true;
            }
          }
          if (ImGui::IsKeyPressed(ImGuiKey_RightArrow)) {
            if (current_tile16_ < total_tiles - 1) {
              RequestTileSwitch(current_tile16_ + 1);
              scroll_to_current_ = true;
            }
          }
          if (ImGui::IsKeyPressed(ImGuiKey_UpArrow)) {
            if (current_tile16_ >= kTilesPerRow) {
              RequestTileSwitch(current_tile16_ - kTilesPerRow);
              scroll_to_current_ = true;
            }
          }
          if (ImGui::IsKeyPressed(ImGuiKey_DownArrow)) {
            if (current_tile16_ + kTilesPerRow < total_tiles) {
              RequestTileSwitch(current_tile16_ + kTilesPerRow);
              scroll_to_current_ = true;
            }
          }
        }
      }
 
    }  // nav_spacing_guard scope
 
    // Blockset canvas with scrolling
    if (BeginChild("##BlocksetScrollable",
                   ImVec2(0, ImGui::GetContentRegionAvail().y), true,
                   ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
      // Handle scroll-to-current request
      if (scroll_to_current_) {
        int tile_row = current_tile16_ / kTilesPerRow;
        float tile_y = tile_row * 32.0f * blockset_canvas_.GetGlobalScale();
        ImGui::SetScrollY(tile_y);
        scroll_to_current_ = false;
      }
 
      // Configure canvas frame options for blockset
      gui::CanvasFrameOptions blockset_frame_opts;
      blockset_frame_opts.draw_grid = true;
      blockset_frame_opts.grid_step = 32.0f;
      blockset_frame_opts.draw_context_menu = true;
      blockset_frame_opts.draw_overlay = true;
      blockset_frame_opts.render_popups = true;
      blockset_frame_opts.use_child_window = false;
 
      auto blockset_rt =
          gui::BeginCanvas(blockset_canvas_, blockset_frame_opts);
 
      // Handle tile selection from blockset
      bool tile_selected = false;
      blockset_canvas_.DrawTileSelector(32.0f);
 
      if (ImGui::IsItemClicked(ImGuiMouseButton_Left) &&
          blockset_canvas_.IsMouseHovering()) {
        tile_selected = true;
      }
 
      if (tile_selected) {
        const ImGuiIO& io = ImGui::GetIO();
        ImVec2 canvas_pos = blockset_canvas_.zero_point();
        ImVec2 mouse_pos =
            ImVec2(io.MousePos.x - canvas_pos.x, io.MousePos.y - canvas_pos.y);
 
        int grid_x = static_cast<int>(mouse_pos.x /
                                      (32 * blockset_canvas_.GetGlobalScale()));
        int grid_y = static_cast<int>(mouse_pos.y /
                                      (32 * blockset_canvas_.GetGlobalScale()));
        int selected_tile = grid_x + grid_y * 8;
 
        if (selected_tile != current_tile16_ && selected_tile >= 0) {
          // Use RequestTileSwitch to handle pending changes confirmation
          RequestTileSwitch(selected_tile);
          util::logf("Selected Tile16 from blockset: %d", selected_tile);
        }
      }
 
      if (tile16_blockset_bmp_ != nullptr) {
        blockset_canvas_.DrawBitmap(*tile16_blockset_bmp_, 0, true, 2);
      }
      DrawTile8UsageOverlay();
 
      gui::EndCanvas(blockset_canvas_, blockset_rt, blockset_frame_opts);
    }
    EndChild();
    ImGui::EndGroup();
 
    // ========== COLUMN 2: Tile8 Source ==========
    ImGui::TableNextColumn();
    ImGui::BeginGroup();
    RETURN_IF_ERROR(DrawTile8SourcePanel());
    ImGui::EndGroup();
 
    // ========== COLUMN 3: Tile16 Editor + Controls ==========
    TableNextColumn();
    ImGui::BeginGroup();
 
    // Fixed size container to prevent canvas expansion
    if (ImGui::BeginChild("##Tile16FixedCanvas", ImVec2(90, 90), true,
                          ImGuiWindowFlags_NoScrollbar |
                              ImGuiWindowFlags_NoScrollWithMouse)) {
      // Configure canvas frame options for tile16 editor
      gui::CanvasFrameOptions tile16_edit_frame_opts;
      tile16_edit_frame_opts.canvas_size = ImVec2(64, 64);
      tile16_edit_frame_opts.draw_grid = true;
      tile16_edit_frame_opts.grid_step = 8.0f;  // 8x8 grid for tile8 placement
      tile16_edit_frame_opts.draw_context_menu = true;
      tile16_edit_frame_opts.draw_overlay = true;
      tile16_edit_frame_opts.render_popups = true;
      tile16_edit_frame_opts.use_child_window = false;
 
      auto tile16_edit_rt =
          gui::BeginCanvas(tile16_edit_canvas_, tile16_edit_frame_opts);
 
      // Draw current tile16 bitmap with dynamic zoom
      if (current_tile16_bmp_.is_active()) {
        tile16_edit_canvas_.DrawBitmap(current_tile16_bmp_, 2, 2, 4);
      }
 
      // Handle tile8 painting with improved hover preview
      if (current_tile8_ >= 0 &&
          current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
        // Create a display tile that shows the current palette selection
        if (!tile8_preview_bmp_.is_active()) {
          tile8_preview_bmp_.Create(8, 8, 8,
                                    std::vector<uint8_t>(kTile8PixelCount, 0));
        }
 
        // Get the original pixel data (already has sheet offsets from
        // ProcessGraphicsBuffer)
        auto& preview_data = tile8_preview_bmp_.mutable_data();
        std::copy(current_gfx_individual_[current_tile8_].begin(),
                  current_gfx_individual_[current_tile8_].end(),
                  preview_data.begin());
 
        // Apply the correct sheet-aware palette slice for the preview
        const gfx::SnesPalette* display_palette = nullptr;
        if (overworld_palette_.size() >= 256) {
          display_palette = &overworld_palette_;
        } else if (palette_.size() >= 256) {
          display_palette = &palette_;
        } else {
          display_palette =
              current_gfx_bmp_ ? &current_gfx_bmp_->palette() : &palette_;
        }
 
        if (display_palette && !display_palette->empty()) {
          if (auto_normalize_pixels_) {
            // Calculate palette slot for the selected tile8
            int sheet_index = GetSheetIndexForTile8(current_tile8_);
            int palette_slot =
                GetActualPaletteSlot(current_palette_, sheet_index);
 
            // SNES palette offset fix: pixel value N maps to sub-palette color N
            // Color 0 is handled by SetPaletteWithTransparent (transparent)
            // Colors 1-15 need to come from palette[slot+1] through palette[slot+15]
            if (palette_slot >= 0 && static_cast<size_t>(palette_slot + 16) <=
                                         display_palette->size()) {
              tile8_preview_bmp_.SetPaletteWithTransparent(
                  *display_palette, static_cast<size_t>(palette_slot + 1), 15);
            } else {
              tile8_preview_bmp_.SetPaletteWithTransparent(*display_palette, 1,
                                                           15);
            }
          } else {
            tile8_preview_bmp_.SetPalette(*display_palette);
          }
        }
 
        // Apply flips if needed
        if (x_flip || y_flip) {
          auto& data = tile8_preview_bmp_.mutable_data();
 
          if (x_flip) {
            for (int y = 0; y < 8; ++y) {
              for (int x = 0; x < 4; ++x) {
                std::swap(data[y * 8 + x], data[y * 8 + (7 - x)]);
              }
            }
          }
 
          if (y_flip) {
            for (int y = 0; y < 4; ++y) {
              for (int x = 0; x < 8; ++x) {
                std::swap(data[y * 8 + x], data[(7 - y) * 8 + x]);
              }
            }
          }
        }
 
        // Push pixel changes to the existing surface before queuing texture work
        tile8_preview_bmp_.UpdateSurfacePixels();
 
        // Queue texture creation/update on the persistent preview bitmap to
        // avoid dangling stack pointers in the arena queue
        const auto preview_command =
            tile8_preview_bmp_.texture()
                ? gfx::Arena::TextureCommandType::UPDATE
                : gfx::Arena::TextureCommandType::CREATE;
        gfx::Arena::Get().QueueTextureCommand(preview_command,
                                              &tile8_preview_bmp_);
 
        // CRITICAL FIX: Handle tile painting with simple click instead of
        // click+drag Draw the preview first
        tile16_edit_canvas_.DrawTilePainter(tile8_preview_bmp_, 8,
                                            kTile8DisplayScale);
 
        const bool left_clicked = ImGui::IsItemClicked(ImGuiMouseButton_Left);
        const bool right_clicked = ImGui::IsItemClicked(ImGuiMouseButton_Right);
 
        if (left_clicked || right_clicked) {
          const ImGuiIO& io = ImGui::GetIO();
          ImVec2 canvas_pos = tile16_edit_canvas_.zero_point();
          ImVec2 mouse_pos = ImVec2(io.MousePos.x - canvas_pos.x,
                                    io.MousePos.y - canvas_pos.y);
 
          // Convert canvas coordinates to tile16 coordinates
          // Account for bitmap offset (2,2) and scale (4x)
          constexpr float kBitmapOffset = 2.0f;
          constexpr float kBitmapScale = 4.0f;
          int tile_x =
              static_cast<int>((mouse_pos.x - kBitmapOffset) / kBitmapScale);
          int tile_y =
              static_cast<int>((mouse_pos.y - kBitmapOffset) / kBitmapScale);
 
          // Clamp to valid range (0-15 for 16x16 tile)
          tile_x = std::max(0, std::min(15, tile_x));
          tile_y = std::max(0, std::min(15, tile_y));
 
          util::logf(
              "Tile16 canvas click: (%.2f, %.2f) -> Tile16: (%d, %d), mode=%s",
              mouse_pos.x, mouse_pos.y, tile_x, tile_y,
              EditModeLabel(edit_mode_));
 
          RETURN_IF_ERROR(HandleTile16CanvasClick(ImVec2(tile_x, tile_y),
                                                  left_clicked, right_clicked));
        }
      }
 
      gui::EndCanvas(tile16_edit_canvas_, tile16_edit_rt,
                     tile16_edit_frame_opts);
    }
    ImGui::EndChild();
 
    Separator();
 
    // === Compact Controls Section ===
 
    // Tile8 info and preview
    if (current_tile8_ >= 0 &&
        current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
      Text("Tile8: %02X", current_tile8_);
      SameLine();
      auto* tile8_texture = tile8_preview_bmp_.texture();
      if (tile8_texture) {
        ImGui::Image((ImTextureID)(intptr_t)tile8_texture, ImVec2(24, 24));
      }
 
      // Show encoded palette row indicator
      // This shows which palette row the tile is encoded to use in the ROM
      int sheet_idx = GetSheetIndexForTile8(current_tile8_);
      int encoded_row = -1;
 
      // Determine encoded row based on sheet and ProcessGraphicsBuffer behavior
      // Sheets 0, 3, 4, 5 have 0x88 added (row 8-9)
      // Other sheets have raw values (row 0)
      switch (sheet_idx) {
        case 0:
        case 3:
        case 4:
        case 5:
          encoded_row = 8;  // 0x88 offset = row 8
          break;
        default:
          encoded_row = 0;  // Raw values = row 0
          break;
      }
 
      // Visual indicator showing sheet and encoded row
      ImGui::SameLine();
      ImGui::TextDisabled("S%d", sheet_idx);
      if (ImGui::IsItemHovered()) {
        ImGui::BeginTooltip();
        ImGui::Text("Sheet: %d", sheet_idx);
        ImGui::Text("Encoded Palette Row: %d", encoded_row);
        ImGui::Separator();
        ImGui::TextWrapped(
            "Graphics sheets have different palette encodings:\n"
            "- Sheets 0,3,4,5: Row 8 (offset 0x88)\n"
            "- Sheets 1,2,6,7: Row 0 (raw)");
        ImGui::EndTooltip();
      }
    }
 
    // Tile8 transform options in compact form
    Checkbox("X Flip", &x_flip);
    SameLine();
    Checkbox("Y Flip", &y_flip);
    SameLine();
    Checkbox("Priority", &priority_tile);
 
    Text("Stamp:");
    SameLine();
    if (ImGui::RadioButton("1x", tile8_stamp_size_ == 1)) {
      tile8_stamp_size_ = 1;
    }
    SameLine();
    if (ImGui::RadioButton("2x", tile8_stamp_size_ == 2)) {
      tile8_stamp_size_ = 2;
    }
    SameLine();
    if (ImGui::RadioButton("4x", tile8_stamp_size_ == 4)) {
      tile8_stamp_size_ = 4;
    }
    HOVER_HINT(
        "1x: paint one quadrant\n2x: fill current tile16 from a 2x2 tile8 "
        "block\n4x: stamp a 2x2 tile16 patch from a 4x4 tile8 block");
 
    Text("Edit Mode:");
    if (ImGui::RadioButton("Paint (P)", edit_mode_ == Tile16EditMode::kPaint)) {
      edit_mode_ = Tile16EditMode::kPaint;
    }
    SameLine();
    if (ImGui::RadioButton("Pick (I)", edit_mode_ == Tile16EditMode::kPick)) {
      edit_mode_ = Tile16EditMode::kPick;
    }
    SameLine();
    if (ImGui::RadioButton("Usage (U)",
                           edit_mode_ == Tile16EditMode::kUsageProbe)) {
      edit_mode_ = Tile16EditMode::kUsageProbe;
    }
    HOVER_HINT(
        "Paint: left-click places Tile8 into Tile16.\n"
        "Pick: left-click samples Tile8 from Tile16.\n"
        "Usage: keeps usage overlay visible and samples on click.\n"
        "Right-click on Tile16 preview always samples.");
 
