From e3b440c9c50b39092a2f887dba9370b21369f2cb Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Tue, 5 Feb 2019 08:23:25 +0000
Subject: [PATCH] Add #5006: Flag to hide rail type from construction.

---
 src/rail.cpp     | 14 ++++++++++++--
 src/rail.h       |  4 ++++
 src/rail_cmd.cpp |  6 +++++-
 src/vehicle.cpp  |  5 ++++-
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/rail.cpp b/src/rail.cpp
index 1664f78e9a..8bd7aa5181 100644
--- a/src/rail.cpp
+++ b/src/rail.cpp
@@ -180,14 +180,24 @@ RailType GetTileRailType(TileIndex tile)
 }
 
 /**
- * Finds out if a company has a certain railtype available
+ * Finds out if a company has a certain buildable railtype available.
  * @param company the company in question
  * @param railtype requested RailType
  * @return true if company has requested RailType available
  */
 bool HasRailtypeAvail(const CompanyID company, const RailType railtype)
 {
-	return HasBit(Company::Get(company)->avail_railtypes, railtype);
+	return !HasBit(_railtypes_hidden_mask, railtype) && HasBit(Company::Get(company)->avail_railtypes, railtype);
+}
+
+/**
+ * Test if any buildable railtype is available for a company.
+ * @param company the company in question
+ * @return true if company has any RailTypes available
+ */
+bool HasAnyRailtypesAvail(const CompanyID company)
+{
+	return (Company::Get(company)->avail_railtypes & ~_railtypes_hidden_mask) != 0;
 }
 
 /**
diff --git a/src/rail.h b/src/rail.h
index b7258d3016..83d1d9b7af 100644
--- a/src/rail.h
+++ b/src/rail.h
@@ -26,10 +26,12 @@
 enum RailTypeFlags {
 	RTF_CATENARY          = 0,                           ///< Bit number for drawing a catenary.
 	RTF_NO_LEVEL_CROSSING = 1,                           ///< Bit number for disallowing level crossings.
+	RTF_HIDDEN            = 2,                           ///< Bit number for hiding from selection.
 
 	RTFB_NONE              = 0,                          ///< All flags cleared.
 	RTFB_CATENARY          = 1 << RTF_CATENARY,          ///< Value for drawing a catenary.
 	RTFB_NO_LEVEL_CROSSING = 1 << RTF_NO_LEVEL_CROSSING, ///< Value for disallowing level crossings.
+	RTFB_HIDDEN            = 1 << RTF_HIDDEN,            ///< Value for hiding from selection.
 };
 DECLARE_ENUM_AS_BIT_SET(RailTypeFlags)
 
@@ -419,6 +421,7 @@ Foundation GetRailFoundation(Slope tileh, TrackBits bits);
 
 
 bool HasRailtypeAvail(const CompanyID company, const RailType railtype);
+bool HasAnyRailtypesAvail(const CompanyID company);
 bool ValParamRailtype(const RailType rail);
 
 RailTypes AddDateIntroducedRailTypes(RailTypes current, Date date);
@@ -434,6 +437,7 @@ RailType AllocateRailType(RailTypeLabel label);
 
 extern RailType _sorted_railtypes[RAILTYPE_END];
 extern uint8 _sorted_railtypes_size;
+extern RailTypes _railtypes_hidden_mask;
 
 /**
  * Loop header for iterating over railtypes, sorted by sortorder.
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index a0fd968cc6..f4b26c092e 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -46,6 +46,7 @@ typedef SmallVector<Train *, 16> TrainList;
 RailtypeInfo _railtypes[RAILTYPE_END];
 RailType _sorted_railtypes[RAILTYPE_END];
 uint8 _sorted_railtypes_size;
+RailTypes _railtypes_hidden_mask;
 
 /** Enum holding the signal offset in the sprite sheet according to the side it is representing. */
 enum SignalOffsets {
@@ -78,6 +79,8 @@ void ResetRailTypes()
 		RailTypeLabelList(), 0, 0, RAILTYPES_NONE, RAILTYPES_NONE, 0,
 		{}, {} };
 	for (; i < lengthof(_railtypes);          i++) _railtypes[i] = empty_railtype;
+
+	_railtypes_hidden_mask = RAILTYPES_NONE;
 }
 
 void ResolveRailTypeGUISprites(RailtypeInfo *rti)
@@ -140,11 +143,12 @@ void InitRailTypes()
 	for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
 		RailtypeInfo *rti = &_railtypes[rt];
 		ResolveRailTypeGUISprites(rti);
+		if (HasBit(rti->flags, RTF_HIDDEN)) SetBit(_railtypes_hidden_mask, rt);
 	}
 
 	_sorted_railtypes_size = 0;
 	for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
-		if (_railtypes[rt].label != 0) {
+		if (_railtypes[rt].label != 0 && !HasBit(_railtypes_hidden_mask, rt)) {
 			_sorted_railtypes[_sorted_railtypes_size++] = rt;
 		}
 	}
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 62d279db62..53220474e5 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -1757,7 +1757,10 @@ bool CanBuildVehicleInfrastructure(VehicleType type)
 
 	UnitID max;
 	switch (type) {
-		case VEH_TRAIN:    max = _settings_game.vehicle.max_trains; break;
+		case VEH_TRAIN:
+			if (!HasAnyRailtypesAvail(_local_company)) return false;
+			max = _settings_game.vehicle.max_trains;
+			break;
 		case VEH_ROAD:     max = _settings_game.vehicle.max_roadveh; break;
 		case VEH_SHIP:     max = _settings_game.vehicle.max_ships; break;
 		case VEH_AIRCRAFT: max = _settings_game.vehicle.max_aircraft; break;