From 3133b97af17c8a11fb3364453b53d970790a1426 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 23 Apr 2010 18:21:12 +0000
Subject: [PATCH] Handle reversing in a way that allows backing out of a dead
 end

---
 source/libmarklin/aicontrol.cpp   | 8 ++++++++
 source/libmarklin/aicontrol.h     | 1 +
 source/libmarklin/controlmodel.h  | 1 +
 source/libmarklin/simplephysics.h | 1 +
 source/libmarklin/train.cpp       | 6 +++---
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/source/libmarklin/aicontrol.cpp b/source/libmarklin/aicontrol.cpp
index b97b037..d5a29c0 100644
--- a/source/libmarklin/aicontrol.cpp
+++ b/source/libmarklin/aicontrol.cpp
@@ -61,6 +61,14 @@ float AIControl::get_speed() const
 	return next_model->get_speed();
 }
 
+bool AIControl::get_reverse() const
+{
+	if(float ns = next_model->get_speed())
+		return ns<0;
+	else
+		return target_speed.value<0;
+}
+
 float AIControl::get_braking_distance() const
 {
 	return next_model->get_braking_distance();
diff --git a/source/libmarklin/aicontrol.h b/source/libmarklin/aicontrol.h
index d02011f..465d2ab 100644
--- a/source/libmarklin/aicontrol.h
+++ b/source/libmarklin/aicontrol.h
@@ -32,6 +32,7 @@ public:
 	virtual const TrainControl &get_control(const std::string &) const;
 
 	virtual float get_speed() const;
+	virtual bool get_reverse() const;
 	virtual float get_braking_distance() const;
 
 	virtual void tick(const Msp::Time::TimeDelta &);
diff --git a/source/libmarklin/controlmodel.h b/source/libmarklin/controlmodel.h
index a45a30e..17bb72b 100644
--- a/source/libmarklin/controlmodel.h
+++ b/source/libmarklin/controlmodel.h
@@ -30,6 +30,7 @@ public:
 	virtual const TrainControl &get_control(const std::string &) const = 0;
 
 	virtual float get_speed() const = 0;
+	virtual bool get_reverse() const = 0;
 	virtual float get_braking_distance() const = 0;
 
 	virtual void tick(const Msp::Time::TimeDelta &) = 0;
diff --git a/source/libmarklin/simplephysics.h b/source/libmarklin/simplephysics.h
index 6e33e4e..64d961b 100644
--- a/source/libmarklin/simplephysics.h
+++ b/source/libmarklin/simplephysics.h
@@ -28,6 +28,7 @@ public:
 	virtual const TrainControl &get_control(const std::string &) const;
 
 	virtual float get_speed() const { return speed; }
+	virtual bool get_reverse() const { return speed<0; }
 	virtual float get_braking_distance() const;
 
 	virtual void tick(const Msp::Time::TimeDelta &);
diff --git a/source/libmarklin/train.cpp b/source/libmarklin/train.cpp
index 44f9298..1abf535 100644
--- a/source/libmarklin/train.cpp
+++ b/source/libmarklin/train.cpp
@@ -322,10 +322,10 @@ void Train::tick(const Time::TimeStamp &t, const Time::TimeDelta &dt)
 	float speed = control->get_speed();
 	unsigned speed_notch = find_speed(abs(speed));
 
-	if(speed && (speed<0)!=reverse)
+	if(control->get_reverse()!=reverse)
 	{
-		driver.set_loco_reverse(address, speed<0);
-		reverse = speed<0;
+		reverse = control->get_reverse();
+		driver.set_loco_reverse(address, reverse);
 
 		release_blocks(rsv_blocks);
 		reverse_blocks(cur_blocks);
-- 
2.45.2