From efed7ba3aec1f77d35e2b3725000640936478a77 Mon Sep 17 00:00:00 2001
From: Joe Crayne <joe@jerkface.net>
Date: Sun, 19 May 2019 05:11:16 -0400
Subject: Use per-primitive index head rather than per-component in
 PointPrimitiveRing.

---
 PointPrimitiveRing.hs | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

(limited to 'PointPrimitiveRing.hs')

diff --git a/PointPrimitiveRing.hs b/PointPrimitiveRing.hs
index ee5a126..4c4b516 100644
--- a/PointPrimitiveRing.hs
+++ b/PointPrimitiveRing.hs
@@ -33,7 +33,7 @@ data Ring = Ring
     , rStorage      :: GLStorage
     , rObject       :: Object
     , rSize         :: IORef CPtrdiff -- Current count of Floats in the ring buffer.
-    , rStart        :: IORef CPtrdiff -- Float-index where next vector will be added. TODO: rename this.
+    , rBack         :: IORef Int      -- Where next vector will be added.
     , ringCapacity  :: CPtrdiff       -- Maximum number of floats in buffer.
     , rPosition     :: AttributeKey (GLVector 3 Float)
     }
@@ -53,7 +53,7 @@ newRing storage sz = do
             , rStorage      = storage
             , rObject       = obj
             , rSize         = sizeRef
-            , rStart        = startRef
+            , rBack         = startRef
             , ringCapacity  = 3 * fromIntegral sz
             , rPosition     = k
             }
@@ -62,30 +62,24 @@ newRing storage sz = do
 
 updateRingCommands :: Ring -> IO ()
 updateRingCommands r = do
-    start <- fmap (fromIntegral . (`div` 3)) $ readIORef $ rStart r
+    back <- fromIntegral <$> readIORef (rBack r)
     size  <- fmap (fromIntegral . (`div` 3)) $ readIORef $ rSize r
     let mask 0   = []
-        mask cnt = case cnt + start - size of
-            st | st > cnt  -> [(st - cnt,size)]
-               | otherwise -> [(0,start), (st,cnt - st)]
+        mask cnt = case cnt + back - size of
+            front | front > cnt -> [(front - cnt,size)]
+                  | otherwise   -> [(0,back), (front,cnt - front)]
     updateCommands (rStorage r) (rObject r) mask
     readIORef (objCommands $ rObject r) >>= mapM_ print
     return ()
 
 pushBack :: Ring -> Float -> Float -> Float -> IO ()
-pushBack r x y z = allocaArray 3 $ \ptr -> do
-    pokeElemOff ptr 0 x
-    pokeElemOff ptr 1 y
-    pokeElemOff ptr 2 z
-    start <- readIORef $ rStart r
-    writeIORef (rStart r) (mod (start + 3) (ringCapacity r))
-    -- incrementalUpdateBuffer (rBufferObject r) (4*start) (4*3) ptr
-    updateAttributes (fromIntegral (start `div` 3)) $ do
+pushBack r x y z = do
+    back <- readIORef $ rBack r
+    writeIORef (rBack r) (mod (back + 1) (fromIntegral $ ringCapacity r `div` 3))
+    updateAttributes back $ do
         rPosition r @<- V3 x y z -- (fromList [x,y,z] :: Vector Float)
-    -- glFlush
-    -- glFinish
     sz <- readIORef (rSize r)
-    putStrLn $ "pushBack "++show (sz,start,(x,y,z))
+    putStrLn $ "pushBack "++show (sz,back,(x,y,z))
     when (sz < ringCapacity r) $ do
         writeIORef (rSize r) (sz + 3)
     updateRingCommands r
-- 
cgit v1.2.3