X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Flibmarklin%2Ftrain.cpp;h=acf8aa51486de42adb8901b98f9c78f2d0b79ac0;hb=97443d96ff3ce51388d2edd1e0dca8f2cd231346;hp=24ccfa2448bf1abf814afc4d728da7c935a9908b;hpb=a9180bc4bb7ff4c403e206cc2c785ff32544a0d6;p=r2c2.git

diff --git a/source/libmarklin/train.cpp b/source/libmarklin/train.cpp
index 24ccfa2..acf8aa5 100644
--- a/source/libmarklin/train.cpp
+++ b/source/libmarklin/train.cpp
@@ -13,25 +13,42 @@ Distributed under the GPL
 #include "catalogue.h"
 #include "driver.h"
 #include "layout.h"
-#include "locotype.h"
 #include "route.h"
-#include "simplephysics.h"
+#include "simplecontroller.h"
 #include "timetable.h"
 #include "tracktype.h"
 #include "train.h"
 #include "vehicle.h"
+#include "vehicletype.h"
 
 using namespace std;
 using namespace Msp;
 
+namespace {
+
+struct SetFlag
+{
+	bool &flag;
+
+	SetFlag(bool &f): flag(f) { flag = true; }
+	~SetFlag() { flag = false; }
+};
+
+}
+
+
 namespace Marklin {
 
-Train::Train(Layout &l, const LocoType &t, unsigned a):
+Train::Train(Layout &l, const VehicleType &t, unsigned a):
 	layout(l),
 	loco_type(t),
 	address(a),
+	priority(0),
+	yielding_to(0),
 	pending_block(0),
-	control(new AIControl(*this, new SimplePhysics)),
+	reserving(false),
+	advancing(false),
+	controller(new AIControl(*this, new SimpleController)),
 	timetable(0),
 	active(false),
 	current_speed(0),
@@ -44,8 +61,13 @@ Train::Train(Layout &l, const LocoType &t, unsigned a):
 	status("Unplaced"),
 	travel_dist(0),
 	pure_speed(false),
-	real_speed(15)
+	real_speed(15),
+	accurate_position(false),
+	overshoot_dist(false)
 {
+	if(!loco_type.is_locomotive())
+		throw InvalidParameterValue("Initial vehicle must be a locomotive");
+
 	vehicles.push_back(new Vehicle(layout, loco_type));
 
 	layout.add_train(*this);
@@ -57,10 +79,16 @@ Train::Train(Layout &l, const LocoType &t, unsigned a):
 	layout.signal_block_reserved.connect(sigc::mem_fun(this, &Train::block_reserved));
 	layout.get_driver().signal_sensor.connect(sigc::mem_fun(this, &Train::sensor_event));
 	layout.get_driver().signal_turnout.connect(sigc::mem_fun(this, &Train::turnout_event));
+
+	layout.get_driver().signal_halt.connect(sigc::mem_fun(this, &Train::halt_event));
+
+	controller->signal_control_changed.connect(sigc::mem_fun(this, &Train::control_changed));
 }
 
 Train::~Train()
 {
+	delete controller;
+	delete timetable;
 	for(vector<Vehicle *>::iterator i=vehicles.begin(); i!=vehicles.end(); ++i)
 		delete *i;
 	layout.remove_train(*this);
@@ -73,6 +101,40 @@ void Train::set_name(const string &n)
 	signal_name_changed.emit(name);
 }
 
