int _nb_orig_names = SPECSTR_TOWNNAME_LAST - SPECSTR_TOWNNAME_START + 1;

static StringID *_town_names = NULL;

static StringID *_grf_names = NULL;

static int _nb_grf_names = 0;

void SortTownGeneratorNames()

{

	int n = 0;

	/* Get Newgrf generators' names */

	free(_grf_names);

	_grf_names = GetGRFTownNameList();

	_nb_grf_names = 0;

	for (StringID *s = _grf_names; *s != INVALID_STRING_ID; s++) _nb_grf_names++;

	/* Prepare the list */

	free(_town_names);

	_town_names = MallocT<StringID>(_nb_orig_names + _nb_grf_names + 1);

	/* Put the original strings */

	for (int i = 0; i < _nb_orig_names; i++) _town_names[n++] = STR_TOWNNAME_ORIGINAL_ENGLISH + i;

	/* Put the grf strings */

	for (int i = 0; i < _nb_grf_names; i++) _town_names[n++] = _grf_names[i];

	/* Put the terminator */

	_town_names[n] = INVALID_STRING_ID;

	/* Sort the strings */

	qsort(&_town_names[0], _nb_orig_names + _nb_grf_names, sizeof(StringID), &StringIDSorter);

}

static inline StringID TownName(int town_name)

{

	if (town_name < _nb_orig_names) return STR_TOWNNAME_ORIGINAL_ENGLISH + town_name;

	town_name -= _nb_orig_names;

	if (town_name < _nb_grf_names) return _grf_names[town_name];

	return STR_UNDEFINED;

}

static int GetCurRes()

{

	int i;

	for (i = 0; i != _num_resolutions; i++) {

		if (_resolutions[i][0] == _screen.width &&

				_resolutions[i][1] == _screen.height) {

			break;

		}

	}

	return i;

}

static inline bool RoadVehiclesAreBuilt()

{

	const Vehicle* v;

	FOR_ALL_VEHICLES(v) {

		if (v->type == VEH_ROAD) return true;

	}

	return false;

}

enum GameOptionsWidgets {

	GAMEOPT_CURRENCY_TXT    =  4,

	GAMEOPT_CURRENCY_BTN,

	GAMEOPT_DISTANCE_TXT    =  7,

	GAMEOPT_DISTANCE_BTN,

	GAMEOPT_ROADSIDE_TXT    = 10,

	GAMEOPT_ROADSIDE_BTN,

	GAMEOPT_TOWNNAME_TXT    = 13,

	GAMEOPT_TOWNNAME_BTN,

	GAMEOPT_AUTOSAVE_TXT    = 16,

	GAMEOPT_AUTOSAVE_BTN,

	GAMEOPT_VEHICLENAME_TXT = 19,

	GAMEOPT_VEHICLENAME_BTN,

	GAMEOPT_VEHICLENAME_SAVE,

	GAMEOPT_LANG_TXT        = 23,

	GAMEOPT_LANG_BTN,

	GAMEOPT_RESOLUTION_TXT  = 26,

	GAMEOPT_RESOLUTION_BTN,

	GAMEOPT_FULLSCREEN,

	GAMEOPT_SCREENSHOT_TXT  = 30,

	GAMEOPT_SCREENSHOT_BTN,

};

static void ShowCustCurrency();

static void GameOptionsWndProc(Window *w, WindowEvent *e)

{

	switch (e->event) {

		case WE_PAINT: {

			int i;

			StringID str = STR_02BE_DEFAULT;

			SetDParam(0, str);

			SetDParam(1, _currency_specs[_opt_ptr->currency].name);

			SetDParam(2, STR_UNITS_IMPERIAL + _opt_ptr->units);

			SetDParam(3, STR_02E9_DRIVE_ON_LEFT + _opt_ptr->road_side);

			SetDParam(4, TownName(_opt_ptr->town_name));

			SetDParam(5, _autosave_dropdown[_opt_ptr->autosave]);

			SetDParam(6, SPECSTR_LANGUAGE_START + _dynlang.curr);

			i = GetCurRes();

			SetDParam(7, i == _num_resolutions ? STR_RES_OTHER : SPECSTR_RESOLUTION_START + i);

			SetDParam(8, SPECSTR_SCREENSHOT_START + _cur_screenshot_format);

			w->SetWidgetLoweredState(GAMEOPT_FULLSCREEN, _fullscreen);

			DrawWindowWidgets(w);

			DrawString(20, 175, STR_OPTIONS_FULLSCREEN, TC_FROMSTRING); // fullscreen

		} break;

		case WE_CLICK:

			switch (e->we.click.widget) {

				case GAMEOPT_CURRENCY_TXT: case GAMEOPT_CURRENCY_BTN: /* Setup currencies dropdown */

