From 24687ba77bba90b05ec866e4cc5ad251203639f4 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 24 Mar 2021 20:29:51 +0000
Subject: [PATCH] Provide for occultation_notify_hook

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/gamestate.rs |  4 ++++
 src/hidden.rs    | 24 +++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/gamestate.rs b/src/gamestate.rs
index 73ffb5b3..7b086ba9 100644
--- a/src/gamestate.rs
+++ b/src/gamestate.rs
@@ -167,6 +167,10 @@ pub trait PieceTrait: OutlineTrait + Send + Debug + 'static {
   }
 
   fn itemname(&self) -> &str;
+
+  fn occultation_notify_hook(&self, _piece: PieceId) -> UnpreparedUpdates {
+    None
+  }
 }
 
 #[typetag::serde]
diff --git a/src/hidden.rs b/src/hidden.rs
index e3289706..7e4bab72 100644
--- a/src/hidden.rs
+++ b/src/hidden.rs
@@ -725,15 +725,37 @@ mod recompute {
                      gpieces: &mut GPieces,
                      goccults: &mut GameOccults,
                      ipieces: &IPieces) -> Implemented {
+      let mut unprepared = vec![];
+
       for occid in self.outdated {
         if let Some(occ) = goccults.occults.get_mut(occid) {
           vpid::permute(occid, occ, gplayers, gpieces, ipieces);
+          if let Some(ipc) = ipieces.get(occ.occulter) {
+            if let Some(uu) = {
+              ipc
+                .direct_trait_access()
+                .occultation_notify_hook(occ.occulter)
+            } {
+              unprepared.push(uu)
+            }
+          }
         }
       }
 
       consistency_check(gplayers, gpieces, goccults);
 
-      Implemented(None)
+      let unprepared = if unprepared.is_empty() {
+        None
+      } else {
+        Some(Box::new(
+          move |updates: &mut PrepareUpdatesBuffer| {
+            for p in unprepared.into_iter() { p(updates) }
+          }
+        ) as SomeUnpreparedUpdates
+        )
+      };
+
+      Implemented(unprepared)
     }
   }
 }
-- 
2.30.2