+void Train::set_priority(int p)
+{
+	priority = p;
+}
+
+void Train::yield_to(const Train &t)
+{
+	yielding_to = &t;
+}
+
+void Train::add_vehicle(const VehicleType &vt)
+{
+	Vehicle *veh = new Vehicle(layout, vt);
+	vehicles.back()->attach_back(*veh);
+	vehicles.push_back(veh);
+}
+
+void Train::remove_vehicle(unsigned i)
+{
+	if(i>=vehicles.size())
+		throw InvalidParameterValue("Vehicle index out of range");
+	if(i==0)
+		throw InvalidParameterValue("Can't remove the locomotive");
+	delete vehicles[i];
+	vehicles.erase(vehicles.begin()+i);
+	if(i<vehicles.size())
+		vehicles[i-1]->attach_back(*vehicles[i]);
+}
+
+unsigned Train::get_n_vehicles() const
+{
+	return vehicles.size();
+}
+
 Vehicle &Train::get_vehicle(unsigned i)
 {
 	if(i>=vehicles.size())
@@ -89,15 +151,14 @@ const Vehicle &Train::get_vehicle(unsigned i) const
 
 void Train::set_control(const string &n, float v)
 {
-	control->set_control(n, v);
-	signal_control_changed.emit(n, control->get_control(n).value);
+	controller->set_control(n, v);
 }
 
 void Train::set_active(bool a)
 {
 	if(a==active)
 		return;
-	if(!a && control->get_speed())
+	if(!a && controller->get_speed())
 		throw InvalidState("Can't deactivate while moving");
 
 	active = a;
@@ -123,11 +184,27 @@ void Train::set_function(unsigned func, bool state)
 		layout.get_driver().set_loco_function(address+1, func-4, state);
 }
 
+float Train::get_control(const string &ctrl) const
+{
+	return controller->get_control(ctrl).value;
+}
+
+float Train::get_speed() const
+{
+	return controller->get_speed();
+}
+
 bool Train::get_function(unsigned func) const
 {
 	return (functions>>func)&1;
 }
 
+void Train::set_timetable(Timetable *tt)
+{
+	delete timetable;
+	timetable = tt;
+}
+
 void Train::set_route(const Route *r)
 {
 	if(!rsv_blocks.empty())
@@ -144,7 +221,7 @@ void Train::set_route(const Route *r)
 	next_route = 0;
 	end_of_route = false;
 
-	if(route)
+	if(route && !cur_blocks.empty())
 	{
 		BlockRef &last = (rsv_blocks.empty() ? cur_blocks.back() : rsv_blocks.back());
 		BlockRef next = last.next();
@@ -156,8 +233,7 @@ void Train::set_route(const Route *r)
 		}
 	}
 
-	if(active)
-		reserve_more();
+	reserve_more();
 
 	signal_route_changed.emit(route);
 }
@@ -190,13 +266,14 @@ void Train::go_to(const Track &to)
 
 void Train::place(Block &block, unsigned entry)
 {
-	if(control->get_speed())
+	if(controller->get_speed())
 		throw InvalidState("Must be stopped before placing");
 
 	release_blocks(rsv_blocks);
 	release_blocks(cur_blocks);
 
 	set_active(false);
+	accurate_position = false;
 
 	if(!block.reserve(this))
 	{
@@ -216,12 +293,16 @@ void Train::place(Block &block, unsigned entry)
 	else
 	{
 		const Block::Endpoint &bep = block.get_endpoints()[entry];
-		vehicles.front()->place(bep.track, bep.track_ep, 0, Vehicle::BACK_BUFFER);
+		vehicles.back()->place(bep.track, bep.track_ep, 0, Vehicle::BACK_BUFFER);
 	}
 }
 
 bool Train::free_block(Block &block)
 {
+	float margin = 10*layout.get_catalogue().get_scale();
+	if(get_reserved_distance_until(&block, false)<controller->get_braking_distance()*1.3+margin)
+		return false;
+
 	unsigned nsens = 0;
 	for(list<BlockRef>::iterator i=rsv_blocks.begin(); i!=rsv_blocks.end(); ++i)
 	{
@@ -252,44 +333,7 @@ int Train::get_entry_to_block(Block &block) const
 
