From c19e3dae5f6087c7e446c6be620c370d9957cf7c Mon Sep 17 00:00:00 2001
From: Griffin Smith <grfn@gws.fyi>
Date: Sat, 12 Jun 2021 14:41:24 -0400
Subject: feat(xanthous): Memoize characterVisiblePositions

Memoize the return value of characterVisiblePositions to a new,
semi-abstracted "memo" field on the GameState, recalcuclated if the
character position ever changes. I'm 90% sure that the perf issues we
were encountering were actually caused by characterVisiblePositions
getting called once for *every tile* on draw, but this slightly larger
change also makes the game perform relatively-usably again.

Since this is only recalculated if the character position changes, if we
ever get non-transparent entities moving around without the characters
influence (maybe something building or knocking down walls?) we'll have
an issue there where the vision won't be updated as a result of those
changes if they happen while the character is taking a non-moving action
- but we can cross that bridge when we come to it.

Change-Id: I3fc745ddf0014d6f164f735ad7e5080da779b92a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3185
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
---
 users/grfn/xanthous/test/Spec.hs                   |  2 ++
 users/grfn/xanthous/test/Xanthous/Data/MemoSpec.hs | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 users/grfn/xanthous/test/Xanthous/Data/MemoSpec.hs

(limited to 'users/grfn/xanthous/test')

diff --git a/users/grfn/xanthous/test/Spec.hs b/users/grfn/xanthous/test/Spec.hs
index f15c393ac917..36bac640b18e 100644
--- a/users/grfn/xanthous/test/Spec.hs
+++ b/users/grfn/xanthous/test/Spec.hs
@@ -6,6 +6,7 @@ import qualified Xanthous.Data.EntityCharSpec
 import qualified Xanthous.Data.EntityMap.GraphicsSpec
 import qualified Xanthous.Data.EntityMapSpec
 import qualified Xanthous.Data.LevelsSpec
+import qualified Xanthous.Data.MemoSpec
 import qualified Xanthous.Data.NestedMapSpec
 import qualified Xanthous.DataSpec
 import qualified Xanthous.Entities.RawsSpec
@@ -30,6 +31,7 @@ test = testGroup "Xanthous"
   , Xanthous.Data.EntityMap.GraphicsSpec.test
   , Xanthous.Data.EntityMapSpec.test
   , Xanthous.Data.LevelsSpec.test
+  , Xanthous.Data.MemoSpec.test
   , Xanthous.Data.NestedMapSpec.test
   , Xanthous.DataSpec.test
   , Xanthous.Entities.RawsSpec.test
diff --git a/users/grfn/xanthous/test/Xanthous/Data/MemoSpec.hs b/users/grfn/xanthous/test/Xanthous/Data/MemoSpec.hs
new file mode 100644
index 000000000000..ad81f1984d8f
--- /dev/null
+++ b/users/grfn/xanthous/test/Xanthous/Data/MemoSpec.hs
@@ -0,0 +1,19 @@
+--------------------------------------------------------------------------------
+module Xanthous.Data.MemoSpec (main, test) where
+--------------------------------------------------------------------------------
+import Test.Prelude
+import Test.QuickCheck.Instances.Text ()
+--------------------------------------------------------------------------------
+import Xanthous.Data.Memo
+--------------------------------------------------------------------------------
+
+main :: IO ()
+main = defaultMain test
+
+test :: TestTree
+test = testGroup "Xanthous.Data.MemoSpec"
+  [ testGroup "getMemoized"
+    [ testProperty "when key matches" $ \k v ->
+        getMemoized @Int @Int k (memoizeWith k v) === Just v
+    ]
+  ]
-- 
cgit 1.4.1