Add road/tram type properties to set road vehicle collision mode

docs/newgrf-additions-nml.html

@@ -178,6 +178,19 @@
 			</dl>
 		</td>
 	</tr>
+	<tr><td>roadtype_collision_mode</td><td>ROADTYPE_COLLISION_MODE_XXX</td>
+		<td>
+			Sets the road vehicle collision mode for road vehicles of this road type.
+			<dl>
+				<dt>NORMAL</dt>
+				<dd>Normal road vehicle collision rules (this is the default)</dd>
+				<dt>NONE</dt>
+				<dd>Do not collide at all with other road vehicles</dd>
+				<dt>ELEVATED</dt>
+				<dd>Collide only with other elevated road vehicles</dd>
+			</dl>
+		</td>
+	</tr>
 	</table>
 	<h3 id="tramtype-properties"><a href="https://newgrf-specs.tt-wiki.net/wiki/NML:Tramtypes#Tramtype_properties">Tramtype properties</a></h3>
 	<table>
@@ -192,6 +205,19 @@
 			</dl>
 		</td>
 	</tr>
+	<tr><td>tramtype_collision_mode</td><td>TRAMTYPE_COLLISION_MODE_XXX</td>
+		<td>
+			Sets the road vehicle collision mode for road vehicles of this tram type.
+			<dl>
+				<dt>NORMAL</dt>
+				<dd>Normal road vehicle collision rules (this is the default)</dd>
+				<dt>NONE</dt>
+				<dd>Do not collide at all with other road vehicles</dd>
+				<dt>ELEVATED</dt>
+				<dd>Collide only with other elevated road vehicles</dd>
+			</dl>
+		</td>
+	</tr>
 	</table>
 	<h3 id="object-ids"><a href="https://newgrf-specs.tt-wiki.net/wiki/NML:Objects#Object_IDs">Object IDs</a></h3>
 	<p>

docs/newgrf-additions.html

@@ -330,6 +330,18 @@
 	</table>
 	</p>
 	<p>This is indicated by the feature name: <font face="monospace">action0_roadtype_extra_flags</font>, version 1</p>
+	<h4 id="roadtype_collision_mode">Road vehicle collision mode (mappable property: roadtype_collision_mode)</h4>
+	<p>This property sets the road vehicle collision mode for road vehicles of this road/tram type.<br />
+	The property length is 1 byte. The format is:
+	<table>
+	<tr><th>Value</th><th>Meaning</th></tr>
+	<tr><td>0</td><td>Normal: Normal road vehicle collision rules (this is the default)</td></tr>
+	<tr><td>1</td><td>None: Do not collide at all with other road vehicles</td></tr>
+	<tr><td>2</td><td>Elevated: Collide only with other elevated road vehicles</td></tr>
+	</table>
+	Unknown values are ignored. More values may be added in future.
+	</p>
+	<p>This is indicated by the feature name: <font face="monospace">action0_roadtype_collision_mode</font>, version 1</p>
 	<br />
 	<h3 id="a0globalsettings"><a href="https://newgrf-specs.tt-wiki.net/wiki/Action0/Global_Settings">Action 0 - Global Settings</a></h3>
 	<h4 id="global_extra_station_names">Extra station names (mappable property: global_extra_station_names)</h4>

src/newgrf.cpp

@@ -4813,6 +4813,13 @@ static ChangeInfoResult RoadTypeChangeInfo(uint id, int numinfo, int prop, const
 				rti->extra_flags = (RoadTypeExtraFlags)buf->ReadByte();
 				break;
 
+			case A0RPI_ROADTYPE_COLLISION_MODE: {
+				if (MappedPropertyLengthMismatch(buf, 1, mapping_entry)) break;
+				uint8 collision_mode = buf->ReadByte();
+				if (collision_mode < RTCM_END) rti->collision_mode = (RoadTypeCollisionMode)collision_mode;
+				break;
+			}
+
 			default:
 				ret = HandleAction0PropertyDefault(buf, prop);
 				break;
@@ -4906,6 +4913,10 @@ static ChangeInfoResult RoadTypeReserveInfo(uint id, int numinfo, int prop, cons
 				buf->Skip(buf->ReadExtendedByte());
 				break;
 