    Separator();
 
    RETURN_IF_ERROR(DrawBrushAndTilePaletteControls(show_debug_info));
 
    Separator();
 
    RETURN_IF_ERROR(DrawPrimaryActionControls());
 
    // Advanced controls (collapsible)
    if (show_advanced_controls) {
      Separator();
      Text("Advanced:");
 
      if (Button("Palette Settings", ImVec2(-1, 0))) {
        show_palette_settings_ = !show_palette_settings_;
      }
 
      if (Button("Analyze Data", ImVec2(-1, 0))) {
        AnalyzeTile8SourceData();
      }
      HOVER_HINT("Analyze tile8 source data format and palette state");
 
      if (Button("Manual Edit", ImVec2(-1, 0))) {
        ImGui::OpenPopup("ManualTile8Editor");
      }
 
      if (Button("Refresh Blockset", ImVec2(-1, 0))) {
        RETURN_IF_ERROR(RefreshTile16Blockset());
      }
 
      // Scratch space in compact form
      Text("Scratch:");
      DrawScratchSpace();
 
      // Manual tile8 editor popup
      DrawManualTile8Inputs();
    }
 
    // Compact debug information panel
    if (show_debug_info) {
      Separator();
      Text("Debug:");
      ImGui::TextDisabled("T16:%02X T8:%d Pal:%d", current_tile16_,
                          current_tile8_, current_palette_);
 
      if (current_tile8_ >= 0) {
        int sheet_index = GetSheetIndexForTile8(current_tile8_);
        int actual_slot = GetActualPaletteSlot(current_palette_, sheet_index);
        ImGui::TextDisabled("Sheet:%d Slot:%d", sheet_index, actual_slot);
      }
 
      // Compact palette mapping table
      if (ImGui::CollapsingHeader("Palette Map",
                                  ImGuiTreeNodeFlags_DefaultOpen)) {
        ImGui::BeginChild("##PaletteMappingScroll", ImVec2(0, 120), true);
        if (ImGui::BeginTable("##PalMap", 3,
                              ImGuiTableFlags_Borders | ImGuiTableFlags_RowBg |
                                  ImGuiTableFlags_SizingFixedFit)) {
          ImGui::TableSetupColumn("Btn", ImGuiTableColumnFlags_WidthFixed, 30);
          ImGui::TableSetupColumn("S0,3-4", ImGuiTableColumnFlags_WidthFixed,
                                  50);
          ImGui::TableSetupColumn("S1-2", ImGuiTableColumnFlags_WidthFixed, 50);
          ImGui::TableHeadersRow();
 
          for (int i = 0; i < 8; ++i) {
            ImGui::TableNextRow();
            ImGui::TableNextColumn();
            ImGui::Text("%d", i);
            ImGui::TableNextColumn();
            ImGui::Text("%d", GetActualPaletteSlot(i, 0));
            ImGui::TableNextColumn();
            ImGui::Text("%d", GetActualPaletteSlot(i, 1));
          }
          ImGui::EndTable();
        }
        ImGui::EndChild();
      }
 
      // Color preview - compact
      if (ImGui::CollapsingHeader("Colors")) {
        if (overworld_palette_.size() >= 256) {
          int actual_slot = GetActualPaletteSlotForCurrentTile16();
          ImGui::Text("Slot %d:", actual_slot);
 
          for (int i = 0;
               i < 8 &&
               (actual_slot + i) < static_cast<int>(overworld_palette_.size());
               ++i) {
            int color_index = actual_slot + i;
            auto color = overworld_palette_[color_index];
            ImVec4 display_color = color.rgb();
 
            ImGui::ColorButton(absl::StrFormat("##c%d", i).c_str(),
                               display_color, ImGuiColorEditFlags_NoTooltip,
                               ImVec2(20, 20));
            if (ImGui::IsItemHovered()) {
              ImGui::SetTooltip("%d:0x%04X", color_index, color.snes());
            }
 
            if ((i + 1) % 4 != 0)
              ImGui::SameLine();
          }
        }
      }
    }
 
    ImGui::EndGroup();
    EndTable();
  }
 
  RETURN_IF_ERROR(
      DrawBottomActionRail(has_pending, current_tile_pending, pending_count));
 
  // Draw palette settings and canvas popups
  DrawPaletteSettings();
 
  // Show canvas popup windows if opened from context menu
  blockset_canvas_.ShowAdvancedCanvasProperties();
  blockset_canvas_.ShowScalingControls();
  tile8_source_canvas_.ShowAdvancedCanvasProperties();
  tile8_source_canvas_.ShowScalingControls();
  tile16_edit_canvas_.ShowAdvancedCanvasProperties();
  tile16_edit_canvas_.ShowScalingControls();
 
  return absl::OkStatus();
}
 
void Tile16Editor::DrawEditorHeader(bool show_debug_info) {
  active_quadrant_ = std::clamp(active_quadrant_, 0, 3);
  static constexpr std::array<const char*, 4> kQuadrantLabels = {"TL", "TR",
                                                                 "BL", "BR"};
  int quadrant_palette_tl = -1;
  int quadrant_palette_tr = -1;
  int quadrant_palette_bl = -1;
  int quadrant_palette_br = -1;
  if (const auto* tile_data = GetCurrentTile16Data()) {
    quadrant_palette_tl = tile_data->tile0_.palette_;
    quadrant_palette_tr = tile_data->tile1_.palette_;
    quadrant_palette_bl = tile_data->tile2_.palette_;
    quadrant_palette_br = tile_data->tile3_.palette_;
  }
 
  ImGui::BeginGroup();
  ImGui::TextColored(ImVec4(0.8f, 0.9f, 1.0f, 1.0f), "Tile16 Editor");
  ImGui::SameLine();
  ImGui::TextDisabled("ID: %02X", current_tile16_);
  ImGui::SameLine();
  ImGui::TextDisabled("| Brush Palette: %d", current_palette_);
  ImGui::SameLine();
  ImGui::TextDisabled("| Active Quadrant: %s",
                      kQuadrantLabels[active_quadrant_]);
  ImGui::SameLine();
  ImGui::TextDisabled("| Edit Mode: %s", EditModeLabel(edit_mode_));
 
  if (quadrant_palette_tl >= 0) {
    ImGui::SameLine();
    ImGui::TextDisabled("| Tile Meta TL/TR/BL/BR: %d/%d/%d/%d",
                        quadrant_palette_tl, quadrant_palette_tr,
                        quadrant_palette_bl, quadrant_palette_br);
  }
 
  ImGui::SameLine();
  const bool usage_mode_active = highlight_tile8_usage_;
  ImGui::TextColored(
      usage_mode_active ? ImVec4(0.55f, 0.90f, 0.60f, 1.0f)
                        : ImVec4(0.95f, 0.86f, 0.46f, 1.0f),
      usage_mode_active ? "Usage Mode: ACTIVE" : "Usage Mode: Hold RMB or U");
  if (ImGui::IsItemHovered()) {
    ImGui::BeginTooltip();
    ImGui::Text("Usage Mode");
    ImGui::Separator();
    ImGui::TextDisabled("Current edit mode: %s", EditModeLabel(edit_mode_));
    ImGui::TextDisabled(
        "Press U to lock usage overlay and probe interactions.");
    ImGui::TextDisabled(
        "Hold RMB on the Tile8 Source panel for temporary usage highlighting.");
    ImGui::TextDisabled(
        "Pick mode (I) and Usage mode (U) sample on left-click.");
    ImGui::TextDisabled(
        "Paint mode (P) places Tile8 data and metadata on left-click.");
    ImGui::TextDisabled("Navigation shortcuts: PgUp/PgDn/Home/End + arrows.");
    ImGui::TextDisabled("Modes: P/I/U | Palette: Ctrl+1..8 | Quadrants: 1..4");
    ImGui::EndTooltip();
  }
 
  if (show_debug_info) {
    ImGui::SameLine();
    const int actual_slot = GetActualPaletteSlotForCurrentTile16();
    ImGui::TextDisabled("(Slot: %d)", actual_slot);
  }
  ImGui::EndGroup();
}
 
void Tile16Editor::DrawEditorHeaderToggles(bool* show_debug_info,
                                           bool* show_advanced_controls) {
  ImGui::SameLine(ImGui::GetContentRegionAvail().x - 180);
  if (ImGui::Button("Debug Info", ImVec2(80, 0))) {
    *show_debug_info = !*show_debug_info;
  }
  ImGui::SameLine();
  if (ImGui::Button("Advanced", ImVec2(80, 0))) {
    *show_advanced_controls = !*show_advanced_controls;
  }
}
 
void Tile16Editor::DrawStagedStateBar(bool has_pending,
                                      bool current_tile_pending,
                                      int pending_count) {
  const ImVec4 staged_bar_bg =
      current_tile_pending ? ImVec4(0.27f, 0.18f, 0.09f, 0.65f)
                           : (has_pending ? ImVec4(0.16f, 0.15f, 0.18f, 0.65f)
                                          : ImVec4(0.12f, 0.17f, 0.13f, 0.65f));
  gui::StyleColorGuard staged_bar_guard(ImGuiCol_ChildBg, staged_bar_bg);
  if (ImGui::BeginChild(
          "##Tile16StagedStateBar", ImVec2(0, 58), true,
          ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse)) {
    if (current_tile_pending) {
      ImGui::TextColored(ImVec4(1.0f, 0.82f, 0.30f, 1.0f), "Tile %02X: STAGED",
                         current_tile16_);
    } else {
      ImGui::TextColored(ImVec4(0.45f, 0.85f, 0.55f, 1.0f), "Tile %02X: CLEAN",
                         current_tile16_);
    }
 
    ImGui::SameLine();
    ImGui::TextDisabled("| Queue: %d tile%s pending", pending_count,
                        pending_count == 1 ? "" : "s");
 
    if (has_rom_write_history_) {
      const auto seconds_since_write =
          std::chrono::duration_cast<std::chrono::seconds>(
              std::chrono::steady_clock::now() - last_rom_write_time_)
              .count();
      ImGui::SameLine();
      ImGui::TextDisabled("| Last write: %d tile%s, %lds ago",
                          last_rom_write_count_,
                          last_rom_write_count_ == 1 ? "" : "s",
                          static_cast<long>(seconds_since_write));
    }
    ImGui::TextDisabled(
        "Action rail at bottom: Write Pending / Discard / Undo");
  }
  ImGui::EndChild();
}
 
absl::Status Tile16Editor::DrawBrushAndTilePaletteControls(
    bool show_debug_info) {
  // Palette selector - this is the paint brush palette for new placements.
  Text("Brush Palette:");
  if (show_debug_info) {
    SameLine();
    int actual_slot = GetActualPaletteSlotForCurrentTile16();
    ImGui::TextDisabled("(Slot %d)", actual_slot);
  }
  ImGui::TextDisabled("Used for new tile8 placements");
 
  // Compact palette grid
  ImGui::BeginGroup();
  float available_width = ImGui::GetContentRegionAvail().x;
  float button_size = std::min(32.0f, (available_width - 16.0f) / 4.0f);
 
  for (int row = 0; row < 2; ++row) {
    for (int col = 0; col < 4; ++col) {
      if (col > 0)
        ImGui::SameLine();
 
      int i = row * 4 + col;
      bool is_current = (current_palette_ == i);
 
      // Modern button styling with better visual hierarchy
      ImGui::PushID(i);
 
      gui::StyleColorGuard palette_btn_colors(
          {{ImGuiCol_Button, is_current ? ImVec4(0.2f, 0.7f, 0.3f, 1.0f)
                                        : ImVec4(0.3f, 0.3f, 0.35f, 1.0f)},
           {ImGuiCol_ButtonHovered, is_current
                                        ? ImVec4(0.3f, 0.8f, 0.4f, 1.0f)
                                        : ImVec4(0.4f, 0.4f, 0.45f, 1.0f)},
           {ImGuiCol_ButtonActive, is_current
                                       ? ImVec4(0.1f, 0.6f, 0.2f, 1.0f)
                                       : ImVec4(0.25f, 0.25f, 0.3f, 1.0f)},
           {ImGuiCol_Border, is_current ? ImVec4(0.4f, 0.9f, 0.5f, 1.0f)
                                        : ImVec4(0.5f, 0.5f, 0.5f, 0.3f)}});
      gui::StyleVarGuard palette_btn_border(ImGuiStyleVar_FrameBorderSize,
                                            1.0f);
 
      if (ImGui::Button(absl::StrFormat("%d", i).c_str(),
                        ImVec2(button_size, button_size))) {
        if (current_palette_ != i) {
          current_palette_ = i;
          auto status = RefreshAllPalettes();
          if (!status.ok()) {
            util::logf("Failed to refresh palettes: %s",
                       status.message().data());
          } else {
            util::logf("Palette successfully changed to %d", current_palette_);
          }
        }
      }
 
      ImGui::PopID();
 
      if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
        current_palette_ = static_cast<uint8_t>(i);
        RETURN_IF_ERROR(ApplyPaletteToAll(current_palette_));
      }
 
