Codechange: Use cached town, station, industry names for list window sorting

This is to avoid needing to expensively regenerate name strings on
every comparison when sorting by name in the town/station/industry
list windows.

3 files changed, 4 insertions, 63 deletions

diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
index 7410cb3a3..a5f03a2b9 100644
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -1251,7 +1251,6 @@ class IndustryDirectoryWindow : public Window {
 protected:
 	/* Runtime saved values */
 	static Listing last_sorting;
-	static const Industry *last_industry;
 
 	/* Constants for sorting stations */
 	static const StringID sorter_names[];
@@ -1350,8 +1349,6 @@ protected:
 			this->industries.RebuildDone();
 		}
 
-		IndustryDirectoryWindow::last_industry = nullptr; // Reset name sorter sort cache
-
 		auto filter = std::make_pair(this->cargo_filter[this->accepted_cargo_filter_criteria],
 		                             this->cargo_filter[this->produced_cargo_filter_criteria]);
 
@@ -1398,19 +1395,7 @@ protected:
 	/** Sort industries by name */
 	static bool IndustryNameSorter(const Industry * const &a, const Industry * const &b)
 	{
-		static char buf_cache[96];
-		static char buf[96];
-
-		SetDParam(0, a->index);
-		GetString(buf, STR_INDUSTRY_NAME, lastof(buf));
-
-		if (b != last_industry) {
-			last_industry = b;
-			SetDParam(0, b->index);
-			GetString(buf_cache, STR_INDUSTRY_NAME, lastof(buf_cache));
-		}
-
-		int r = strnatcmp(buf, buf_cache); // Sort by name (natural sorting).
+		int r = strnatcmp(a->GetCachedName(), b->GetCachedName()); // Sort by name (natural sorting).
 		if (r == 0) return a->index < b->index;
 		return r < 0;
 	}
@@ -1726,7 +1711,6 @@ public:
 };
 
 Listing IndustryDirectoryWindow::last_sorting = {false, 0};
-const Industry *IndustryDirectoryWindow::last_industry = nullptr;
 
 /* Available station sorting functions. */
 GUIIndustryList::SortFunction * const IndustryDirectoryWindow::sorter_funcs[] = {
diff --git a/src/station_gui.cpp b/src/station_gui.cpp
index a4804528c..764d34748 100644
--- a/src/station_gui.cpp
+++ b/src/station_gui.cpp
@@ -207,7 +207,6 @@ protected:
 	static bool include_empty;            // whether we should include stations without waiting cargo
 	static const CargoTypes cargo_filter_max;
 	static CargoTypes cargo_filter;           // bitmap of cargo types to include
-	static const Station *last_station;
 
 	/* Constants for sorting stations */
 	static const StringID sorter_names[];
@@ -259,19 +258,7 @@ protected:
 	/** Sort stations by their name */
 	static bool StationNameSorter(const Station * const &a, const Station * const &b)
 	{
-		static char buf_cache[64];
-		char buf[64];
-
-		SetDParam(0, a->index);
-		GetString(buf, STR_STATION_NAME, lastof(buf));
-
-		if (b != last_station) {
-			last_station = b;
-			SetDParam(0, b->index);
-			GetString(buf_cache, STR_STATION_NAME, lastof(buf_cache));
-		}
-
-		int r = strnatcmp(buf, buf_cache); // Sort by name (natural sorting).
+		int r = strnatcmp(a->GetCachedName(), b->GetCachedName()); // Sort by name (natural sorting).
 		if (r == 0) return a->index < b->index;
 		return r < 0;
 	}
@@ -343,9 +330,6 @@ protected:
 	{
 		if (!this->stations.Sort()) return;
 
