Tighten safety measures

Remove opportunistic freeing of blocks from behind the train and counting
of noncritical blocks from the simulated vehicle position.  Both features
are now implemented in terms of what can be ascertained from sensors.  I'm
developing infrared gates which will provide similar functionality with
actual physical (or simulated) feedback.

diff --git a/source/libr2c2/blockallocator.cpp b/source/libr2c2/blockallocator.cpp
index 55f932e4233f0652f368a75f2fe9607654f9e125..fc414cc99825d25b94140438923b9ed9f46bfff7 100644 (file)
--- a/source/libr2c2/blockallocator.cpp
+++ b/source/libr2c2/blockallocator.cpp
@@ -227,17 +227,6 @@ bool BlockAllocator::reserve_block(const BlockIter &block)
        }
 }
 
-void BlockAllocator::release_until(const Block &block)
-{
-       for(BlockList::iterator i=blocks.begin(); i!=cur_blocks_end; ++i)
-               if(i->block()==&block)
-               {
-                       if(++i!=cur_blocks_end)
-                               release_blocks_begin(i);
-                       return;
-               }
-}
-
 bool BlockAllocator::release_from(const Block &block)
 {
        bool have_sensor = false;

diff --git a/source/libr2c2/blockallocator.h b/source/libr2c2/blockallocator.h
index c90b450bb52f11248ce1f8d016a0e73163e5b0a0..39a327b9fa95810030267952a174cbd2073ffb02 100644 (file)
--- a/source/libr2c2/blockallocator.h
+++ b/source/libr2c2/blockallocator.h
@@ -60,7 +60,6 @@ public:
 private:
        bool reserve_block(const BlockIter &);
 public:
-       void release_until(const Block &);
        bool release_from(const Block &);
        void release_noncurrent();
 private:

diff --git a/source/libr2c2/train.cpp b/source/libr2c2/train.cpp
index b7dc2470c4c1a98e98e5aae789c39e4130e1f31f..91387d85297e7f2a6b5bed13a1b620cf01f687b9 100644 (file)
--- a/source/libr2c2/train.cpp
+++ b/source/libr2c2/train.cpp
@@ -232,7 +232,7 @@ void Train::stop_at(Block *block)
 
 bool Train::free_block(Block &block)
 {
-       if(get_reserved_distance_until(&block, false)<controller->get_braking_distance()*1.3)
+       if(get_reserved_distance_until(&block)<controller->get_braking_distance()*1.3)
                return false;
 
        return allocator.release_from(block);
@@ -252,53 +252,21 @@ void Train::free_noncritical_blocks()
        float margin = 10*layout.get_catalogue().get_scale();
        float min_dist = controller->get_braking_distance()*1.3+margin;
 
-       Vehicle &veh = *(reverse ? vehicles.back() : vehicles.front());
-
-       TrackIter track = veh.get_track_iter();
-       BlockIter block = allocator.first();
-       const BlockIter &last_cur = allocator.last_current();
-       const BlockIter &last = allocator.last();
-       bool in_rsv = false;
-       while(!block->has_track(*track))
-       {
-               if(&*block==&*last_cur)
-                       in_rsv = true;
-               if(&*block==&*last)
-                       break;
-               block = block.next();
-       }
-
-       float dist = veh.get_offset();
-       if(reverse)
-               track.reverse();
-       else
-               dist = track->get_type().get_path_length(track->get_active_path())-dist;
-       dist -= veh.get_type().get_length()/2;
-
-       bool nsens = 0;
-       while(1)
+       BlockIter i = allocator.last_current().next();
+       float dist = 0;
+       bool sensor_seen = false;
+       for(; i->get_train()==this; i=i.next())
        {
-               track = track.next();
-
-               if(!block->has_track(*track))
+               if(dist>min_dist && sensor_seen)
                {
-                       if(&*block==&*last_cur)
-                               in_rsv = true;
-                       if(&*block==&*last)
-                               return;
-                       block = block.next();
-
-                       if(dist>min_dist && nsens>0)
-                       {
-                               allocator.release_from(*block);
-                               return;
-                       }
-
-                       if(in_rsv && block->get_sensor_id())
-                               ++nsens;
+                       allocator.release_from(*i);
+                       return;
                }
 