      // Tooltip with palette info
      if (ImGui::IsItemHovered()) {
        ImGui::BeginTooltip();
        if (show_debug_info) {
          ImGui::Text("Palette %d -> Slots:", i);
          ImGui::Text("  S0,3,4: %d", GetActualPaletteSlot(i, 0));
          ImGui::Text("  S1,2: %d", GetActualPaletteSlot(i, 1));
          ImGui::Text("  S5,6: %d", GetActualPaletteSlot(i, 5));
          ImGui::Text("  S7: %d", GetActualPaletteSlot(i, 7));
        } else {
          ImGui::Text("Brush Palette %d", i);
          ImGui::TextDisabled("Applied to new tile8 placements");
          ImGui::TextDisabled("RMB: apply to all tile quadrants");
          ImGui::TextDisabled("Quadrant metadata is shown in strip below");
          ImGui::TextDisabled(
              "Hotkeys: Ctrl+1..8 palette, 1..4 quadrant focus");
          if (is_current) {
            ImGui::TextColored(ImVec4(0.3f, 0.8f, 0.3f, 1.0f), "Active");
          }
        }
        ImGui::EndTooltip();
      }
    }
  }
  ImGui::EndGroup();
 
  if (auto* tile_data = GetCurrentTile16Data(); tile_data != nullptr) {
    active_quadrant_ = std::clamp(active_quadrant_, 0, 3);
    Text("Quadrant Focus:");
    SameLine();
    ImGui::TextDisabled("1-4");
    static constexpr std::array<const char*, 4> kQuadrantLabels = {"TL", "TR",
                                                                   "BL", "BR"};
    const float quadrant_button_width = std::max(58.0f, button_size + 24.0f);
    for (int q = 0; q < 4; ++q) {
      if (q > 0) {
        SameLine();
      }
 
      const gfx::TileInfo& info = TileInfoForQuadrant(*tile_data, q);
      const uint8_t quadrant_palette = info.palette_;
      const bool is_active_quadrant = (active_quadrant_ == q);
      const bool matches_brush = (quadrant_palette == current_palette_);
 
      ImGui::PushID(100 + q);
      gui::StyleColorGuard quadrant_btn_colors(
          {{ImGuiCol_Button,
            is_active_quadrant
                ? ImVec4(0.16f, 0.48f, 0.72f, 1.0f)
                : (matches_brush ? ImVec4(0.23f, 0.35f, 0.50f, 1.0f)
                                 : ImVec4(0.28f, 0.28f, 0.32f, 1.0f))},
           {ImGuiCol_ButtonHovered,
            is_active_quadrant
                ? ImVec4(0.20f, 0.56f, 0.82f, 1.0f)
                : (matches_brush ? ImVec4(0.28f, 0.43f, 0.60f, 1.0f)
                                 : ImVec4(0.38f, 0.38f, 0.42f, 1.0f))},
           {ImGuiCol_ButtonActive,
            is_active_quadrant
                ? ImVec4(0.12f, 0.40f, 0.62f, 1.0f)
                : (matches_brush ? ImVec4(0.18f, 0.30f, 0.44f, 1.0f)
                                 : ImVec4(0.24f, 0.24f, 0.28f, 1.0f))},
           {ImGuiCol_Border, is_active_quadrant
                                 ? ImVec4(0.45f, 0.78f, 1.0f, 1.0f)
                                 : ImVec4(0.4f, 0.4f, 0.4f, 0.4f)}});
      gui::StyleVarGuard quadrant_btn_border(ImGuiStyleVar_FrameBorderSize,
                                             is_active_quadrant ? 2.0f : 1.0f);
 
      if (ImGui::Button(absl::StrFormat("%d %s:%d", q + 1, kQuadrantLabels[q],
                                        quadrant_palette)
                            .c_str(),
                        ImVec2(quadrant_button_width, 0))) {
        active_quadrant_ = q;
        if (current_palette_ != quadrant_palette) {
          current_palette_ = quadrant_palette;
          auto status = RefreshAllPalettes();
          if (!status.ok()) {
            util::logf("Failed to refresh palettes: %s",
                       status.message().data());
          }
        }
      }
 
      if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
        active_quadrant_ = q;
        RETURN_IF_ERROR(ApplyPaletteToQuadrant(q, current_palette_));
      }
 
      if (ImGui::IsItemHovered()) {
        ImGui::BeginTooltip();
        ImGui::Text("Quadrant %s metadata", kQuadrantLabels[q]);
        ImGui::Separator();
        ImGui::Text("Tile8: %02X", info.id_);
        ImGui::Text("Palette: %d", quadrant_palette);
        ImGui::Text("Flip: H:%s V:%s", info.horizontal_mirror_ ? "Y" : "N",
                    info.vertical_mirror_ ? "Y" : "N");
        ImGui::Text("Priority: %s", info.over_ ? "Y" : "N");
        ImGui::TextDisabled("LMB: set brush palette from this quadrant");
        ImGui::TextDisabled(
            "RMB: apply current brush palette to this quadrant");
        ImGui::TextDisabled("Keys 1..4: focus TL/TR/BL/BR");
        ImGui::EndTooltip();
      }
 
      ImGui::PopID();
    }
 
    const gfx::TileInfo& active_info =
        TileInfoForQuadrant(*tile_data, active_quadrant_);
    ImGui::TextDisabled("Active %s: Tile8 %02X | P%d | H:%s V:%s | Pri:%s",
                        kQuadrantLabels[active_quadrant_], active_info.id_,
                        active_info.palette_,
                        active_info.horizontal_mirror_ ? "Y" : "N",
                        active_info.vertical_mirror_ ? "Y" : "N",
                        active_info.over_ ? "Y" : "N");
 
    if (Button("Apply Brush to Active Quadrant", ImVec2(-1, 0))) {
      RETURN_IF_ERROR(
          ApplyPaletteToQuadrant(active_quadrant_, current_palette_));
    }
    HOVER_HINT(
        "Copy the Brush Palette into the selected quadrant metadata.\n"
        "Use keys 1..4 to change active quadrant quickly.");
  }
 
  // Copy the current brush palette into all stored quadrant palette fields.
  if (Button("Apply Brush to All Quadrants", ImVec2(-1, 0))) {
    RETURN_IF_ERROR(ApplyPaletteToAll(current_palette_));
  }
  HOVER_HINT(
      "Copy the Brush Palette into Tile Palette metadata for all 4 "
      "quadrants.\n"
      "Tip: right-click any brush palette button above for a one-step apply.");
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::DrawTile8SourcePanel() {
  ImGui::TextColored(ImVec4(0.9f, 0.9f, 0.9f, 1.0f), "Tile8 Source");
 
  tile8_source_canvas_.set_draggable(false);
 
  if (BeginChild("##Tile8SourceScrollable", ImVec2(0, 0), true,
                 ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
    gui::CanvasFrameOptions tile8_frame_opts;
    tile8_frame_opts.draw_grid = true;
    tile8_frame_opts.grid_step = 32.0f;  // Tile8 grid (8px * 4 scale)
    tile8_frame_opts.draw_context_menu = true;
    tile8_frame_opts.draw_overlay = true;
    tile8_frame_opts.render_popups = true;
    tile8_frame_opts.use_child_window = false;
 
    auto tile8_rt = gui::BeginCanvas(tile8_source_canvas_, tile8_frame_opts);
 
    tile8_source_canvas_.DrawTileSelector(32.0F);
 
    const bool left_clicked = ImGui::IsItemClicked(ImGuiMouseButton_Left);
    const bool right_clicked = ImGui::IsItemClicked(ImGuiMouseButton_Right);
 
    // ZScream parity: hold right-click on tile8 source to show usage overlay.
    const bool temporary_usage = ComputeTile8UsageHighlight(
        ImGui::IsItemHovered(), ImGui::IsMouseDown(ImGuiMouseButton_Right));
    highlight_tile8_usage_ =
        (edit_mode_ == Tile16EditMode::kUsageProbe) || temporary_usage;
 
    if (left_clicked || right_clicked) {
      RETURN_IF_ERROR(HandleTile8SourceSelection(right_clicked));
    }
 
    if (current_gfx_bmp_ != nullptr) {
      tile8_source_canvas_.DrawBitmap(*current_gfx_bmp_, 2, 2,
                                      kTile8DisplayScale);
    }
 
    gui::EndCanvas(tile8_source_canvas_, tile8_rt, tile8_frame_opts);
  }
  EndChild();
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::HandleTile8SourceSelection(bool right_clicked) {
  const ImGuiIO& io = ImGui::GetIO();
  ImVec2 canvas_pos = tile8_source_canvas_.zero_point();
  ImVec2 mouse_pos =
      ImVec2(io.MousePos.x - canvas_pos.x, io.MousePos.y - canvas_pos.y);
 
  const int new_tile8 = ComputeTile8IndexFromCanvasMouse(
      mouse_pos.x, mouse_pos.y, current_gfx_bmp_->width(),
      static_cast<int>(current_gfx_individual_.size()), kTile8DisplayScale);
  if (new_tile8 < 0 || new_tile8 == current_tile8_) {
    return absl::OkStatus();
  }
 
  current_tile8_ = new_tile8;
  RETURN_IF_ERROR(UpdateTile8Palette(current_tile8_));
  if (right_clicked) {
    tile8_usage_cache_dirty_ = true;
  }
  util::logf("Selected Tile8: %d", current_tile8_);
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::DrawPrimaryActionControls() {
  // Local tile-shaping actions stay in the right column.
  if (Button("Clear", ImVec2(-1, 0))) {
    RETURN_IF_ERROR(ClearTile16());
  }
 
  if (Button("Copy", ImVec2(-1, 0))) {
    RETURN_IF_ERROR(CopyTile16ToClipboard(current_tile16_));
  }
 
  if (Button("Paste", ImVec2(-1, 0))) {
    RETURN_IF_ERROR(PasteTile16FromClipboard());
  }
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::DrawBottomActionRail(bool has_pending,
                                                bool current_tile_pending,
                                                int pending_count) {
  const Tile16ActionControlState action_state = ComputeTile16ActionControlState(
      has_pending, current_tile_pending, undo_manager_.CanUndo());
 
  gui::StyleColorGuard rail_bg(
      {{ImGuiCol_ChildBg, ImVec4(0.10f, 0.13f, 0.16f, 0.85f)}});
  if (ImGui::BeginChild(
          "##Tile16BottomActionRail", ImVec2(0, 64), true,
          ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse)) {
    ImGui::TextDisabled("Queue: %d tile%s staged", pending_count,
                        pending_count == 1 ? "" : "s");
    ImGui::SameLine();
    ImGui::TextDisabled("| Mode: %s", EditModeLabel(edit_mode_));
 
    const float spacing = ImGui::GetStyle().ItemSpacing.x;
    const float avail = ImGui::GetContentRegionAvail().x;
    const float button_width =
        std::max(110.0f, (avail - spacing * 3.0f) / 4.0f);
 
    if (!action_state.can_write_pending) {
      ImGui::BeginDisabled();
    }
    if (gui::SuccessButton("Write Pending", ImVec2(button_width, 0))) {
      RETURN_IF_ERROR(CommitAllChanges());
    }
    if (!action_state.can_write_pending) {
      ImGui::EndDisabled();
    }
    if (ImGui::IsItemHovered()) {
      ImGui::SetTooltip("Write all %d pending tile16 edits to ROM",
                        pending_count);
    }
 
    ImGui::SameLine();
    if (!action_state.can_discard_current) {
      ImGui::BeginDisabled();
    }
    if (ImGui::Button("Discard Current", ImVec2(button_width, 0))) {
      DiscardCurrentTileChanges();
    }
    if (!action_state.can_discard_current) {
      ImGui::EndDisabled();
    }
 
    ImGui::SameLine();
    if (!action_state.can_write_pending) {
      ImGui::BeginDisabled();
    }
    if (gui::DangerButton("Discard All", ImVec2(button_width, 0))) {
      DiscardAllChanges();
    }
    if (!action_state.can_write_pending) {
      ImGui::EndDisabled();
    }
 
    ImGui::SameLine();
    if (!action_state.can_undo) {
      ImGui::BeginDisabled();
    }
    if (ImGui::Button("Undo", ImVec2(button_width, 0))) {
      RETURN_IF_ERROR(Undo());
    }
    if (!action_state.can_undo) {
      ImGui::EndDisabled();
    }
  }
  ImGui::EndChild();
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::LoadTile8() {
  if (!HasCurrentGfxBitmap() || current_gfx_bmp_->data() == nullptr) {
    return absl::FailedPreconditionError(
        "Current graphics bitmap not initialized");
  }
 
  current_gfx_individual_.clear();
 
  // Calculate how many 8x8 tiles we can fit based on the current graphics
  // bitmap size SNES graphics are typically 128 pixels wide (16 tiles of 8
  // pixels each)
  const int tiles_per_row = current_gfx_bmp_->width() / 8;
  const int total_rows = current_gfx_bmp_->height() / 8;
  const int total_tiles = tiles_per_row * total_rows;
 
  current_gfx_individual_.reserve(total_tiles);
 
  // Extract individual 8x8 tiles from the graphics bitmap
  for (int tile_y = 0; tile_y < total_rows; ++tile_y) {
    for (int tile_x = 0; tile_x < tiles_per_row; ++tile_x) {
      zelda3::Tile8PixelData tile_data{};
 