-		/* Reset name sorter sort cache */
-		this->last_station = nullptr;
-
 		/* Set the modified widget dirty */
 		this->SetWidgetDirty(WID_STL_LIST);
 	}
@@ -703,7 +687,6 @@ byte CompanyStationsWindow::facilities = FACIL_TRAIN | FACIL_TRUCK_STOP | FACIL_
 bool CompanyStationsWindow::include_empty = true;
 const CargoTypes CompanyStationsWindow::cargo_filter_max = ALL_CARGOTYPES;
 CargoTypes CompanyStationsWindow::cargo_filter = ALL_CARGOTYPES;
-const Station *CompanyStationsWindow::last_station = nullptr;
 
 /* Available station sorting functions */
 GUIStationList::SortFunction * const CompanyStationsWindow::sorter_funcs[] = {
@@ -1222,21 +1205,13 @@ bool CargoSorter::SortCount(const CargoDataEntry *cd1, const CargoDataEntry *cd2
 
 bool CargoSorter::SortStation(StationID st1, StationID st2) const
 {
-	static char buf1[MAX_LENGTH_STATION_NAME_CHARS];
-	static char buf2[MAX_LENGTH_STATION_NAME_CHARS];
-
 	if (!Station::IsValidID(st1)) {
 		return Station::IsValidID(st2) ? this->order == SO_ASCENDING : this->SortId(st1, st2);
 	} else if (!Station::IsValidID(st2)) {
 		return order == SO_DESCENDING;
 	}
 
-	SetDParam(0, st1);
-	GetString(buf1, STR_STATION_NAME, lastof(buf1));
-	SetDParam(0, st2);
-	GetString(buf2, STR_STATION_NAME, lastof(buf2));
-
-	int res = strnatcmp(buf1, buf2); // Sort by name (natural sorting).
+	int res = strnatcmp(Station::Get(st1)->GetCachedName(), Station::Get(st2)->GetCachedName()); // Sort by name (natural sorting).
 	if (res == 0) {
 		return this->SortId(st1, st2);
 	} else {
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index fc781fad0..1dcd65cb5 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -671,7 +671,6 @@ struct TownDirectoryWindow : public Window {
 private:
 	/* Runtime saved values */
 	static Listing last_sorting;
-	static const Town *last_town;
 
 	/* Constants for sorting towns */
 	static const StringID sorter_names[];
@@ -710,7 +709,6 @@ private:
 			this->vscroll->SetCount((uint)this->towns.size()); // Update scrollbar as well.
 		}
 		/* Always sort the towns. */
-		this->last_town = nullptr;
 		this->towns.Sort();
 		this->SetWidgetDirty(WID_TD_LIST); // Force repaint of the displayed towns.
 	}
@@ -718,22 +716,7 @@ private:
 	/** Sort by town name */
 	static bool TownNameSorter(const Town * const &a, const Town * const &b)
 	{
-		static char buf_cache[MAX_LENGTH_TOWN_NAME_CHARS * MAX_CHAR_LENGTH];
-		char buf[MAX_LENGTH_TOWN_NAME_CHARS * MAX_CHAR_LENGTH];
-
-		SetDParam(0, a->index);
-		GetString(buf, STR_TOWN_NAME, lastof(buf));
-
-		/* If 'b' is the same town as in the last round, use the cached value
-		 * We do this to speed stuff up ('b' is called with the same value a lot of
-		 * times after each other) */
-		if (b != last_town) {
-			last_town = b;
-			SetDParam(0, b->index);
-			GetString(buf_cache, STR_TOWN_NAME, lastof(buf_cache));
-		}
-
-		return strnatcmp(buf, buf_cache) < 0; // Sort by name (natural sorting).
+		return strnatcmp(a->GetCachedName(), b->GetCachedName()) < 0; // Sort by name (natural sorting).
 	}
 
 	/** Sort by population (default descending, as big towns are of the most interest). */
@@ -1005,7 +988,6 @@ public:
 };
 
 Listing TownDirectoryWindow::last_sorting = {false, 0};
-const Town *TownDirectoryWindow::last_town = nullptr;
 
 /** Names of the sorting functions. */
 const StringID TownDirectoryWindow::sorter_names[] = {