 float Train::get_reserved_distance() const
 {
-	Vehicle &veh = *(reverse ? vehicles.back() : vehicles.front());
-	const VehicleType &vtype = veh.get_type();
-
-	Track *track = veh.get_track();
-	unsigned entry = veh.get_entry();
-
-	float result = -vtype.get_length()/2;
-	if(reverse)
-	{
-		entry = track->traverse(entry);
-		result += veh.get_offset();
-	}
-	else
-		result -= veh.get_offset();
-
-	bool first = true;
-	list<BlockRef>::const_iterator block = cur_blocks.begin();
-	while(1)
-	{
-		if(!first || !reverse)
-			result += track->get_type().get_path_length(track->get_active_path());
-		first = false;
-
-		unsigned exit = track->traverse(entry);
-		Track *next = track->get_link(exit);
-
-		while(!block->block->get_tracks().count(next))
-		{
-			++block;
-			if(block==cur_blocks.end())
-				block = rsv_blocks.begin();
-			if(block==rsv_blocks.end())
-				return result;
-		}
-
-		entry = next->get_endpoint_by_link(*track);
-		track = next;
-	}
+	return get_reserved_distance_until(0, false);
 }
 
 void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
@@ -301,26 +345,28 @@ void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
 		stop_timeout = Time::TimeStamp();
 	}
 
+	Driver &driver = layout.get_driver();
+
 	if(timetable)
 		timetable->tick(t);
-	control->tick(dt);
-	float speed = control->get_speed();
-	unsigned speed_notch = find_speed(abs(speed));
+	controller->tick(dt);
+	float speed = controller->get_speed();
+	unsigned speed_notch = find_speed(speed);
 
-	if(speed && (speed<0)!=reverse)
+	if(controller->get_reverse()!=reverse)
 	{
-		layout.get_driver().set_loco_reverse(address, speed<0);
-		reverse = speed<0;
+		reverse = controller->get_reverse();
+		driver.set_loco_reverse(address, reverse);
 
 		release_blocks(rsv_blocks);
 		reverse_blocks(cur_blocks);
 
 		reserve_more();
 	}
-	if(speed_notch!=current_speed && !speed_changing)
+	if(speed_notch!=current_speed && !speed_changing && !driver.is_halted() && driver.get_power())
 	{
 		speed_changing = true;
-		layout.get_driver().set_loco_speed(address, speed_notch);
+		driver.set_loco_speed(address, speed_notch);
 
 		pure_speed = false;
 
@@ -335,25 +381,57 @@ void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
 		if(!active)
 			set_active(true);
 
-		Track *track = vehicles[0]->get_track();
+		Vehicle &vehicle = *(reverse ? vehicles.back() : vehicles.front());
+		Track *track = vehicle.get_track();
 
 		bool ok = false;
 		for(list<BlockRef>::const_iterator i=cur_blocks.begin(); (!ok && i!=cur_blocks.end()); ++i)
 			ok = i->block->get_tracks().count(track);
 
+		float d = get_real_speed(current_speed)*(dt/Time::sec);
 		if(ok)
 		{
-			float d = get_real_speed(current_speed)*(dt/Time::sec);
-			vehicles[0]->advance(reverse ? -d : d);
+			SetFlag setf(advancing);
+			vehicle.advance(reverse ? -d : d);
+		}
+		else if(accurate_position)
+		{
+			overshoot_dist += d;
+			if(overshoot_dist>40*layout.get_catalogue().get_scale())
+			{
+				layout.emergency(name+" has not arrived at sensor");
+				accurate_position = false;
+			}
 		}
 	}
-	else if(end_of_route)
+	else if(end_of_route && rsv_blocks.empty())
+	{
+		signal_arrived.emit();
 		set_route(0);
+	}
+
+	if(!cur_blocks.empty() && !cur_blocks.front().block->get_sensor_id())
+	{
+		float dist = get_reserved_distance_until(cur_blocks.front().block, true);
+
+		if(dist>10*layout.get_catalogue().get_scale())
+		{
+			cur_blocks.front().block->reserve(0);
+			cur_blocks.erase(cur_blocks.begin());
+		}
+	}
 }
 