+			case A0RPI_ROADTYPE_COLLISION_MODE:
+				buf->Skip(buf->ReadExtendedByte());
+				break;
+
 			default:
 				ret = HandleAction0PropertyDefault(buf, prop);
 				break;
@@ -11427,6 +11438,7 @@ static void AfterLoadGRFs()
 	/* Set up custom rail types */
 	InitRailTypes();
 	InitRoadTypes();
+	InitRoadTypesCaches();
 
 	for (Engine *e : Engine::IterateType(VEH_ROAD)) {
 		if (_gted[e->index].rv_max_speed != 0) {

src/newgrf_extension.cpp

@@ -39,6 +39,7 @@ extern const GRFFeatureInfo _grf_feature_list[] = {
 	GRFFeatureInfo("action0_railtype_recolour", 1),
 	GRFFeatureInfo("action0_railtype_extra_aspects", 1),
 	GRFFeatureInfo("action0_roadtype_extra_flags", 1),
+	GRFFeatureInfo("action0_roadtype_collision_mode", 1),
 	GRFFeatureInfo("varaction2_railtype_signal_context", 1),
 	GRFFeatureInfo("action0_global_extra_station_names", 2),
 	GRFFeatureInfo("action0_global_default_object_generate_amount", 1),
@@ -83,7 +84,9 @@ extern const GRFPropertyMapDefinition _grf_action0_remappable_properties[] = {
 	GRFPropertyMapDefinition(GSF_RAILTYPES, A0RPI_RAILTYPE_ENABLE_SIGNAL_RECOLOUR, "railtype_enable_signal_recolour"),
 	GRFPropertyMapDefinition(GSF_RAILTYPES, A0RPI_RAILTYPE_EXTRA_ASPECTS, "railtype_extra_aspects"),
 	GRFPropertyMapDefinition(GSF_ROADTYPES, A0RPI_ROADTYPE_EXTRA_FLAGS, "roadtype_extra_flags"),
+	GRFPropertyMapDefinition(GSF_ROADTYPES, A0RPI_ROADTYPE_COLLISION_MODE, "roadtype_collision_mode"),
 	GRFPropertyMapDefinition(GSF_TRAMTYPES, A0RPI_ROADTYPE_EXTRA_FLAGS, "roadtype_extra_flags"),
+	GRFPropertyMapDefinition(GSF_TRAMTYPES, A0RPI_ROADTYPE_COLLISION_MODE, "roadtype_collision_mode"),
 	GRFPropertyMapDefinition(GSF_GLOBALVAR, A0RPI_GLOBALVAR_EXTRA_STATION_NAMES, "global_extra_station_names"),
 	GRFPropertyMapDefinition(GSF_GLOBALVAR, A0RPI_GLOBALVAR_EXTRA_STATION_NAMES_PROBABILITY, "global_extra_station_names_probability"),
 	GRFPropertyMapDefinition(GSF_GLOBALVAR, A0RPI_GLOBALVAR_LIGHTHOUSE_GENERATE_AMOUNT, "global_lighthouse_generate_amount"),

src/newgrf_extension.h

@@ -26,6 +26,7 @@ enum Action0RemapPropertyIds {
 	A0RPI_RAILTYPE_ENABLE_SIGNAL_RECOLOUR,
 	A0RPI_RAILTYPE_EXTRA_ASPECTS,
 	A0RPI_ROADTYPE_EXTRA_FLAGS,
+	A0RPI_ROADTYPE_COLLISION_MODE,
 	A0RPI_GLOBALVAR_EXTRA_STATION_NAMES,
 	A0RPI_GLOBALVAR_EXTRA_STATION_NAMES_PROBABILITY,
 	A0RPI_GLOBALVAR_LIGHTHOUSE_GENERATE_AMOUNT,

src/road.h

@@ -62,6 +62,14 @@ enum RoadTypeExtraFlags {
 };
 DECLARE_ENUM_AS_BIT_SET(RoadTypeExtraFlags)
 
