From b25bbfa6dddc939169581da8f0821b58812c3f8c Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 22 May 2022 23:43:49 +0100
Subject: [PATCH] Support stack_pos on PickupDeck

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 docs/gamespec.rst | 3 +++
 src/deck.rs       | 8 +++++++-
 src/spec.rs       | 1 +
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/docs/gamespec.rst b/docs/gamespec.rst
index d1f13bdc..a47e3672 100644
--- a/docs/gamespec.rst
+++ b/docs/gamespec.rst
@@ -237,6 +237,9 @@ Honours ``edges``, ``edge_width``.
 
 Honours ``label``, displaying the number of of pieces in (on) this deck.
 
+ * ``stack_pos``: When stacking neatly, stack here relative to the
+   deck centre.  [two numbers, ``[0,0]``]
+
 Example::
   
   [[pieces]]
diff --git a/src/deck.rs b/src/deck.rs
index ab460342..08137254 100644
--- a/src/deck.rs
+++ b/src/deck.rs
@@ -14,6 +14,7 @@ pub const ENABLED_DESC : HtmlLit = Html::lit("a pickup deck (enabled)");
 struct Deck {
   shape: GenericSimpleShape<(), RectOutline>,
   label: Option<PieceLabelLoaded>,
+  stack_pos: Pos,
 }
 
 #[derive(Debug,Clone,Copy,Ord,PartialOrd,Eq,PartialEq)]
@@ -60,6 +61,7 @@ impl PieceSpec for piece_specs::Deck {
     gpc.rotateable = false;
     let p = Box::new(Deck {
       shape,
+      stack_pos: PosC { coords: self.stack_pos },
       label: self.label.load()?,
     }) as Box<dyn PieceTrait>;
     SpecLoaded {
@@ -196,7 +198,11 @@ impl PieceTrait for Deck {
       Disabled => None,
       Counting => Some(OccKG::Visible),
       Enabled  => {
-        let displace = OccDisplacement::Stack { pos: gpc.pos };
+        let pos = (|| {
+          (gpc.pos + self.stack_pos).ok()?
+            .clamped(gs.table_size).ok()
+        })().ok_or_else(|| Ia::PosOffTable)?;
+        let displace = OccDisplacement::Stack { pos };
         let displace = (displace, gpc.zlevel.z.clone());
                   Some(OccKG::Displaced(displace))
       },
diff --git a/src/spec.rs b/src/spec.rs
index 7ba438cc..9fea2654 100644
--- a/src/spec.rs
+++ b/src/spec.rs
@@ -335,6 +335,7 @@ pub mod piece_specs {
     pub edge_width: Option<f64>,
     pub shape: Outline,
     pub label: Option<PieceLabel>,
+    #[serde(default)] pub stack_pos: [Coord; 2],
   }
 }
 
-- 
2.30.2