(svn r21842) -Feature [FS#4393]: [NewGRF] Introduction dates/required types for rail types; e.g. introduce a particular rail type in 1960 (or when a vehicle using it is introduced), but also allow limiting its introduction to only happen when the required railtypes are available

1 files changed, 44 insertions, 2 deletions

diff --git a/src/engine.cpp b/src/engine.cpp
index 198434a88..048fcc82f 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -44,6 +44,11 @@ EngineOverrideManager _engine_mngr;
  */
 static Year _year_engine_aging_stops;
 
+/**
+ * The railtypes that have been or never will be introduced, or
+ * an inverse bitmap of rail types that have to be introduced. */
+static uint16 _introduced_railtypes;
+
 /** Number of engines of each vehicle type in original engine data */
 const uint8 _engine_counts[4] = {
 	lengthof(_orig_rail_vehicle_info),
@@ -474,8 +479,30 @@ void SetupEngines()
 		const Engine *e = new Engine(eid->type, eid->internal_id);
 		assert(e->index == index);
 	}
+
+	_introduced_railtypes = 0;
 }
 
+/**
+ * Check whether the railtypes should be introduced.
+ */
+static void CheckRailIntroduction()
+{
+	/* All railtypes have been introduced. */
+	if (_introduced_railtypes == UINT16_MAX || Company::GetPoolSize() == 0) return;
+
+	/* We need to find the railtypes that are known to all companies. */
+	RailTypes rts = (RailTypes)UINT16_MAX;
+
+	/* We are at, or past the introduction date of the rail. */
+	Company *c;
+	FOR_ALL_COMPANIES(c) {
+		c->avail_railtypes = AddDateIntroducedRailTypes(c->avail_railtypes, _date);
+		rts &= c->avail_railtypes;
+	}
+
+	_introduced_railtypes |= rts;
+}
 
 void ShowEnginePreviewWindow(EngineID engine);
 
@@ -602,6 +629,19 @@ void StartupEngines()
 		c->avail_roadtypes = GetCompanyRoadtypes(c->index);
 	}
 
+	/* Rail types that are invalid or never introduced are marked as
+	 * being introduced upon start. That way we can easily check whether
+	 * there is any date related introduction that is still going to
+	 * happen somewhere in the future. */
+	for (RailType rt = RAILTYPE_BEGIN; rt != RAILTYPE_END; rt++) {
+		const RailtypeInfo *rti = GetRailTypeInfo(rt);
+		if (rti->label != 0 && IsInsideMM(rti->introduction_date, 0, MAX_DAY)) continue;
+
+		SetBit(_introduced_railtypes, rt);
+	}
+
+	CheckRailIntroduction();
+
 	/* Invalidate any open purchase lists */
 	InvalidateWindowClassesData(WC_BUILD_VEHICLE);
 }
@@ -614,7 +654,7 @@ static void AcceptEnginePreview(EngineID eid, CompanyID company)
 	SetBit(e->company_avail, company);
 	if (e->type == VEH_TRAIN) {
 		assert(e->u.rail.railtype < RAILTYPE_END);
-		c->avail_railtypes |= GetRailTypeInfo(e->u.rail.railtype)->introduces_railtypes;
+		c->avail_railtypes = AddDateIntroducedRailTypes(c->avail_railtypes | GetRailTypeInfo(e->u.rail.railtype)->introduces_railtypes, _date);
 	} else if (e->type == VEH_ROAD) {
 		SetBit(c->avail_roadtypes, HasBit(e->info.misc_flags, EF_ROAD_TRAM) ? ROADTYPE_TRAM : ROADTYPE_ROAD);
 	}
@@ -663,6 +703,8 @@ static CompanyID GetBestCompany(uint8 pp)
 /** Daily check to offer an exclusive engine preview to the companies. */
 void EnginesDailyLoop()
 {
+	CheckRailIntroduction();
+
 	if (_cur_year >= _year_engine_aging_stops) return;
 
 	Engine *e;
@@ -760,7 +802,7 @@ static void NewVehicleAvailable(Engine *e)
 		/* maybe make another rail type available */
 		RailType railtype = e->u.rail.railtype;
 		assert(railtype < RAILTYPE_END);
-		FOR_ALL_COMPANIES(c) c->avail_railtypes |= GetRailTypeInfo(e->u.rail.railtype)->introduces_railtypes;
+		FOR_ALL_COMPANIES(c) c->avail_railtypes = AddDateIntroducedRailTypes(c->avail_railtypes | GetRailTypeInfo(e->u.rail.railtype)->introduces_railtypes, _date);
 	} else if (e->type == VEH_ROAD) {
 		/* maybe make another road type available */
 		FOR_ALL_COMPANIES(c) SetBit(c->avail_roadtypes, HasBit(e->info.misc_flags, EF_ROAD_TRAM) ? ROADTYPE_TRAM : ROADTYPE_ROAD);