diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,12 @@
 # Changelog for geomancy
 
+## 0.2.6.0
+
+* `Geomancy.Gl.Block` extract to `gl-block` package as `Graphics.Gl.Block`.
+* Added `convert` function to vector modules to facilitate type-changing operations like rounding.
+* Added `Ix` instances for integral vectors.
+* Added `dot` for integral vectors.
+
 ## 0.2.5.0
 
 * Added Geomancy.Gl.Block to derive packed/std140/std430 layouts generically.
diff --git a/geomancy.cabal b/geomancy.cabal
--- a/geomancy.cabal
+++ b/geomancy.cabal
@@ -1,13 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.35.1.
+-- This file has been generated from package.yaml by hpack version 0.35.2.
 --
 -- see: https://github.com/sol/hpack
---
--- hash: 59ae45be42c160113744e837a79c301457335f8547aae5b17d0c74f61a052e60
 
 name:           geomancy
-version:        0.2.5.0
+version:        0.2.6.0
 synopsis:       Geometry and matrix manipulation
 description:    Sometimes it is unavoidable you have to do stuff on CPU.
                 Let's at least do it faster.
@@ -30,7 +28,6 @@
   exposed-modules:
       Geomancy
       Geomancy.Elementwise
-      Geomancy.Gl.Block
       Geomancy.Gl.Funs
       Geomancy.Interpolate
       Geomancy.IVec2
@@ -63,6 +60,7 @@
       base >=4.7 && <5
     , containers
     , deepseq
+    , gl-block
     , mono-traversable
     , ptrdiff
     , simple-affine-space
diff --git a/src/Geomancy/Gl/Block.hs b/src/Geomancy/Gl/Block.hs
deleted file mode 100644
--- a/src/Geomancy/Gl/Block.hs
+++ /dev/null
@@ -1,392 +0,0 @@
-{-# LANGUAGE DefaultSignatures #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeSynonymInstances #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE PolyKinds #-}
-{-# LANGUAGE BlockArguments #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE DeriveFoldable #-}
-{-# LANGUAGE DeriveFunctor #-}
-{-# LANGUAGE DeriveTraversable #-}
-{-# LANGUAGE DeriveGeneric #-}
-
--- |
--- Copyright :  (c) 2014-2019 Edward Kmett
--- License   :  BSD-2-Clause OR Apache-2.0
--- Maintainer:  Edward Kmett <ekmett@gmail.com>
--- Stability :  experimental
--- Portability: non-portable
---
--- OpenGL STD140 and STD430 support
---
--- Note STD430 can only be used for shader storage blocks, NOT
--- uniform blocks!
-module Geomancy.Gl.Block
-( Block(..)
-, GBlock(..)
-, Packed(..)
-, STD140(..)
-, STD430(..)
-) where
-
-import Control.Monad.IO.Class (MonadIO(..))
-import Data.Word (Word32)
-import Data.Int (Int32)
-import Data.Proxy (Proxy(..))
-import Foreign.Ptr (Ptr)
-import Foreign.Ptr.Diff (Diff(..), peekDiffOff, pokeDiffOff)
-import Foreign.Storable (Storable(..))
-import GHC.Generics (Generic, Rep, M1(..), K1(..), U1(..), C, D, S, (:*:)(..), from, to)
-import Data.Data (Data, Typeable)
-
-newtype Packed a = Packed { getPacked :: a }
-  deriving (Data,Typeable,Generic,Functor,Foldable,Traversable,Eq,Ord,Show,Read)
-
-instance Block a => Storable (Packed a) where
-  alignment _ = 1
-  sizeOf _ = sizeOfPacked (Proxy :: Proxy a)
-  peekByteOff p o = Packed <$> readPacked p (Diff o)
-  pokeByteOff p o = writePacked p (Diff o) . getPacked
-
-newtype STD140 a = STD140 { getSTD140 :: a }
-  deriving (Data,Typeable,Generic,Functor,Foldable,Traversable,Eq,Ord,Show,Read)
-
-instance Block a => Storable (STD140 a) where
-  alignment _ = alignment140 (Proxy :: Proxy a)
-  sizeOf _ = sizeOf140 (Proxy :: Proxy a)
