packer can optionally pack a source rectangle of an image

useful for packing tilesets

include/blah/images/packer.h

@@ -82,6 +82,9 @@ namespace Blah
 		// add a new entry
 		void add(u64 id, const Image& bitmap);
 
+		// add a new entry
+		void add(u64 id, const Image& bitmap, const RectI& source);
+
 		// add a new entry
 		void add(u64 id, const FilePath& path);
 
@@ -120,6 +123,6 @@ namespace Blah
 		Vector<Entry> m_entries;
 
 		// adds a new entry
-		void add_entry(u64 id, int w, int h, const Color* pixels);
+		void add_entry(u64 id, int w, int h, const Color* pixels, const RectI& source);
 	};
 }