From 55ff72655fe7bc0eeaa839edd8813f1280d6e333 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Thu, 1 Apr 2021 12:40:02 +0100
Subject: [PATCH] updates: Provide facehint in PreparedUpdateEntry

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/pcrender.rs | 8 ++++++++
 src/updates.rs  | 1 +
 2 files changed, 9 insertions(+)

diff --git a/src/pcrender.rs b/src/pcrender.rs
index f5c889a0..2e1fa00d 100644
--- a/src/pcrender.rs
+++ b/src/pcrender.rs
@@ -129,6 +129,7 @@ impl PieceRenderInstructions {
       pinned     : gpc.pinned,
       uos        : pri.ui_operations(gs, gpc, ipc)?,
       moveable   : gpc.moveable(),
+      facehint   : pri.facehint(gpc),
       occregion,
     };
     dbgc!(pri, ipc, gpc, r);
@@ -155,6 +156,13 @@ impl PieceRenderInstructions {
     }
   }
 
+  pub fn facehint(&self, gpc: &GPiece) -> Option<FaceId> {
+    match self.occulted {
+      PriOcculted::Visible(_)                            => Some(gpc.face),
+      PriOcculted::Occulted | PriOcculted::Displaced(..) => None,
+    }
+  }
+
   pub fn pos_zlevel<'r>(&'r self, gpc: &'r GPiece) -> (Pos, &'r ZLevel) {
     use PriOcculted as PO;
     match &self.occulted {
diff --git a/src/updates.rs b/src/updates.rs
index 61e9509a..830f3bb2 100644
--- a/src/updates.rs
+++ b/src/updates.rs
@@ -100,6 +100,7 @@ pub struct PreparedPieceUpdateGeneral<U> {
 pub struct PreparedPieceState {
   pub pos: Pos,
   pub svg: Html,
+  pub facehint: Option<FaceId>,
   pub held: Option<PlayerId>,
   pub z: ZCoord,
   pub zg: Generation,
-- 
2.30.2