hidden: Provide PieceOccult::is_active

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/src/hidden.rs b/src/hidden.rs
index 84bef6f2cdea8f058d65e8a72da5872b7b4d9c85..2a9cbbf79c87a4612d1d8fe97e65d6d5c5f01b7c 100644 (file)
--- a/src/hidden.rs
+++ b/src/hidden.rs
@@ -63,6 +63,10 @@ pub enum OccultationKindGeneral<D> {
 }
 pub type OccultationKind = OccultationKindGeneral<(Area, ZCoord)>;
 
+impl PieceOccult {
+  pub fn is_active(&self) -> bool { self.active.is_some() }
+}
+
 impl Default for OccultationKind {
   fn default() -> Self { OccK::Visible }
 }