Add #6887: Option to show zone inside local authority boundary of towns

Can be found at town information > local authority window
Layout for button is same as Graph Keys
Turn on/off for every town individually

10 files changed, 82 insertions, 0 deletions

diff --git a/src/core/kdtree.hpp b/src/core/kdtree.hpp
index c7f66ebff..59f3da810 100644
--- a/src/core/kdtree.hpp
+++ b/src/core/kdtree.hpp
@@ -373,6 +373,17 @@ public:
 	}
 
 	/**
+	 * Clear the tree.
+	 */
+	void Clear()
+	{
+		this->nodes.clear();
+		this->free_list.clear();
+		this->unbalanced = 0;
+		return;
+	}
+
+	/**
 	 * Reconstruct the tree with the same elements, letting it be fully balanced.
 	 */
 	void Rebuild()
diff --git a/src/lang/english.txt b/src/lang/english.txt
index e6e4bb930..8d13ee196 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -3122,6 +3122,8 @@ STR_TOWN_VIEW_RENAME_TOWN_BUTTON                                :Rename Town
 
 # Town local authority window
 STR_LOCAL_AUTHORITY_CAPTION                                     :{WHITE}{TOWN} local authority
+STR_LOCAL_AUTHORITY_ZONE                                        :{BLACK}Zone
+STR_LOCAL_AUTHORITY_ZONE_TOOLTIP                                :{BLACK}Show zone within local authority boundaries
 STR_LOCAL_AUTHORITY_COMPANY_RATINGS                             :{BLACK}Transport company ratings:
 STR_LOCAL_AUTHORITY_COMPANY_RATING                              :{YELLOW}{COMPANY} {COMPANY_NUM}: {ORANGE}{STRING}
 STR_LOCAL_AUTHORITY_ACTIONS_TITLE                               :{BLACK}Actions available:
diff --git a/src/misc.cpp b/src/misc.cpp
index 3d09f26f2..ffdadecd3 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -47,6 +47,7 @@ void InitializeAirportGui();
 void InitializeDockGui();
 void InitializeGraphGui();
 void InitializeObjectGui();
+void InitializeTownGui();
 void InitializeIndustries();
 void InitializeObjects();
 void InitializeTrees();
@@ -97,6 +98,7 @@ void InitializeGame(uint size_x, uint size_y, bool reset_date, bool reset_settin
 	InitializeDockGui();
 	InitializeGraphGui();
 	InitializeObjectGui();
+	InitializeTownGui();
 	InitializeAIGui();
 	InitializeTrees();
 	InitializeIndustries();
diff --git a/src/script/api/script_window.hpp b/src/script/api/script_window.hpp
index 3abc091d6..252cb3e54 100644
--- a/src/script/api/script_window.hpp
+++ b/src/script/api/script_window.hpp
@@ -2495,6 +2495,7 @@ public:
 	/** Widgets of the #TownAuthorityWindow class. */
 	enum TownAuthorityWidgets {
 		WID_TA_CAPTION                               = ::WID_TA_CAPTION,                               ///< Caption of window.
+		WID_TA_ZONE_BUTTON                           = ::WID_TA_ZONE_BUTTON,                           ///< Turn on/off showing local authority zone.
 		WID_TA_RATING_INFO                           = ::WID_TA_RATING_INFO,                           ///< Overview with ratings for each company.
 		WID_TA_COMMAND_LIST                          = ::WID_TA_COMMAND_LIST,                          ///< List of commands for the player.
 		WID_TA_SCROLLBAR                             = ::WID_TA_SCROLLBAR,                             ///< Scrollbar of the list of commands.
diff --git a/src/town.h b/src/town.h
index ce938ea06..b0f4a5c72 100644
--- a/src/town.h
+++ b/src/town.h
@@ -101,6 +101,8 @@ struct Town : TownPool::PoolItem<&_town_pool> {
 	bool larger_town;                ///< if this is a larger town and should grow more quickly
 	TownLayout layout;               ///< town specific road layout
 