-  peekByteOff p o = STD140 <$> read140 p (Diff o)
-  pokeByteOff p o = write140 p (Diff o) . getSTD140
-
-newtype STD430 a = STD430 { getSTD430 :: a }
-  deriving (Data,Typeable,Generic,Functor,Foldable,Traversable,Eq,Ord,Show,Read)
-
-instance Block a => Storable (STD430 a) where
-  alignment _ = alignment430 (Proxy :: Proxy a)
-  sizeOf _ = sizeOf430 (Proxy :: Proxy a)
-  peekByteOff p o = STD430 <$> read430 p (Diff o)
-  pokeByteOff p o = write430 p (Diff o) . getSTD430
-
--- | This describes how to load and store primitives
--- through a uniform/shader storage blocks according to
--- OpenGL STD140 and STD430.
---
--- There are lots of fiddly little constants around, beware.
-class Block b where
-  -- | As per 'Storable' 'alignment', but matching OpenGL STD140.
-  alignment140 :: proxy b -> Int
-  default alignment140 :: GBlock (Rep b) => proxy b -> Int
-  alignment140 _ = galignment140 (Proxy :: Proxy (Rep b))
-
-  -- | As per 'Storable' 'sizeOf', but matching OpenGL STD140.
-  sizeOf140 :: proxy b -> Int
-  default sizeOf140 :: GBlock (Rep b) => proxy b -> Int
-  sizeOf140 _ = gsizeOf140 (Proxy :: Proxy (Rep b))
-
-  -- | Structures get smashed up to a minimum of a vec4 alignment in 140 mode
-  isStruct :: proxy b -> Bool
-  isStruct _ = True
-
-  read140 :: MonadIO m => Ptr a -> Diff a b -> m b
-  default read140 :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> m b
-  read140 p (Diff o) = liftIO $ to <$> gread140 p o
-
-  write140 :: MonadIO m => Ptr a -> Diff a b -> b -> m ()
-  default write140 :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> b -> m ()
-  write140 p (Diff o) b = liftIO $ gwrite140 p o (from b)
-
-  -- | As per 'Storable' 'alignment', but matching OpenGL STD430.
-  alignment430 :: proxy b -> Int
-  default alignment430 :: GBlock (Rep b) => proxy b -> Int
-  alignment430 _ = galignment430 (Proxy :: Proxy (Rep b))
-
-  -- | As per 'Storable' 'sizeOf', but matching OpenGL STD430.
-  sizeOf430 :: proxy b -> Int
-  default sizeOf430 :: GBlock (Rep b) => proxy b -> Int
-  sizeOf430 _ = gsizeOf430 (Proxy :: Proxy (Rep b))
-
-  read430 :: MonadIO m => Ptr a -> Diff a b -> m b
-  default read430 :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> m b
-  read430 p (Diff o) = liftIO $ to <$> gread430 p o
-
-  write430 :: MonadIO m => Ptr a -> Diff a b -> b -> m ()
-  default write430 :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> b -> m ()
-  write430 p (Diff o) b = liftIO $ gwrite430 p o (from b)
-
-  -- | As per 'Storable' 'sizeOf', but without padding and no alignment
-  sizeOfPacked :: proxy b -> Int
-  default sizeOfPacked :: GBlock (Rep b) => proxy b -> Int
-  sizeOfPacked _ = gsizeOfPacked (Proxy :: Proxy (Rep b))
-
-  readPacked :: MonadIO m => Ptr a -> Diff a b -> m b
-  default readPacked :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> m b
-  readPacked p (Diff o) = liftIO $ to <$> greadPacked p o
-
-  writePacked :: MonadIO m => Ptr a -> Diff a b -> b -> m ()
-  default writePacked :: (MonadIO m, Generic b, GBlock (Rep b)) => Ptr a -> Diff a b -> b -> m ()
-  writePacked p (Diff o) b = liftIO $ gwritePacked p o (from b)
-
--- | Automatically derive STD140 and STD430 alignment using GHC Generics
-class GBlock f where
-  galignment140    :: p f -> Int
-  galignment430    :: p f -> Int
-  gsizeOf140    :: p f -> Int
-  gsizeOf430    :: p f -> Int
