1 files changed, 88 insertions, 0 deletions
diff --git a/src/Blocks/MetaRotater.h b/src/Blocks/MetaRotater.h
new file mode 100644
index 000000000..b83ed177a
--- /dev/null
+++ b/src/Blocks/MetaRotater.h
@@ -0,0 +1,88 @@
+
+#pragma once
+
+template<class Base, NIBBLETYPE BitFilter, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched = false>
+class cMetaRotater : public Base
+{
+public:
+
+	cMetaRotater(BLOCKTYPE a_BlockType) :
+		Base(a_BlockType)
+	{}
+	
+	virtual ~cMetaRotater() {}
+
+	virtual NIBBLETYPE MetaRotateCCW(NIBBLETYPE a_Meta)  override;
+	virtual NIBBLETYPE MetaRotateCW(NIBBLETYPE a_Meta)  override;
+	virtual NIBBLETYPE MetaMirrorXY(NIBBLETYPE a_Meta)  override;
+	virtual NIBBLETYPE MetaMirrorYZ(NIBBLETYPE a_Meta)  override;
+};
+
+
+template<class Base, NIBBLETYPE BitFilter, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched>
+NIBBLETYPE cMetaRotater<Base, BitFilter, North, East, South, West, AssertIfNotMatched>::MetaRotateCW(NIBBLETYPE a_Meta)
+{
+	NIBBLETYPE OtherMeta = a_Meta & (~BitFilter);
+	switch (a_Meta & BitFilter)
+	{
+		case South: return West  | OtherMeta; 
+		case West:  return North | OtherMeta; 
+		case North: return East  | OtherMeta;
+		case East:  return South | OtherMeta;
+	}
+	if(AssertIfNotMatched)
+	{
+		ASSERT(!"Invalid Meta value");
+		return a_Meta;
+	}
+}
+
+
+template<class Base, NIBBLETYPE BitFilter, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched>
+NIBBLETYPE cMetaRotater<Base, BitFilter, North, East, South, West, AssertIfNotMatched>::MetaRotateCCW(NIBBLETYPE a_Meta)
+{
+	NIBBLETYPE OtherMeta = a_Meta & (~BitFilter);
+	switch (a_Meta & BitFilter)
+	{
+		case South: return East  | OtherMeta; 
+		case East:  return North | OtherMeta;
+		case North: return West  | OtherMeta;
+		case West:  return South | OtherMeta;
+	}
+	if(AssertIfNotMatched)
+	{
+		ASSERT(!"Invalid Meta value");
+		return a_Meta;
+	}
+}
+
+
+
+template<class Base, NIBBLETYPE BitFilter, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched>
+NIBBLETYPE cMetaRotater<Base, BitFilter, North, East, South, West, AssertIfNotMatched>::MetaMirrorXY(NIBBLETYPE a_Meta)
+{
+	NIBBLETYPE OtherMeta = a_Meta & (~BitFilter);
+	switch (a_Meta & BitFilter)
+	{
+		case South: return North | OtherMeta;
+		case North: return South | OtherMeta;
+	}
+	// Not Facing North or South; No change.
+	return a_Meta;
+}
+
+
+
+
+template<class Base, NIBBLETYPE BitFilter, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched>
+NIBBLETYPE cMetaRotater<Base, BitFilter, North, East, South, West, AssertIfNotMatched>::MetaMirrorYZ(NIBBLETYPE a_Meta)
+{
+	NIBBLETYPE OtherMeta = a_Meta & (~BitFilter);
+	switch (a_Meta & BitFilter)
+	{
+		case West: return East | OtherMeta;
+		case East: return West | OtherMeta;
+	}
+	// Not Facing East or West; No change.
+	return a_Meta;
+}