      // Extract tile data from the main graphics bitmap.
      // Preserve encoded palette offsets unless normalization is enabled.
      for (int py = 0; py < 8; ++py) {
        for (int px = 0; px < 8; ++px) {
          int src_x = tile_x * 8 + px;
          int src_y = tile_y * 8 + py;
          int src_index = src_y * current_gfx_bmp_->width() + src_x;
          int dst_index = py * 8 + px;
 
          if (src_index < static_cast<int>(current_gfx_bmp_->size()) &&
              dst_index < 64) {
            uint8_t pixel_value = current_gfx_bmp_->data()[src_index];
 
            if (auto_normalize_pixels_) {
              pixel_value &= palette_normalization_mask_;
            }
 
            tile_data[dst_index] = pixel_value;
          }
        }
      }
 
      current_gfx_individual_.push_back(tile_data);
    }
  }
 
  // Apply current palette settings to all tiles when a display palette is ready.
  // Some integration/headless initialization paths populate tile graphics before
  // the overworld palette is available; defer palette refresh in that case.
  if (rom_) {
    const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
    if (display_palette && !display_palette->empty()) {
      RETURN_IF_ERROR(RefreshAllPalettes());
    } else {
      util::logf(
          "LoadTile8: display palette not available yet; deferring refresh");
    }
  }
 
  // Ensure canvas scroll size matches the full tilesheet at preview scale
  tile8_source_canvas_.SetCanvasSize(
      ImVec2(current_gfx_bmp_->width() * kTile8DisplayScale,
             current_gfx_bmp_->height() * kTile8DisplayScale));
 
  util::logf("Loaded %zu individual tile8 graphics",
             current_gfx_individual_.size());
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::SetCurrentTile(int tile_id) {
  if (tile_id < 0 || tile_id >= kTile16Count) {
    return absl::OutOfRangeError(
        absl::StrFormat("Invalid tile16 id: %d", tile_id));
  }
 
  if (!tile16_blockset_ || !rom_) {
    return absl::FailedPreconditionError(
        "Tile16 blockset or ROM not initialized");
  }
 
  // Commit any in-progress edits before switching the current tile selection so
  // undo/redo captures the correct "after" state.
  FinalizePendingUndo();
 
  current_tile16_ = tile_id;
  jump_to_tile_id_ = tile_id;  // Sync input field with current tile
 
  // Load editable tile16 metadata from pending state first, then ROM.
  auto pending_it = pending_tile16_changes_.find(current_tile16_);
  if (pending_it != pending_tile16_changes_.end()) {
    current_tile16_data_ = pending_it->second;
  } else {
    ASSIGN_OR_RETURN(current_tile16_data_,
                     rom_->ReadTile16(current_tile16_, zelda3::kTile16Ptr));
  }
  SyncTilesInfoArray(&current_tile16_data_);
 
  bool bitmap_loaded = false;
 
  auto pending_bitmap_it = pending_tile16_bitmaps_.find(current_tile16_);
  if (pending_bitmap_it != pending_tile16_bitmaps_.end() &&
      pending_bitmap_it->second.is_active()) {
    current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8,
                               pending_bitmap_it->second.vector());
    current_tile16_bmp_.SetPalette(pending_bitmap_it->second.palette());
    bitmap_loaded = true;
  } else {
    auto tile_data = gfx::GetTilemapData(*tile16_blockset_, tile_id);
    if (!tile_data.empty()) {
      for (auto& pixel : tile_data) {
        if (auto_normalize_pixels_) {
          pixel &= palette_normalization_mask_;
        }
      }
      current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8, tile_data);
      bitmap_loaded = true;
    }
  }
 
  if (!bitmap_loaded) {
    RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  } else {
    ApplyPaletteToCurrentTile16Bitmap();
    if (current_tile16_bmp_.is_active() && current_tile16_bmp_.surface()) {
      gfx::Arena::Get().QueueTextureCommand(
          gfx::Arena::TextureCommandType::CREATE, &current_tile16_bmp_);
    }
  }
 
  util::logf("SetCurrentTile: loaded tile %d successfully", tile_id);
 
  if (on_current_tile_changed_) {
    on_current_tile_changed_(current_tile16_);
  }
  return absl::OkStatus();
}
 
void Tile16Editor::RequestTileSwitch(int target_tile_id) {
  // Validate that the tile16 editor is properly initialized
  if (!tile16_blockset_ || !rom_) {
    util::logf(
        "RequestTileSwitch: Editor not initialized (blockset=%p, rom=%p)",
        tile16_blockset_, rom_);
    return;
  }
 
  // Validate target tile ID
  if (target_tile_id < 0 || target_tile_id >= kTile16Count) {
    util::logf("RequestTileSwitch: Invalid target tile ID %d", target_tile_id);
    return;
  }
 
  // Check if we're already on this tile
  if (target_tile_id == current_tile16_) {
    return;
  }
 
  // Check if current tile has pending changes
  if (is_tile_modified(current_tile16_)) {
    // Store target and show dialog
    pending_tile_switch_target_ = target_tile_id;
    show_unsaved_changes_dialog_ = true;
    util::logf("Tile %d has pending changes, showing confirmation dialog",
               current_tile16_);
  } else {
    // No pending changes, switch directly
    auto status = SetCurrentTile(target_tile_id);
    if (!status.ok()) {
      util::logf("Failed to switch to tile %d: %s", target_tile_id,
                 status.message().data());
    }
  }
}
 
absl::Status Tile16Editor::CopyTile16ToClipboard(int tile_id) {
  if (tile_id < 0 || tile_id >= kTile16Count) {
    return absl::InvalidArgumentError("Invalid tile ID");
  }
  if (!rom_) {
    return absl::FailedPreconditionError("ROM not available");
  }
 
  auto pending_tile_it = pending_tile16_changes_.find(tile_id);
  if (tile_id == current_tile16_) {
    clipboard_tile16_.tile_data = current_tile16_data_;
  } else if (pending_tile_it != pending_tile16_changes_.end()) {
    clipboard_tile16_.tile_data = pending_tile_it->second;
  } else {
    ASSIGN_OR_RETURN(clipboard_tile16_.tile_data,
                     rom_->ReadTile16(tile_id, zelda3::kTile16Ptr));
  }
  SyncTilesInfoArray(&clipboard_tile16_.tile_data);
 
  bool bitmap_copied = false;
  auto pending_bitmap_it = pending_tile16_bitmaps_.find(tile_id);
  if (tile_id == current_tile16_ && current_tile16_bmp_.is_active()) {
    clipboard_tile16_.bitmap.Create(kTile16Size, kTile16Size, 8,
                                    current_tile16_bmp_.vector());
    clipboard_tile16_.bitmap.SetPalette(current_tile16_bmp_.palette());
    bitmap_copied = true;
  } else if (pending_bitmap_it != pending_tile16_bitmaps_.end() &&
             pending_bitmap_it->second.is_active()) {
    clipboard_tile16_.bitmap.Create(kTile16Size, kTile16Size, 8,
                                    pending_bitmap_it->second.vector());
    clipboard_tile16_.bitmap.SetPalette(pending_bitmap_it->second.palette());
    bitmap_copied = true;
  } else if (tile16_blockset_) {
    auto tile_pixels = gfx::GetTilemapData(*tile16_blockset_, tile_id);
    if (!tile_pixels.empty()) {
      clipboard_tile16_.bitmap.Create(kTile16Size, kTile16Size, 8, tile_pixels);
      clipboard_tile16_.bitmap.SetPalette(tile16_blockset_->atlas.palette());
      bitmap_copied = true;
    }
  }
 
  if (bitmap_copied) {
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::CREATE, &clipboard_tile16_.bitmap);
  }
 
  clipboard_tile16_.has_data = true;
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::PasteTile16FromClipboard() {
  if (!clipboard_tile16_.has_data) {
    return absl::FailedPreconditionError("Clipboard is empty");
  }
 
  SaveUndoState();
 
  current_tile16_data_ = clipboard_tile16_.tile_data;
  SyncTilesInfoArray(&current_tile16_data_);
 
  if (clipboard_tile16_.bitmap.is_active()) {
    current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8,
                               clipboard_tile16_.bitmap.vector());
    current_tile16_bmp_.SetPalette(clipboard_tile16_.bitmap.palette());
    ApplyPaletteToCurrentTile16Bitmap();
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::CREATE, &current_tile16_bmp_);
  } else {
    RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  }
 
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
  MarkCurrentTileModified();
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::SaveTile16ToScratchSpace(int slot) {
  if (slot < 0 || slot >= kNumScratchSlots) {
    return absl::InvalidArgumentError("Invalid scratch space slot");
  }
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to save");
  }
 
  scratch_space_[slot].tile_data = current_tile16_data_;
  SyncTilesInfoArray(&scratch_space_[slot].tile_data);
  scratch_space_[slot].bitmap.Create(kTile16Size, kTile16Size, 8,
                                     current_tile16_bmp_.vector());
  scratch_space_[slot].bitmap.SetPalette(current_tile16_bmp_.palette());
  // Queue texture creation via Arena's deferred system
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::CREATE,
                                        &scratch_space_[slot].bitmap);
 
  scratch_space_[slot].has_data = true;
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::LoadTile16FromScratchSpace(int slot) {
  if (slot < 0 || slot >= kNumScratchSlots) {
    return absl::InvalidArgumentError("Invalid scratch space slot");
  }
 
  if (!scratch_space_[slot].has_data) {
    return absl::FailedPreconditionError("Scratch space slot is empty");
  }
 
  SaveUndoState();
 
  current_tile16_data_ = scratch_space_[slot].tile_data;
  SyncTilesInfoArray(&current_tile16_data_);
 
  if (scratch_space_[slot].bitmap.is_active()) {
    current_tile16_bmp_.Create(kTile16Size, kTile16Size, 8,
                               scratch_space_[slot].bitmap.vector());
    current_tile16_bmp_.SetPalette(scratch_space_[slot].bitmap.palette());
    ApplyPaletteToCurrentTile16Bitmap();
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::CREATE, &current_tile16_bmp_);
  } else {
    RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  }
 
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
  MarkCurrentTileModified();
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::ClearScratchSpace(int slot) {
  if (slot < 0 || slot >= kNumScratchSlots) {
    return absl::InvalidArgumentError("Invalid scratch space slot");
  }
 
  scratch_space_[slot].has_data = false;
  return absl::OkStatus();
}
 
// Advanced editing features
absl::Status Tile16Editor::FlipTile16Horizontal() {
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to flip");
  }
 
  SaveUndoState();
 
  current_tile16_data_ = zelda3::HorizontalFlipTile16(current_tile16_data_);
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Track this tile as having pending changes
  MarkCurrentTileModified();
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::FlipTile16Vertical() {
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to flip");
  }
 
  SaveUndoState();
 
  current_tile16_data_ = zelda3::VerticalFlipTile16(current_tile16_data_);
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Track this tile as having pending changes
  MarkCurrentTileModified();
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::RotateTile16() {
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to rotate");
  }
 
  SaveUndoState();
 
  // Tile16 metadata does not support arbitrary 8x8 rotation flags.
  // Rotate the 2x2 quadrant layout in a persistable way.
  current_tile16_data_ = zelda3::RotateTile16Clockwise(current_tile16_data_);
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Track this tile as having pending changes
  MarkCurrentTileModified();
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::FillTile16WithTile8(int tile8_id) {
  if (current_gfx_individual_.empty()) {
    if (!HasCurrentGfxBitmap()) {
      return absl::FailedPreconditionError("Source tile8 bitmap not active");
    }
    RETURN_IF_ERROR(LoadTile8());
  }
 
  if (tile8_id < 0 ||
      tile8_id >= static_cast<int>(current_gfx_individual_.size())) {
    return absl::InvalidArgumentError("Invalid tile8 ID");
  }
 
  SaveUndoState();
 
  const gfx::TileInfo fill_info(static_cast<uint16_t>(tile8_id),
                                current_palette_, y_flip, x_flip,
                                priority_tile);
  for (int quadrant = 0; quadrant < 4; ++quadrant) {
    TileInfoForQuadrant(&current_tile16_data_, quadrant) = fill_info;
  }
  SyncTilesInfoArray(&current_tile16_data_);
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Track this tile as having pending changes
  MarkCurrentTileModified();
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::ClearTile16() {
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to clear");
  }
 
  SaveUndoState();
 
  const gfx::TileInfo clear_info(0, current_palette_, false, false, false);
  for (int quadrant = 0; quadrant < 4; ++quadrant) {
    TileInfoForQuadrant(&current_tile16_data_, quadrant) = clear_info;
  }
  SyncTilesInfoArray(&current_tile16_data_);
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Track this tile as having pending changes
  MarkCurrentTileModified();
 
  return absl::OkStatus();
}
 
// Palette management
absl::Status Tile16Editor::CyclePalette(bool forward) {
  uint8_t new_palette = current_palette_;
 
  if (forward) {
    new_palette = (new_palette + 1) % 8;
  } else {
    new_palette = (new_palette == 0) ? 7 : new_palette - 1;
  }
 
  current_palette_ = new_palette;
 
  // Use the RefreshAllPalettes method which handles all the coordination
  RETURN_IF_ERROR(RefreshAllPalettes());
 
  util::logf("Cycled to palette slot %d", current_palette_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::PreviewPaletteChange(uint8_t palette_id) {
  if (!show_palette_preview_) {
    return absl::OkStatus();
  }
 
  if (palette_id >= 8) {
    return absl::InvalidArgumentError("Invalid palette ID");
  }
 
