Feature: Highlight tiles of a depot and adjacent depot tiles when building.

src/depot_func.h

@@ -41,4 +41,7 @@ CommandCost FindJoiningDepot(TileArea ta, VehicleType veh_type, DepotID &join_to
 using DepotPickerCmdProc = std::function<bool(DepotID join_to)>;
 void ShowSelectDepotIfNeeded(TileArea ta, DepotPickerCmdProc proc, VehicleType veh_type);
 
+struct Window;
+void CheckRedrawDepotHighlight(const Window *w, VehicleType veh_type);
+
 #endif /* DEPOT_FUNC_H */

src/depot_gui.cpp

@@ -80,6 +80,7 @@ static constexpr NWidgetPart _nested_train_depot_widgets[] = {
 	NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 		NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, WID_D_BUILD), SetDataTip(0x0, STR_NULL), SetFill(1, 1), SetResize(1, 0),
 		NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_D_CLONE), SetDataTip(0x0, STR_NULL), SetFill(1, 1), SetResize(1, 0),
+		NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_D_HIGHLIGHT), SetDataTip(STR_BUTTON_HIGHLIGHT_DEPOT, STR_TOOLTIP_HIGHLIGHT_DEPOT), SetFill(1, 1), SetResize(1, 0),
 		NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, WID_D_VEHICLE_LIST), SetDataTip(0x0, STR_NULL), SetAspect(WidgetDimensions::ASPECT_VEHICLE_ICON), SetFill(0, 1),
 		NWidget(WWT_PUSHIMGBTN, COLOUR_GREY, WID_D_STOP_ALL), SetDataTip(SPR_FLAG_VEH_STOPPED, STR_NULL), SetAspect(WidgetDimensions::ASPECT_VEHICLE_FLAG), SetFill(0, 1),
 		NWidget(WWT_PUSHIMGBTN, COLOUR_GREY, WID_D_START_ALL), SetDataTip(SPR_FLAG_VEH_RUNNING, STR_NULL), SetAspect(WidgetDimensions::ASPECT_VEHICLE_FLAG), SetFill(0, 1),
@@ -303,6 +304,7 @@ struct DepotWindow : Window {
 		CloseWindowById(WC_BUILD_VEHICLE, this->window_number);
 		CloseWindowById(GetWindowClassForVehicleType(this->type), VehicleListIdentifier(VL_DEPOT_LIST, this->type, this->owner, this->window_number).Pack(), false);
 		OrderBackup::Reset(this->window_number);
+		SetViewportHighlightDepot(this->window_number, false);
 		this->Window::Close();
 	}
 
@@ -712,6 +714,9 @@ struct DepotWindow : Window {
 
 	void OnPaint() override
 	{
+		extern DepotID _viewport_highlight_depot;
+		this->SetWidgetLoweredState(WID_D_HIGHLIGHT, _viewport_highlight_depot == this->window_number);
+
 		if (this->generate_list) {
 			/* Generate the vehicle list
 			 * It's ok to use the wagon pointers for non-trains as they will be ignored */
@@ -804,6 +809,11 @@ struct DepotWindow : Window {
 				ShowQueryString(STR_DEPOT_NAME, STR_DEPOT_RENAME_DEPOT_CAPTION, MAX_LENGTH_DEPOT_NAME_CHARS, this, CS_ALPHANUMERAL, QSF_ENABLE_DEFAULT | QSF_LEN_IN_CHARS);
 				break;
 
+			case WID_D_HIGHLIGHT:
+				this->SetWidgetDirty(WID_D_HIGHLIGHT);
+				SetViewportHighlightDepot(this->window_number, !this->IsWidgetLowered(WID_D_HIGHLIGHT));
+				break;
+
 			case WID_D_STOP_ALL:
 			case WID_D_START_ALL: {
 				VehicleListIdentifier vli(VL_DEPOT_LIST, this->type, this->owner);
@@ -1286,6 +1296,15 @@ struct SelectDepotWindow : Window {
 		this->vscroll = this->GetScrollbar(WID_JD_SCROLLBAR);
 		this->FinishInitNested(veh_type);
 		this->OnInvalidateData(0);
+
+		_thd.freeze = true;
+	}
+
+	~SelectDepotWindow()
+	{
+		SetViewportHighlightDepot(INVALID_DEPOT, true);
+
+		_thd.freeze = false;
 	}
 