+	bool show_zone;                  ///< NOSAVE: mark town to show the local authority zone in the viewports
+
 	std::list<PersistentStorage *> psa_list;
 
 	/**
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 65032c1fb..2049cbddc 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1746,6 +1746,7 @@ static void DoCreateTown(Town *t, TileIndex tile, uint32 townnameparts, TownSize
 	 * similar towns they're unlikely to grow all in one tick */
 	t->grow_counter = t->index % TOWN_GROWTH_TICKS;
 	t->growth_rate = TownTicksToGameTicks(250);
+	t->show_zone = false;
 
 	_town_kdtree.Insert(t->index);
 
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index f9670e84e..0436e87e0 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -33,6 +33,7 @@
 #include "genworld.h"
 #include "stringfilter_type.h"
 #include "widgets/dropdown_func.h"
+#include "town_kdtree.h"
 
 #include "widgets/town_widget.h"
 
@@ -40,12 +41,15 @@
 
 #include "safeguards.h"
 
+TownKdtree _town_local_authority_kdtree(&Kdtree_TownXYFunc);
+
 typedef GUIList<const Town*> GUITownList;
 
 static const NWidgetPart _nested_town_authority_widgets[] = {
 	NWidget(NWID_HORIZONTAL),
 		NWidget(WWT_CLOSEBOX, COLOUR_BROWN),
 		NWidget(WWT_CAPTION, COLOUR_BROWN, WID_TA_CAPTION), SetDataTip(STR_LOCAL_AUTHORITY_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
+		NWidget(WWT_TEXTBTN, COLOUR_BROWN, WID_TA_ZONE_BUTTON), SetMinimalSize(50, 0), SetMinimalTextLines(1, WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM + 2), SetDataTip(STR_LOCAL_AUTHORITY_ZONE, STR_LOCAL_AUTHORITY_ZONE_TOOLTIP),
 		NWidget(WWT_SHADEBOX, COLOUR_BROWN),
 		NWidget(WWT_DEFSIZEBOX, COLOUR_BROWN),
 		NWidget(WWT_STICKYBOX, COLOUR_BROWN),
@@ -113,6 +117,7 @@ public:
 			this->sel_index = -1;
 		}
 
+		this->SetWidgetLoweredState(WID_TA_ZONE_BUTTON, this->town->show_zone);
 		this->SetWidgetDisabledState(WID_TA_EXECUTE, this->sel_index == -1);
 
 		this->DrawWidgets();
@@ -258,6 +263,18 @@ public:
 	void OnClick(Point pt, int widget, int click_count) override
 	{
 		switch (widget) {
+			case WID_TA_ZONE_BUTTON: {
+				bool new_show_state = !this->town->show_zone;
+				TownID index = this->town->index;
+
+				new_show_state ? _town_local_authority_kdtree.Insert(index) : _town_local_authority_kdtree.Remove(index);
+
+				this->town->show_zone = new_show_state;
+				this->SetWidgetLoweredState(widget, new_show_state);
+				MarkWholeScreenDirty();
+				break;
+			}
+
 			case WID_TA_COMMAND_LIST: {
 				int y = this->GetRowFromWidget(pt.y, WID_TA_COMMAND_LIST, 1, FONT_HEIGHT_NORMAL);
 				if (!IsInsideMM(y, 0, 5)) return;
@@ -1274,3 +1291,8 @@ void ShowFoundTownWindow()
 	if (_game_mode != GM_EDITOR && !Company::IsValidID(_local_company)) return;
 	AllocateWindowDescFront<FoundTownWindow>(&_found_town_desc, 0);
 }
+
+void InitializeTownGui()
+{
+	_town_local_authority_kdtree.Clear();
+}
diff --git a/src/town_kdtree.h b/src/town_kdtree.h
index ae6b9e4ea..924165585 100644
--- a/src/town_kdtree.h
+++ b/src/town_kdtree.h
@@ -15,6 +15,8 @@
 
