Switch to using a single flag sheet image/textureflag-sheet

4 files changed, 138 insertions, 38 deletions

diff --git a/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.cpp b/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.cpp
index 2c315a9..51a4235 100644
--- a/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.cpp
+++ b/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.cpp
@@ -34,7 +34,7 @@ Error GFXMaskedFlagTexture::_generate_combined_image() {
 		set_region({ {}, button_image->get_size() });
 	}
 
-	if (mask_image.is_valid() && flag_image.is_valid()) {
+	if (mask_image.is_valid() && flag_image.is_valid() && flag_image_rect.has_area()) {
 		const Vector2i centre_translation = (mask_image->get_size() - button_image->get_size()) / 2;
 		for (Vector2i combined_image_point { 0, 0 }; combined_image_point.y < button_image->get_height(); ++combined_image_point.y) {
 			for (combined_image_point.x = 0; combined_image_point.x < button_image->get_width(); ++combined_image_point.x) {
@@ -46,10 +46,14 @@ Error GFXMaskedFlagTexture::_generate_combined_image() {
 					0 <= mask_image_point.y && mask_image_point.y < mask_image->get_height()
 				) {
 					const Color mask_image_colour = mask_image->get_pixelv(mask_image_point);
+
 					// Rescale from mask_image to flag_image coordinates.
-					const Vector2i flag_image_point = mask_image_point * flag_image->get_size() / mask_image->get_size();
+					const Vector2i flag_image_point =
+						flag_image_rect.position + mask_image_point * flag_image_rect.size / mask_image->get_size();
+
 					Color flag_image_colour = flag_image->get_pixelv(flag_image_point);
 					flag_image_colour.a = mask_image_colour.a;
+
 					button_image->set_pixelv(combined_image_point, flag_image_colour.blend(overlay_image_colour));
 				} else {
 					button_image->set_pixelv(combined_image_point, overlay_image_colour);
@@ -157,12 +161,12 @@ Error GFXMaskedFlagTexture::set_flag_country_and_type(Country const* new_flag_co
 		GameSingleton* game_singleton = GameSingleton::get_singleton();
 		ERR_FAIL_NULL_V(game_singleton, FAILED);
 
-		const Ref<Image> new_flag_image = game_singleton->get_flag_image(new_flag_country, new_flag_type);
-		ERR_FAIL_NULL_V(new_flag_image, FAILED);
+		flag_image_rect = game_singleton->get_flag_sheet_rect(new_flag_country->get_index(), new_flag_type);
+		ERR_FAIL_COND_V(!flag_image_rect.has_area(), FAILED);
 
 		flag_country = new_flag_country;
 		flag_type = new_flag_type;
-		flag_image = new_flag_image;
+		flag_image = game_singleton->get_flag_sheet_image();
 	} else {
 		// TODO - use REB flag as default/error flag
 		flag_country = nullptr;
diff --git a/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.hpp b/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.hpp
index cc28fe6..9290d5c 100644
--- a/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.hpp
+++ b/extension/src/openvic-extension/classes/GFXMaskedFlagTexture.hpp
@@ -14,6 +14,7 @@ namespace OpenVic {
 		godot::StringName PROPERTY(flag_type);
 
 		godot::Ref<godot::Image> overlay_image, mask_image, flag_image;
+		godot::Rect2i flag_image_rect;
 		godot::Ref<godot::ImageTexture> combined_texture;
 
 		godot::Error _generate_combined_image();
diff --git a/extension/src/openvic-extension/singletons/GameSingleton.cpp b/extension/src/openvic-extension/singletons/GameSingleton.cpp
index b8aef4f..8618276 100644
--- a/extension/src/openvic-extension/singletons/GameSingleton.cpp
+++ b/extension/src/openvic-extension/singletons/GameSingleton.cpp
@@ -54,6 +54,8 @@ void GameSingleton::_bind_methods() {
 	OV_BIND_METHOD(GameSingleton::get_map_dims);
 	OV_BIND_METHOD(GameSingleton::get_map_aspect_ratio);
 	OV_BIND_METHOD(GameSingleton::get_terrain_texture);
+	OV_BIND_METHOD(GameSingleton::get_flag_dims);
+	OV_BIND_METHOD(GameSingleton::get_flag_sheet_texture);
 	OV_BIND_METHOD(GameSingleton::get_province_shape_image_subdivisions);
 	OV_BIND_METHOD(GameSingleton::get_province_shape_texture);
 	OV_BIND_METHOD(GameSingleton::get_province_colour_texture);
@@ -158,19 +160,36 @@ Ref<Texture2DArray> GameSingleton::get_terrain_texture() const {
 	return terrain_texture;
 }
 
