Feature: Add station coverage area display for towns.

src/script/api/game/game_window.hpp.sq

@@ -1259,6 +1259,7 @@ void SQGSWindow_Register(Squirrel *engine)
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_CENTER_VIEW,                        "WID_TV_CENTER_VIEW");
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_SHOW_AUTHORITY,                     "WID_TV_SHOW_AUTHORITY");
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_CHANGE_NAME,                        "WID_TV_CHANGE_NAME");
+	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_CATCHMENT,                          "WID_TV_CATCHMENT");
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_EXPAND,                             "WID_TV_EXPAND");
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TV_DELETE,                             "WID_TV_DELETE");
 	SQGSWindow.DefSQConst(engine, ScriptWindow::WID_TF_NEW_TOWN,                           "WID_TF_NEW_TOWN");

src/script/api/script_window.hpp

@@ -2498,6 +2498,7 @@ class ScriptWindow : public ScriptObject {
 		WID_TV_CENTER_VIEW                           = ::WID_TV_CENTER_VIEW,                           ///< Center the main view on this town.
 		WID_TV_SHOW_AUTHORITY                        = ::WID_TV_SHOW_AUTHORITY,                        ///< Show the town authority window.
 		WID_TV_CHANGE_NAME                           = ::WID_TV_CHANGE_NAME,                           ///< Change the name of this town.
+		WID_TV_CATCHMENT                             = ::WID_TV_CATCHMENT,                             ///< Toggle catchment area highlight.
 		WID_TV_EXPAND                                = ::WID_TV_EXPAND,                                ///< Expand this town (scenario editor only).
 		WID_TV_DELETE                                = ::WID_TV_DELETE,                                ///< Delete this town (scenario editor only).
 	};

src/town_gui.cpp

@@ -321,11 +321,24 @@ struct TownViewWindow : Window {
 		this->SetWidgetDisabledState(WID_TV_CHANGE_NAME, _networking && !_network_server);
 	}
 
+	~TownViewWindow()
+	{
+		SetViewportCatchmentTown(Town::Get(this->window_number), false);
+	}
+
 	void SetStringParameters(int widget) const override
 	{
 		if (widget == WID_TV_CAPTION) SetDParam(0, this->town->index);
 	}
 
+	void OnPaint() override
+	{
+		extern const Town *_viewport_highlight_town;
+		this->SetWidgetLoweredState(WID_TV_CATCHMENT, _viewport_highlight_town == this->town);
+
+		this->DrawWidgets();
+	}
+
 	void DrawWidget(const Rect &r, int widget) const override
 	{
 		if (widget != WID_TV_INFO) return;
@@ -432,6 +445,10 @@ struct TownViewWindow : Window {
 				ShowQueryString(STR_TOWN_NAME, STR_TOWN_VIEW_RENAME_TOWN_BUTTON, MAX_LENGTH_TOWN_NAME_CHARS, this, CS_ALPHANUMERAL, QSF_ENABLE_DEFAULT | QSF_LEN_IN_CHARS);
 				break;
 
+			case WID_TV_CATCHMENT:
+				SetViewportCatchmentTown(Town::Get(this->window_number), !this->IsWidgetLowered(WID_TV_CATCHMENT));
+				break;
+
 			case WID_TV_EXPAND: { // expand town - only available on Scenario editor
 				/* Warn the user if towns are not allowed to build roads, but do this only once per OpenTTD run. */
 				static bool _warn_town_no_roads = false;
@@ -552,6 +569,7 @@ static const NWidgetPart _nested_town_game_view_widgets[] = {
 			NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_TV_SHOW_AUTHORITY), SetMinimalSize(80, 12), SetFill(1, 1), SetResize(1, 0), SetDataTip(STR_TOWN_VIEW_LOCAL_AUTHORITY_BUTTON, STR_TOWN_VIEW_LOCAL_AUTHORITY_TOOLTIP),
 			NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_TV_CHANGE_NAME), SetMinimalSize(80, 12), SetFill(1, 1), SetResize(1, 0), SetDataTip(STR_BUTTON_RENAME, STR_TOWN_VIEW_RENAME_TOOLTIP),
 		EndContainer(),
+		NWidget(WWT_TEXTBTN, COLOUR_BROWN, WID_TV_CATCHMENT), SetMinimalSize(14, 12), SetFill(0, 1), SetDataTip(STR_BUTTON_CATCHMENT, STR_TOOLTIP_CATCHMENT),
 		NWidget(WWT_RESIZEBOX, COLOUR_BROWN),
 	EndContainer(),
 };

src/viewport.cpp

@@ -983,9 +983,11 @@ enum TileHighlightType {
 	THT_NONE,
 	THT_WHITE,
 	THT_BLUE,
+	THT_RED,
 };
 
 const Station *_viewport_highlight_station; ///< Currently selected station for coverage area highlight
+const Town *_viewport_highlight_town;       ///< Currently selected town for coverage area highlight
 
