[nostalgia/core] Get TileSheetEditor's palette view working

src/nostalgia/core/studio/tilesheeteditormodel.cpp

@@ -14,15 +14,27 @@ TileSheetEditorModel::TileSheetEditorModel(Context *ctx, const ox::String &path)
 	oxThrowError(readObj<NostalgiaPalette>(ctx, m_img.defaultPalette).moveTo(&m_pal));
 }
 
-void TileSheetEditorModel::draw(const geo::Point &pt, std::size_t palIdx) noexcept {
+void TileSheetEditorModel::cut() {
+}
+
+void TileSheetEditorModel::copy() {
+}
+
+void TileSheetEditorModel::paste() {
+}
+
+void TileSheetEditorModel::drawCommand(const geo::Point &pt, std::size_t palIdx) noexcept {
 	if (m_ongoingDrawCommand) {
 		m_updated = m_ongoingDrawCommand->append(ptToIdx(pt, m_img.columns));
 	} else {
-		pushCommand(new DrawCommand(&m_img, ptToIdx(pt, m_img.columns), palIdx));
+		const auto idx = ptToIdx(pt, m_img.columns);
+		if (m_img.getPixel(idx) != palIdx) {
+			pushCommand(new DrawCommand(&m_img, idx, palIdx));
+		}
 	}
 }
 
-void TileSheetEditorModel::endDraw() noexcept {
+void TileSheetEditorModel::endDrawCommand() noexcept {
 	m_ongoingDrawCommand = nullptr;
 }