 void Train::save(list<DataFile::Statement> &st) const
 {
 	st.push_back((DataFile::Statement("name"), name));
+
+	st.push_back((DataFile::Statement("priority"), priority));
+
+	for(vector<Vehicle *>::const_iterator i=vehicles.begin(); i!=vehicles.end(); ++i)
+		if(i!=vehicles.begin())
+			st.push_back((DataFile::Statement("vehicle"), (*i)->get_type().get_article_number()));
+
 	for(unsigned i=0; i<=14; ++i)
 		if(real_speed[i].weight)
 			st.push_back((DataFile::Statement("real_speed"), i, real_speed[i].speed, real_speed[i].weight));
@@ -372,7 +450,12 @@ void Train::save(list<DataFile::Statement> &st) const
 	}
 
 	if(route)
-		st.push_back((DataFile::Statement("route"), route->get_name()));
+	{
+		if(!route->is_temporary())
+			st.push_back((DataFile::Statement("route"), route->get_name()));
+		else if(next_route && !next_route->is_temporary())
+			st.push_back((DataFile::Statement("route"), next_route->get_name()));
+	}
 
 	if(timetable)
 	{
@@ -382,12 +465,18 @@ void Train::save(list<DataFile::Statement> &st) const
 	}
 }
 
+void Train::control_changed(const Controller::Control &ctrl)
+{
+	signal_control_changed.emit(ctrl.name, ctrl.value);
+}
+
 void Train::loco_speed_event(unsigned addr, unsigned speed, bool)
 {
 	if(addr==address)
 	{
 		current_speed = speed;
 		speed_changing = false;
+		pure_speed = false;
 	}
 }
 
@@ -412,19 +501,35 @@ void Train::sensor_event(unsigned addr, bool state)
 	{
 		// Find the first sensor block from our reserved blocks that isn't this sensor
 		list<BlockRef>::iterator i;
+		unsigned result = 0;
 		for(i=rsv_blocks.begin(); i!=rsv_blocks.end(); ++i)
-			if(i->block->get_sensor_id() && i->block->get_sensor_id()!=addr)
-				break;
+			if(i->block->get_sensor_id())
+			{
+				if(i->block->get_sensor_id()!=addr)
+				{
+					if(result==0)
+						result = 2;
+					else if(result==1)
+						break;
+				}
+				else if(result==0)
+					result = 1;
+				else if(result==2)
+					result = 3;
+			}
 
-		if(i!=rsv_blocks.begin())
+		if(result==1 && i!=rsv_blocks.begin())
 		{
 			// Compute speed and update related state
 			float travel_time_secs = (Time::now()-last_entry_time)/Time::sec;
 
 			if(pure_speed)
 			{
-				RealSpeed &rs = real_speed[current_speed];
-				rs.add(travel_dist/travel_time_secs, travel_time_secs);
+				if(current_speed)
+				{
+					RealSpeed &rs = real_speed[current_speed];
+					rs.add(travel_dist/travel_time_secs, travel_time_secs);
+				}
 				set_status(format("Traveling %d kmh", get_travel_speed()));
 			}
 
@@ -435,7 +540,7 @@ void Train::sensor_event(unsigned addr, bool state)
 				j->block->traverse(j->entry, &block_len);
 				travel_dist += block_len;
 
-				if(j->block->get_sensor_id()==addr)
+				if(j->block->get_sensor_id()==addr && !advancing)
 				{
 					const Block::Endpoint &bep = j->block->get_endpoints()[j->entry];
 					if(reverse)
@@ -450,6 +555,8 @@ void Train::sensor_event(unsigned addr, bool state)
 			}
 			last_entry_time = Time::now();
 			pure_speed = true;
+			accurate_position = true;
+			overshoot_dist = 0;
 