 /**
  * Get tile highlight type of coverage area for a given tile.
@@ -1000,6 +1002,25 @@ static TileHighlightType GetTileHighlightType(TileIndex t)
 		return THT_NONE;
 	}
 
+	if (_viewport_highlight_town != nullptr) {
+		if (IsTileType(t, MP_HOUSE)) {
+			if (GetTownIndex(t) == _viewport_highlight_town->index) {
+				TileHighlightType type = THT_RED;
+				for (const Station *st : _viewport_highlight_town->stations_near) {
+					if (st->owner != _current_company) continue;
+					if (st->TileIsInCatchment(t)) return THT_BLUE;
+				}
+				return type;
+			}
+		} else if (IsTileType(t, MP_STATION)) {
+			for (const Station *st : _viewport_highlight_town->stations_near) {
+				if (st->owner != _current_company) continue;
+				if (GetStationIndex(t) == st->index) return THT_WHITE;
+			}
+		}
+		return THT_NONE;
+	}
+
 	return THT_NONE;
 }
 
@@ -1015,6 +1036,7 @@ static void DrawTileHighlightType(const TileInfo *ti, TileHighlightType tht)
 		case THT_NONE: break;
 		case THT_WHITE: DrawTileSelectionRect(ti, PAL_NONE); break;
 		case THT_BLUE:  DrawTileSelectionRect(ti, PALETTE_SEL_TILE_BLUE); break;
+		case THT_RED:   DrawTileSelectionRect(ti, PALETTE_TILE_RED_PULSATING); break;
 	}
 }
 
@@ -3404,19 +3426,43 @@ static void MarkCatchmentTilesDirty()
 
 /**
  * Select or deselect station for coverage area highlight.
+ * Selecting a station will deselect a town.
  * @param *st Station in question
  * @param sel Select or deselect given station
  */
 void SetViewportCatchmentStation(const Station *st, bool sel)
 {
 	if (_viewport_highlight_station != nullptr) SetWindowDirty(WC_STATION_VIEW, _viewport_highlight_station->index);
+	if (_viewport_highlight_town != nullptr) SetWindowDirty(WC_TOWN_VIEW, _viewport_highlight_town->index);
 	if (sel && _viewport_highlight_station != st) {
 		MarkCatchmentTilesDirty();
 		_viewport_highlight_station = st;
+		_viewport_highlight_town = nullptr;
 		MarkCatchmentTilesDirty();
 	} else if (!sel && _viewport_highlight_station == st) {
 		MarkCatchmentTilesDirty();
 		_viewport_highlight_station = nullptr;
 	}
 	if (_viewport_highlight_station != nullptr) SetWindowDirty(WC_STATION_VIEW, _viewport_highlight_station->index);
 }
+
+/**
+ * Select or deselect town for coverage area highlight.
+ * Selecting a town will deselect a station.
+ * @param *t Town in question
+ * @param sel Select or deselect given town
+ */
+void SetViewportCatchmentTown(const Town *t, bool sel)
+{
+	if (_viewport_highlight_town != nullptr) SetWindowDirty(WC_TOWN_VIEW, _viewport_highlight_town->index);
+	if (_viewport_highlight_station != nullptr) SetWindowDirty(WC_STATION_VIEW, _viewport_highlight_station->index);
+	if (sel && _viewport_highlight_town != t) {
+		_viewport_highlight_station = nullptr;
+		_viewport_highlight_town = t;
+		MarkWholeScreenDirty();
+	} else if (!sel && _viewport_highlight_town == t) {
+		_viewport_highlight_town = nullptr;
+		MarkWholeScreenDirty();
+	}
+	if (_viewport_highlight_town != nullptr) SetWindowDirty(WC_TOWN_VIEW, _viewport_highlight_town->index);
+}

src/viewport_func.h

@@ -94,7 +94,9 @@ static inline void MarkTileDirtyByTile(TileIndex tile, int bridge_level_offset =
 Point GetViewportStationMiddle(const ViewPort *vp, const Station *st);
 
 struct Station;
+struct Town;
 
 void SetViewportCatchmentStation(const Station *st, bool sel);
+void SetViewportCatchmentTown(const Town *t, bool sel);
 
 #endif /* VIEWPORT_FUNC_H */

src/widgets/town_widget.h

@@ -39,6 +39,7 @@ enum TownViewWidgets {
 	WID_TV_CENTER_VIEW,    ///< Center the main view on this town.
 	WID_TV_SHOW_AUTHORITY, ///< Show the town authority window.
 	WID_TV_CHANGE_NAME,    ///< Change the name of this town.
+	WID_TV_CATCHMENT,      ///< Toggle catchment area highlight.
 	WID_TV_EXPAND,         ///< Expand this town (scenario editor only).
 	WID_TV_DELETE,         ///< Delete this town (scenario editor only).
 };