-  gsizeOfPacked :: p f -> Int
-  gread140    :: Ptr a -> Int -> IO (f b)
-  gread430    :: Ptr a -> Int -> IO (f b)
-  greadPacked :: Ptr a -> Int -> IO (f b)
-  gwrite140    :: Ptr a -> Int -> f b -> IO ()
-  gwrite430    :: Ptr a -> Int -> f b -> IO ()
-  gwritePacked :: Ptr a -> Int -> f b -> IO ()
-
-instance GBlock U1 where
-  galignment140 _ = 1
-  gsizeOf140    _ = 0
-  galignment430 _ = 1
-  gsizeOf430    _ = 0
-  gsizeOfPacked    _ = 0
-  gread140 _ _ = return U1
-  gread430 _ _ = return U1
-  greadPacked _ _ = return U1
-  gwrite140 _ _ U1 = return ()
-  gwrite430 _ _ U1 = return ()
-  gwritePacked _ _ U1 = return ()
-
-instance (GBlock f, GBlock g) => GBlock (f :*: g) where
-  gsizeOfPacked _ = gsizeOfPacked (Proxy :: Proxy f) + gsizeOfPacked (Proxy :: Proxy g)
-  galignment140 _ = galignment140 (Proxy :: Proxy f)
-              `max` galignment140 (Proxy :: Proxy g)
-  galignment430 _ = galignment430 (Proxy :: Proxy f)
-              `max` galignment430 (Proxy :: Proxy g)
-  gsizeOf140 _ = roundUp (gsizeOf140 (Proxy :: Proxy f)) (galignment140 (Proxy :: Proxy g)) + gsizeOf140 (Proxy :: Proxy g)
-  gsizeOf430 _ = roundUp (gsizeOf430 (Proxy :: Proxy f)) (galignment430 (Proxy :: Proxy g)) + gsizeOf430 (Proxy :: Proxy g)
-  gread140 p o = (:*:) <$> gread140 p o <*> gread140 p (o + roundUp (gsizeOf140 (Proxy :: Proxy f)) (galignment140 (Proxy :: Proxy g)))
-  gread430 p o = (:*:) <$> gread430 p o <*> gread430 p (o + roundUp (gsizeOf430 (Proxy :: Proxy f)) (galignment430 (Proxy :: Proxy g)))
-  greadPacked p o = (:*:) <$> greadPacked p o <*> greadPacked p (o + gsizeOfPacked (Proxy :: Proxy f))
-  gwrite140 p o (a :*: b) = do
-    gwrite140 p o a
-    gwrite140 p (o + roundUp (gsizeOf140 (Proxy :: Proxy f)) (galignment140 (Proxy :: Proxy g))) b
-  gwrite430 p o (a :*: b) = do
-    gwrite430 p o a
-    gwrite430 p (o + roundUp (gsizeOf430 (Proxy :: Proxy f)) (galignment430 (Proxy :: Proxy g))) b
-  gwritePacked p o (a :*: b) = do
-    gwritePacked p o a
-    gwritePacked p (o + gsizeOfPacked (Proxy :: Proxy f)) b
-
-instance GBlock f => GBlock (M1 S c f) where
-  galignment140    _ = galignment140 (Proxy :: Proxy f)
-  galignment430    _ = galignment430 (Proxy :: Proxy f)
-  gsizeOf140    _ = gsizeOf140 (Proxy :: Proxy f)
-  gsizeOf430    _ = gsizeOf430 (Proxy :: Proxy f)
-  gsizeOfPacked _ = gsizeOfPacked (Proxy :: Proxy f)
-  gread140 p o = M1 <$> gread140 p o
-  gread430 p o = M1 <$> gread430 p o
-  greadPacked p o = M1 <$> greadPacked p o
-  gwrite140 p o (M1 a) = gwrite140 p o a
-  gwrite430 p o (M1 a) = gwrite430 p o a
-  gwritePacked p o (M1 a) = gwritePacked p o a
-
-instance GBlock f => GBlock (M1 C c f) where
-  galignment140    _ = lcm 16 $ galignment140 (Proxy :: Proxy f) -- std140 rule 9
-  galignment430    _ = galignment430 (Proxy :: Proxy f) -- std140 rule 9, relaxed by std430
-  gsizeOf140    _ = roundUp (gsizeOf140 (Proxy :: Proxy f)) (galignment140 (Proxy :: Proxy f)) -- std140 rule 9
-  gsizeOf430    _ = roundUp (gsizeOf430 (Proxy :: Proxy f)) (galignment430 (Proxy :: Proxy f)) -- std140 rule 9, relaxed by std430
-  gsizeOfPacked _ = gsizeOfPacked (Proxy :: Proxy f)
-  gread140 p o = M1 <$> gread140 p o
-  gread430 p o = M1 <$> gread430 p o
-  greadPacked p o = M1 <$> greadPacked p o
-  gwrite140 p o (M1 a) = gwrite140 p o a
-  gwrite430 p o (M1 a) = gwrite430 p o a