 			// Check if we've reached the next route
 			if(next_route)
@@ -471,12 +578,10 @@ void Train::sensor_event(unsigned addr, bool state)
 
 			// Try to get more blocks if we're moving
 			if(active)
-			{
-				unsigned nsens = reserve_more();
-				if(!nsens && end_of_route)
-					signal_arrived.emit();
-			}
+				reserve_more();
 		}
+		else if(result==3)
+			layout.emergency("Sensor for "+name+" triggered out of order");
 	}
 	else
 	{
@@ -488,15 +593,15 @@ void Train::sensor_event(unsigned addr, bool state)
 				if(layout.get_driver().get_sensor(i->block->get_sensor_id()))
 					break;
 				else
+				{
 					end = i;
+					++end;
+				}
 			}
 		
-		if(end!=cur_blocks.begin())
-		{
+		if(end!=cur_blocks.begin() && end!=cur_blocks.end())
 			// Free blocks up to the last inactive sensor
-			++end;
 			release_blocks(cur_blocks, cur_blocks.begin(), end);
-		}
 	}
 }
 
@@ -507,10 +612,21 @@ void Train::turnout_event(unsigned addr, bool)
 		unsigned pending_addr = pending_block->get_turnout_id();
 		bool double_addr = (*pending_block->get_tracks().begin())->get_type().is_double_address();
 		if(addr==pending_addr || (double_addr && addr==pending_addr+1))
-			reserve_more();
+		{
+			if(reserving)
+				pending_block = 0;
+			else
+				reserve_more();
+		}
 	}
 }
 
+void Train::halt_event(bool h)
+{
+	if(h)
+		accurate_position = false;
+}
+
 void Train::block_reserved(const Block &block, const Train *train)
 {
 	if(&block==pending_block && !train)
@@ -519,21 +635,33 @@ void Train::block_reserved(const Block &block, const Train *train)
 
 unsigned Train::reserve_more()
 {
-	BlockRef *last = 0;
+	if(!active)
+		return 0;
+
+	BlockRef *start = 0;
 	if(!rsv_blocks.empty())
-		last = &rsv_blocks.back();
+		start = &rsv_blocks.back();
 	else if(!cur_blocks.empty())
-		last = &cur_blocks.back();
-	if(!last)
+		start = &cur_blocks.back();
+	if(!start)
 		return 0;
 
 	pending_block = 0;
 
-	// See how many sensor blocks we already have
+	// See how many sensor blocks and how much track we already have
 	unsigned nsens = 0;
+	float dist = 0;
 	for(list<BlockRef>::const_iterator i=rsv_blocks.begin(); i!=rsv_blocks.end(); ++i)
+	{
 		if(i->block->get_sensor_id())
 			++nsens;
+		if(nsens>0)
+		{
+			float length = 0;
+			i->block->traverse(i->entry, &length);
+			dist += length;
+		}
+	}
 	
 	if(end_of_route)
 		return nsens;
@@ -541,7 +669,7 @@ unsigned Train::reserve_more()
 	const Route *cur_route = 0;
 	if(route)
 	{
-		const set<Track *> &tracks = last->block->get_tracks();
+		const set<Track *> &tracks = start->block->get_tracks();
 		for(set<Track *>::const_iterator i=tracks.begin(); (cur_route!=route && i!=tracks.end()); ++i)
 		{
 			if(route->get_tracks().count(*i))
@@ -551,13 +679,23 @@ unsigned Train::reserve_more()
 		}
 	}
 
