From f83dfe3a388a9f137432eb1173384559cd7a8204 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sat, 6 Feb 2010 21:42:22 +0000
Subject: [PATCH] Only allowing setting of points when choice possible

---
 include/ITrackSegment.hpp | 10 +++++++---
 src/CrossoverTrack.cpp    |  3 ++-
 src/CurvedTrack.cpp       |  3 ++-
 src/IterateTrack.cpp      |  8 +++++++-
 src/Points.cpp            | 18 +++++++++---------
 src/StraightTrack.cpp     |  3 ++-
 6 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/include/ITrackSegment.hpp b/include/ITrackSegment.hpp
index 96e92e6..58fb864 100644
--- a/include/ITrackSegment.hpp
+++ b/include/ITrackSegment.hpp
@@ -55,11 +55,15 @@ namespace track {
 	// Position of entry
 	Position position;
 
-	// A function that transforms the location of the train
-	// so it will render in the correct place for this track segment
-	// The functions assumes that it is initially placed at the origin
+	// A function that transforms the location of the train so it will
+	// render in the correct place for this track segment The functions
+	// assumes that it is initially placed at the origin
 	TransformFunc transformer;
 
+	// Number of possible exits from this track segment given the direction
+	// we are travelling in
+	int numExits;
+
 	// Wrapper for the above
 	void transform(double aDelta) const
 	{
diff --git a/src/CrossoverTrack.cpp b/src/CrossoverTrack.cpp
index 1910872..c91c325 100644
--- a/src/CrossoverTrack.cpp
+++ b/src/CrossoverTrack.cpp
@@ -111,7 +111,8 @@ CrossoverTrack::getTravelToken(track::Position aPosition,
     track::TravelToken tok = {
 	aDirection,
 	aPosition,
-	bind(&CrossoverTrack::transform, this, _1, _2)
+	bind(&CrossoverTrack::transform, this, _1, _2),
+	1
     };
     return tok;
 }
diff --git a/src/CurvedTrack.cpp b/src/CurvedTrack.cpp
index 03e0328..0cf8030 100644
--- a/src/CurvedTrack.cpp
+++ b/src/CurvedTrack.cpp
@@ -93,7 +93,8 @@ CurvedTrack::getTravelToken(track::Position aPosition,
     track::TravelToken tok = {
 	aDirection,
 	aPosition,
-	bind(&CurvedTrack::transform, this, _1, _2)
+	bind(&CurvedTrack::transform, this, _1, _2),
+	1
     };
     return tok;
 }
diff --git a/src/IterateTrack.cpp b/src/IterateTrack.cpp
index b6d01e7..4dd9d73 100644
--- a/src/IterateTrack.cpp
+++ b/src/IterateTrack.cpp
@@ -17,6 +17,8 @@
 
 #include "IterateTrack.hpp"
 
+#include <cassert>
+
 // Find the next piece of track
 TrackIterator TrackIterator::next() const
 {
@@ -62,8 +64,12 @@ TrackIterator iterateTrack(IMapPtr aMap, track::Position aPosition,
          break;
       }
 
-   if (it.track->hasMultipleStates())
+   if (it.token.numExits > 1) {
+       assert(it.track->hasMultipleStates());
        it.status = TRACK_CHOICE;
+   }
+   else
+       assert(it.token.numExits == 1);
    
    return it;   
 }
diff --git a/src/Points.cpp b/src/Points.cpp
index a17dbbe..0d65310 100644
--- a/src/Points.cpp
+++ b/src/Points.cpp
@@ -179,22 +179,22 @@ double Points::segmentLength(const track::TravelToken& aToken) const
 	return 3.0;
 }
 
-track::TravelToken Points::getTravelToken(track::Position aPosition,
-    track::Direction aDirection) const
+track::TravelToken Points::getTravelToken(track::Position position,
+    track::Direction direction) const
 {
     using namespace placeholders;
    
-    ensureValidDirection(aDirection);
+    ensureValidDirection(direction);
 
+    const int nExits = position.x == myX && position.y == myY ? 2 : 1;
+    
     track::TravelToken tok = {
-	aDirection,
-	aPosition,
-	bind(&Points::transform, this, _1, _2)
+	direction,
+	position,
+	bind(&Points::transform, this, _1, _2),
+	nExits
     };
     
-    //if (aPosition.x == myX && aPosition.y == myY)
-    //	tok.choices.insert(track::CHOOSE_GO_RIGHT);
-   
     return tok;
 }
 
diff --git a/src/StraightTrack.cpp b/src/StraightTrack.cpp
index fd1675a..ac17dbd 100644
--- a/src/StraightTrack.cpp
+++ b/src/StraightTrack.cpp
@@ -86,7 +86,8 @@ StraightTrack::getTravelToken(track::Position aPosition,
     track::TravelToken tok = {
 	aDirection,
 	aPosition,
-	bind(&StraightTrack::transform, this, _1, _2)
+	bind(&StraightTrack::transform, this, _1, _2),
+	1
     };
     return tok;
 }
-- 
2.39.2