-  gwritePacked p o (M1 a) = gwritePacked p o a
-
-instance GBlock f => GBlock (M1 D c f) where
-  galignment140 _ = galignment140 (Proxy :: Proxy f)
-  galignment430 _ = galignment430 (Proxy :: Proxy f)
-  gsizeOf140    _ = gsizeOf140 (Proxy :: Proxy f)
-  gsizeOf430    _ = gsizeOf430 (Proxy :: Proxy f)
-  gsizeOfPacked    _ = gsizeOfPacked (Proxy :: Proxy f)
-  gread140 p o = M1 <$> gread140 p o
-  gread430 p o = M1 <$> gread430 p o
-  greadPacked p o = M1 <$> greadPacked p o
-  gwrite140 p o (M1 a) = gwrite140 p o a
-  gwrite430 p o (M1 a) = gwrite430 p o a
-  gwritePacked p o (M1 a) = gwritePacked p o a
-
-instance Block c => GBlock (K1 i c) where
-  galignment140 _ = alignment140 (Proxy :: Proxy c)
-  galignment430 _ = alignment430 (Proxy :: Proxy c)
-  gsizeOf140    _ = sizeOf140 (Proxy :: Proxy c)
-  gsizeOf430    _ = sizeOf430 (Proxy :: Proxy c)
-  gsizeOfPacked    _ = sizeOfPacked (Proxy :: Proxy c)
-  gread140 p o = K1 <$> read140 p (Diff o)
-  gread430 p o = K1 <$> read430 p (Diff o)
-  greadPacked p o = K1 <$> readPacked p (Diff o)
-  gwrite140 p o (K1 a) = write140 p (Diff o) a
-  gwrite430 p o (K1 a) = write430 p (Diff o) a
-  gwritePacked p o (K1 a) = writePacked p (Diff o) a
-
-toBool :: Int32 -> Bool
-toBool 0 = False
-toBool _ = True
-
-fromBool :: Bool -> Int32
-fromBool False = 0
-fromBool True = 1
-
-instance Block Bool where
-  sizeOfPacked _ = 4
-  alignment140 _ = 4
-  sizeOf140      = sizeOfPacked
-  alignment430   = alignment140
-  sizeOf430      = sizeOf140
-  isStruct _     = False
-  read140 p (Diff d) = fmap toBool $ peekDiffOff p (Diff d)
-  write140 p (Diff d) = pokeDiffOff p (Diff d) . fromBool
-  read430     = read140
-  write430    = write140
-  readPacked  = read140
-  writePacked = write140
-  {-# INLINE sizeOfPacked #-}
-  {-# INLINE alignment140 #-}
-  {-# INLINE sizeOf140 #-}
-  {-# INLINE alignment430 #-}
-  {-# INLINE sizeOf430 #-}
-  {-# INLINE isStruct #-}
-  {-# INLINE read140 #-}
-  {-# INLINE write140 #-}
-  {-# INLINE read430 #-}
-  {-# INLINE write430 #-}
-  {-# INLINE readPacked #-}
-  {-# INLINE writePacked #-}
-
-instance Block Int32 where
-  sizeOfPacked _ = 4
-  alignment140 _ = 4
-  sizeOf140      = sizeOfPacked
-  alignment430   = alignment140
-  sizeOf430      = sizeOf140
-  isStruct _     = False
-  read140     = peekDiffOff
-  write140    = pokeDiffOff
-  read430     = read140
-  write430    = write140
-  readPacked  = read140
-  writePacked = write140
-  {-# INLINE sizeOfPacked #-}
-  {-# INLINE alignment140 #-}
-  {-# INLINE sizeOf140 #-}
-  {-# INLINE alignment430 #-}
-  {-# INLINE sizeOf430 #-}
-  {-# INLINE isStruct #-}
-  {-# INLINE read140 #-}
-  {-# INLINE write140 #-}
-  {-# INLINE read430 #-}
-  {-# INLINE write430 #-}
-  {-# INLINE readPacked #-}
-  {-# INLINE writePacked #-}
-
-instance Block Word32 where
-  sizeOfPacked _ = 4
-  alignment140 _ = 4
-  sizeOf140      = sizeOfPacked
-  alignment430   = alignment140
-  sizeOf430      = sizeOf140
-  isStruct _     = False
-  read140     = peekDiffOff
-  write140    = pokeDiffOff
-  read430     = read140
-  write430    = write140
-  readPacked  = read140
-  writePacked = write140
-  {-# INLINE sizeOfPacked #-}
-  {-# INLINE alignment140 #-}
-  {-# INLINE sizeOf140 #-}
-  {-# INLINE alignment430 #-}
-  {-# INLINE sizeOf430 #-}
-  {-# INLINE isStruct #-}
-  {-# INLINE read140 #-}
-  {-# INLINE write140 #-}