-	bool got_more = false;
-	BlockRef *good = last;
+	float approach_margin = 50*layout.get_catalogue().get_scale();
+	float min_dist = controller->get_braking_distance()*1.3+approach_margin*2;
+
+	BlockRef *last = start;
+	BlockRef *good = start;
 	unsigned good_sens = nsens;
-	while(good_sens<3)
+	float good_dist = dist;
+	Train *blocking_train = 0;
+	std::list<BlockRef> contested_blocks;
+
+	SetFlag setf(reserving);
+
+	while(good_sens<3 || good_dist<min_dist || !contested_blocks.empty())
 	{
 		// Traverse to the next block
-		unsigned exit = last->block->traverse(last->entry);
+		float length = 0;
+		unsigned exit = last->block->traverse(last->entry, cur_route, &length);
 		Block *link = last->block->get_link(exit);
 		if(!link)
 			break;
@@ -575,28 +713,103 @@ unsigned Train::reserve_more()
 			else if(!cur_route->get_tracks().count(entry_ep.track))
 			{
 				// Keep the blocks if we arrived at the end of the route
-				good = last;
-				good_sens = nsens;
-				end_of_route = true;
+				if(!blocking_train)
+				{
+					good = last;
+					good_sens = nsens;
+					good_dist = dist;
+					end_of_route = true;
+				}
 				break;
 			}
 		}
 		else if(route && route->get_tracks().count(entry_ep.track))
 			cur_route = route;
 
-		if(!link->reserve(this))
+		if(link->get_endpoints().size()<2)
+		{
+			if(!blocking_train)
+			{
+				good = last;
+				good_sens = nsens;
+				good_dist = dist;
+			}
+			break;
+		}
+
+		if(blocking_train)
+		{
+			if(link->get_train()!=blocking_train)
+			{
+				// XXX is it possible that this won't free all the blocks we want?
+				if(blocking_train->free_block(*contested_blocks.back().block))
+				{
+					// Roll back and start actually reserving the blocks
+					last = &rsv_blocks.back();
+					if(blocking_train->get_priority()==priority)
+						blocking_train->yield_to(*this);
+					blocking_train = 0;
+					continue;
+				}
+				else
+				{
+					pending_block = contested_blocks.front().block;
+					break;
+				}
+			}
+			else
+			{
+				contested_blocks.push_back(BlockRef(link, entry));
+				last = &contested_blocks.back();
+				continue;
+			}
+		}
+
+		bool reserved = link->reserve(this);
+		if(!reserved)
 		{
-			// If we found another train and it's not headed straight for us, we can keep the blocks we got
-			int other_entry = link->get_train()->get_entry_to_block(*link);
+			/* We've found another train.  If it wants to exit the block from the
+			same endpoint we're trying to enter from or the other way around,
+			treat it as coming towards us.  Otherwise treat it as going in the
+			same direction. */
+			Train *other_train = link->get_train();
+			int other_entry = other_train->get_entry_to_block(*link);
 			if(other_entry<0)
 				throw LogicError("Block reservation inconsistency");
-			if(static_cast<unsigned>(entry)!=link->traverse(other_entry))
+
+			int other_prio = other_train->get_priority();
+
+			bool entry_conflict = (static_cast<unsigned>(entry)==link->traverse(other_entry));
+			bool exit_conflict = (link->traverse(entry)==static_cast<unsigned>(other_entry));
+			if(!entry_conflict && !exit_conflict)
 			{
+				/* Same direction, keep the blocks we got so far and wait for the
+				other train to pass */
 				good = last;
 				good_sens = nsens;
+				good_dist = dist;
+
+				// Ask a lesser priority train to free the block for us
+				if(other_train->get_priority()<priority)
+					if(other_train->free_block(*link))
+						reserved = link->reserve(this);
+			}
+			else if(other_prio<priority || (other_prio==priority && other_train!=yielding_to && entry_conflict))
+			{
+				/* A lesser priority train is coming at us, we must ask it to free
+				enough blocks to get clear of it to avoid a potential deadlock */
+				blocking_train = other_train;
+				contested_blocks.clear();
+				contested_blocks.push_back(BlockRef(link, entry));
+				last = &contested_blocks.back();
+				continue;
+			}
+
+			if(!reserved)
+			{
+				pending_block = link;
+				break;
 			}
-			pending_block = link;
-			break;
 		}
 
 		if(link->get_turnout_id())
@@ -606,6 +819,7 @@ unsigned Train::reserve_more()
 			// Keep the blocks reserved so far, as either us or the other train can diverge
 			good = last;
 			good_sens = nsens;
+			good_dist = dist;
 