 	void UpdateWidgetSize(int widget, Dimension &size, const Dimension &padding, [[maybe_unused]] Dimension &fill, Dimension &resize) override
@@ -1370,6 +1389,19 @@ struct SelectDepotWindow : Window {
 		this->vscroll->SetCount((uint)_depots_nearby_list.size());
 		this->SetDirty();
 	}
+
+	void OnMouseOver(Point pt, int widget) override
+	{
+		if (widget != WID_JD_PANEL) {
+			SetViewportHighlightDepot(INVALID_DEPOT, true);
+			return;
+		}
+
+		/* Highlight depot under cursor */
+		auto it = this->vscroll->GetScrolledItemFromWidget(_depots_nearby_list, pt.y, this, WID_JD_PANEL, WidgetDimensions::scaled.framerect.top);
+		SetViewportHighlightDepot(*it, true);
+	}
+
 };
 
 static const NWidgetPart _nested_select_depot_widgets[] = {
@@ -1409,3 +1441,76 @@ void ShowSelectDepotIfNeeded(TileArea ta, DepotPickerCmdProc proc, VehicleType v
 		proc(INVALID_DEPOT);
 	}
 }
+
+/**
+ * Find depots adjacent to the current tile highlight area, so that all depot tiles
+ * can be highlighted.
+ * @param v_type Vehicle type to check.
+ */
+static void HighlightSingleAdjacentDepot(VehicleType v_type)
+{
+	/* With distant join we don't know which depot will be selected, so don't show any */
+	if (_ctrl_pressed) {
+		SetViewportHighlightDepot(INVALID_DEPOT, true);
+		return;
+	}
+
+	/* Tile area for TileHighlightData */
+	TileArea location(TileVirtXY(_thd.pos.x, _thd.pos.y), _thd.size.x / TILE_SIZE - 1, _thd.size.y / TILE_SIZE - 1);
+
+	/* If the current tile is already a depot, then it must be the nearest depot. */
+	if (IsDepotTypeTile(location.tile, (TransportType)v_type) &&
+			GetTileOwner(location.tile) == _local_company) {
+		SetViewportHighlightDepot(GetDepotIndex(location.tile), true);
+		return;
+	}
+
+	/* Extended area by one tile */
+	uint x = TileX(location.tile);
+	uint y = TileY(location.tile);
+
+	int max_c = 1;
+	TileArea ta(TileXY(std::max<int>(0, x - max_c), std::max<int>(0, y - max_c)), TileXY(std::min<int>(Map::MaxX(), x + location.w + max_c), std::min<int>(Map::MaxY(), y + location.h + max_c)));
+
+	DepotID adjacent = INVALID_DEPOT;
+
+	for (TileIndex tile : ta) {
+		if (IsDepotTile(tile) && GetTileOwner(tile) == _local_company) {
+			Depot *depot = Depot::GetByTile(tile);
+			if (depot == nullptr) continue;
+			if (depot->veh_type != v_type) continue;
+			if (adjacent != INVALID_DEPOT && depot->index != adjacent) {
+				/* Multiple nearby, distant join is required. */
+				adjacent = INVALID_DEPOT;
+				break;
+			}
+			adjacent = depot->index;
+		}
+	}
+	SetViewportHighlightDepot(adjacent, true);
+}
+
+/**
+ * Check whether we need to redraw the depot highlight.
+ * If it is needed actually make the window for redrawing.
+ * @param w the window to check.
+ * @param veh_type vehicle type to check.
+ */
+void CheckRedrawDepotHighlight(const Window *w, VehicleType veh_type)
+{
+	/* Test if ctrl state changed */
+	static bool _last_ctrl_pressed;
+	if (_ctrl_pressed != _last_ctrl_pressed) {
+		_thd.dirty = 0xff;
+		_last_ctrl_pressed = _ctrl_pressed;
+	}
+
+	if (_thd.dirty & 1) {
+		_thd.dirty &= ~1;
+		w->SetDirty();
+
+		if (_thd.drawstyle == HT_RECT) {
+			HighlightSingleAdjacentDepot(veh_type);
+		}
+	}
+}

src/dock_gui.cpp

@@ -32,6 +32,7 @@
 #include "waypoint_cmd.h"
 #include "timer/timer.h"
 #include "timer/timer_game_calendar.h"
+#include "depot_func.h"
 