-  {-# INLINE read430 #-}
-  {-# INLINE write430 #-}
-  {-# INLINE readPacked #-}
-  {-# INLINE writePacked #-}
-
-instance Block Float where
-  sizeOfPacked _ = 4
-  alignment140 _ = 4
-  sizeOf140      = sizeOfPacked
-  alignment430   = alignment140
-  sizeOf430      = sizeOf140
-  isStruct _     = False
-  read140     = peekDiffOff
-  write140    = pokeDiffOff
-  read430     = read140
-  write430    = write140
-  readPacked  = read140
-  writePacked = write140
-  {-# INLINE sizeOfPacked #-}
-  {-# INLINE alignment140 #-}
-  {-# INLINE sizeOf140 #-}
-  {-# INLINE alignment430 #-}
-  {-# INLINE sizeOf430 #-}
-  {-# INLINE isStruct #-}
-  {-# INLINE read140 #-}
-  {-# INLINE write140 #-}
-  {-# INLINE read430 #-}
-  {-# INLINE write430 #-}
-  {-# INLINE readPacked #-}
-  {-# INLINE writePacked #-}
-
-instance Block Double where
-  sizeOfPacked _ = 8
-  alignment140 _ = 8
-  sizeOf140      = sizeOfPacked
-  alignment430   = alignment140
-  sizeOf430      = sizeOf140
-  isStruct _     = False
-  read140     = peekDiffOff
-  write140    = pokeDiffOff
-  read430     = read140
-  write430    = write140
-  readPacked  = read140
-  writePacked = write140
-  {-# INLINE sizeOfPacked #-}
-  {-# INLINE alignment140 #-}
-  {-# INLINE sizeOf140 #-}
-  {-# INLINE alignment430 #-}
-  {-# INLINE sizeOf430 #-}
-  {-# INLINE isStruct #-}
-  {-# INLINE read140 #-}
-  {-# INLINE write140 #-}
-  {-# INLINE read430 #-}
-  {-# INLINE write430 #-}
-  {-# INLINE readPacked #-}
-  {-# INLINE writePacked #-}
-
--- -- | Can be used for fixed-sized arrays
--- instance (Dim n, Block a) => Block (V n a) where
---   isStruct _ = isStruct (Proxy :: Proxy a)
---   alignment140 _
---     | isStruct (Proxy :: Proxy a) = lcm 16 n -- std140 rule 9
---     | otherwise = n
---     where n = alignment140 (Proxy :: Proxy a)
---   alignment430 _ = alignment430 (Proxy :: Proxy a)
---   sizeOf140 _ = roundUp (sizeOf140 (Proxy :: Proxy a)) (alignment140 (Proxy :: Proxy a)) * reflectDim (Proxy :: Proxy n)
---   sizeOf430 _ = roundUp (sizeOf430 (Proxy :: Proxy a)) (alignment430 (Proxy :: Proxy a)) * reflectDim (Proxy :: Proxy n)
---   read140 p (Diff o) = liftIO $ sequence $ tabulate \i -> read140 p $ Diff (o + i*d) where
---     d = roundUp (sizeOf140 (Proxy :: Proxy a)) (alignment140 (Proxy :: Proxy a))
---   write140 p (Diff o) v = liftIO $ iforM_ v \i -> write140 p (Diff (o + i*d)) where
---     d = roundUp (sizeOf140 (Proxy :: Proxy a)) (alignment140 (Proxy :: Proxy a))
---   read430 p (Diff o) = liftIO $ sequence $ tabulate \i -> read430 p $ Diff (o + i*d) where
---     d = roundUp (sizeOf430 (Proxy :: Proxy a)) (alignment430 (Proxy :: Proxy a))
---   write430 p (Diff o) v = liftIO $ iforM_ v \i -> write430 p (Diff (o + i*d)) where
---     d = roundUp (sizeOf430 (Proxy :: Proxy a)) (alignment430 (Proxy :: Proxy a))
-
--- | @roundUp k n@ rounds up k up to an integral multiple of n
-roundUp :: Int -> Int -> Int
-roundUp k n = k + mod (n - k) n
-
-instance (Block a, Block b) => Block (a, b)
-instance (Block a, Block b, Block c) => Block (a, b, c)
diff --git a/src/Geomancy/IVec2.hs b/src/Geomancy/IVec2.hs
--- a/src/Geomancy/IVec2.hs
+++ b/src/Geomancy/IVec2.hs
@@ -1,7 +1,9 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE PatternSynonyms #-}
-{-# LANGUAGE ViewPatterns #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE ViewPatterns #-}
 
