a

1 files changed, 7 insertions, 0 deletions

diff --git a/src/tile.hpp b/src/tile.hpp
index 169c941b..f559ce79 100644
--- a/src/tile.hpp
+++ b/src/tile.hpp
@@ -36,12 +36,19 @@ struct tile final
 
 struct local_coords final {
     std::uint8_t x = 0, y = 0;
+    explicit constexpr local_coords(std::size_t idx);
     constexpr local_coords() = default;
     constexpr local_coords(std::size_t x, std::size_t y);
     constexpr local_coords(std::uint8_t x, std::uint8_t y) : x{x}, y{y} {}
     constexpr std::size_t to_index() const { return y*TILE_MAX_DIM + x; }
 };
 
+constexpr local_coords::local_coords(std::size_t index) :
+      x{(std::uint8_t)(index % TILE_MAX_DIM)},
+      y{(std::uint8_t)(index / TILE_MAX_DIM)}
+{
+}
+
 constexpr local_coords::local_coords(std::size_t x, std::size_t y)
     : x{(std::uint8_t)x}, y{(std::uint8_t)y}
 {