4 files changed, 47 insertions, 7 deletions

diff --git a/src/Map.cpp b/src/Map.cpp
index 9e3c364b1..3691d0ab0 100644
--- a/src/Map.cpp
+++ b/src/Map.cpp
@@ -23,6 +23,7 @@ cMap::cMap(unsigned int a_ID, cWorld * a_World):
 	m_Scale(3),
 	m_CenterX(0),
 	m_CenterZ(0),
+	m_Dirty(false),  // This constructor is for an empty map object which will be filled by the caller with the correct values - it does not need saving.
 	m_World(a_World),
 	m_Name(fmt::format(FMT_STRING("map_{}"), m_ID))
 {
@@ -40,6 +41,7 @@ cMap::cMap(unsigned int a_ID, int a_CenterX, int a_CenterZ, cWorld * a_World, un
 	m_Scale(a_Scale),
 	m_CenterX(a_CenterX),
 	m_CenterZ(a_CenterZ),
+	m_Dirty(true),  // This constructor is for creating a brand new map in game, it will always need saving.
 	m_World(a_World),
 	m_Name(fmt::format(FMT_STRING("map_{}"), m_ID))
 {
@@ -223,7 +225,13 @@ bool cMap::SetPixel(unsigned int a_X, unsigned int a_Z, cMap::ColorID a_Data)
 {
 	if ((a_X < m_Width) && (a_Z < m_Height))
 	{
-		m_Data[a_Z * m_Width + a_X] = a_Data;
+		auto index = a_Z * m_Width + a_X;
+
+		if (m_Data[index] != a_Data)
+		{
+			m_Data[index] = a_Data;
+			m_Dirty = true;
+		}
 
 		return true;
 	}
diff --git a/src/Map.h b/src/Map.h
index 493b0883e..645f84c08 100644
--- a/src/Map.h
+++ b/src/Map.h
@@ -185,6 +185,8 @@ private:
 	int m_CenterX;
 	int m_CenterZ;
 
+	bool m_Dirty;
+
 	/** Column-major array of colours */
 	cColorList m_Data;
 
@@ -196,6 +198,7 @@ private:
 
 	AString m_Name;
 
+	friend class cMapManager;
 	friend class cMapSerializer;
 
 };  // tolua_export
diff --git a/src/MapManager.cpp b/src/MapManager.cpp
index ae020d800..f7b393648 100644
--- a/src/MapManager.cpp
+++ b/src/MapManager.cpp
@@ -12,8 +12,16 @@
 
 
 
-cMapManager::cMapManager(cWorld * a_World)
-	: m_World(a_World)
+// 6000 ticks or 5 minutes
+#define MAP_DATA_SAVE_INTERVAL 6000
+
+
+
+
+
+cMapManager::cMapManager(cWorld * a_World) :
+	m_World(a_World),
+	m_TicksUntilNextSave(MAP_DATA_SAVE_INTERVAL)
 {
 	ASSERT(m_World != nullptr);
 }
@@ -49,6 +57,16 @@ void cMapManager::TickMaps()
 	{
 		Map.Tick();
 	}
+
+	if (m_TicksUntilNextSave == 0)
+	{
+		m_TicksUntilNextSave = MAP_DATA_SAVE_INTERVAL;
+		SaveMapData();
+	}
+	else
+	{
+		m_TicksUntilNextSave--;
+	}
 }
 
 
@@ -149,11 +167,18 @@ void cMapManager::SaveMapData(void)
 	{
 		cMap & Map = *it;
 
-		cMapSerializer Serializer(m_World->GetDataPath(), &Map);
-
-		if (!Serializer.Save())
+		if (Map.m_Dirty)
 		{
-			LOGWARN("Could not save map #%i", Map.GetID());
+			cMapSerializer Serializer(m_World->GetDataPath(), &Map);
+
+			if (Serializer.Save())
+			{
+				Map.m_Dirty = false;
+			}
+			else
+			{
+				LOGWARN("Could not save map #%i", Map.GetID());
+			}
 		}
 	}
 }
diff --git a/src/MapManager.h b/src/MapManager.h
index 8959b1d8b..d20fe6683 100644
--- a/src/MapManager.h
+++ b/src/MapManager.h
@@ -64,6 +64,10 @@ private:
 
 	cWorld * m_World;
 
+	/** How long till the map data will be saved
+	Default save interval is #defined in MAP_DATA_SAVE_INTERVAL */
+	unsigned int m_TicksUntilNextSave;
+
 };  // tolua_export