 -- | Specialized and inlined @V2 Int32@.
 
@@ -10,17 +12,21 @@
   , ivec2
   , withIVec2
   , pattern WithIVec2
+  , convert
   , fromTuple
+  , dot
   ) where
 
 import Control.DeepSeq (NFData(rnf))
+import Data.Coerce (Coercible, coerce)
 import Data.Int (Int32)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data IVec2 = IVec2
   {-# UNPACK #-} !Int32
@@ -38,6 +44,12 @@
   -> r
 withIVec2 (IVec2 a b) f = f a b
 
+{-# INLINE convert #-}
+convert :: Coercible v IVec2 => (Int32 -> a) -> (a -> a -> r) -> v -> r
+convert f t v =
+  withIVec2 (coerce v) \a b ->
+    t (f a) (f b)
+
 pattern WithIVec2 :: Int32 -> Int32 -> IVec2
 pattern WithIVec2 a b <- ((`withIVec2` (,)) -> (a, b))
 {-# COMPLETE WithIVec2 #-}
@@ -46,6 +58,11 @@
 fromTuple :: (Int32, Int32) -> IVec2
 fromTuple (x, y) = ivec2 x y
 
+{-# INLINE dot #-}
+dot :: IVec2 -> IVec2 -> Int32
+dot (IVec2 l1 l2) (IVec2 r1 r2) =
+  l1 * r1 + l2 * r2
+
 instance NFData IVec2 where
   rnf IVec2{} = ()
 