					ShowDropDownMenu(w, BuildCurrencyDropdown(), _opt_ptr->currency, GAMEOPT_CURRENCY_BTN, _game_mode == GM_MENU ? 0 : ~GetMaskOfAllowedCurrencies(), 0);

					break;

				case GAMEOPT_DISTANCE_TXT: case GAMEOPT_DISTANCE_BTN: /* Setup distance unit dropdown */

					ShowDropDownMenu(w, _units_dropdown, _opt_ptr->units, GAMEOPT_DISTANCE_BTN, 0, 0);

					break;

				case GAMEOPT_ROADSIDE_TXT: case GAMEOPT_ROADSIDE_BTN: { /* Setup road-side dropdown */

					int i = 0;

					/* You can only change the drive side if you are in the menu or ingame with

					 * no vehicles present. In a networking game only the server can change it */

					if ((_game_mode != GM_MENU && RoadVehiclesAreBuilt()) || (_networking && !_network_server))

						i = (-1) ^ (1 << _opt_ptr->road_side); // disable the other value

					ShowDropDownMenu(w, _driveside_dropdown, _opt_ptr->road_side, GAMEOPT_ROADSIDE_BTN, i, 0);

				} break;

				case GAMEOPT_TOWNNAME_TXT: case GAMEOPT_TOWNNAME_BTN: { /* Setup townname dropdown */

					uint sel = 0;

					for (uint i = 0; _town_names[i] != INVALID_STRING_ID; i++) {

						if (_town_names[i] == TownName(_opt_ptr->town_name)) {

							sel = i;

							break;

						}

					}

					ShowDropDownMenu(w, _town_names, sel, GAMEOPT_TOWNNAME_BTN, (_game_mode == GM_MENU) ? 0 : (-1) ^ (1 << sel), 0);

				} break;

				case GAMEOPT_AUTOSAVE_TXT: case GAMEOPT_AUTOSAVE_BTN: /* Setup autosave dropdown */

					ShowDropDownMenu(w, _autosave_dropdown, _opt_ptr->autosave, GAMEOPT_AUTOSAVE_BTN, 0, 0);

					break;

				case GAMEOPT_VEHICLENAME_TXT: case GAMEOPT_VEHICLENAME_BTN: /* Setup customized vehicle-names dropdown */

					ShowDropDownMenu(w, _designnames_dropdown, (_vehicle_design_names & 1) ? 1 : 0, GAMEOPT_VEHICLENAME_BTN, (_vehicle_design_names & 2) ? 0 : 2, 0);

					break;

				case GAMEOPT_VEHICLENAME_SAVE: /* Save customized vehicle-names to disk */

					break;  // not implemented

				case GAMEOPT_LANG_TXT: case GAMEOPT_LANG_BTN: /* Setup interface language dropdown */

					ShowDropDownMenu(w, _dynlang.dropdown, _dynlang.curr, GAMEOPT_LANG_BTN, 0, 0);

					break;

				case GAMEOPT_RESOLUTION_TXT: case GAMEOPT_RESOLUTION_BTN: /* Setup resolution dropdown */

					ShowDropDownMenu(w, BuildDynamicDropdown(SPECSTR_RESOLUTION_START, _num_resolutions), GetCurRes(), GAMEOPT_RESOLUTION_BTN, 0, 0);

					break;

				case GAMEOPT_FULLSCREEN: /* Click fullscreen on/off */

					/* try to toggle full-screen on/off */

					if (!ToggleFullScreen(!_fullscreen)) {

						ShowErrorMessage(INVALID_STRING_ID, STR_FULLSCREEN_FAILED, 0, 0);

					}

					w->SetWidgetLoweredState(GAMEOPT_FULLSCREEN, _fullscreen);

					SetWindowDirty(w);

					break;

				case GAMEOPT_SCREENSHOT_TXT: case GAMEOPT_SCREENSHOT_BTN: /* Setup screenshot format dropdown */

					ShowDropDownMenu(w, BuildDynamicDropdown(SPECSTR_SCREENSHOT_START, _num_screenshot_formats), _cur_screenshot_format, GAMEOPT_SCREENSHOT_BTN, 0, 0);

					break;

			}

			break;

		case WE_DROPDOWN_SELECT:

			switch (e->we.dropdown.button) {

				case GAMEOPT_VEHICLENAME_BTN: /* Vehicle design names */

					if (e->we.dropdown.index == 0) {

						DeleteCustomEngineNames();

						MarkWholeScreenDirty();

					} else if (!(_vehicle_design_names & 1)) {

						LoadCustomEngineNames();

						MarkWholeScreenDirty();

					}

					break;

				case GAMEOPT_CURRENCY_BTN: /* Currency */

					if (e->we.dropdown.index == CUSTOM_CURRENCY_ID) ShowCustCurrency();