 			// Figure out what path we'd like to take on the turnout
 			int path = -1;
@@ -623,34 +837,111 @@ unsigned Train::reserve_more()
 			if(path!=static_cast<int>(entry_ep.track->get_active_path()))
 			{
 				// The turnout is set to wrong path - switch and wait for it
-				link->reserve(0);
 				pending_block = link;
 				entry_ep.track->set_active_path(path);
-				break;
+				if(pending_block)
+				{
+					link->reserve(0);
+					break;
+				}
 			}
 		}
 
+		if(!contested_blocks.empty() && contested_blocks.front().block==link)
+			contested_blocks.pop_front();
+
 		rsv_blocks.push_back(BlockRef(link, entry));
 		last = &rsv_blocks.back();
 		if(last->block->get_sensor_id())
-		{
 			++nsens;
-			got_more = true;
-		}
+		if(nsens>0)
+			dist += length;
 	}
 
 	// Unreserve blocks that were not good
-	while(!rsv_blocks.empty() && last!=good)
+	while(!rsv_blocks.empty() && &rsv_blocks.back()!=good)
 	{
-		last->block->reserve(0);
+		rsv_blocks.back().block->reserve(0);
 		rsv_blocks.erase(--rsv_blocks.end());
-		if(!rsv_blocks.empty())
-			last = &rsv_blocks.back();
 	}
 
+	if(!rsv_blocks.empty() && &rsv_blocks.back()!=start)
+		// We got some new blocks, so no longer need to yield
+		yielding_to = 0;
+
+	// Make any sensorless blocks at the beginning immediately current
+	list<BlockRef>::iterator i;
+	for(i=rsv_blocks.begin(); (i!=rsv_blocks.end() && !i->block->get_sensor_id()); ++i) ;
+	if(i!=rsv_blocks.begin())
+		cur_blocks.splice(cur_blocks.end(), rsv_blocks, rsv_blocks.begin(), i);
+
 	return good_sens;
 }
 
+float Train::get_reserved_distance_until(const Block *until_block, bool back) const
+{
+	if(cur_blocks.empty())
+		return 0;
+
+	Vehicle &veh = *(reverse!=back ? vehicles.back() : vehicles.front());
+	const VehicleType &vtype = veh.get_type();
+
+	Track *track = veh.get_track();
+	if(!track)
+		return 0;
+
+	list<BlockRef>::const_iterator block = cur_blocks.begin();
+	while(block!=cur_blocks.end() && !block->block->get_tracks().count(track))
+		++block;
+	if(block==cur_blocks.end() || block->block==until_block)
+		return 0;
+
+	unsigned entry = veh.get_entry();
+
+	float result = veh.get_offset();
+	if(reverse!=back)
+		entry = track->traverse(entry);
+	else
+		result = track->get_type().get_path_length(track->get_active_path())-result;
+	result -= vtype.get_length()/2;
+
+	while(1)
+	{
+		if(track->get_type().get_endpoints().size()<2)
+			break;
+
+		Track *next = track->get_link(track->traverse(entry));
+
+		if(!block->block->get_tracks().count(next))
+		{
+			if(back)
+			{
+				if(block==cur_blocks.begin())
+					break;
+				--block;
+			}
+			else
+			{
+				++block;
+				if(block==cur_blocks.end())
+					block = rsv_blocks.begin();
+				if(block==rsv_blocks.end())
+					break;
+			}
+
+			if(block->block==until_block)
+				break;
+		}
+
+		entry = next->get_endpoint_by_link(*track);
+		track = next;
+
+		result += track->get_type().get_path_length(track->get_active_path());
+	}
+
+	return result;
+}
+
 float Train::get_real_speed(unsigned i) const
 {
 	if(real_speed[i].weight)
@@ -699,7 +990,12 @@ unsigned Train::find_speed(float real) const
 	if(!high)
 	{
 		if(!low)
-			return 0;
+		{
+			if(real)
+				return 3;
+			else
+				return 0;
+		}
 		return min(static_cast<unsigned>(low*real/real_speed[low].speed), 14U);
 	}
 