  // Create a preview bitmap with the new palette
  if (!preview_tile16_.is_active()) {
    preview_tile16_.Create(16, 16, 8, current_tile16_bmp_.vector());
  } else {
    // Recreate the preview bitmap with new data
    preview_tile16_.Create(16, 16, 8, current_tile16_bmp_.vector());
  }
 
  const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
  if (!display_palette || display_palette->empty()) {
    return absl::OkStatus();
  }
 
  const bool use_sub_palette_view =
      auto_normalize_pixels_ && !BitmapHasEncodedPaletteRows(preview_tile16_);
  if (use_sub_palette_view) {
    const int sheet_index = GetSheetIndexForTile8(current_tile8_);
    const int palette_slot =
        GetActualPaletteSlot(static_cast<int>(palette_id), sheet_index);
    if (palette_slot >= 0 &&
        static_cast<size_t>(palette_slot + 16) <= display_palette->size()) {
      preview_tile16_.SetPaletteWithTransparent(
          *display_palette, static_cast<size_t>(palette_slot + 1), 15);
    } else {
      preview_tile16_.SetPaletteWithTransparent(*display_palette, 1, 15);
    }
  } else {
    preview_tile16_.SetPalette(*display_palette);
  }
 
  // Queue texture update via Arena's deferred system
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &preview_tile16_);
  preview_dirty_ = true;
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::ApplyPaletteToAll(uint8_t palette_id) {
  if (palette_id >= 8) {
    return absl::InvalidArgumentError("Invalid palette ID");
  }
 
  auto* tile_data = GetCurrentTile16Data();
  if (!tile_data) {
    return absl::FailedPreconditionError("No current tile16 data");
  }
 
  SaveUndoState();
  zelda3::SetTile16AllQuadrantPalettes(tile_data, palette_id);
 
  // Update current palette to match
  current_palette_ = palette_id;
 
  // Regenerate bitmap with new per-quadrant palette metadata
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
 
  // Keep blockset/editor previews in sync with other tile16 edit operations.
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  // Mark as modified
  MarkCurrentTileModified();
 
  util::logf("Applied palette %d to all quadrants of tile %d", palette_id,
             current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::ApplyPaletteToQuadrant(int quadrant,
                                                  uint8_t palette_id) {
  if (palette_id >= 8) {
    return absl::InvalidArgumentError("Invalid palette ID");
  }
  if (quadrant < 0 || quadrant > 3) {
    return absl::InvalidArgumentError("Invalid quadrant index");
  }
 
  auto* tile_data = GetCurrentTile16Data();
  if (!tile_data) {
    return absl::FailedPreconditionError("No current tile16 data");
  }
 
  SaveUndoState();
  if (!zelda3::SetTile16QuadrantPalette(tile_data, quadrant, palette_id)) {
    return absl::InvalidArgumentError("Invalid quadrant index");
  }
  current_palette_ = palette_id;
 
  RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
  if (live_preview_enabled_) {
    RETURN_IF_ERROR(UpdateOverworldTilemap());
  }
 
  MarkCurrentTileModified();
  util::logf("Applied palette %d to quadrant %d of tile %d", palette_id,
             quadrant, current_tile16_);
  return absl::OkStatus();
}
 
// Undo/Redo system (unified UndoManager framework)
 
void Tile16Editor::RestoreFromSnapshot(const Tile16Snapshot& snapshot) {
  current_tile16_ = snapshot.tile_id;
  current_tile16_bmp_.Create(16, 16, 8, snapshot.bitmap_data);
  current_tile16_bmp_.SetPalette(snapshot.bitmap_palette);
  current_tile16_data_ = snapshot.tile_data;
  SyncTilesInfoArray(&current_tile16_data_);
  current_palette_ = snapshot.palette;
  x_flip = snapshot.x_flip;
  y_flip = snapshot.y_flip;
  priority_tile = snapshot.priority;
  pending_tile16_changes_[current_tile16_] = current_tile16_data_;
  pending_tile16_bitmaps_[current_tile16_] = current_tile16_bmp_;
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &current_tile16_bmp_);
}
 
void Tile16Editor::FinalizePendingUndo() {
  if (!pending_undo_before_.has_value())
    return;
  if (!current_tile16_bmp_.is_active()) {
    pending_undo_before_.reset();
    return;
  }
 
  // Capture the current (post-edit) state as the "after" snapshot
  Tile16Snapshot after;
  after.tile_id = current_tile16_;
  after.bitmap_data = current_tile16_bmp_.vector();
  after.bitmap_palette = current_tile16_bmp_.palette();
  after.tile_data = current_tile16_data_;
  after.palette = current_palette_;
  after.x_flip = x_flip;
  after.y_flip = y_flip;
  after.priority = priority_tile;
 
  // Build the restore callback that captures `this`
  auto restore_fn = [this](const Tile16Snapshot& snap) {
    RestoreFromSnapshot(snap);
  };
 
  undo_manager_.Push(std::make_unique<Tile16EditAction>(
      std::move(*pending_undo_before_), std::move(after), restore_fn));
 
  pending_undo_before_.reset();
}
 
void Tile16Editor::SaveUndoState() {
  if (!current_tile16_bmp_.is_active()) {
    return;
  }
 
  // Finalize any previously pending snapshot before starting a new one
  FinalizePendingUndo();
 
  Tile16Snapshot before;
  before.tile_id = current_tile16_;
  before.bitmap_data = current_tile16_bmp_.vector();
  before.bitmap_palette = current_tile16_bmp_.palette();
  before.tile_data = current_tile16_data_;
  before.palette = current_palette_;
  before.x_flip = x_flip;
  before.y_flip = y_flip;
  before.priority = priority_tile;
 
  pending_undo_before_ = std::move(before);
}
 
absl::Status Tile16Editor::Undo() {
  FinalizePendingUndo();
  return undo_manager_.Undo();
}
 
absl::Status Tile16Editor::Redo() {
  return undo_manager_.Redo();
}
 
absl::Status Tile16Editor::ValidateTile16Data() {
  if (!tile16_blockset_) {
    return absl::FailedPreconditionError("Tile16 blockset not initialized");
  }
 
  if (current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return absl::OutOfRangeError("Current tile16 ID out of range");
  }
 
  if (current_palette_ >= 8) {
    return absl::OutOfRangeError("Current palette ID out of range");
  }
 
  return absl::OkStatus();
}
 
bool Tile16Editor::IsTile16Valid(int tile_id) const {
  return tile16_blockset_ != nullptr && tile_id >= 0 && tile_id < kTile16Count;
}
 
// Integration with overworld system
absl::Status Tile16Editor::SaveTile16ToROM() {
  if (!rom_) {
    return absl::FailedPreconditionError("ROM not available");
  }
 
  if (!current_tile16_bmp_.is_active()) {
    return absl::FailedPreconditionError("No active tile16 to save");
  }
 
  // Write the tile16 data to ROM first
  RETURN_IF_ERROR(UpdateROMTile16Data());
 
  // Update the tile16 blockset with current changes
  RETURN_IF_ERROR(UpdateOverworldTilemap());
 
  // Commit changes to the tile16 blockset
  RETURN_IF_ERROR(CommitChangesToBlockset());
 
  pending_tile16_changes_.erase(current_tile16_);
  pending_tile16_bitmaps_.erase(current_tile16_);
 
  // Mark ROM as dirty so changes persist when saving
  rom_->set_dirty(true);
  has_rom_write_history_ = true;
  last_rom_write_count_ = 1;
  last_rom_write_time_ = std::chrono::steady_clock::now();
  tile8_usage_cache_dirty_ = true;
 
  util::logf("Tile16 %d saved to ROM", current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::UpdateOverworldTilemap() {
  if (!tile16_blockset_) {
    return absl::FailedPreconditionError("Tile16 blockset not initialized");
  }
 
  if (current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return absl::OutOfRangeError("Current tile16 ID out of range");
  }
 
  // Update atlas directly instead of using problematic tile cache
  CopyTile16ToAtlas(current_tile16_);
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::CommitChangesToBlockset() {
  if (!tile16_blockset_) {
    return absl::FailedPreconditionError("Tile16 blockset not initialized");
  }
 
  // Regenerate the tilemap data if needed
  if (tile16_blockset_->atlas.modified()) {
    // Queue texture update via Arena's deferred system
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, &tile16_blockset_->atlas);
  }
 
  // Update individual cached tiles
  // Note: With the new tile cache system, tiles are automatically managed
  // and don't need manual modification tracking like the old system
  // The cache handles LRU eviction and automatic updates
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::CommitChangesToOverworld() {
  // Step 1: Update ROM data with current tile16 changes
  RETURN_IF_ERROR(UpdateROMTile16Data());
 
  // Step 2: Update the local blockset to reflect changes
  RETURN_IF_ERROR(UpdateBlocksetBitmap());
 
  // Step 3: Update the atlas directly
  CopyTile16ToAtlas(current_tile16_);
 
  // Step 4: Notify the parent editor (overworld editor) to regenerate its
  // blockset
  if (on_changes_committed_) {
    RETURN_IF_ERROR(on_changes_committed_());
  }
 
  pending_tile16_changes_.erase(current_tile16_);
  pending_tile16_bitmaps_.erase(current_tile16_);
  has_rom_write_history_ = true;
  last_rom_write_count_ = 1;
  last_rom_write_time_ = std::chrono::steady_clock::now();
  tile8_usage_cache_dirty_ = true;
 
  util::logf("Committed Tile16 %d changes to overworld system",
             current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::DiscardChanges() {
  // Drop the current tile's staged copy first; SetCurrentTile consults pending
  // state before ROM state.
  pending_tile16_changes_.erase(current_tile16_);
  pending_tile16_bitmaps_.erase(current_tile16_);
  tile8_usage_cache_dirty_ = true;
 
  // Reload the current tile16 from ROM to discard any local changes
  RETURN_IF_ERROR(SetCurrentTile(current_tile16_));
 
  util::logf("Discarded Tile16 changes for tile %d", current_tile16_);
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::CommitAllChanges() {
  if (pending_tile16_changes_.empty()) {
    return absl::OkStatus();  // Nothing to commit
  }
 
  const int written_count = static_cast<int>(pending_tile16_changes_.size());
  util::logf("Committing %zu pending tile16 changes to ROM",
             pending_tile16_changes_.size());
 
  // Write all pending changes to ROM
  for (const auto& [tile_id, tile_data] : pending_tile16_changes_) {
    auto status = rom_->WriteTile16(tile_id, zelda3::kTile16Ptr, tile_data);
    if (!status.ok()) {
      util::logf("Failed to write tile16 %d: %s", tile_id,
                 status.message().data());
      return status;
    }
  }
 
  // Clear pending changes before parent refresh (overworld reads committed ROM).
  pending_tile16_changes_.clear();
  pending_tile16_bitmaps_.clear();
 
  // Local atlas hint; full rebuild is typically done in overworld callback.
  RETURN_IF_ERROR(RefreshTile16Blockset());
 
  // Notify parent editor to refresh overworld display
  if (on_changes_committed_) {
    RETURN_IF_ERROR(on_changes_committed_());
  }
 
  rom_->set_dirty(true);
  has_rom_write_history_ = true;
  last_rom_write_count_ = written_count;
  last_rom_write_time_ = std::chrono::steady_clock::now();
  tile8_usage_cache_dirty_ = true;
  util::logf("All pending tile16 changes committed successfully");
  return absl::OkStatus();
}
 
void Tile16Editor::DiscardAllChanges() {
  if (pending_tile16_changes_.empty()) {
    return;
  }
 
  util::logf("Discarding %zu pending tile16 changes",
             pending_tile16_changes_.size());
 
  pending_tile16_changes_.clear();
  pending_tile16_bitmaps_.clear();
  tile8_usage_cache_dirty_ = true;
 
  // Reload current tile to restore original state
  auto status = SetCurrentTile(current_tile16_);
  if (!status.ok()) {
    util::logf("Failed to reload tile after discard: %s",
               status.message().data());
  }
}
 
void Tile16Editor::DiscardCurrentTileChanges() {
  auto it = pending_tile16_changes_.find(current_tile16_);
  if (it != pending_tile16_changes_.end()) {
    pending_tile16_changes_.erase(it);
    pending_tile16_bitmaps_.erase(current_tile16_);
    tile8_usage_cache_dirty_ = true;
    util::logf("Discarded pending changes for tile %d", current_tile16_);
  }
 
  // Reload tile from ROM
  auto status = SetCurrentTile(current_tile16_);
  if (!status.ok()) {
    util::logf("Failed to reload tile after discard: %s",
               status.message().data());
  }
}
 
void Tile16Editor::MarkCurrentTileModified() {
  if (current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return;
  }
 