@@ -152,7 +169,7 @@
     <*> peekByteOff ptr 4
 
 instance Block IVec2 where
-  sizeOfPacked _  = 8
+  type PackedSize IVec2 = 8
   alignment140 _  = 8
   sizeOf140 _     = 8
   alignment430    = alignment140
@@ -164,7 +181,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -176,3 +192,28 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix IVec2 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withIVec2 l \l1 l2 ->
+      withIVec2 u \u1 u2 ->
+        ivec2
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withIVec2 l \l1 l2 ->
+      withIVec2 u \u1 u2 ->
+        withIVec2 i \i1 i2 ->
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) *
+          unsafeIndex (l1, u1) i1
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withIVec2 l \l1 l2 ->
+      withIVec2 u \u1 u2 ->
+        withIVec2 i \i1 i2 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2
diff --git a/src/Geomancy/IVec3.hs b/src/Geomancy/IVec3.hs
--- a/src/Geomancy/IVec3.hs
+++ b/src/Geomancy/IVec3.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -11,20 +13,24 @@
   , ivec3
   , withIVec3
   , pattern WithIVec3
+  , convert
   , fromTuple
+  , dot
 
   , Packed(..)
   , packed
   ) where
 
 import Control.DeepSeq (NFData(rnf))
+import Data.Coerce (Coercible, coerce)
 import Data.Int (Int32)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data IVec3 = IVec3
   {-# UNPACK #-} !Int32
@@ -47,10 +53,21 @@
 pattern WithIVec3 a b c <- ((`withIVec3` (,,)) -> (a, b, c))
 {-# COMPLETE WithIVec3 #-}
 
+{-# INLINE convert #-}
+convert :: Coercible v IVec3 => (Int32 -> a) -> (a -> a -> a -> r) -> v -> r
+convert f t v =
+  withIVec3 (coerce v) \a b c ->
+    t (f a) (f b) (f c)
+
 {-# INLINE fromTuple #-}
 fromTuple :: (Int32, Int32, Int32) -> IVec3
 fromTuple (a, b, c) = ivec3 a b c
 
+{-# INLINE dot #-}
+dot :: IVec3 -> IVec3 -> Int32
+dot (IVec3 l1 l2 l3) (IVec3 r1 r2 r3) =
+  l1 * r1 + l2 * r2 + l3 * r3
+
 instance NFData IVec3 where
   rnf IVec3{} = ()
 
@@ -191,7 +208,7 @@
     <*> peekByteOff ptr 8
 
 instance Block IVec3 where
-  sizeOfPacked _  = 12
+  type PackedSize IVec3 = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -203,7 +220,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -217,7 +233,7 @@
   {-# INLINE writePacked #-}
 
 instance Block Packed where
-  sizeOfPacked _  = 12
+  type PackedSize Packed = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -229,7 +245,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -241,3 +256,31 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix IVec3 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withIVec3 l \l1 l2 l3 ->
+      withIVec3 u \u1 u2 u3 ->
+        ivec3
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+          <*> range (l3, u3)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withIVec3 l \l1 l2 l3 ->
+      withIVec3 u \u1 u2 u3 ->
+        withIVec3 i \i1 i2 i3 ->
+          unsafeIndex (l3, u3) i3 + unsafeRangeSize (l3, u3) * (
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) * (
+          unsafeIndex (l1, u1) i1))
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withIVec3 l \l1 l2 l3 ->
+      withIVec3 u \u1 u2 u3 ->
+        withIVec3 i \i1 i2 i3 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2 &&
+          inRange (l3, u3) i3
diff --git a/src/Geomancy/IVec4.hs b/src/Geomancy/IVec4.hs
--- a/src/Geomancy/IVec4.hs
+++ b/src/Geomancy/IVec4.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -10,17 +12,21 @@
   , ivec4
   , withIVec4
   , pattern WithIVec4
+  , convert
   , fromTuple
+  , dot
   ) where
 
 import Control.DeepSeq (NFData(rnf))
+import Data.Coerce (Coercible, coerce)
 import Data.Int (Int32)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data IVec4 = IVec4
   {-# UNPACK #-} !Int32
@@ -44,10 +50,21 @@
 pattern WithIVec4 a b c d <- ((`withIVec4` (,,,)) -> (a, b, c, d))
 {-# COMPLETE WithIVec4 #-}
 