@@ -776,40 +1072,72 @@ void Train::RealSpeed::add(float s, float w)
 
 Train::Loader::Loader(Train &t):
 	DataFile::BasicLoader<Train>(t),
-	prev_block(0)
+	prev_block(0),
+	blocks_valid(true)
 {
 	add("block",       &Loader::block);
 	add("block_hint",  &Loader::block_hint);
 	add("name",        &Loader::name);
+	add("priority",    &Train::priority);
 	add("real_speed",  &Loader::real_speed);
 	add("route",       &Loader::route);
 	add("timetable",   &Loader::timetable);
+	add("vehicle",     &Loader::vehicle);
+}
+
+void Train::Loader::finish()
+{
+	if(!obj.cur_blocks.empty())
+	{
+		const BlockRef &blkref = obj.cur_blocks.front();
+		const Block::Endpoint &bep = blkref.block->get_endpoints()[blkref.entry];
+		obj.vehicles.back()->place(bep.track, bep.track_ep, 0, Vehicle::BACK_BUFFER);
+
+		obj.set_status("Stopped");
+	}
 }
 
 void Train::Loader::block(unsigned id)
 {
-	Block &blk = obj.layout.get_block(id);
+	if(!blocks_valid)
+		return;
+
+	Block *blk;
+	try
+	{
+		blk = &obj.layout.get_block(id);
+	}
+	catch(const KeyError &)
+	{
+		blocks_valid = false;
+		return;
+	}
+
 	int entry = -1;
 	if(prev_block)
-		entry = blk.get_endpoint_by_link(*prev_block);
+		entry = blk->get_endpoint_by_link(*prev_block);
 	if(entry<0)
 		entry = 0;
 
-	blk.reserve(&obj);
-	obj.cur_blocks.push_back(BlockRef(&blk, entry));
-	obj.set_status("Stopped");
-	const Block::Endpoint &bep = blk.get_endpoints()[entry];
-	obj.vehicles.back()->place(bep.track, bep.track_ep, 0, Vehicle::BACK_BUFFER);
+	blk->reserve(&obj);
+	obj.cur_blocks.push_back(BlockRef(blk, entry));
 
-	if(blk.get_sensor_id())
-		obj.layout.get_driver().set_sensor(blk.get_sensor_id(), true);
+	if(blk->get_sensor_id())
+		obj.layout.get_driver().set_sensor(blk->get_sensor_id(), true);
 
-	prev_block = &blk;
+	prev_block = blk;
 }
 
 void Train::Loader::block_hint(unsigned id)
 {
-	prev_block = &obj.layout.get_block(id);
+	try
+	{
+		prev_block = &obj.layout.get_block(id);
+	}
+	catch(const KeyError &)
+	{
+		blocks_valid = false;
+	}
 }
 
 void Train::Loader::name(const string &n)
@@ -837,4 +1165,12 @@ void Train::Loader::timetable()
 	load_sub(*obj.timetable);
 }
 
+void Train::Loader::vehicle(unsigned n)
+{
+	const VehicleType &vtype = obj.layout.get_catalogue().get_vehicle(n);
+	Vehicle *veh = new Vehicle(obj.layout, vtype);
+	obj.vehicles.back()->attach_back(*veh);
+	obj.vehicles.push_back(veh);
+}
+
 } // namespace Marklin