Update texture array layers individually

src/generated_texture.cpp

@@ -39,6 +39,11 @@ RID GeneratedTexture::create(const TypedArray<Image> &p_layers) {
 	return _rid;
 }
 
+void GeneratedTexture::update(const Ref<Image> &p_image, const int &p_layer) {
+	LOG(EXTREME, "RenderingServer updating Texture2DArray at index: ", p_layer);
+	RS->texture_2d_update(_rid, p_image, p_layer);
+}
+
 RID GeneratedTexture::create(const Ref<Image> &p_image) {
 	LOG(EXTREME, "RenderingServer creating Texture2D");
 	_image = p_image;

src/generated_texture.h

@@ -21,6 +21,7 @@ class GeneratedTexture {
 	void clear();
 	bool is_dirty() const { return _dirty; }
 	RID create(const TypedArray<Image> &p_layers);
+	void update(const Ref<Image> &p_image, const int &p_layer);
 	RID create(const Ref<Image> &p_image);
 	Ref<Image> get_image() const { return _image; }
 	RID get_rid() const { return _rid; }

src/terrain_3d_data.cpp

@@ -471,7 +471,7 @@ void Terrain3DData::force_update_maps(const MapType p_map_type, const bool p_gen
 	update_maps();
 }
 
-void Terrain3DData::update_maps() {
+void Terrain3DData::update_maps(const MapType p_map_type) {
 	bool any_changed = false;
 
 	if (_region_map_dirty) {
@@ -545,6 +545,32 @@ void Terrain3DData::update_maps() {
 
 	if (any_changed) {
 		emit_signal("maps_changed");
+	} else {
+		// If no maps have been rebuilt, it's safe to update individual layers. Regions marked Edited
+		// have either been recently changed by Terrain3DEditor::_operate_map or were marked by undo / redo.
+		for (int i = 0; i < _region_locations.size(); i++) {
+			Vector2i region_loc = _region_locations[i];
+			Ref<Terrain3DRegion> region = _regions[region_loc];
+			if (region->is_edited()) {
+				int region_id = get_region_id(region_loc);
+				switch (p_map_type) {
+					case TYPE_HEIGHT:
+						_generated_height_maps.update(region->get_height_map(), region_id);
+						break;
+					case TYPE_CONTROL:
+						_generated_control_maps.update(region->get_control_map(), region_id);
+						break;
+					case TYPE_COLOR:
+						_generated_color_maps.update(region->get_color_map(), region_id);
+						break;
+					default:
+						_generated_height_maps.update(region->get_height_map(), region_id);
+						_generated_control_maps.update(region->get_control_map(), region_id);
+						_generated_color_maps.update(region->get_color_map(), region_id);
+						break;
+				}
+			}
+		}
 	}
 }
 

src/terrain_3d_data.h

@@ -130,8 +130,9 @@ class Terrain3DData : public Object {
 	TypedArray<Image> get_color_maps() const { return _color_maps; }
 	TypedArray<Image> get_maps(const MapType p_map_type) const;
 
-	void force_update_maps(const MapType p_map = TYPE_MAX, const bool p_generate_mipmaps = false);
-	void update_maps();
+	void force_update_maps(const MapType p_map_type = TYPE_MAX, const bool p_generate_mipmaps = false);
+	void update_maps(const MapType p_map_type = TYPE_MAX);
+
 	RID get_height_maps_rid() const { return _generated_height_maps.get_rid(); }
 	RID get_control_maps_rid() const { return _generated_control_maps.get_rid(); }
 	RID get_color_maps_rid() const { return _generated_color_maps.get_rid(); }

src/terrain_3d_editor.cpp

@@ -171,6 +171,12 @@ void Terrain3DEditor::_operate_map(const Vector3 &p_global_position, const real_
 
 	// MAP Operations
 	real_t vertex_spacing = _terrain->get_vertex_spacing();
+
+	// save region count before brush pixel loop. Any regions added will have caused an Array
+	// rebuild at the end of the last _operate() call, but until painting is finished we only
+	// need to track if _added_removed_locations has changed between now and the end of the loop
+	int regions_added_removed = _added_removed_locations.size();
+
 	for (real_t x = 0.f; x < brush_size; x += vertex_spacing) {
 		for (real_t y = 0.f; y < brush_size; y += vertex_spacing) {
 			Vector2 brush_offset = Vector2(x, y) - (Vector2(brush_size, brush_size) / 2.f);
@@ -459,7 +465,13 @@ void Terrain3DEditor::_operate_map(const Vector3 &p_global_position, const real_
 			region->get_map(map_type)->generate_mipmaps();
 		}
 	}
-	data->force_update_maps(map_type);
+	// If no added or removed regions, update only changed texture array layers from the edited regions in the rendering server
+	if (_added_removed_locations.size() == regions_added_removed) {
+		data->update_maps(map_type);
+	} else {
+	// If region qty was changed, must fully rebuild the maps
+		data->force_update_maps(map_type);
+	}
 	data->add_edited_area(edited_area);
 }
 
@@ -537,6 +549,8 @@ void Terrain3DEditor::_apply_undo(const Dictionary &p_data) {
 			Dictionary regions = data->get_regions_all();
 			regions[region->get_location()] = region;
 			region->set_modified(true);
+			// Tell update_maps() this region has layers that can be individually updated
+			region->set_edited(true);
 			LOG(DEBUG, "Edited: ", region->get_data());
 		}
 	}
@@ -567,8 +581,20 @@ void Terrain3DEditor::_apply_undo(const Dictionary &p_data) {
 		Array locations = data->get_region_locations();
 		LOG(DEBUG, "Locations(", locations.size(), "): ", locations);
 	}
-
-	data->force_update_maps();
+	// If this undo set modifies the region qty, we must rebuild the arrays. Otherwise we can update individual layers
+	if (p_data.has("added_regions") || p_data.has("removed_regions")) {
+		data->force_update_maps();
+	} else {
+		data->update_maps();
+	}
+	// After TextureArray updates clear edited regions flag.
+	if (p_data.has("edited_regions")) {
+		TypedArray<Terrain3DRegion> undo_regions = p_data["edited_regions"];
+		for (int i = 0; i < undo_regions.size(); i++) {
+			Ref<Terrain3DRegion> region = undo_regions[i];
+			region->set_edited(false);
+		}
+	}
 	_terrain->get_instancer()->force_update_mmis();
 	if (_terrain->get_plugin()->has_method("update_grid")) {
 		LOG(DEBUG, "Calling GDScript update_grid()");