Smoother resizing.

2 files changed, 15 insertions, 21 deletions

diff --git a/Spear/App.hs b/Spear/App.hs
index b0c7141..96d45f1 100644
--- a/Spear/App.hs
+++ b/Spear/App.hs
@@ -55,9 +55,10 @@ loop' ::
   App s ->
   Game s ()
 loop' window ddt inputTimer elapsed timeBudget app = do
-  timer <- gameIO $ tick inputTimer
-
-  inputEvents <- gameIO $ pollInputEvents window
+  timer        <- gameIO $ tick inputTimer
+  inputEvents  <- gameIO $ pollInputEvents window
+  windowEvents <- gameIO $ pollWindowEvents window
+  close        <- gameIO $ shouldWindowClose window
 
   let timeBudgetThisFrame = timeBudget + deltaTime timer
   let steps = timeBudgetThisFrame `div` ddt
@@ -69,27 +70,21 @@ loop' window ddt inputTimer elapsed timeBudget app = do
     let dt = timeDeltaToSec ddt
     stepApp app t dt inputEvents)
 
-  let elapsed'    = elapsed + steps * ddt
-  let timeBudget' = timeBudgetThisFrame `mod` ddt
+  let elapsedNextFrame    = elapsed + steps * ddt
+  let timeBudgetNextFrame = timeBudgetThisFrame `mod` ddt
+
+  when (continue && not close) $ do
+    resized <- or <$> forM windowEvents (\event -> case event of
+      ResizeEvent {} -> resizeApp app event >> return True)
 
-  when continue $ do
-    windowEvents <- gameIO $ pollWindowEvents window
-    forM_ windowEvents $ \event -> case event of
-      ResizeEvent {} -> resizeApp app event
-    renderApp app
-    gameIO $ swapBuffers window
+    -- For smoother resizing, render only while not resizing.
+    unless resized $ do
+      renderApp app
+      gameIO $ swapBuffers window
 
     frameEnd <- gameIO now
     let frameTime = timeDiff (lastTick timer) frameEnd
     when (frameTime < ddt) $ do
       gameIO $ Timer.sleep (ddt - frameTime)
 
-    close <- gameIO $ shouldWindowClose window
-    when (continue && not close) $
-      loop'
-        window
-        ddt
-        timer
-        elapsed'
-        timeBudget'
-        app
+    loop' window ddt timer elapsedNextFrame timeBudgetNextFrame app
diff --git a/Spear/Render/Core/State.hs b/Spear/Render/Core/State.hs
index f7e5627..dac7b9a 100644
--- a/Spear/Render/Core/State.hs
+++ b/Spear/Render/Core/State.hs
@@ -123,7 +123,6 @@ type ShaderHash = Int
 type ShaderProgramHash = Int
 
 
-
 instance ResourceClass Buffer where
   getResource = bufferResource