From e536be49146f43aae6aaaa4455eb44d8e170a773 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 22 Nov 2013 13:09:16 +0200
Subject: [PATCH] Produce more compact saves of terrains

---
 source/libr2c2/terrain.cpp | 44 ++++++++++++++++++++++++--------------
 source/libr2c2/terrain.h   |  2 ++
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/source/libr2c2/terrain.cpp b/source/libr2c2/terrain.cpp
index 7b8f9f5..e012bc9 100644
--- a/source/libr2c2/terrain.cpp
+++ b/source/libr2c2/terrain.cpp
@@ -201,26 +201,38 @@ void Terrain::Tile::update_axis()
 
 void Terrain::Tile::save(list<DataFile::Statement> &st) const
 {
-	bool flat = true;
-	for(unsigned i=1; (flat && i<4); ++i)
-		flat = (nodes[i].elevation==nodes[0].elevation && nodes[i].ground==nodes[0].ground && nodes[i].wall==nodes[0].wall);
-	if(flat)
-	{
-		st.push_back((DataFile::Statement("elevation"), nodes[0].elevation));
-		st.push_back((DataFile::Statement("ground"), nodes[0].ground));
-	}
-	else
+	float elevation_mode = find_mode(&Node::elevation);
+	unsigned ground_mode = find_mode(&Node::ground);
+	if(elevation_mode)
+		st.push_back((DataFile::Statement("elevation"), elevation_mode));
+	if(ground_mode)
+		st.push_back((DataFile::Statement("ground"), ground_mode));
+
+	for(unsigned i=0; i<4; ++i)
 	{
-		for(unsigned i=0; i<4; ++i)
-		{
-			DataFile::Statement ss("node");
-			ss.append(i);
-			nodes[i].save(ss.sub);
-			st.push_back(ss);
-		}
+		if(nodes[i].elevation==elevation_mode && nodes[i].ground==ground_mode)
+			continue;
+
+		DataFile::Statement ss("node");
+		ss.append(i);
+		if(nodes[i].elevation!=elevation_mode)
+			ss.sub.push_back((DataFile::Statement("elevation"), nodes[i].elevation));
+		if(nodes[i].ground!=ground_mode)
+			ss.sub.push_back((DataFile::Statement("ground"), nodes[i].ground));
+		st.push_back(ss);
 	}
 }
 
+template<typename T>
+T Terrain::Tile::find_mode(T Node::*member) const
+{
+	for(unsigned i=0; i<3; ++i)
+		for(unsigned j=i+1; j<4; ++j)
+			if(nodes[i].*member==nodes[j].*member)
+				return nodes[i].*member;
+	return T();
+}
+
 
 Terrain::NodeCoordinates::NodeCoordinates():
 	x(0),
diff --git a/source/libr2c2/terrain.h b/source/libr2c2/terrain.h
index 01571cc..5b5a889 100644
--- a/source/libr2c2/terrain.h
+++ b/source/libr2c2/terrain.h
@@ -72,6 +72,8 @@ public:
 		void set_node_elevation(unsigned, float);
 		void update_axis();
 		void save(std::list<Msp::DataFile::Statement> &) const;
+		template<typename T>
+		T find_mode(T Node::*) const;
 	};
 
 	struct NodeCoordinates
-- 
2.43.0