+enum RoadTypeCollisionMode : uint8 {
+	RTCM_NORMAL = 0,
+	RTCM_NONE,
+	RTCM_ELEVATED,
+
+	RTCM_END,
+};
+
 struct SpriteGroup;
 
 /** Sprite groups for a roadtype. */
@@ -140,6 +148,11 @@ public:
 	 */
 	RoadTypeExtraFlags extra_flags;
 
+	/**
+	 * Collision mode
+	 */
+	RoadTypeCollisionMode collision_mode;
+
 	/**
 	 * Cost multiplier for building this road type
 	 */
@@ -316,10 +329,12 @@ RoadType GetRoadTypeByLabel(RoadTypeLabel label, bool allow_alternate_labels = t
 
 void ResetRoadTypes();
 void InitRoadTypes();
+void InitRoadTypesCaches();
 RoadType AllocateRoadType(RoadTypeLabel label, RoadTramType rtt);
 bool HasAnyRoadTypesAvail(CompanyID company, RoadTramType rtt);
 
 extern std::vector<RoadType> _sorted_roadtypes;
 extern RoadTypes _roadtypes_hidden_mask;
+extern std::array<RoadTypes, RTCM_END> _collision_mode_roadtypes;
 
 #endif /* ROAD_H */

src/road_cmd.cpp

@@ -51,6 +51,7 @@ typedef std::vector<RoadVehicle *> RoadVehicleList;
 RoadTypeInfo _roadtypes[ROADTYPE_END];
 std::vector<RoadType> _sorted_roadtypes;
 RoadTypes _roadtypes_hidden_mask;
+std::array<RoadTypes, RTCM_END> _collision_mode_roadtypes;
 
 /**
  * Bitmap of road/tram types.
@@ -72,7 +73,7 @@ void ResetRoadTypes()
 		{ 0, 0, 0, 0, 0, 0 },
 		{ 0, 0, 0, 0, 0, 0 },
 		{ 0, 0, 0, 0, 0, 0, 0, 0, 0, {}, {}, 0, {}, {} },
-		ROADTYPES_NONE, ROTFB_NONE, RXTFB_NONE, 0, 0, 0, 0,
+		ROADTYPES_NONE, ROTFB_NONE, RXTFB_NONE, RTCM_NORMAL, 0, 0, 0, 0,
 		RoadTypeLabelList(), 0, 0, ROADTYPES_NONE, ROADTYPES_NONE, 0,
 		{}, {} };
 	for (; i < lengthof(_roadtypes);          i++) _roadtypes[i] = empty_roadtype;
@@ -134,6 +135,16 @@ void InitRoadTypes()
 	std::sort(_sorted_roadtypes.begin(), _sorted_roadtypes.end(), CompareRoadTypes);
 }
 
+void InitRoadTypesCaches()
+{
+	std::fill(_collision_mode_roadtypes.begin(), _collision_mode_roadtypes.end(), ROADTYPES_NONE);
+
+	for (RoadType rt = ROADTYPE_BEGIN; rt != ROADTYPE_END; rt++) {
+		const RoadTypeInfo &rti = _roadtypes[rt];
+		SetBit(_collision_mode_roadtypes[rti.collision_mode], rt);
+	}
+}
+
 /**
  * Allocate a new road type label
  */
@@ -149,6 +160,7 @@ RoadType AllocateRoadType(RoadTypeLabel label, RoadTramType rtt)
 			rti->alternate_labels.clear();
 			rti->flags = ROTFB_NONE;
 			rti->extra_flags = RXTFB_NONE;
+			rti->collision_mode = RTCM_NORMAL;
 			rti->introduction_date = INVALID_DATE;
 
