1 files changed, 44 insertions, 0 deletions

diff --git a/src/BlockTypePalette.h b/src/BlockTypePalette.h
new file mode 100644
index 000000000..47318f171
--- /dev/null
+++ b/src/BlockTypePalette.h
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <utility>
+#include "BlockState.h"
+
+
+
+
+
+/** Holds a palette that maps block type + state into numbers.
+Used primarily by PalettedBlockArea to translate between numeric and stringular block representation.
+The object itself provides no thread safety, users of this class need to handle locking, if required. */
+class BlockTypePalette
+{
+public:
+
+	/** Create a new empty instance. */
+	BlockTypePalette();
+
+	/** Returns the index of the specified block type name and state.
+	If the combination is not found, it is added to the palette and the new index is returned. */
+	UInt32 index(const AString & aBlockTypeName, const BlockState & aBlockState);
+
+	/** Returns the <index, true> of the specified block type name and state, if it exists.
+	If the combination is not found, returns <undefined, false>. */
+	std::pair<UInt32, bool> maybeIndex(const AString & aBlockTypeName, const BlockState & aBlockState) const;
+
+	/** Returns the total number of entries in the palette. */
+	UInt32 count() const;
+
+	/** Returns the blockspec represented by the specified palette index.
+	The index must be valid (ASSERTed). */
+	const std::pair<AString, BlockState> & entry(UInt32 aIndex) const;
+
+	/** Adds missing entries from aOther to this, and returns an index-transform map from aOther to this.
+	Used when pasting two areas, to transform the src palette to dst palette. */
+	std::map<UInt32, UInt32> createTransformMap(const BlockTypePalette & aOther);
+
+
+protected:
+
+	/** The palette. Each item in the vector represents a single entry in the palette, the vector index is the palette index. */
+	std::vector<std::pair<AString, BlockState>> mPalette;
+};