-Ref<Image> GameSingleton::get_flag_image(Country const* country, StringName const& flag_type) const {
-	ERR_FAIL_NULL_V(country, nullptr);
-	const typename decltype(flag_image_map)::const_iterator it = flag_image_map.find(country);
+Ref<Image> GameSingleton::get_flag_sheet_image() const {
+	return flag_sheet_image;
+}
+
+Ref<ImageTexture> GameSingleton::get_flag_sheet_texture() const {
+	return flag_sheet_texture;
+}
+
+int32_t GameSingleton::get_flag_sheet_index(int32_t country_index, godot::StringName const& flag_type) const {
 	ERR_FAIL_COND_V_MSG(
-		it == flag_image_map.end(), nullptr,
-		vformat("Failed to find flags for country: %s", std_view_to_godot_string(country->get_identifier()))
+		country_index < 0 || country_index >= game_manager.get_country_manager().get_country_count(), -1,
+		vformat("Invalid country index: %d", country_index)
 	);
-	const typename decltype(it->second)::const_iterator it2 = it->second.find(flag_type);
+
+	const typename decltype(flag_type_index_map)::const_iterator it = flag_type_index_map.find(flag_type);
+	ERR_FAIL_COND_V_MSG(it == flag_type_index_map.end(), -1, vformat("Invalid flag type %s", flag_type));
+
+	return flag_type_index_map.size() * country_index + it->second;
+}
+
+Rect2i GameSingleton::get_flag_sheet_rect(int32_t flag_index) const {
 	ERR_FAIL_COND_V_MSG(
-		it2 == it->second.end(), nullptr,
-		vformat("Failed to find %s flag for country: %s", flag_type, std_view_to_godot_string(country->get_identifier()))
+		flag_index < 0 || flag_index >= flag_sheet_count, {}, vformat("Invalid flag sheet index: %d", flag_index)
 	);
-	return it2->second;
+
+	return { Vector2i { flag_index % flag_sheet_dims.x, flag_index / flag_sheet_dims.x } * flag_dims, flag_dims };
+}
+
+Rect2i GameSingleton::get_flag_sheet_rect(int32_t country_index, godot::StringName const& flag_type) const {
+	return get_flag_sheet_rect(get_flag_sheet_index(country_index, flag_type));
 }
 
 Vector2i GameSingleton::get_province_shape_image_subdivisions() const {
@@ -383,50 +402,115 @@ Error GameSingleton::_load_terrain_variants() {
 	return OK;
 }
 
-Error GameSingleton::_load_flag_images() {
-	ERR_FAIL_COND_V_MSG(!flag_image_map.empty(), FAILED, "Flag images have already been loaded!");
+const Vector2i GameSingleton::flag_dims { 128, 64 };
+
+Error GameSingleton::_load_flag_sheet() {
+	ERR_FAIL_COND_V_MSG(
+		flag_sheet_image.is_valid() || flag_sheet_texture.is_valid(), FAILED,
+		"Flag sheet image and/or texture has already been generated!"
+	);
 
 	GovernmentTypeManager const& government_type_manager = game_manager.get_politics_manager().get_government_type_manager();
 	ERR_FAIL_COND_V_MSG(
-		!government_type_manager.government_types_are_locked(), FAILED,
-		"Cannot load flag images before government types are locked!"
+		government_type_manager.get_flag_types().empty() || !government_type_manager.government_types_are_locked(), FAILED,
+		"Cannot load flag images if flag types are empty or government types are not locked!"
 	);
 	CountryManager const& country_manager = game_manager.get_country_manager();
 	ERR_FAIL_COND_V_MSG(
-		!country_manager.countries_are_locked(), FAILED, "Cannot load flag images before countries are locked!"
+		country_manager.countries_empty() || !country_manager.countries_are_locked(), FAILED,
+		"Cannot load flag images if countries are empty or not locked!"
 	);
 
