Fix block releasing logic

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

diff --git a/source/libr2c2/blockallocator.cpp b/source/libr2c2/blockallocator.cpp
index 8d3381da20ecada6172781d064b9feba998e669a..a054c157331c9b5e9ed074da4fc99469e2b0ee8e 100644 (file)
--- a/source/libr2c2/blockallocator.cpp
+++ b/source/libr2c2/blockallocator.cpp
@@ -312,14 +312,14 @@ void BlockAllocator::advance_back()
 
        /* 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 +329,32 @@ 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;
                }
        }
 }