Add a utility function to get path length from Track

[r2c2.git] / source / libr2c2 / blockallocator.cpp

diff --git a/source/libr2c2/blockallocator.cpp b/source/libr2c2/blockallocator.cpp
index 8d3381da20ecada6172781d064b9feba998e669a..674722bb9d21b6951bd0f8b0405fad8e4ecd4db3 100644 (file)
--- a/source/libr2c2/blockallocator.cpp
+++ b/source/libr2c2/blockallocator.cpp
@@ -60,13 +60,53 @@ void BlockAllocator::set_active(bool a)
        }
 }
 
-void BlockAllocator::start_from(const BlockIter &block)
+bool BlockAllocator::start_from(const BlockIter &block)
 {
        if(!block)
                throw invalid_argument("BlockAllocator::start_from");
 
+       float remaining_length = 0;
+       unsigned n_vehs = train.get_n_vehicles();
+       for(unsigned i=0; i<n_vehs; ++i)
+               remaining_length += train.get_vehicle(i).get_type().get_length();
+
        clear();
-       reserve_block(block);
+
+       BlockList blocks_to_reserve;
+       for(BlockIter b=block; b; b=b.next())
+       {
+               if(b->get_train())
+                       break;
+               blocks_to_reserve.push_back(b);
+               for(TrackIter t=b.track_iter(); (t && &t->get_block()==&*b); t=t.next())
+                       remaining_length -= t->get_path_length();
+               if(remaining_length<=0)
+                       break;
+       }
+
+       if(remaining_length>0)
+               return false;
+
+       for(BlockList::iterator i=blocks_to_reserve.begin(); i!=blocks_to_reserve.end(); ++i)
+       {
+               blocks.push_back(*i);
+               try
+               {
+                       (*i)->reserve(&train);
+               }
+               catch(...)
+               {
+                       blocks.pop_back();
+                       while(i!=blocks_to_reserve.begin())
+                       {
+                               blocks.pop_back();
+                               (*--i)->reserve(0);
+                       }
+                       throw;
+               }
+       }
+
+       return true;
 }
 
 void BlockAllocator::rewind_to(const Block &block)
@@ -257,10 +297,17 @@ bool BlockAllocator::reserve_block(const BlockIter &block)
        /* Add it to the list first to present a consistent state in block_reserved
        signal. */
        blocks.push_back(block);
+
+       bool first_reserve = (cur_blocks_end==blocks.end());
+       if(first_reserve)
+               --cur_blocks_end;
+
        try
        {
                if(!block->reserve(&train))
                {
+                       if(first_reserve)
+                               cur_blocks_end = blocks.end();
                        blocks.pop_back();
                        return false;
                }
@@ -269,6 +316,8 @@ bool BlockAllocator::reserve_block(const BlockIter &block)
        }
        catch(...)
        {
+               if(first_reserve)
+                       cur_blocks_end = blocks.end();
                blocks.pop_back();
                throw;
        }
@@ -307,19 +356,20 @@ void BlockAllocator::advance_front(const Sensor *sensor)
 
 void BlockAllocator::advance_back()
 {
-       const Vehicle &veh = train.get_vehicle(train.get_controller().get_reverse() ? 0 : train.get_n_vehicles()-1);
-       const Block &veh_block = veh.get_track()->get_block();
+       bool rev = train.get_controller().get_reverse();
+       const Vehicle &veh = train.get_vehicle(rev ? 0 : train.get_n_vehicles()-1);
+       const Block &veh_block = veh.get_placement().get_position(rev ? VehiclePlacement::FRONT_AXLE : VehiclePlacement::BACK_AXLE)->get_block();
 
        /* Sensors aren't guaranteed to be detriggered in order.  Go through the
        block list and locate the first sensor that's still active. */
-       Sensor *last_inactive = 0;
-       for(BlockList::iterator i=blocks.begin(); (i!=cur_blocks_end && i->block()!=&veh_block); ++i)
+       BlockList::iterator end = blocks.end();
+       for(BlockList::iterator i=blocks.begin(); i!=cur_blocks_end; ++i)
        {
+               Block *block = &**i;
                list<Sensor *> sensors;
-               if(Sensor *sensor = (*i)->get_sensor())
-                       sensors.push_back(sensor);
 
-               Block *block = &**i;
+               /* Collect all sensors from the block in the order they are expected to
+               detrigger. */
                for(TrackIter j=i->track_iter(); (j && &j->get_block()==block); j=j.next())
                        if(!j->get_attachments().empty())
                        {
@@ -329,20 +379,32 @@ void BlockAllocator::advance_back()
                                                sensors.push_back(gate);
                        }
 
-               for(list<Sensor *>::const_iterator j=sensors.begin(); j!=sensors.end(); ++j)
+               if(Sensor *sensor = (*i)->get_sensor())
+                       sensors.push_back(sensor);
+
+               /* See if any sensor is still active, and record the position of the
+               last inactive sensor. */
+               bool active_sensor = false;
+               for(list<Sensor *>::const_iterator j=sensors.begin(); (!active_sensor && j!=sensors.end()); ++j)
                {
                        if((*j)->get_state())
+                               active_sensor = true;
+                       else
+                               end = i;
+               }
+
+               // Stop if we encounter an active sensor or the train's last vehicle
+               if(block==&veh_block || active_sensor)
+               {
+                       if(end!=blocks.end())
                        {
-                               if(last_inactive)
-                               {
-                                       if(dynamic_cast<BeamGate *>(*j))
-                                               ++i;
-                                       release_blocks_begin(i);
-                               }
-                               return;
+                               /* If the last inactive sensor was in an earlier block, release
+                               that block as well. */
+                               if(i!=end)
+                                       ++end;
+                               release_blocks_begin(end);
                        }
-                       else
-                               last_inactive = *j;
+                       return;
                }
        }
 }
@@ -401,7 +463,7 @@ void BlockAllocator::reverse()
 
 void BlockAllocator::turnout_path_changing(Track &track)
 {
-       BlockList::iterator i = find_if(blocks.begin(), blocks.end(), BlockMatch(track.get_block()));
+       BlockList::iterator i = find_if(cur_blocks_end, blocks.end(), BlockMatch(track.get_block()));
        if(i!=blocks.end())
        {
                ++i;