 #include "widgets/dock_widget.h"
 
@@ -112,6 +113,8 @@ struct BuildDocksToolbarWindow : Window {
 	{
 		if (_game_mode == GM_NORMAL && this->IsWidgetLowered(WID_DT_STATION)) SetViewportCatchmentStation(nullptr, true);
 		if (_settings_client.gui.link_terraform_toolbar) CloseWindowById(WC_SCEN_LAND_GEN, 0, false);
+		if (_game_mode == GM_NORMAL && this->IsWidgetLowered(WID_DT_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
+
 		this->Window::Close();
 	}
 
@@ -270,6 +273,8 @@ struct BuildDocksToolbarWindow : Window {
 	{
 		if (_game_mode != GM_EDITOR && this->IsWidgetLowered(WID_DT_STATION)) SetViewportCatchmentStation(nullptr, true);
 
+		if (_game_mode != GM_EDITOR && this->IsWidgetLowered(WID_DT_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
+
 		this->RaiseButtons();
 
 		CloseWindowById(WC_BUILD_STATION, TRANSPORT_WATER);
@@ -586,6 +591,11 @@ public:
 				break;
 		}
 	}
+
+	void OnRealtimeTick([[maybe_unused]] uint delta_ms) override
+	{
+		CheckRedrawDepotHighlight(this, VEH_SHIP);
+	}
 };
 
 static constexpr NWidgetPart _nested_build_docks_depot_widgets[] = {

src/lang/english.txt

@@ -278,6 +278,8 @@ STR_TOOLTIP_FILTER_CRITERIA                                     :{BLACK}Select f
 STR_BUTTON_SORT_BY                                              :{BLACK}Sort by
 STR_BUTTON_CATCHMENT                                            :{BLACK}Coverage
 STR_TOOLTIP_CATCHMENT                                           :{BLACK}Toggle coverage area display
+STR_BUTTON_HIGHLIGHT_DEPOT                                      :{BLACK}Highlight
+STR_TOOLTIP_HIGHLIGHT_DEPOT                                     :{BLACK}Toggle highlight on viewport for this depot
 
 STR_TOOLTIP_CLOSE_WINDOW                                        :{BLACK}Close window
 STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS                              :{BLACK}Window title - drag this to move window

src/rail_gui.cpp

@@ -41,6 +41,7 @@
 #include "timer/timer.h"
 #include "timer/timer_game_calendar.h"
 #include "picker_gui.h"
+#include "depot_func.h"
 
 #include "station_map.h"
 #include "tunnelbridge_map.h"
@@ -454,6 +455,7 @@ struct BuildRailToolbarWindow : Window {
 		if (this->IsWidgetLowered(WID_RAT_BUILD_WAYPOINT)) SetViewportCatchmentWaypoint(nullptr, true);
 		if (_settings_client.gui.link_terraform_toolbar) CloseWindowById(WC_SCEN_LAND_GEN, 0, false);
 		CloseWindowById(WC_SELECT_STATION, 0);
+		if (this->IsWidgetLowered(WID_RAT_BUILD_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
 		this->Window::Close();
 	}
 
@@ -795,6 +797,8 @@ struct BuildRailToolbarWindow : Window {
 		if (this->IsWidgetLowered(WID_RAT_BUILD_STATION)) SetViewportCatchmentStation(nullptr, true);
 		if (this->IsWidgetLowered(WID_RAT_BUILD_WAYPOINT)) SetViewportCatchmentWaypoint(nullptr, true);
 