 			/* Make us compatible with ourself. */

src/roadveh_cmd.cpp

@@ -681,6 +681,7 @@ struct RoadVehFindData {
 	Vehicle *best;
 	uint best_diff;
 	Direction dir;
+	RoadTypeCollisionMode collision_mode;
 };
 
 static Vehicle *EnumCheckRoadVehClose(Vehicle *v, void *data)
@@ -697,6 +698,7 @@ static Vehicle *EnumCheckRoadVehClose(Vehicle *v, void *data)
 			abs(v->z_pos - rvf->veh->z_pos) < 6 &&
 			v->direction == rvf->dir &&
 			rvf->veh->First() != v->First() &&
+			HasBit(_collision_mode_roadtypes[rvf->collision_mode], RoadVehicle::From(v)->roadtype) &&
 			(dist_x[v->direction] >= 0 || (x_diff > dist_x[v->direction] && x_diff <= 0)) &&
 			(dist_x[v->direction] <= 0 || (x_diff < dist_x[v->direction] && x_diff >= 0)) &&
 			(dist_y[v->direction] >= 0 || (y_diff > dist_y[v->direction] && y_diff <= 0)) &&
@@ -714,16 +716,19 @@ static Vehicle *EnumCheckRoadVehClose(Vehicle *v, void *data)
 
 static RoadVehicle *RoadVehFindCloseTo(RoadVehicle *v, int x, int y, Direction dir, bool update_blocked_ctr = true)
 {
-	RoadVehFindData rvf;
+	RoadTypeCollisionMode collision_mode = GetRoadTypeInfo(v->roadtype)->collision_mode;
-	RoadVehicle *front = v->First();
+	if (collision_mode == RTCM_NONE) return nullptr;
 
+	RoadVehicle *front = v->First();
 	if (front->reverse_ctr != 0) return nullptr;
 
+	RoadVehFindData rvf;
 	rvf.x = x;
 	rvf.y = y;
 	rvf.dir = dir;
 	rvf.veh = v;
 	rvf.best_diff = UINT_MAX;
+	rvf.collision_mode = collision_mode;
 
 	if (front->state == RVSB_WORMHOLE) {
 		FindVehicleOnPos(v->tile, VEH_ROAD, &rvf, EnumCheckRoadVehClose);
@@ -741,7 +746,7 @@ static RoadVehicle *RoadVehFindCloseTo(RoadVehicle *v, int x, int y, Direction d
 		return nullptr;
 	}
 
-	if (update_blocked_ctr && ++front->blocked_ctr > 1480  && (!_settings_game.vehicle.roadveh_cant_quantum_tunnel)) return nullptr;
+	if (update_blocked_ctr && ++front->blocked_ctr > 1480 && (!_settings_game.vehicle.roadveh_cant_quantum_tunnel)) return nullptr;
 
 	RoadVehicle *rv = RoadVehicle::From(rvf.best);
 	if (rv != nullptr && front->IsRoadVehicleOnLevelCrossing() && (rv->First()->cur_speed == 0 || rv->First()->IsRoadVehicleStopped())) return nullptr;
@@ -845,6 +850,7 @@ struct OvertakeData {
 	Trackdir trackdir;
 	int tunnelbridge_min;
 	int tunnelbridge_max;
+	RoadTypeCollisionMode collision_mode;
 };
 
 static Vehicle *EnumFindVehBlockingOvertake(Vehicle *v, void *data)
@@ -852,6 +858,7 @@ static Vehicle *EnumFindVehBlockingOvertake(Vehicle *v, void *data)
 	const OvertakeData *od = (OvertakeData*)data;
 
 	if (v->First() == od->u || v->First() == od->v) return nullptr;
+	if (!HasBit(_collision_mode_roadtypes[od->collision_mode], RoadVehicle::From(v)->roadtype)) return nullptr;
 	if (RoadVehicle::From(v)->overtaking != 0 || v->direction != od->v->direction) return v;
 
