Method ReadIntroGameViewportCommands

src/intro_gui.cpp:115–178

* Find and parse all viewport command signs. * Fills the intro_viewport_commands vector and deletes parsed signs from the world. */

	 * Fills the intro_viewport_commands vector and deletes parsed signs from the world.
	 */
	void ReadIntroGameViewportCommands()
	{
		intro_viewport_commands.clear();

		/* Regular expression matching the commands: T, spaces, integer, spaces, flags, spaces, integer */
		static const std::string sign_language = "^T\\s*([0-9]+)\\s*([-+A-Z0-9]+)\\s*([0-9]+)";
		std::regex re(sign_language, std::regex_constants::icase);

		/* List of signs successfully parsed to delete afterwards. */
		std::vector<SignID> signs_to_delete;

		for (const Sign *sign : Sign::Iterate()) {
			std::smatch match;
			if (!std::regex_search(sign->name, match, re)) continue;

			IntroGameViewportCommand vc;
			/* Sequence index from the first matching group. */
			if (auto value = ParseInteger<int>(match[1].str()); value.has_value()) {
				vc.command_index = *value;
			} else {
				continue;
			}
			/* Sign coordinates for positioning. */
			vc.position = RemapCoords(sign->x, sign->y, sign->z);
			/* Delay from the third matching group. */
			if (auto value = ParseInteger<uint>(match[3].str()); value.has_value()) {
				vc.delay = *value * 1000; // milliseconds
			} else {
				continue;
			}

			/* Parse flags from second matching group. */
			auto flags = match[2].str();
			StringConsumer consumer{flags};
			while (consumer.AnyBytesLeft()) {
				auto c = consumer.ReadUtf8();
				switch (toupper(c)) {
					case '-': vc.zoom_adjust = +1; break;
					case '+': vc.zoom_adjust = -1; break;
					case 'T': vc.align_v = IntroGameViewportCommand::TOP; break;
					case 'M': vc.align_v = IntroGameViewportCommand::MIDDLE; break;
					case 'B': vc.align_v = IntroGameViewportCommand::BOTTOM; break;
					case 'L': vc.align_h = IntroGameViewportCommand::LEFT; break;
					case 'C': vc.align_h = IntroGameViewportCommand::CENTRE; break;
					case 'R': vc.align_h = IntroGameViewportCommand::RIGHT; break;
					case 'P': vc.pan_to_next = true; break;
					case 'V': vc.vehicle = static_cast<VehicleID>(consumer.ReadIntegerBase<uint32_t>(10, VehicleID::Invalid().base())); break;
				}
			}

			/* Successfully parsed, store. */
			intro_viewport_commands.push_back(vc);
			signs_to_delete.push_back(sign->index);
		}

		/* Sort the commands by sequence index. */
		std::sort(intro_viewport_commands.begin(), intro_viewport_commands.end(), [](const IntroGameViewportCommand &a, const IntroGameViewportCommand &b) { return a.command_index < b.command_index; });