+		if (this->IsWidgetLowered(WID_RAT_BUILD_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
+
 		this->RaiseButtons();
 		this->DisableWidget(WID_RAT_REMOVE);
 		this->SetWidgetDirty(WID_RAT_REMOVE);
@@ -1750,6 +1754,11 @@ struct BuildRailDepotWindow : public PickerWindowBase {
 				break;
 		}
 	}
+
+	void OnRealtimeTick([[maybe_unused]] uint delta_ms) override
+	{
+		CheckRedrawDepotHighlight(this, VEH_TRAIN);
+	}
 };
 
 /** Nested widget definition of the build rail depot window */

src/road_gui.cpp

@@ -43,6 +43,7 @@
 #include "picker_gui.h"
 #include "timer/timer.h"
 #include "timer/timer_game_calendar.h"
+#include "depot_func.h"
 
 #include "widgets/road_widget.h"
 
@@ -368,6 +369,7 @@ struct BuildRoadToolbarWindow : Window {
 	{
 		if (_game_mode == GM_NORMAL && (this->IsWidgetLowered(WID_ROT_BUS_STATION) || this->IsWidgetLowered(WID_ROT_TRUCK_STATION))) SetViewportCatchmentStation(nullptr, true);
 		if (_settings_client.gui.link_terraform_toolbar) CloseWindowById(WC_SCEN_LAND_GEN, 0, false);
+		if (_game_mode == GM_NORMAL && this->IsWidgetLowered(WID_ROT_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
 		this->Window::Close();
 	}
 
@@ -673,6 +675,8 @@ struct BuildRoadToolbarWindow : Window {
 	{
 		if (_game_mode != GM_EDITOR && (this->IsWidgetLowered(WID_ROT_BUS_STATION) || this->IsWidgetLowered(WID_ROT_TRUCK_STATION))) SetViewportCatchmentStation(nullptr, true);
 
+		if (_game_mode == GM_NORMAL && this->IsWidgetLowered(WID_ROT_DEPOT)) SetViewportHighlightDepot(INVALID_DEPOT, true);
+
 		this->RaiseButtons();
 		this->SetWidgetDisabledState(WID_ROT_REMOVE, true);
 		this->SetWidgetDirty(WID_ROT_REMOVE);
@@ -1154,6 +1158,11 @@ struct BuildRoadDepotWindow : public PickerWindowBase {
 				break;
 		}
 	}
+
+	void OnRealtimeTick([[maybe_unused]] uint delta_ms) override
+	{
+		CheckRedrawDepotHighlight(this, VEH_ROAD);
+	}
 };
 
 static constexpr NWidgetPart _nested_build_road_depot_widgets[] = {

src/viewport.cpp

@@ -90,6 +90,7 @@
 #include "network/network_func.h"
 #include "framerate_type.h"
 #include "viewport_cmd.h"
+#include "depot_map.h"
 
 #include <forward_list>
 #include <stack>
@@ -1002,6 +1003,7 @@ enum TileHighlightType {
 const Station *_viewport_highlight_station; ///< Currently selected station for coverage area highlight
 const Waypoint *_viewport_highlight_waypoint; ///< Currently selected waypoint for coverage area highlight
 const Town *_viewport_highlight_town; ///< Currently selected town for coverage area highlight
+DepotID _viewport_highlight_depot = INVALID_DEPOT; ///< Currently selected depot for depot highlight
 
 /**
  * Get tile highlight type of coverage area for a given tile.
@@ -1010,6 +1012,10 @@ const Town *_viewport_highlight_town; ///< Currently selected town for coverage
  */
 static TileHighlightType GetTileHighlightType(TileIndex t)
 {
+	if (_viewport_highlight_depot != INVALID_DEPOT) {
+		if (IsDepotTile(t) && GetDepotIndex(t) == _viewport_highlight_depot) return THT_WHITE;
+	}
+
 	if (_viewport_highlight_station != nullptr) {
 		if (IsTileType(t, MP_STATION) && GetStationIndex(t) == _viewport_highlight_station->index) return THT_WHITE;
 		if (_viewport_highlight_station->TileIsInCatchment(t)) return THT_BLUE;
@@ -3589,6 +3595,9 @@ void MarkCatchmentTilesDirty()
 		}
 		MarkWholeScreenDirty();
 	}
+	if (_viewport_highlight_depot != INVALID_DEPOT) {
+		MarkWholeScreenDirty();
+	}
 }
 
