From 377700d5cec4dee002b3805e49af36c1af832f5b Mon Sep 17 00:00:00 2001
From: Nikita Leonov <nikita.leonov@gmail.com>
Date: Sun, 8 Oct 2017 13:00:39 -0700
Subject: [PATCH] Fixed an incorrect computation of delay.

---
 src/Helm.hs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Helm.hs b/src/Helm.hs
index 76550e4..c8c4836 100644
--- a/src/Helm.hs
+++ b/src/Helm.hs
@@ -167,9 +167,10 @@ delayIfNeeded
   -> Double   -- ^ Current time.
   -> IO ()    -- ^ An IO monad that delays the main thread to ensure that frames are not rendered faster than limit allows.
 delayIfNeeded Unlimited _ _ = return ()
-delayIfNeeded (Limited fpsLimit) lastRender currentTime =  do
-  if delay > 0
+delayIfNeeded (Limited fpsLimit) lastRender currentTime = if delay > 0
   then threadDelay delay
   else putStrLn "Warning: FPS degradation. You may want to tune your update or FPS limits."
   where
-    delay = ceiling $ 1000*(currentTime - lastRender) - (fromIntegral fpsLimit)
+    microsecondsLimitPerFrame = ceiling $ 1000000.0 / (fromIntegral fpsLimit)
+    microsecondsForLastFrame = ceiling $ currentTime - lastRender
+    delay = microsecondsLimitPerFrame - microsecondsForLastFrame