 	/* Check if other vehicle is behind */
@@ -896,6 +903,7 @@ static Vehicle *EnumFindVehBlockingOvertakeBehind(Vehicle *v, void *data)
 	const OvertakeData *od = (OvertakeData*)data;
 
 	if (v->First() == od->u || v->First() == od->v) return nullptr;
+	if (!HasBit(_collision_mode_roadtypes[od->collision_mode], RoadVehicle::From(v)->roadtype)) return nullptr;
 	if (RoadVehicle::From(v)->overtaking != 0 && TileVirtXY(v->x_pos, v->y_pos) == od->tile) return v;
 	return nullptr;
 }
@@ -1040,6 +1048,7 @@ static void RoadVehCheckOvertake(RoadVehicle *v, RoadVehicle *u)
 	od.v = v;
 	od.u = u;
 	od.trackdir = DiagDirToDiagTrackdir(DirToDiagDir(v->direction));
+	od.collision_mode = GetRoadTypeInfo(v->roadtype)->collision_mode;
 
 	/* Are the current and the next tile suitable for overtaking?
 	 *  - Does the track continue along od.trackdir
@@ -1447,6 +1456,7 @@ struct FinishOvertakeData {
 	int min_coord;
 	int max_coord;
 	uint8 not_road_pos;
+	RoadTypeCollisionMode collision_mode;
 };
 
 static Vehicle *EnumFindVehBlockingFinishOvertake(Vehicle *v, void *data)
@@ -1454,6 +1464,7 @@ static Vehicle *EnumFindVehBlockingFinishOvertake(Vehicle *v, void *data)
 	const FinishOvertakeData *od = (FinishOvertakeData*)data;
 
 	if (v->First() == od->v) return nullptr;
+	if (!HasBit(_collision_mode_roadtypes[od->collision_mode], RoadVehicle::From(v)->roadtype)) return nullptr;
 
 	/* Check if other vehicle is behind */
 	switch (DirToDiagDir(v->direction)) {
@@ -1484,6 +1495,8 @@ static void RoadVehCheckFinishOvertake(RoadVehicle *v)
 	FinishOvertakeData od;
 	od.direction = v->direction;
 	od.v = v;
+	od.collision_mode = GetRoadTypeInfo(v->roadtype)->collision_mode;
+
 	const RoadVehicle *last = v->Last();
 	const int front_margin = 10;
 	const int back_margin = 10;

src/saveload/afterload.cpp

@@ -4270,6 +4270,8 @@ void ReloadNewGRFData()
 
 	UpdateExtraAspectsVariable();
 
+	InitRoadTypesCaches();
+
 	ReInitAllWindows(false);
 
 	/* Update company statistics. */

src/table/newgrf_debug_data.h

@@ -1795,6 +1795,8 @@ class NIHRoadType : public NIHelper {
 					HasBit(rti->extra_flags, RXTF_NOT_AVAILABLE_AI_GS) ? 's' : '-',
 					HasBit(rti->extra_flags, RXTF_NO_TOWN_MODIFICATION) ? 't' : '-');
 			output.print(buffer);
+			seprintf(buffer, lastof(buffer), "    Collision mode: %u", rti->collision_mode);
+			output.print(buffer);
 			seprintf(buffer, lastof(buffer), "    Powered: 0x" OTTD_PRINTFHEX64, rti->powered_roadtypes);
 			output.print(buffer);
 			PrintTypeLabels(buffer, lastof(buffer), rti->label, (const uint32*) rti->alternate_labels.data(), rti->alternate_labels.size(), output.print);

src/table/roadtypes.h

@@ -66,6 +66,9 @@ static const RoadTypeInfo _original_roadtypes[] = {
 		/* extra flags */
 		RXTFB_NONE,
 
+		/* collision mode */
+		RTCM_NORMAL,
+
 		/* cost multiplier */
 		8,
 
@@ -149,6 +152,9 @@ static const RoadTypeInfo _original_roadtypes[] = {
 		/* extra flags */
 		RXTFB_NONE,
 
+		/* collision mode */
+		RTCM_NORMAL,
+
 		/* cost multiplier */
 		16,