 inline uint16 Kdtree_TownXYFunc(TownID tid, int dim) { return (dim == 0) ? TileX(Town::Get(tid)->xy) : TileY(Town::Get(tid)->xy); }
 typedef Kdtree<TownID, decltype(&Kdtree_TownXYFunc), uint16, int> TownKdtree;
+
 extern TownKdtree _town_kdtree;
+extern TownKdtree _town_local_authority_kdtree;
 
 #endif
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 534de090b..5a5756dfe 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -83,6 +83,7 @@
 #include "window_gui.h"
 #include "linkgraph/linkgraph_gui.h"
 #include "viewport_kdtree.h"
+#include "town_kdtree.h"
 #include "viewport_sprite_sorter.h"
 #include "bridge_map.h"
 #include "company_base.h"
@@ -1039,11 +1040,48 @@ static void DrawTileHighlightType(const TileInfo *ti, TileHighlightType tht)
 }
 
 /**
+ * Highlights tiles insede local authority of selected towns.
+ * @param *ti TileInfo Tile that is being drawn
+ */
+static void HighlightTownLocalAuthorityTiles(const TileInfo *ti)
+{
+	/* Going through cases in order of computational time. */
+
+	if (_town_local_authority_kdtree.Count() == 0) return;
+
+	/* Tile belongs to town regardless of distance from town. */
+	if (GetTileType(ti->tile) == MP_HOUSE) {
+		if (!Town::GetByTile(ti->tile)->show_zone) return;
+
+		DrawTileSelectionRect(ti, PALETTE_CRASH);
+		return;
+	}
+
+	/* If the closest town in the highlighted list is far, we can stop searching. */
+	TownID tid = _town_local_authority_kdtree.FindNearest(TileX(ti->tile), TileY(ti->tile));
+	Town *closest_highlighted_town = Town::Get(tid);
+
+	if (DistanceManhattan(ti->tile, closest_highlighted_town->xy) >= _settings_game.economy.dist_local_authority) return;
+
+	/* Tile is inside of the local autrhority distance of a highlighted town,
+	   but it is possible that a non-highlighted town is even closer. */
+	Town *closest_town = ClosestTownFromTile(ti->tile, _settings_game.economy.dist_local_authority);
+
+	if (closest_town->show_zone) {
+		DrawTileSelectionRect(ti, PALETTE_CRASH);
+	}
+
+}
+
+/**
  * Checks if the specified tile is selected and if so draws selection using correct selectionstyle.
  * @param *ti TileInfo Tile that is being drawn
  */
 static void DrawTileSelection(const TileInfo *ti)
 {
+	/* Highlight tiles insede local authority of selected towns. */
+	HighlightTownLocalAuthorityTiles(ti);
+
 	/* Draw a red error square? */
 	bool is_redsq = _thd.redsq == ti->tile;
 	if (is_redsq) DrawTileSelectionRect(ti, PALETTE_TILE_RED_PULSATING);
diff --git a/src/widgets/town_widget.h b/src/widgets/town_widget.h
index e5ac66184..bd6e0b954 100644
--- a/src/widgets/town_widget.h
+++ b/src/widgets/town_widget.h
@@ -25,6 +25,7 @@ enum TownDirectoryWidgets {
 /** Widgets of the #TownAuthorityWindow class. */
 enum TownAuthorityWidgets {
 	WID_TA_CAPTION,      ///< Caption of window.
+	WID_TA_ZONE_BUTTON,  ///< Turn on/off showing local authority zone.
 	WID_TA_RATING_INFO,  ///< Overview with ratings for each company.
 	WID_TA_COMMAND_LIST, ///< List of commands for the player.
 	WID_TA_SCROLLBAR,    ///< Scrollbar of the list of commands.