 	AssetManager* asset_manager = AssetManager::get_singleton();
 	ERR_FAIL_NULL_V(asset_manager, FAILED);
 
-	static const String flag_directory = "gfx/flags/";
-	static const String flag_separator = "_";
-	static const String flag_extension = ".tga";
-
-	std::vector<StringName> flag_types;
+	/* Generate flag type - index lookup map */
+	flag_type_index_map.clear();
 	for (std::string const& type : government_type_manager.get_flag_types()) {
-		flag_types.emplace_back(std_to_godot_string_name(type));
+		flag_type_index_map.emplace(std_to_godot_string_name(type), static_cast<int32_t>(flag_type_index_map.size()));
 	}
 
-	flag_image_map.reserve(country_manager.get_countries().size());
+	flag_sheet_count = country_manager.get_countries().size() * flag_type_index_map.size();
+
+	std::vector<Ref<Image>> flag_images;
+	flag_images.reserve(flag_sheet_count);
+
+	static constexpr Image::Format flag_format = Image::FORMAT_RGB8;
 
 	Error ret = OK;
 	for (Country const& country : country_manager.get_countries()) {
-		ordered_map<StringName, Ref<Image>>& flag_images = flag_image_map[&country];
-		flag_images.reserve(flag_types.size());
 		const String country_name = std_view_to_godot_string(country.get_identifier());
-		for (StringName const& flag_type : flag_types) {
+
+		for (auto const& [flag_type, flag_type_index] : flag_type_index_map) {
+			static const String flag_directory = "gfx/flags/";
+			static const String flag_separator = "_";
+			static const String flag_extension = ".tga";
+
 			const StringName flag_path =
 				flag_directory + country_name + (flag_type.is_empty() ? "" : flag_separator + flag_type) + flag_extension;
-			const Ref<Image> flag_image = asset_manager->get_image(flag_path);
+
+			/* Do not cache flag image, they should be freed after the flag sheet has been generated. */
+			const Ref<Image> flag_image = asset_manager->get_image(flag_path, AssetManager::LOAD_FLAG_NONE);
+
 			if (flag_image.is_valid()) {
-				flag_images.emplace(flag_type, flag_image);
+
+				if (flag_image->get_format() != flag_format) {
+					flag_image->convert(flag_format);
+				}
+
+				if (flag_image->get_size() != flag_dims) {
+					if (flag_image->get_width() > flag_dims.x || flag_image->get_height() > flag_dims.y) {
+						UtilityFunctions::push_warning(
+							"Flag image ", flag_path, " (", flag_image->get_size(), ") is larger than the sheet flag size (",
+							flag_dims, ")"
+						);
+					}
+
+					flag_image->resize(flag_dims.x, flag_dims.y, Image::INTERPOLATE_NEAREST);
+				}
 			} else {
 				UtilityFunctions::push_error("Failed to load flag image: ", flag_path);
 				ret = FAILED;
 			}
+
+			/* Add flag_image to the vector even if it's null to ensure each flag has the right index. */
+			flag_images.push_back(flag_image);
 		}
 	}
+
+	ERR_FAIL_COND_V(flag_images.size() != flag_sheet_count, FAILED);
+
+	/* Calculate the width that will make the sheet as close to a square as possible (taking flag dimensions into account.) */
+	flag_sheet_dims.x = (fixed_point_t { static_cast<int32_t>(flag_images.size()) } * flag_dims.y / flag_dims.x).sqrt().ceil();
+
+	/* Calculated corresponding height (rounded up). */
+	flag_sheet_dims.y = (static_cast<int32_t>(flag_images.size()) + flag_sheet_dims.x - 1 ) / flag_sheet_dims.x;
+
+	const Vector2i sheet_dims = flag_sheet_dims * flag_dims;
+
+	flag_sheet_image = Image::create(sheet_dims.x, sheet_dims.y, false, flag_format);
+	ERR_FAIL_NULL_V_MSG(flag_sheet_image, FAILED, "Failed to create flag sheet image!");
+
+	static const Rect2i flag_rect { { 0, 0 }, flag_dims };
+
+	/* Fill the flag sheet with the flag images. */
+	for (int32_t index = 0; index < flag_images.size(); ++index) {
+		Ref<Image> const& flag_image = flag_images[index];
+
+		const Vector2i sheet_pos = Vector2i { index % flag_sheet_dims.x, index / flag_sheet_dims.x } * flag_dims;
+
+		if (flag_image.is_valid()) {
+			flag_sheet_image->blit_rect(flag_image, flag_rect, sheet_pos);
+		} else {
+			static const Color error_colour { 1.0f, 0.0f, 1.0f, 1.0f }; /* Magenta */
+
+			flag_sheet_image->fill_rect({ sheet_pos, flag_dims }, error_colour);
+		}
+	}
+
+	flag_sheet_texture = ImageTexture::create_from_image(flag_sheet_image);
+	ERR_FAIL_NULL_V_MSG(flag_sheet_texture, FAILED, "Failed to create flag sheet texture!");
+
 	return ret;
 }
 