-               dist += track->get_type().get_path_length(track->get_active_path());
+               dist += i->get_path_length(i.entry());
+
+               if(i->get_sensor_id())
+                       sensor_seen = true;
        }
 }
 
@@ -312,7 +280,7 @@ float Train::get_reserved_distance() const
        if(next && next->get_type().is_turnout())
                margin = 15*layout.get_catalogue().get_scale();
 
-       return max(get_reserved_distance_until(0, false)-margin, 0.0f);
+       return max(get_reserved_distance_until(0)-margin, 0.0f);
 }
 
 void Train::reserve_more()
@@ -386,14 +354,6 @@ void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
                        }
                }
        }
-
-       if(!allocator.empty() && !allocator.first()->get_sensor_id())
-       {
-               float dist = get_reserved_distance_until(&*allocator.first(), true);
-
-               if(dist>10*layout.get_catalogue().get_scale())
-                       allocator.release_until(*allocator.first());
-       }
 }
 
 void Train::save(list<DataFile::Statement> &st) const
@@ -521,65 +481,44 @@ void Train::halt_event(bool h)
                accurate_position = false;
 }
 
-float Train::get_reserved_distance_until(const Block *until_block, bool back) const
+float Train::get_reserved_distance_until(const Block *until_block) const
 {
        if(allocator.empty())
                return 0;
 
-       Vehicle &veh = *(reverse!=back ? vehicles.back() : vehicles.front());
-       const VehicleType &vtype = veh.get_type();
+       Vehicle &veh = *(reverse ? vehicles.back() : vehicles.front());
 
        TrackIter track = veh.get_track_iter();
        if(!track)  // XXX Probably unnecessary
                return 0;
 
-       const BlockIter &first = allocator.first();
-       const BlockIter &last = allocator.last();
-       BlockIter block = first;
-       while(!block->has_track(*track))
-       {
-               if(&*block==&*last)
-                       return 0;
-               block = block.next();
-       }
+       BlockIter block = track.block_iter();
        if(&*block==until_block)
                return 0;
 
-       if(back)
-               block = block.reverse();
-
+       // Account for the vehicle's offset on its current track
        float result = veh.get_offset();
-       if(reverse!=back)
+       if(reverse)
                track = track.reverse();
        else
                result = track->get_type().get_path_length(track->get_active_path())-result;
-       result -= vtype.get_length()/2;
+       result -= veh.get_type().get_length()/2;
 
-       while(1)
-       {
-               track = track.next();
-               if(!track)
-                       break;
+       // Count remaining distance in the vehicle's current block
+       for(track=track.next(); &track->get_block()==&*block; track=track.next())
+               result += track->get_type().get_path_length(track->get_active_path());
 
-               if(!block->has_track(*track))
-               {
-                       if(back)
-                       {
-                               if(&*block==&*first)
-                                       break;
-                       }
-                       else
-                       {
-                               if(&*block==&*last)
-                                       break;
-                       }
-                       block = block.next();
+       const BlockIter &last = allocator.last();
+       if(&*block==&*last)
+               return result;
 
-                       if(&*block==until_block)
-                               break;
-               }
+       // Count any remaining blocks
+       for(block=block.next(); (&*block!=until_block && block->get_train()==this); block=block.next())
+       {
+               result += block->get_path_length(block.entry());
 
-               result += track->get_type().get_path_length(track->get_active_path());
+               if(&*block==&*last)
+                       break;
        }
 
        return result;

diff --git a/source/libr2c2/train.h b/source/libr2c2/train.h
index 03b8b66d3e1e929869431c0ec472853d823dbdaf..42bbc375b25b1346fc55b457b04cf41ca45dab22 100644 (file)
--- a/source/libr2c2/train.h
+++ b/source/libr2c2/train.h
@@ -133,7 +133,7 @@ private:
        void block_state_changed(Block &, Block::State);
        void halt_event(bool);
        void block_reserved(const Block &, const Train *);
-       float get_reserved_distance_until(const Block *, bool) const;
+       float get_reserved_distance_until(const Block *) const;
 };
 
 } // namespace R2C2