show fps

src/Init.hs

@@ -55,6 +55,8 @@ load = do
   mwalltsw <- createImage nvg (FileName "assets/walls/wall_t_sw.png") 0
   mwalltnw <- createImage nvg (FileName "assets/walls/wall_t_nw.png") 0
   mwallcross <- createImage nvg (FileName "assets/walls/wall_cross.png") 0
+  _ <- createFont nvg "bedstead"
+    (FileName "assets/font/Bedstead-Semicondensed.ttf")
   let mwalls = [ mwallasc, mwalldesc,
         mwallcornern, mwallcornere, mwallcorners, mwallcornerw,
         mwalltne, mwalltse, mwalltsw, mwalltnw,
@@ -68,6 +70,9 @@ load = do
     , subsystems  = subs
     , assetImages = M.fromList
       walls
+    , assetFonts  = M.fromList
+      [ (FontBedstead, "bedstead")
+      ]
     , nano        = nvg
     , uuid        = []
     , worldState  = ws

src/Test.hs

@@ -10,6 +10,8 @@ import Control.Monad (when, void)
 import Control.Monad.IO.Class (liftIO)
 
 import Data.Map.Strict as Map
+import qualified Data.Set as S
+import qualified Data.Text as T
 import Data.Matrix as M (toLists, (!), Matrix, safeGet)
 import Data.Ecstasy as E
 
@@ -95,9 +97,17 @@ movePlayer _ = return ()
 drawMap :: Affection UserData ()
 drawMap = do
   ud <- getAffection
+  dt <- getDelta
   let matrix = mapMat (stateData ud)
   mapM_ (\(i, ls) -> mapM_ (uncurry $ drawTile i) (reverse $ zip [1..] ls))
     (zip [1..] (toLists matrix))
+  liftIO $ do
+    let ctx = nano ud
+    fontSize ctx 20
+    fontFace ctx (assetFonts ud Map.! FontBedstead)
+    textAlign ctx (S.fromList [AlignCenter,AlignTop])
+    fillColor ctx (rgb 255 128 0)
+    textBox ctx 0 0 200 ("FPS: " `T.append` (T.pack $ Prelude.take 5 $ show (1/dt)))
 
 updateMap :: Double -> Affection UserData ()
 updateMap dt = do

src/Types/UserData.hs

@@ -10,6 +10,7 @@ import Control.Concurrent.STM
 import NanoVG hiding (V2(..), V3(..))
 
 import qualified Data.Map.Strict as M
+import qualified Data.Text as T
 import Data.Matrix
 import Data.Ecstasy
 
@@ -19,6 +20,7 @@ data UserData = UserData
   { state       :: State
   , subsystems  :: Subsystems
   , assetImages :: M.Map ImgId Image
+  , assetFonts  :: M.Map FontId T.Text
   , nano        :: Context
   , uuid        :: [UUID]
   , worldState  :: SystemState Entity
@@ -50,6 +52,10 @@ data ImgId
   | ImgWallCross
   deriving (Show, Eq, Ord, Enum)
 
+data FontId
+  = FontBedstead
+  deriving (Show, Eq, Ord, Enum)
+
 data Direction
   = N
   | W