From 6b975afddf5baa83d882b44bfa0a5560fce8d85b Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 18 Apr 2022 11:20:12 +0100
Subject: [PATCH] Move special rendering instructions to PieceSpecialProperties

This gets rid of an ipc method (meaning we get rid of one method call
during piece rendering) and is also more principled, than a call which
might conceivably give different answers at different times.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/dice.rs      | 11 +++++------
 src/gamestate.rs |  7 +------
 src/pcrender.rs  |  5 ++---
 3 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/src/dice.rs b/src/dice.rs
index 1701b52c..76fb300a 100644
--- a/src/dice.rs
+++ b/src/dice.rs
@@ -221,10 +221,14 @@ impl PieceSpec for Spec {
       image: image.into()
     };
 
+    let special = PieceSpecialProperties {
+      rendering: Some(SpecialClientRendering::Die{}),
+      ..default()
+    };
     SpecLoaded {
       p: Box::new(die) as _,
       occultable,
-      special: default(),
+      special,
     }
   }
 }
@@ -315,11 +319,6 @@ impl PieceBaseTrait for Die {
   fn nfaces(&self) -> RawFaceId { self.nfaces }
 
   fn itemname(&self) -> &str { &self.itemname }
-
-  #[throws(IE)]
-  fn special(&self) -> Option<SpecialClientRendering> {
-    Some(SpecialClientRendering::Die{})
-  }
 }
 
 #[typetag::serde(name="Die")]
diff --git a/src/gamestate.rs b/src/gamestate.rs
index 85b7e011..1eaf95b1 100644
--- a/src/gamestate.rs
+++ b/src/gamestate.rs
@@ -181,12 +181,6 @@ pub trait PieceBaseTrait: OutlineTrait + Send + Debug + 'static {
   fn nfaces(&self) -> RawFaceId;
 
   fn itemname(&self) -> &str;
-
-  // Don't add an xdata argument to this.  Implementors must not make
-  // this depend on the piece state, because the piece state might change
-  // between svg() (which sets up information in the DOM) and special()
-  // (which arranges to use that information).
-  fn special(&self) -> Result<Option<SpecialClientRendering>,IE> { Ok(None) }
 }
 
 #[typetag::serde] // usual variable: p
@@ -300,6 +294,7 @@ pub type PieceSpecLoadedOccultable =
 /// so they are mostly "can/do we do this thing".
 #[derive(Debug,Clone,Default,Serialize,Deserialize)]
 pub struct PieceSpecialProperties {
+  pub rendering: Option<SpecialClientRendering>,
 }
 
 #[typetag::serde(tag="type")]
diff --git a/src/pcrender.rs b/src/pcrender.rs
index f41aa71d..c29b3387 100644
--- a/src/pcrender.rs
+++ b/src/pcrender.rs
@@ -13,7 +13,7 @@ pub struct VisibleAngleTransform(Html);
 
 const DEFKEY_FLIP: UoKey = 'f';
 
-#[derive(Serialize,Debug)]
+#[derive(Deserialize,Serialize,Clone,Debug)]
 #[serde(tag="kind")]
 pub enum SpecialClientRendering {
   Die { },
@@ -194,7 +194,6 @@ impl PieceRenderInstructions {
 
     let angle = pri.angle(gpc);
     let bbox = o.bbox_approx()?;
-    let special = o.special()?;
 
     let dragraise = match o.thresh_dragraise()? {
       Some(n) if n < 0 => throw!(SvgE::NegativeDragraise),
@@ -208,7 +207,7 @@ impl PieceRenderInstructions {
     hwrite!(&mut defs,
            r##"<g id="piece{}" transform="{}" data-dragraise="{}""##,
            pri.vpid, &transform.0, dragraise)?;
-    if let Some(special) = &special {
+    if let Some(special) = &ipc.special.rendering {
       let special = serde_json::to_string(&special).map_err(IE::JSONEncode)?;
       hwrite!(&mut defs,
               r##" data-special="{}""##,
-- 
2.30.2