Type-safe incremental attribute update.

1 files changed, 7 insertions, 2 deletions

diff --git a/PointPrimitiveRing.hs b/PointPrimitiveRing.hs
index 3f2258b..ee5a126 100644
--- a/PointPrimitiveRing.hs
+++ b/PointPrimitiveRing.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE LambdaCase, RecordWildCards #-}
+{-# LANGUAGE LambdaCase, RecordWildCards, DataKinds #-}
 module PointPrimitiveRing where
 
 import Control.Monad
@@ -35,6 +35,7 @@ data Ring = Ring
     , 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.
     , ringCapacity  :: CPtrdiff       -- Maximum number of floats in buffer.
+    , rPosition     :: AttributeKey (GLVector 3 Float)
     }
 
 newRing :: GLStorage -> Int -> IO Ring
@@ -42,6 +43,7 @@ newRing storage sz = do
     startRef <- newIORef 0
     sizeRef <- newIORef 0
     gd <- uploadDynamicBuffer sz [Parameter "position" V3F]
+    let Just k = attributeKey gd "position"
     obj <- addToObjectArray storage "Points" [] gd
     readIORef (objCommands obj) >>= mapM_ print
         -- [[GLSetUniform 0 GLUniform M44F,GLSetVertexAttribArray 0 5 3 5126 0x0000000000000000,GLDrawArrays 0 0 1],[],[],[]]
@@ -53,6 +55,7 @@ newRing storage sz = do
             , rSize         = sizeRef
             , rStart        = startRef
             , ringCapacity  = 3 * fromIntegral sz
+            , rPosition     = k
             }
     updateRingCommands r
     return r
@@ -76,7 +79,9 @@ pushBack r x y z = allocaArray 3 $ \ptr -> do
     pokeElemOff ptr 2 z
     start <- readIORef $ rStart r
     writeIORef (rStart r) (mod (start + 3) (ringCapacity r))
-    incrementalUpdateBuffer (rBufferObject r) (4*start) (4*3) ptr
+    -- incrementalUpdateBuffer (rBufferObject r) (4*start) (4*3) ptr
+    updateAttributes (fromIntegral (start `div` 3)) $ do
+        rPosition r @<- V3 x y z -- (fromList [x,y,z] :: Vector Float)
     -- glFlush
     -- glFinish
     sz <- readIORef (rSize r)