  SyncTilesInfoArray(&current_tile16_data_);
  pending_tile16_changes_[current_tile16_] = current_tile16_data_;
  pending_tile16_bitmaps_[current_tile16_] = current_tile16_bmp_;
  preview_dirty_ = true;
  tile8_usage_cache_dirty_ = true;
 
  util::logf("Marked tile %d as modified (total pending: %zu)", current_tile16_,
             pending_tile16_changes_.size());
}
 
absl::Status Tile16Editor::RebuildTile8UsageCache() {
  if (!rom_) {
    return absl::FailedPreconditionError("ROM not available for usage cache");
  }
 
  const int total_tiles = zelda3::ComputeTile16Count(tile16_blockset_);
  auto tile_provider = [this](int tile_id) -> absl::StatusOr<gfx::Tile16> {
    auto pending_it = pending_tile16_changes_.find(tile_id);
    if (pending_it != pending_tile16_changes_.end()) {
      return pending_it->second;
    }
    return rom_->ReadTile16(tile_id, zelda3::kTile16Ptr);
  };
 
  RETURN_IF_ERROR(zelda3::BuildTile8UsageIndex(total_tiles, tile_provider,
                                               &tile8_usage_cache_));
 
  tile8_usage_cache_dirty_ = false;
  return absl::OkStatus();
}
 
void Tile16Editor::DrawTile8UsageOverlay() {
  if (!highlight_tile8_usage_ || current_tile8_ < 0 ||
      current_tile8_ >= zelda3::kMaxTile8UsageId) {
    return;
  }
 
  if (tile8_usage_cache_dirty_) {
    auto cache_status = RebuildTile8UsageCache();
    if (!cache_status.ok()) {
      util::logf("Tile8 usage cache rebuild failed: %s",
                 cache_status.message().data());
      return;
    }
  }
 
  const auto& hits = tile8_usage_cache_[current_tile8_];
  if (hits.empty()) {
    return;
  }
 
  ImDrawList* draw_list = ImGui::GetWindowDrawList();
  const ImVec2 canvas_pos = blockset_canvas_.zero_point();
  const float scale = blockset_canvas_.GetGlobalScale();
  const float tile16_display = 32.0f * scale;
  const float quadrant_display = 16.0f * scale;
  const int tiles_per_row =
      std::max(1, tile16_blockset_bmp_->width() / kTile16Size);
 
  for (const auto& hit : hits) {
    const int tile_x = hit.tile16_id % tiles_per_row;
    const int tile_y = hit.tile16_id / tiles_per_row;
    const int quad_x = hit.quadrant % 2;
    const int quad_y = hit.quadrant / 2;
 
    const ImVec2 min(
        canvas_pos.x + (tile_x * tile16_display) + (quad_x * quadrant_display),
        canvas_pos.y + (tile_y * tile16_display) + (quad_y * quadrant_display));
    const ImVec2 max(min.x + quadrant_display, min.y + quadrant_display);
 
    // Mirrors ZScream's right-click usage tint (purple, transparent).
    draw_list->AddRectFilled(min, max, IM_COL32(150, 0, 210, 80));
    draw_list->AddRect(min, max, IM_COL32(215, 170, 255, 180));
  }
}
 
absl::Status Tile16Editor::PickTile8FromTile16(const ImVec2& position) {
  if (!rom_ || current_tile16_ < 0 || current_tile16_ >= kTile16Count) {
    return absl::InvalidArgumentError("Invalid tile16 or ROM not set");
  }
 
  // Determine which quadrant of the tile16 was clicked
  int quad_x = (position.x < 8) ? 0 : 1;  // Left or right half
  int quad_y = (position.y < 8) ? 0 : 1;  // Top or bottom half
  int quadrant = quad_x + (quad_y * 2);   // 0=TL, 1=TR, 2=BL, 3=BR
  active_quadrant_ = std::clamp(quadrant, 0, 3);
 
  // Get the tile16 data structure
  auto* tile16_data = GetCurrentTile16Data();
  if (!tile16_data) {
    return absl::FailedPreconditionError("Failed to get tile16 data");
  }
 
  // Extract tile metadata from the clicked quadrant.
  gfx::TileInfo tile_info = TileInfoForQuadrant(*tile16_data, quadrant);
 
  // Set the current tile8 and palette
  current_tile8_ = tile_info.id_;
  current_palette_ = tile_info.palette_;
 
  // Update the flip states based on the tile info
  x_flip = tile_info.horizontal_mirror_;
  y_flip = tile_info.vertical_mirror_;
  priority_tile = tile_info.over_;
 
  // Refresh the palette to match the picked tile
  RETURN_IF_ERROR(UpdateTile8Palette(current_tile8_));
  RETURN_IF_ERROR(RefreshAllPalettes());
 
  util::logf("Picked tile8 %d with palette %d from quadrant %d of tile16 %d",
             current_tile8_, current_palette_, quadrant, current_tile16_);
 
  return absl::OkStatus();
}
 
// Get the appropriate palette slot for current graphics sheet
int Tile16Editor::GetPaletteSlotForSheet(int sheet_index) const {
  // Based on ProcessGraphicsBuffer logic and overworld palette coordination:
  // Sheets 0,3-6: Use AUX palettes (slots 10-15 in 256-color palette)
  // Sheets 1-2: Use MAIN palette (slots 2-6 in 256-color palette)
  // Sheet 7: Use ANIMATED palette (slot 7 in 256-color palette)
 
  switch (sheet_index) {
    case 0:
      return 10;  // Main blockset -> AUX1 palette region
    case 1:
      return 2;  // Main graphics -> MAIN palette region
    case 2:
      return 3;  // Main graphics -> MAIN palette region
    case 3:
      return 11;  // Area graphics -> AUX1 palette region
    case 4:
      return 12;  // Area graphics -> AUX1 palette region
    case 5:
      return 13;  // Area graphics -> AUX2 palette region
    case 6:
      return 14;  // Area graphics -> AUX2 palette region
    case 7:
      return 7;  // Animated tiles -> ANIMATED palette region
    default:
      return static_cast<int>(
          current_palette_);  // Use current selection for other sheets
  }
}
 
// NEW: Get the actual palette slot for a given palette button and sheet index
// This uses row-based addressing to match the overworld's approach:
// The 256-color palette is organized as 16 rows of 16 colors each.
// Palette buttons 0-7 map to CGRAM rows starting at the sheet's base row,
// skipping HUD rows for overworld visuals.
int Tile16Editor::GetActualPaletteSlot(int palette_button,
                                       int sheet_index) const {
  const int clamped_button = std::clamp(palette_button, 0, 7);
  const int base_row = GetPaletteBaseForSheet(sheet_index);
  const int actual_row = std::clamp(base_row + clamped_button, 0, 15);
 
  // Palette buttons map to CGRAM rows starting from the sheet base.
  return actual_row * 16;
}
 
// NEW: Get the sheet index for a given tile8 ID
int Tile16Editor::GetSheetIndexForTile8(int tile8_id) const {
  // Determine which graphics sheet a tile8 belongs to based on its position
  // This is based on the 256-tile per sheet organization
 
  constexpr int kTilesPerSheet = 256;  // 16x16 tiles per sheet
  int sheet_index = tile8_id / kTilesPerSheet;
 
  // Clamp to valid sheet range (0-7)
  return std::min(7, std::max(0, sheet_index));
}
 
// NEW: Get the actual palette slot for the current tile16 being edited
int Tile16Editor::GetActualPaletteSlotForCurrentTile16() const {
  // For the current tile16, we need to determine which sheet the tile8s belong
  // to and use the most appropriate palette region
 
  if (current_tile8_ >= 0 &&
      current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
    int sheet_index = GetSheetIndexForTile8(current_tile8_);
    return GetActualPaletteSlot(current_palette_, sheet_index);
  }
 
  // Default to sheet 0 (main blockset) if no tile8 selected
  return GetActualPaletteSlot(current_palette_, 0);
}
 
int Tile16Editor::GetPaletteBaseForSheet(int sheet_index) const {
  // Based on overworld palette structure and how ProcessGraphicsBuffer assigns
  // colors: The 256-color palette is organized as 16 rows of 16 colors each.
  // Different graphics sheets map to different palette regions:
  //
  // Row 0: Transparent/system colors
  // Row 1: HUD colors (palette index 0x10-0x1F)
  // Rows 2-4: MAIN/AUX1 palette region for main graphics
  // Rows 5-7: AUX2 palette region for area-specific graphics
  // Row 7: ANIMATED palette for animated tiles
  //
  // The palette_button (0-7) selects within the region.
  switch (sheet_index) {
    case 0:      // Main blockset
    case 3:      // Area graphics set 1
    case 4:      // Area graphics set 2
      return 2;  // AUX1 palette region starts at row 2
    case 5:      // Area graphics set 3
    case 6:      // Area graphics set 4
      return 5;  // AUX2 palette region starts at row 5
    case 1:      // Main graphics
    case 2:      // Main graphics
      return 2;  // MAIN palette region starts at row 2
    case 7:      // Animated tiles
      return 7;  // ANIMATED palette region at row 7
    default:
      return 2;  // Default to MAIN region
  }
}
 
gfx::SnesPalette Tile16Editor::CreateRemappedPaletteForViewing(
    const gfx::SnesPalette& source, int target_row) const {
  // Create a remapped 256-color palette where all pixel values (0-255)
  // are mapped to the target palette row based on their low nibble.
  //
  // This allows the source bitmap (which has pre-encoded palette offsets)
  // to be viewed with the user-selected palette row.
  //
  // For each palette index i:
  //   - Extract the color index: low_nibble = i & 0x0F
  //   - Map to target row: (base_row + target_row) * 16 + low_nibble
  //   - Copy the color from source palette at that position
 
  gfx::SnesPalette remapped;
 
  // Map palette buttons to actual CGRAM rows based on the current sheet.
  int sheet_index = 0;
  if (current_tile8_ >= 0 &&
      current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
    sheet_index = GetSheetIndexForTile8(current_tile8_);
  }
  const int base_row = GetPaletteBaseForSheet(sheet_index);
  const int actual_target_row = std::clamp(base_row + target_row, 0, 15);
 
  for (int i = 0; i < 256; ++i) {
    int low_nibble = i & 0x0F;
    int target_index = (actual_target_row * 16) + low_nibble;
 
    // Make color 0 of each row transparent
    if (low_nibble == 0) {
      // Use transparent color (alpha = 0)
      remapped.AddColor(gfx::SnesColor(0));
    } else if (target_index < static_cast<int>(source.size())) {
      remapped.AddColor(source[target_index]);
    } else {
      // Fallback to black if out of bounds
      remapped.AddColor(gfx::SnesColor(0));
    }
  }
 
  return remapped;
}
 
int Tile16Editor::GetEncodedPaletteRow(uint8_t pixel_value) const {
  // Determine which palette row a pixel value encodes
  // ProcessGraphicsBuffer adds 0x88 (136) to sheets 0, 3, 4, 5
  // So pixel values map to rows as follows:
  //   0x00-0x0F (0-15): Row 0
  //   0x10-0x1F (16-31): Row 1
  //   ...
  //   0x80-0x8F (128-143): Row 8
  //   0x90-0x9F (144-159): Row 9
  //   etc.
  return pixel_value / 16;
}
 
const gfx::SnesPalette* Tile16Editor::ResolveDisplayPalette() const {
  if (overworld_palette_.size() >= 256) {
    return &overworld_palette_;
  }
  if (palette_.size() >= 256) {
    return &palette_;
  }
  if (game_data() && !game_data()->palette_groups.overworld_main.empty()) {
    return &game_data()->palette_groups.overworld_main.palette_ref(0);
  }
  return nullptr;
}
 
bool Tile16Editor::BitmapHasEncodedPaletteRows(
    const gfx::Bitmap& bitmap) const {
  if (!bitmap.is_active() || bitmap.data() == nullptr) {
    return false;
  }
 
  for (size_t i = 0; i < bitmap.size(); ++i) {
    if ((bitmap.data()[i] & 0xF0) != 0) {
      return true;
    }
  }
  return false;
}
 
void Tile16Editor::ApplyPaletteToCurrentTile16Bitmap() {
  if (!current_tile16_bmp_.is_active()) {
    return;
  }
 
  const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
  gfx::SnesPalette fallback_palette;
  if (!display_palette || display_palette->empty()) {
    fallback_palette = BuildFallbackDisplayPalette();
    display_palette = &fallback_palette;
  }
 
  // Most tile16 edit paths now encode the palette row directly in pixel indices
  // via (pixel & 0x0F) + (palette * 0x10). In that case, apply the full palette.
  // If normalization produced low-nibble-only pixels, keep the legacy sub-palette
  // view path so the advanced normalization workflow still renders correctly.
  if (auto_normalize_pixels_ &&
      !BitmapHasEncodedPaletteRows(current_tile16_bmp_)) {
    const int palette_slot = GetActualPaletteSlotForCurrentTile16();
    if (palette_slot >= 0 &&
        static_cast<size_t>(palette_slot + 16) <= display_palette->size()) {
      current_tile16_bmp_.SetPaletteWithTransparent(
          *display_palette, static_cast<size_t>(palette_slot + 1), 15);
    } else {
      current_tile16_bmp_.SetPaletteWithTransparent(*display_palette, 1, 15);
    }
  } else {
    current_tile16_bmp_.SetPalette(*display_palette);
  }
 
  current_tile16_bmp_.set_modified(true);
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &current_tile16_bmp_);
}
 
// Helper methods for palette management
absl::Status Tile16Editor::UpdateTile8Palette(int tile8_id) {
  if (tile8_id < 0 ||
      tile8_id >= static_cast<int>(current_gfx_individual_.size())) {
    return absl::InvalidArgumentError("Invalid tile8 ID");
  }
 
  if (!rom_) {
    return absl::FailedPreconditionError("ROM not set");
  }
 
  const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
  if (!display_palette || display_palette->empty()) {
    return absl::FailedPreconditionError("No overworld palette available");
  }
 