 static void SetWindowDirtyForViewportCatchment()
@@ -3596,6 +3605,7 @@ static void SetWindowDirtyForViewportCatchment()
 	if (_viewport_highlight_station != nullptr) SetWindowDirty(WC_STATION_VIEW, _viewport_highlight_station->index);
 	if (_viewport_highlight_waypoint != nullptr) SetWindowDirty(WC_WAYPOINT_VIEW, _viewport_highlight_waypoint->index);
 	if (_viewport_highlight_town != nullptr) SetWindowDirty(WC_TOWN_VIEW, _viewport_highlight_town->index);
+	if (_viewport_highlight_depot != INVALID_DEPOT) SetWindowDirty(WC_VEHICLE_DEPOT, _viewport_highlight_depot);
 }
 
 static void ClearViewportCatchment()
@@ -3604,6 +3614,7 @@ static void ClearViewportCatchment()
 	_viewport_highlight_station = nullptr;
 	_viewport_highlight_waypoint = nullptr;
 	_viewport_highlight_town = nullptr;
+	_viewport_highlight_depot = INVALID_DEPOT;
 }
 
 /**
@@ -3665,3 +3676,30 @@ void SetViewportCatchmentTown(const Town *t, bool sel)
 	}
 	if (_viewport_highlight_town != nullptr) SetWindowDirty(WC_TOWN_VIEW, _viewport_highlight_town->index);
 }
+
+static void MarkDepotTilesDirty()
+{
+	if (_viewport_highlight_depot != INVALID_DEPOT) {
+		MarkWholeScreenDirty();
+		return;
+	}
+}
+
+/**
+ * Select or deselect depot to highlight.
+ * @param *dep Depot in question
+ * @param sel Select or deselect given depot
+ */
+void SetViewportHighlightDepot(const DepotID dep, bool sel)
+{
+	SetWindowDirtyForViewportCatchment();
+	if (sel && _viewport_highlight_depot != dep) {
+		ClearViewportCatchment();
+		_viewport_highlight_depot = dep;
+		MarkDepotTilesDirty();
+	} else if (!sel && _viewport_highlight_depot == dep) {
+		MarkDepotTilesDirty();
+		_viewport_highlight_depot = INVALID_DEPOT;
+	}
+	if (_viewport_highlight_depot != INVALID_DEPOT) SetWindowDirty(WC_VEHICLE_DEPOT, _viewport_highlight_depot);
+}

src/viewport_func.h

@@ -16,6 +16,7 @@
 #include "tile_map.h"
 #include "station_type.h"
 #include "vehicle_type.h"
+#include "depot_type.h"
 
 static const int TILE_HEIGHT_STEP = 50; ///< One Z unit tile height difference is displayed as 50m.
 
@@ -102,6 +103,8 @@ struct Town;
 void SetViewportCatchmentStation(const Station *st, bool sel);
 void SetViewportCatchmentWaypoint(const Waypoint *wp, bool sel);
 void SetViewportCatchmentTown(const Town *t, bool sel);
+void SetViewportHighlightDepot(const DepotID dep, bool sel);
+
 void MarkCatchmentTilesDirty();
 
 template<class T>

src/widgets/depot_widget.h

@@ -27,6 +27,7 @@ enum DepotWidgets : WidgetID {
 	WID_D_LOCATION,        ///< Location button.
 	WID_D_SHOW_RENAME,     ///< Show rename panel.
 	WID_D_RENAME,          ///< Rename button.
+	WID_D_HIGHLIGHT,       ///< Highlight button.
 	WID_D_VEHICLE_LIST,    ///< List of vehicles.
 	WID_D_STOP_ALL,        ///< Stop all button.
 	WID_D_START_ALL,       ///< Start all button.