1 files changed, 7 insertions, 1 deletions
diff --git a/src/tile.hpp b/src/tile.hpp
index 067df3c7..499acd97 100644
--- a/src/tile.hpp
+++ b/src/tile.hpp
@@ -12,9 +12,15 @@ struct tile_atlas;
 struct tile_image final
 {
     std::shared_ptr<tile_atlas> atlas;
-    std::uint8_t variant = 0xff;
+    std::size_t variant = (std::size_t)-1;
 
     explicit operator bool() const noexcept { return !!atlas; }
+
+    std::strong_ordering operator<=>(const tile_image& o) const noexcept
+    {
+        const auto ret = atlas.get() <=> o.atlas.get();
+        return ret != std::strong_ordering::equal ? ret : variant <=> o.variant;
+    }
 };
 
 struct tile final