  // Validate current_palette_ index
  if (current_palette_ < 0 || current_palette_ >= 8) {
    util::logf("Warning: Invalid palette index %d, using 0", current_palette_);
    current_palette_ = 0;
  }
 
  const int sheet_index = GetSheetIndexForTile8(tile8_id);
  const int palette_slot =
      GetActualPaletteSlot(static_cast<int>(current_palette_), sheet_index);
 
  util::logf("Updated tile8 %d with palette slot %d (palette size: %zu colors)",
             tile8_id, current_palette_, display_palette->size());
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::RefreshAllPalettes() {
  if (!rom_) {
    return absl::FailedPreconditionError("ROM not set");
  }
 
  // Validate current_palette_ index
  if (current_palette_ < 0 || current_palette_ >= 8) {
    util::logf("Warning: Invalid palette index %d, using 0", current_palette_);
    current_palette_ = 0;
  }
 
  const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
  gfx::SnesPalette fallback_palette;
  if (!display_palette || display_palette->empty()) {
    fallback_palette = BuildFallbackDisplayPalette();
    display_palette = &fallback_palette;
    util::logf("Display palette unavailable; using fallback grayscale palette");
  }
  util::logf("Using resolved display palette with %zu colors",
             display_palette->size());
 
  // The source bitmap (current_gfx_bmp_) contains 8bpp indexed pixel data.
  // If palette offsets are preserved, apply the full CGRAM palette. Otherwise,
  // remap the palette to the user-selected row.
  if (HasCurrentGfxBitmap()) {
    if (auto_normalize_pixels_) {
      gfx::SnesPalette remapped_palette =
          CreateRemappedPaletteForViewing(*display_palette, current_palette_);
      current_gfx_bmp_->SetPalette(remapped_palette);
      util::logf("Applied remapped palette (button %d) to source bitmap",
                 current_palette_);
    } else {
      current_gfx_bmp_->SetPalette(*display_palette);
      util::logf("Applied full CGRAM palette to source bitmap");
    }
 
    current_gfx_bmp_->set_modified(true);
    // Queue texture update via Arena's deferred system
    gfx::Arena::Get().QueueTextureCommand(
        gfx::Arena::TextureCommandType::UPDATE, current_gfx_bmp_);
  }
 
  // Update current tile16 being edited - regenerate from ROM so per-quadrant
  // palette metadata is applied via the pixel transform
  if (current_tile16_bmp_.is_active() && !current_gfx_individual_.empty()) {
    auto regen_status = RegenerateTile16BitmapFromROM();
    if (!regen_status.ok()) {
      // Fallback: just apply palette directly
      current_tile16_bmp_.SetPalette(*display_palette);
      current_tile16_bmp_.set_modified(true);
      gfx::Arena::Get().QueueTextureCommand(
          gfx::Arena::TextureCommandType::UPDATE, &current_tile16_bmp_);
    }
  }
 
  util::logf(
      "Successfully refreshed all palettes in tile16 editor with palette %d",
      current_palette_);
  return absl::OkStatus();
}
 
void Tile16Editor::AnalyzeTile8SourceData() const {
  util::logf("=== TILE8 SOURCE DATA ANALYSIS ===");
 
  // Analyze current_gfx_bmp_
  util::logf("current_gfx_bmp_:");
  util::logf("  - Active: %s", HasCurrentGfxBitmap() ? "yes" : "no");
  util::logf("  - Size: %dx%d", current_gfx_bmp_->width(),
             current_gfx_bmp_->height());
  util::logf("  - Depth: %d bpp", current_gfx_bmp_->depth());
  util::logf("  - Data size: %zu bytes", current_gfx_bmp_->size());
  util::logf("  - Palette size: %zu colors",
             current_gfx_bmp_->palette().size());
 
  // Analyze pixel value distribution in first 64 pixels (first tile8)
  if (current_gfx_bmp_->data() && current_gfx_bmp_->size() >= 64) {
    std::map<uint8_t, int> pixel_counts;
    for (size_t i = 0; i < 64; ++i) {
      uint8_t val = current_gfx_bmp_->data()[i];
      pixel_counts[val]++;
    }
    util::logf("  - First tile8 (Sheet 0) pixel distribution:");
    for (const auto& [val, count] : pixel_counts) {
      int row = GetEncodedPaletteRow(val);
      int col = val & 0x0F;
      util::logf("    Value 0x%02X (%3d) = Row %d, Col %d: %d pixels", val, val,
                 row, col, count);
    }
 
    // Check if values are in expected 4bpp range
    bool all_4bpp = true;
    for (const auto& [val, count] : pixel_counts) {
      if (val > 15) {
        all_4bpp = false;
        break;
      }
    }
    util::logf("  - Values in raw 4bpp range (0-15): %s",
               all_4bpp ? "yes" : "NO (pre-encoded)");
 
    // Show what the remapping does
    util::logf("  - Palette remapping for viewing:");
    util::logf("    Selected palette: %d (row %d)", current_palette_,
               current_palette_);
    util::logf("    Pixels are remapped: (value & 0x0F) + (selected_row * 16)");
  }
 
  // Analyze current_gfx_individual_
  util::logf("current_gfx_individual_:");
  util::logf("  - Count: %zu tiles", current_gfx_individual_.size());
 
  if (!current_gfx_individual_.empty()) {
    const auto& first_tile = current_gfx_individual_[0];
    util::logf("  - First tile:");
    util::logf("    - Size: 8x8");
    util::logf("    - Depth: 8 bpp");
    std::map<uint8_t, int> pixel_counts;
    for (uint8_t val : first_tile) {
      pixel_counts[val]++;
    }
    util::logf("    - Pixel distribution:");
    for (const auto& [val, count] : pixel_counts) {
      util::logf("      Value 0x%02X (%3d): %d pixels", val, val, count);
    }
  }
 
  // Analyze palette state
  util::logf("Palette state:");
  util::logf("  - current_palette_: %d", current_palette_);
  util::logf("  - overworld_palette_ size: %zu", overworld_palette_.size());
  util::logf("  - palette_ size: %zu", palette_.size());
 
  // Calculate expected palette slot
  int palette_slot = GetActualPaletteSlot(current_palette_, 0);
  util::logf("  - GetActualPaletteSlot(%d, 0) = %d", current_palette_,
             palette_slot);
  util::logf("  - Expected palette offset for SetPaletteWithTransparent: %d",
             palette_slot + 1);
 
  // Show first 16 colors of the overworld palette
  if (overworld_palette_.size() >= 16) {
    util::logf("  - First 16 palette colors (row 0):");
    for (int i = 0; i < 16; ++i) {
      auto color = overworld_palette_[i];
      util::logf("    [%2d] SNES: 0x%04X RGB: (%d,%d,%d)", i, color.snes(),
                 static_cast<int>(color.rgb().x),
                 static_cast<int>(color.rgb().y),
                 static_cast<int>(color.rgb().z));
    }
  }
 
  // Show colors at the selected palette slot
  if (overworld_palette_.size() >= static_cast<size_t>(palette_slot + 16)) {
    util::logf("  - Colors at palette slot %d (row %d):", palette_slot,
               palette_slot / 16);
    for (int i = 0; i < 16; ++i) {
      auto color = overworld_palette_[palette_slot + i];
      util::logf("    [%2d] SNES: 0x%04X RGB: (%d,%d,%d)", i, color.snes(),
                 static_cast<int>(color.rgb().x),
                 static_cast<int>(color.rgb().y),
                 static_cast<int>(color.rgb().z));
    }
  }
 
  util::logf("=== END ANALYSIS ===");
}
 
void Tile16Editor::DrawPaletteSettings() {
  if (show_palette_settings_) {
    if (Begin("Advanced Palette Settings", &show_palette_settings_)) {
      Text("Pixel Normalization & Color Correction:");
 
      int mask_value = static_cast<int>(palette_normalization_mask_);
      if (SliderInt("Normalization Mask", &mask_value, 1, 255, "0x%02X")) {
        palette_normalization_mask_ = static_cast<uint8_t>(mask_value);
      }
 
      Checkbox("Auto Normalize Pixels", &auto_normalize_pixels_);
 
      if (Button("Apply to All Graphics")) {
        auto reload_result = LoadTile8();
        if (!reload_result.ok()) {
          Text("Error: %s", reload_result.message().data());
        }
      }
 
      SameLine();
      if (Button("Reset Defaults")) {
        palette_normalization_mask_ = 0x0F;
        auto_normalize_pixels_ = true;
        auto reload_result = LoadTile8();
        (void)reload_result;  // Suppress warning
      }
 
      Separator();
      Text("Current State:");
      static constexpr std::array<const char*, 7> palette_group_names = {
          "OW Main", "OW Aux", "OW Anim", "Dungeon",
          "Sprites", "Armor",  "Sword"};
      Text("Palette Group: %d (%s)", current_palette_group_,
           (current_palette_group_ < 7)
               ? palette_group_names[current_palette_group_]
               : "Unknown");
      Text("Current Palette: %d", current_palette_);
 
      Separator();
      Text("Sheet-Specific Fixes:");
 
      // Sheet-specific palette fixes
      static bool fix_sheet_0 = true;
      static bool fix_sprite_sheets = true;
      static bool use_transparent_for_terrain = false;
 
      if (Checkbox("Fix Sheet 0 (Trees)", &fix_sheet_0)) {
        auto reload_result = LoadTile8();
        if (!reload_result.ok()) {
          Text("Error reloading: %s", reload_result.message().data());
        }
      }
      HOVER_HINT(
          "Use direct palette for sheet 0 instead of transparent palette");
 
      if (Checkbox("Fix Sprite Sheets", &fix_sprite_sheets)) {
        auto reload_result = LoadTile8();
        if (!reload_result.ok()) {
          Text("Error reloading: %s", reload_result.message().data());
        }
      }
      HOVER_HINT("Use direct palette for sprite graphics sheets");
 
      if (Checkbox("Transparent for Terrain", &use_transparent_for_terrain)) {
        auto reload_result = LoadTile8();
        if (!reload_result.ok()) {
          Text("Error reloading: %s", reload_result.message().data());
        }
      }
      HOVER_HINT("Force transparent palette for terrain graphics");
 
      Separator();
      Text("Color Analysis:");
      if (current_tile8_ >= 0 &&
          current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
        Text("Selected Tile8 Analysis:");
        const auto& tile_data = current_gfx_individual_[current_tile8_];
        std::map<uint8_t, int> pixel_counts;
        for (uint8_t pixel : tile_data) {
          pixel_counts[pixel & 0x0F]++;  // Normalize to 4-bit
        }
 
        Text("Pixel Value Distribution:");
        for (const auto& pair : pixel_counts) {
          int value = pair.first;
          int count = pair.second;
          Text("  Value %d (0x%X): %d pixels", value, value, count);
        }
 
        Text("Palette Colors Used:");
        const gfx::SnesPalette* analysis_palette = ResolveDisplayPalette();
        if (analysis_palette == nullptr || analysis_palette->empty()) {
          analysis_palette =
              current_gfx_bmp_ ? &current_gfx_bmp_->palette() : &palette_;
        }
        for (const auto& pair : pixel_counts) {
          int value = pair.first;
          int count = pair.second;
          if (value < static_cast<int>(analysis_palette->size())) {
            auto color = (*analysis_palette)[value];
            ImVec4 display_color = color.rgb();
            ImGui::ColorButton(("##analysis" + std::to_string(value)).c_str(),
                               display_color, ImGuiColorEditFlags_NoTooltip,
                               ImVec2(16, 16));
            if (ImGui::IsItemHovered()) {
              ImGui::SetTooltip("Index %d: 0x%04X (%d pixels)", value,
                                color.snes(), count);
            }
            if (value % 8 != 7)
              ImGui::SameLine();
          }
        }
      }
 
      // Enhanced ROM Palette Management Section
      Separator();
      if (CollapsingHeader("ROM Palette Manager") && rom_) {
        Text("Experimental ROM Palette Selection:");
        HOVER_HINT(
            "Use ROM palettes to experiment with different color schemes");
 
        if (Button("Open Enhanced Palette Editor")) {
          tile16_edit_canvas_.ShowPaletteEditor();
        }
        SameLine();
        if (Button("Show Color Analysis")) {
          tile16_edit_canvas_.ShowColorAnalysis();
        }
 
        // Quick palette application
        static int quick_group = 0;
        static int quick_index = 0;
 