@@ -450,8 +534,8 @@ Error GameSingleton::load_defines_compatibility_mode(PackedStringArray const& fi
 		UtilityFunctions::push_error("Failed to load terrain variants!");
 		err = FAILED;
 	}
-	if (_load_flag_images() != OK) {
-		UtilityFunctions::push_error("Failed to load flag textures!");
+	if (_load_flag_sheet() != OK) {
+		UtilityFunctions::push_error("Failed to load flag sheet!");
 		err = FAILED;
 	}
 	if (_load_map_images() != OK) {
diff --git a/extension/src/openvic-extension/singletons/GameSingleton.hpp b/extension/src/openvic-extension/singletons/GameSingleton.hpp
index a741331..397b64c 100644
--- a/extension/src/openvic-extension/singletons/GameSingleton.hpp
+++ b/extension/src/openvic-extension/singletons/GameSingleton.hpp
@@ -22,7 +22,13 @@ namespace OpenVic {
 		godot::Ref<godot::ImageTexture> province_colour_texture;
 		Mapmode::index_t mapmode_index = 0;
 		godot::Ref<godot::Texture2DArray> terrain_texture;
-		ordered_map<Country const*, ordered_map<godot::StringName, godot::Ref<godot::Image>>> flag_image_map;
+
+		static const godot::Vector2i PROPERTY(flag_dims); /* The size in pixels of an individual flag. */
+		int32_t flag_sheet_count = 0; /* The number of flags in the flag sheet. */
+		godot::Vector2i flag_sheet_dims; /* The size of the flag sheet in flags, rather than pixels. */
+		godot::Ref<godot::Image> flag_sheet_image;
+		godot::Ref<godot::ImageTexture> flag_sheet_texture;
+		ordered_map<godot::StringName, int32_t> flag_type_index_map;
 
 		static godot::StringName const& _signal_gamestate_updated();
 		static godot::StringName const& _signal_province_selected();
@@ -30,7 +36,7 @@ namespace OpenVic {
 
 		godot::Error _load_map_images();
 		godot::Error _load_terrain_variants();
-		godot::Error _load_flag_images();
+		godot::Error _load_flag_sheet();
 
 		/* Generate the province_colour_texture from the current mapmode. */
 		godot::Error _update_colour_image();
@@ -67,9 +73,14 @@ namespace OpenVic {
 		/* The cosmetic terrain textures stored in a Texture2DArray. */
 		godot::Ref<godot::Texture2DArray> get_terrain_texture() const;
 
-		/* The flag image corresponding to the requested country / flag_type
-		 * combination, or nullptr if no such flag can be found. */
-		godot::Ref<godot::Image> get_flag_image(Country const* country, godot::StringName const& flag_type) const;
+		godot::Ref<godot::Image> get_flag_sheet_image() const;
+		godot::Ref<godot::ImageTexture> get_flag_sheet_texture() const;
+
+		/* The index of the flag in the flag sheet corresponding to the requested country / flag_type
+		 * combination, or -1 if no such flag can be found. */
+		int32_t get_flag_sheet_index(int32_t country_index, godot::StringName const& flag_type) const;
+		godot::Rect2i get_flag_sheet_rect(int32_t flag_index) const;
+		godot::Rect2i get_flag_sheet_rect(int32_t country_index, godot::StringName const& flag_type) const;
 
 		/* Number of (vertical, horizontal) subdivisions the province shape image
 		 * was split into when making the province_shape_texture to ensure no