From 47ed629d26f9aa64ca2c8c780762bf04be2ef7a1 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 7 Apr 2021 19:19:57 +0100
Subject: [PATCH] Prevent occultation by rotated pieces

* Add a OcculterRotationChecked proof token to create_occultation
* Make a function to get the proof token from the GPiece
* In ui_operation (do the thing) functions, check it and plumb it through
* In the load functions, set rotateable to false

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/deck.rs   |  8 +++++---
 src/error.rs  |  1 +
 src/hand.rs   |  7 +++++--
 src/hidden.rs | 11 +++++++++++
 4 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/deck.rs b/src/deck.rs
index 26020797..505bd522 100644
--- a/src/deck.rs
+++ b/src/deck.rs
@@ -59,6 +59,7 @@ impl PieceSpec for piece_specs::Deck {
       throw!(SpE::WrongNumberOfFaces);
     }
     gpc.moveable = PieceMoveable::IfWresting;
+    gpc.rotateable = false;
     let p = Box::new(Deck {
       shape,
       label: self.label.load()?,
@@ -161,7 +162,7 @@ impl PieceTrait for Deck {
   }
 
   #[throws(ApiPieceOpError)]
-  fn ui_operation(&self, _: ShowUnocculted,
+  fn ui_operation(&self, vis: ShowUnocculted,
                   a: ApiPieceOpArgs<'_>,
                   opname: &str, wrc: WhatResponseToClientOp)
                   -> UpdateFromOpComplex {
@@ -177,7 +178,8 @@ impl PieceTrait for Deck {
     let nick = gpl.nick.to_html();
 
     dbgc!("ui op k entry", &opname);
-    
+
+    let rot_checked = gpc.occulter_check_unrotated(vis)?;
     let old_state = self.state(gpc, &goccults)?;
   
     let (new_state, did) = match opname {
@@ -222,7 +224,7 @@ impl PieceTrait for Deck {
       xupdates.extend(
         create_occultation(&mut gen.unique_gen(), &mut gs.max_z,
                            gplayers, gpieces, goccults, ipieces, ioccults,
-                           to_recalculate,
+                           to_recalculate, rot_checked,
                            region, piece, views)?
       );
       dbgc!("creating occ done", &xupdates);
diff --git a/src/error.rs b/src/error.rs
index 784465b8..c515b370 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -181,6 +181,7 @@ pub enum PieceOpError {
   PieceGone,
   Occultation,
   PieceUnrotateable,
+  OcculterAlreadyRotated,
   OrganisedPlacementOverfull,
 }
 display_as_debug!{PieceOpError}
diff --git a/src/hand.rs b/src/hand.rs
index e09b1173..2b10686a 100644
--- a/src/hand.rs
+++ b/src/hand.rs
@@ -123,6 +123,7 @@ impl PieceSpec for piece_specs::Hand {
           _pcaliases: &PieceAliases, _ir: &InstanceRef)
           -> PieceSpecLoaded {
     gpc.moveable = PieceMoveable::IfWresting;
+    gpc.rotateable = false;
     self.c.load(Behaviour::Hand)?
   }
 }
@@ -217,7 +218,7 @@ impl PieceTrait for Hand {
   }
 
   #[throws(ApiPieceOpError)]
-  fn ui_operation(&self, _: ShowUnocculted, mut a: ApiPieceOpArgs<'_>,
+  fn ui_operation(&self, vis: ShowUnocculted, mut a: ApiPieceOpArgs<'_>,
                   opname: &str, wrc: WhatResponseToClientOp)
                   -> UpdateFromOpComplex {
     if let Some(r) = {
@@ -237,6 +238,7 @@ impl PieceTrait for Hand {
 
     let goccults = &mut gs.occults;
     let gpc = gpieces.byid_mut(piece)?;
+    let rot_checked = gpc.occulter_check_unrotated(vis);
     let xdata = gpc.xdata.get_mut::<HandState,_>(default)?;
     let old_desc = self.behaviour.describe_html_inner(Some(xdata));
     let old_player = xdata.player();
@@ -261,6 +263,7 @@ impl PieceTrait for Hand {
         let xupdates = match self.behaviour.views() {
           None => default(),
           Some((mk_owner, mk_defview)) => {
+            let rot_checked = rot_checked?;
             let (region, views) = (||{
               dbgc!("claiming region");
               let rect   = self.shape.outline.rect  (gpc.pos)?;
@@ -281,7 +284,7 @@ impl PieceTrait for Hand {
               create_occultation(&mut gen.unique_gen(), &mut gs.max_z,
                                  gplayers, gpieces, goccults,
                                  ipieces, ioccults,
-                                 to_recalculate,
+                                 to_recalculate, rot_checked,
                                  region, piece, views)?;
             xupdates
           }
diff --git a/src/hidden.rs b/src/hidden.rs
index 74397d3e..01a0227d 100644
--- a/src/hidden.rs
+++ b/src/hidden.rs
@@ -19,6 +19,9 @@ visible_slotmap_key!{ OccId(b'H') }
 #[derive(Copy,Clone,Debug)]
 pub struct ShowUnocculted(());
 
+#[derive(Copy,Clone,Debug)]
+pub struct OcculterRotationChecked(());
+
 #[derive(Debug,Serialize,Deserialize)]
 #[serde(transparent)]
 pub struct IPieceTraitObj(Box<dyn PieceTrait>);
@@ -414,6 +417,13 @@ impl GPiece {
     }
   }
 
+  pub fn occulter_check_unrotated(&self, _:ShowUnocculted)
+      -> Result<OcculterRotationChecked, PieceOpError> {
+    if self.angle.is_rotated() { Err(POE::OcculterAlreadyRotated) }
+    else { Ok(OcculterRotationChecked(())) }
+  }
+
+
   pub fn fully_visible_to(&self, goccults: &GameOccults, player: PlayerId)
                           -> Option<ShowUnocculted>
   {
@@ -871,6 +881,7 @@ pub fn create_occultation(
   ipieces: &IPieces,
   ioccults: &IOccults,
   to_recalculate: &mut ToRecalculate,
+  _: OcculterRotationChecked,
   region: Region,
   occulter: PieceId,
   views: OccultationViews,
-- 
2.30.2