1 files changed, 31 insertions, 0 deletions
diff --git a/src/TextViewport/Render/RenderBuffer.hs b/src/TextViewport/Render/RenderBuffer.hs
new file mode 100644
index 0000000..a1122a4
--- /dev/null
+++ b/src/TextViewport/Render/RenderBuffer.hs
@@ -0,0 +1,31 @@
+module TextViewport.Render.RenderBuffer where
+
+import Data.Sequence qualified as Seq
+import TextViewport.Buffer.Buffer (Buffer(..))
+import TextViewport.Render.CachedRender
+import TextViewport.Render.RenderCache
+import TextViewport.Render.RenderItem (renderItem)
+import TextViewport.Render.RenderedBuffer
+
+renderBuffer :: Int -> Buffer -> RenderCache -> (RenderCache, RenderedBuffer)
+renderBuffer width (Buffer items) (RenderCache cache) =
+  let n = Seq.length items
+      go i (cAcc, rAcc)
+        | i >= n    = (RenderCache cAcc, RenderedBuffer rAcc)
+        | otherwise =
+            let item     = Seq.index items i
+                mOld     = Seq.index cache i
+                newEntry = renderItem width i item mOld
+                cAcc'    = Seq.update i (Just newEntry) cAcc
+                rAcc'    = rAcc Seq.|> crRendered newEntry
+            in go (i + 1) (cAcc', rAcc')
+  in go 0 (cache, Seq.empty)
+
+updateRenderedItem :: Int -> Int -> Buffer -> RenderCache -> RenderedBuffer -> (RenderCache, RenderedBuffer)
+updateRenderedItem width itemIx (Buffer items) (RenderCache cache) (RenderedBuffer rb) =
+    let item    = Seq.index items itemIx
+        mOld     = Seq.index cache itemIx
+        newEntry = renderItem width itemIx item mOld
+        newCache = Seq.update itemIx (Just newEntry) cache
+        newRB    = Seq.update itemIx (crRendered newEntry) rb
+    in (RenderCache newCache, RenderedBuffer newRB)