From 784af742440b2319fefb0b35c9d778eb595a529f Mon Sep 17 00:00:00 2001
From: Glenn Maynard <gmaynard@users.sourceforge.net>
Date: Wed, 2 Jun 2004 07:15:19 +0000
Subject: [PATCH] add GetTrails make GetTrail return value not become invalid
 after ClearCache() is called

---
 stepmania/src/Course.cpp | 36 ++++++++++++++++++++++++------------
 stepmania/src/Course.h   |  6 +++---
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/stepmania/src/Course.cpp b/stepmania/src/Course.cpp
index 7f77d1640c..1f305fcca5 100644
--- a/stepmania/src/Course.cpp
+++ b/stepmania/src/Course.cpp
@@ -266,6 +266,7 @@ void Course::Init()
 	ZERO( m_iCustomMeter );
 	m_entries.clear();
 	m_sPath = m_sName = m_sNameTranslit = m_sBannerPath = m_sCDTitlePath = "";
+	ZERO( m_TrailCacheValid );
 }
 
 void Course::Save()
@@ -554,23 +555,21 @@ CString Course::GetDisplayName() const
 
 /* This is called by many simple functions, like Course::GetTotalSeconds, and may
  * be called on all songs to sort.  It can take time to execute, so we cache the
- * results. */
+ * results.  Returned pointers remain valid for the lifetime of the Course. */
+/* XXX: if !HasCourseDifficulty(cd), return NULL instead of COURSE_DIFFICULTY_REGULAR */
 Trail* Course::GetTrail( StepsType st, CourseDifficulty cd ) const
 {
 	//
 	// Look in the Trail cache
 	//
-	const TrailParams params( st, cd );
-	TrailCache::iterator it = m_TrailCache.find( params );
-	if( it != m_TrailCache.end() )
-	{
-		return &it->second;
-	}
+	if( m_TrailCacheValid[st][cd] )
+		return &m_TrailCache[st][cd];
 
 	//
 	// Construct a new Trail, add it to the cache, then return it.
 	//
-	Trail trail;
+	Trail &trail = m_TrailCache[st][cd];
+	trail = Trail();
 	GetTrailUnsorted( st, cd, trail );
 
 	if( this->m_bSortByMeter )
@@ -599,9 +598,8 @@ Trail* Course::GetTrail( StepsType st, CourseDifficulty cd ) const
 			trail.m_vEntries[i] = entries[i].entry;
 	}
 
-	/* Cache results. */
-	m_TrailCache[params] = trail;
-	return &m_TrailCache[params];
+	m_TrailCacheValid[st][cd] = true;
+	return &m_TrailCache[st][cd];
 }
 
 void Course::GetTrailUnsorted( StepsType st, CourseDifficulty cd, Trail &trail ) const
@@ -803,6 +801,20 @@ void Course::GetTrailUnsorted( StepsType st, CourseDifficulty cd, Trail &trail )
 	}
 }
 
+void Course::GetTrails( vector<Trail*> &out, StepsType st ) const
+{
+	FOREACH_CourseDifficulty( cd )
+	{
+		if( !HasCourseDifficulty(st, cd) )
+			continue;
+
+		Trail *pTrail = GetTrail( st, cd );
+		if( pTrail == NULL )
+			continue;
+		out.push_back( pTrail );
+	}
+}
+
 bool Course::HasMods() const
 {
 	for( unsigned i=0; i<m_entries.size(); i++ )
@@ -826,7 +838,7 @@ bool Course::AllSongsAreFixed() const
 
 void Course::ClearCache()
 {
-	m_TrailCache.clear();
+	ZERO( m_TrailCacheValid );
 }
 
 RageColor Course::GetColor() const
diff --git a/stepmania/src/Course.h b/stepmania/src/Course.h
index df28f03100..f3313b2c6f 100644
--- a/stepmania/src/Course.h
+++ b/stepmania/src/Course.h
@@ -96,6 +96,7 @@ public:
 
 	// Dereferences course_entries and returns only the playable Songs and Steps
 	Trail* GetTrail( StepsType st, CourseDifficulty cd ) const;
+	void GetTrails( vector<Trail*> &out, StepsType st ) const;
 	float GetMeter( StepsType st, CourseDifficulty cd ) const;
 	bool HasMods() const;
 	bool AllSongsAreFixed() const;
@@ -134,9 +135,8 @@ public:
 private:
 	void GetTrailUnsorted( StepsType st, CourseDifficulty cd, Trail &trail ) const;
 
-	typedef pair<StepsType,CourseDifficulty> TrailParams;
-	typedef map<TrailParams, Trail> TrailCache;
-	mutable TrailCache m_TrailCache;
+	mutable Trail m_TrailCache[NUM_STEPS_TYPES][NUM_COURSE_DIFFICULTIES];
+	mutable bool m_TrailCacheValid[NUM_STEPS_TYPES][NUM_COURSE_DIFFICULTIES];
 };
 
 #endif