        SliderInt("ROM Group", &quick_group, 0, 6);
        SliderInt("Palette Index", &quick_index, 0, 7);
 
        if (Button("Apply to Tile8 Source")) {
          if (tile8_source_canvas_.ApplyROMPalette(quick_group, quick_index)) {
            util::logf("Applied ROM palette group %d, index %d to Tile8 source",
                       quick_group, quick_index);
          }
        }
        SameLine();
        if (Button("Apply to Tile16 Editor")) {
          if (tile16_edit_canvas_.ApplyROMPalette(quick_group, quick_index)) {
            util::logf(
                "Applied ROM palette group %d, index %d to Tile16 editor",
                quick_group, quick_index);
          }
        }
      }
    }
    End();
  }
}
 
void Tile16Editor::DrawScratchSpace() {
  Text("Layout Scratch:");
  for (int i = 0; i < 4; ++i) {
    ImGui::PushID(i);
    std::string slot_name = "S" + std::to_string(i + 1);
 
    if (Button((slot_name + " Save").c_str(), ImVec2(70, 20))) {
      status_ = SaveLayoutToScratch(i);
    }
    SameLine();
 
    bool can_load = layout_scratch_[i].in_use;
    if (!can_load) {
      ImGui::BeginDisabled();
    }
    if (Button((slot_name + " Load").c_str(), ImVec2(70, 20)) && can_load) {
      status_ = LoadLayoutFromScratch(i);
    }
    if (!can_load) {
      ImGui::EndDisabled();
    }
    SameLine();
    TextDisabled("%s", layout_scratch_[i].name.c_str());
    ImGui::PopID();
  }
}
 
absl::Status Tile16Editor::SaveLayoutToScratch(int slot) {
  if (slot < 0 || slot >= 4) {
    return absl::InvalidArgumentError("Invalid scratch slot");
  }
 
  int total_tiles = zelda3::ComputeTile16Count(tile16_blockset_);
  if (total_tiles <= 0) {
    return absl::FailedPreconditionError("Tile16 blockset is not available");
  }
 
  const int start_tile = std::clamp(current_tile16_, 0, total_tiles - 1);
  for (int y = 0; y < 8; ++y) {
    for (int x = 0; x < 8; ++x) {
      const int tile_id = start_tile + (y * 8) + x;
      layout_scratch_[slot].tile_layout[y][x] =
          (tile_id < total_tiles) ? tile_id : -1;
    }
  }
 
  layout_scratch_[slot].in_use = true;
  layout_scratch_[slot].name =
      absl::StrFormat("From %03X", static_cast<uint16_t>(start_tile));
 
  return absl::OkStatus();
}
 
absl::Status Tile16Editor::LoadLayoutFromScratch(int slot) {
  if (slot < 0 || slot >= 4) {
    return absl::InvalidArgumentError("Invalid scratch slot");
  }
 
  if (!layout_scratch_[slot].in_use) {
    return absl::FailedPreconditionError("Scratch slot is empty");
  }
 
  const int first_tile = layout_scratch_[slot].tile_layout[0][0];
  if (first_tile < 0) {
    return absl::FailedPreconditionError("Scratch slot has no valid tile data");
  }
 
  RETURN_IF_ERROR(SetCurrentTile(first_tile));
  blockset_selector_.SetSelectedTile(first_tile);
  scroll_to_current_ = true;
 
  selected_tiles_.clear();
  selected_tiles_.reserve(64);
  for (int y = 0; y < 8; ++y) {
    for (int x = 0; x < 8; ++x) {
      const int tile_id = layout_scratch_[slot].tile_layout[y][x];
      if (tile_id >= 0) {
        selected_tiles_.push_back(tile_id);
      }
    }
  }
  selection_start_tile_ = first_tile;
 
  return absl::OkStatus();
}
 
void Tile16Editor::DrawManualTile8Inputs() {
  if (ImGui::BeginPopupModal("ManualTile8Editor", nullptr,
                             ImGuiWindowFlags_AlwaysAutoResize)) {
    ImGui::Text("Manual Tile8 Configuration for Tile16 %02X", current_tile16_);
    ImGui::Separator();
 
    auto* tile_data = GetCurrentTile16Data();
    if (tile_data) {
      ImGui::Text("Current Tile16 Staged Data:");
 
      auto stage_current_tile = [&]() -> absl::Status {
        SyncTilesInfoArray(tile_data);
        RETURN_IF_ERROR(RegenerateTile16BitmapFromROM());
        RETURN_IF_ERROR(UpdateBlocksetBitmap());
        if (live_preview_enabled_) {
          RETURN_IF_ERROR(UpdateOverworldTilemap());
        }
        MarkCurrentTileModified();
        return absl::OkStatus();
      };
 
      // Display and edit each quadrant using TileInfo structure
      const char* quadrant_names[] = {"Top-Left", "Top-Right", "Bottom-Left",
                                      "Bottom-Right"};
 
      for (int q = 0; q < 4; q++) {
        ImGui::Text("%s Quadrant:", quadrant_names[q]);
        ImGui::TextDisabled("Tile Palette metadata + Tile8/flip flags");
 
        // Get the current TileInfo for this quadrant
        gfx::TileInfo* tile_info = nullptr;
        switch (q) {
          case 0:
            tile_info = &tile_data->tile0_;
            break;
          case 1:
            tile_info = &tile_data->tile1_;
            break;
          case 2:
            tile_info = &tile_data->tile2_;
            break;
          case 3:
            tile_info = &tile_data->tile3_;
            break;
        }
 
        if (tile_info) {
          // Editable inputs for TileInfo components
          ImGui::PushID(q);
 
          int tile_id_int = static_cast<int>(tile_info->id_);
          if (ImGui::InputInt("Tile8 ID", &tile_id_int, 1, 10)) {
            tile_info->id_ =
                static_cast<uint16_t>(std::max(0, std::min(tile_id_int, 1023)));
          }
 
          int palette_int = static_cast<int>(tile_info->palette_);
          if (ImGui::SliderInt("Tile Palette", &palette_int, 0, 7)) {
            tile_info->palette_ = static_cast<uint8_t>(palette_int);
          }
 
          ImGui::Checkbox("X Flip", &tile_info->horizontal_mirror_);
          ImGui::SameLine();
          ImGui::Checkbox("Y Flip", &tile_info->vertical_mirror_);
          ImGui::SameLine();
          ImGui::Checkbox("Priority", &tile_info->over_);
 
          if (ImGui::Button("Stage Quadrant Edit")) {
            auto stage_result = stage_current_tile();
            if (!stage_result.ok()) {
              ImGui::Text("Stage Error: %s", stage_result.message().data());
            }
          }
 
          ImGui::PopID();
        }
 
        if (q < 3)
          ImGui::Separator();
      }
 
      ImGui::Separator();
      if (ImGui::Button("Stage All Edits")) {
        auto stage_result = stage_current_tile();
        if (!stage_result.ok()) {
          ImGui::Text("Stage Error: %s", stage_result.message().data());
        }
      }
      ImGui::SameLine();
      if (ImGui::Button("Write Pending to ROM")) {
        auto write_result = CommitAllChanges();
        if (!write_result.ok()) {
          ImGui::Text("Write Error: %s", write_result.message().data());
        }
      }
      ImGui::SameLine();
      if (ImGui::Button("Refresh Display")) {
        auto refresh_result = SetCurrentTile(current_tile16_);
        if (!refresh_result.ok()) {
          ImGui::Text("Refresh Error: %s", refresh_result.message().data());
        }
      }
 
    } else {
      ImGui::Text("Tile16 data not accessible");
      ImGui::Text("Current tile16: %d", current_tile16_);
      if (rom_) {
        ImGui::Text("Valid range: 0-4095 (4096 total tiles)");
      }
    }
 
    ImGui::Separator();
    if (ImGui::Button("Close")) {
      ImGui::CloseCurrentPopup();
    }
 
    ImGui::EndPopup();
  }
}
 
absl::Status Tile16Editor::UpdateLivePreview() {
  // Skip if live preview is disabled
  if (!live_preview_enabled_) {
    return absl::OkStatus();
  }
 
  // Check if preview needs updating
  if (!preview_dirty_) {
    return absl::OkStatus();
  }
 
  // Ensure we have valid tile data
  if (!current_tile16_bmp_.is_active()) {
    preview_dirty_ = false;
    return absl::OkStatus();
  }
 
  // Update the preview bitmap from current tile16
  if (!preview_tile16_.is_active()) {
    preview_tile16_.Create(16, 16, 8, current_tile16_bmp_.vector());
  } else {
    // Recreate with updated data
    preview_tile16_.Create(16, 16, 8, current_tile16_bmp_.vector());
  }
 
  // Apply the current palette
  const gfx::SnesPalette* display_palette = ResolveDisplayPalette();
  if (display_palette && !display_palette->empty()) {
    const bool use_sub_palette_view =
        auto_normalize_pixels_ && !BitmapHasEncodedPaletteRows(preview_tile16_);
    if (use_sub_palette_view) {
      const int sheet_index = GetSheetIndexForTile8(current_tile8_);
      const int palette_slot =
          GetActualPaletteSlot(static_cast<int>(current_palette_), sheet_index);
      if (palette_slot >= 0 &&
          static_cast<size_t>(palette_slot + 16) <= display_palette->size()) {
        preview_tile16_.SetPaletteWithTransparent(
            *display_palette, static_cast<size_t>(palette_slot + 1), 15);
      } else {
        preview_tile16_.SetPaletteWithTransparent(*display_palette, 1, 15);
      }
    } else {
      preview_tile16_.SetPalette(*display_palette);
    }
  }
 
  // Queue texture update
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &preview_tile16_);
 
  // Clear the dirty flag
  preview_dirty_ = false;
 
  return absl::OkStatus();
}
 
void Tile16Editor::HandleKeyboardShortcuts() {
  if (!ImGui::IsAnyItemActive()) {
    const ImGuiIO& io = ImGui::GetIO();
#if defined(__APPLE__)
    const bool platform_primary_held = io.KeyCtrl || io.KeySuper;
#else
    const bool platform_primary_held = io.KeyCtrl;
#endif
    const bool ctrl_held = platform_primary_held ||
                           ImGui::IsKeyDown(ImGuiKey_LeftCtrl) ||
                           ImGui::IsKeyDown(ImGuiKey_RightCtrl);
 
    // Editing shortcuts (only fire without Ctrl to avoid conflicts)
    if (ImGui::IsKeyPressed(ImGuiKey_Delete)) {
      status_ = ClearTile16();
    }
    if (ImGui::IsKeyPressed(ImGuiKey_H) && !ctrl_held) {
      status_ = FlipTile16Horizontal();
    }
    if (ImGui::IsKeyPressed(ImGuiKey_V) && !ctrl_held) {
      status_ = FlipTile16Vertical();
    }
    if (ImGui::IsKeyPressed(ImGuiKey_R) && !ctrl_held) {
      status_ = RotateTile16();
    }
    if (ImGui::IsKeyPressed(ImGuiKey_F) && !ctrl_held) {
      if (current_tile8_ >= 0 &&
          current_tile8_ < static_cast<int>(current_gfx_individual_.size())) {
        status_ = FillTile16WithTile8(current_tile8_);
      }
    }
 
    if (!ctrl_held) {
      if (ImGui::IsKeyPressed(ImGuiKey_P)) {
        edit_mode_ = Tile16EditMode::kPaint;
      }
      if (ImGui::IsKeyPressed(ImGuiKey_I)) {
        edit_mode_ = Tile16EditMode::kPick;
      }
      if (ImGui::IsKeyPressed(ImGuiKey_U)) {
        edit_mode_ = Tile16EditMode::kUsageProbe;
      }
    }
 
    // Palette shortcuts
    if (ImGui::IsKeyPressed(ImGuiKey_Q)) {
      status_ = CyclePalette(false);
    }
    if (ImGui::IsKeyPressed(ImGuiKey_E)) {
      status_ = CyclePalette(true);
    }
 
    // Numeric shortcuts:
    //  - 1..4 focus tile16 quadrants
    //  - Ctrl+1..8 switch brush palette rows
    for (int i = 0; i < 8; ++i) {
      if (!ImGui::IsKeyPressed(static_cast<ImGuiKey>(ImGuiKey_1 + i))) {
        continue;
      }
      const Tile16NumericShortcutResult shortcut =
          ResolveTile16NumericShortcut(ctrl_held, i);
      if (shortcut.quadrant_focus.has_value()) {
        active_quadrant_ = *shortcut.quadrant_focus;
      }
      if (shortcut.palette_id.has_value()) {
        current_palette_ = *shortcut.palette_id;
        status_ = RefreshAllPalettes();
      }
    }
 
    // Ctrl-modified shortcuts
    if (ctrl_held) {
      if (ImGui::IsKeyPressed(ImGuiKey_Z)) {
        status_ = Undo();
      }
      if (ImGui::IsKeyPressed(ImGuiKey_Y)) {
        status_ = Redo();
      }
      if (ImGui::IsKeyPressed(ImGuiKey_C)) {
        status_ = CopyTile16ToClipboard(current_tile16_);
      }
      if (ImGui::IsKeyPressed(ImGuiKey_V)) {
        status_ = PasteTile16FromClipboard();
      }
      if (ImGui::IsKeyPressed(ImGuiKey_S)) {
        if (ImGui::IsKeyDown(ImGuiKey_LeftShift) ||
            ImGui::IsKeyDown(ImGuiKey_RightShift)) {
          status_ = CommitChangesToBlockset();
        } else {
          status_ = CommitAllChanges();
        }
      }
    }
  }
}
 
void Tile16Editor::CopyTile16ToAtlas(int tile_id) {
  if (!tile16_blockset_ || !tile16_blockset_->atlas.is_active() ||
      !current_tile16_bmp_.is_active()) {
    return;
  }
 
  zelda3::BlitTile16BitmapToAtlas(&tile16_blockset_->atlas, tile_id,
                                  current_tile16_bmp_);
 
  tile16_blockset_->atlas.set_modified(true);
  gfx::Arena::Get().QueueTextureCommand(gfx::Arena::TextureCommandType::UPDATE,
                                        &tile16_blockset_->atlas);
}
 
}  // namespace editor
}  // namespace yaze