+{-# INLINE convert #-}
+convert :: Coercible v IVec4 => (Int32 -> a) -> (a -> a -> a -> a -> r) -> v -> r
+convert f t v =
+  withIVec4 (coerce v) \a b c d ->
+    t (f a) (f b) (f c) (f d)
+
 {-# INLINE fromTuple #-}
 fromTuple :: (Int32, Int32, Int32, Int32) -> IVec4
 fromTuple (x, y, z, w) = ivec4 x y z w
 
+{-# INLINE dot #-}
+dot :: IVec4 -> IVec4 -> Int32
+dot (IVec4 l1 l2 l3 l4) (IVec4 r1 r2 r3 r4) =
+  l1 * r1 + l2 * r2 + l3 * r3 + l4 * r4
+
 instance NFData IVec4 where
   rnf IVec4{} = ()
 
@@ -170,7 +187,7 @@
     <*> peekByteOff ptr 12
 
 instance Block IVec4 where
-  sizeOfPacked _  = 16
+  type PackedSize IVec4 = 16
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -182,7 +199,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -194,3 +210,34 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix IVec4 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withIVec4 l \l1 l2 l3 l4 ->
+      withIVec4 u \u1 u2 u3 u4 ->
+        ivec4
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+          <*> range (l3, u3)
+          <*> range (l4, u4)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withIVec4 l \l1 l2 l3 l4 ->
+      withIVec4 u \u1 u2 u3 u4 ->
+        withIVec4 i \i1 i2 i3 i4 ->
+          unsafeIndex (l4, u4) i4 + unsafeRangeSize (l4, u4) * (
+          unsafeIndex (l3, u3) i3 + unsafeRangeSize (l3, u3) * (
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) * (
+          unsafeIndex (l1, u1) i1)))
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withIVec4 l \l1 l2 l3 l4 ->
+      withIVec4 u \u1 u2 u3 u4 ->
+        withIVec4 i \i1 i2 i3 i4 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2 &&
+          inRange (l3, u3) i3 &&
+          inRange (l4, u4) i4
diff --git a/src/Geomancy/Mat4.hs b/src/Geomancy/Mat4.hs
--- a/src/Geomancy/Mat4.hs
+++ b/src/Geomancy/Mat4.hs
@@ -1,8 +1,10 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UnboxedTuples #-}
 {-# LANGUAGE UnliftedFFITypes #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -46,7 +48,7 @@
 import qualified Data.Foldable as Foldable
 import qualified Data.List as List
 
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Vec4 (Vec4(..), unsafeNewVec4)
 
 data Mat4 = Mat4 ByteArray#
@@ -510,7 +512,7 @@
       (# world', Mat4 arr' #)
 
 instance Block Mat4 where
-  sizeOfPacked _  = 64
+  type PackedSize Mat4 = 64
   alignment140 _  = 16
   sizeOf140       = sizeOfPacked
   alignment430    = alignment140
@@ -522,7 +524,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
diff --git a/src/Geomancy/Point.hs b/src/Geomancy/Point.hs
--- a/src/Geomancy/Point.hs
+++ b/src/Geomancy/Point.hs
@@ -1,16 +1,17 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralisedNewtypeDeriving #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE UndecidableInstances #-}
 
 module Geomancy.Point
   ( Point(..)
@@ -35,10 +36,12 @@
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
 import Foreign.Storable (Storable)
 import GHC.Generics (Generic)
+import GHC.Ix (Ix)
+import GHC.TypeNats (KnownNat)
 import qualified Data.AffineSpace as AffineSpace
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Vec2 (Vec2)
 import Geomancy.Vec3 (Vec3, Packed)
 import Geomancy.Vec4 (Vec4)
@@ -47,9 +50,13 @@
 
 newtype Point v = Point v
   deriving (Generic)
-  deriving anyclass (Block)
   deriving stock (Eq, Ord, Show)
-  deriving newtype (NFData, Num, Fractional, MonoFunctor, MonoPointed, Elementwise, Storable)
+  deriving newtype (Ix, NFData, Num, Fractional, MonoFunctor, MonoPointed, Elementwise, Storable)
+
+deriving anyclass instance
+  ( KnownNat (PackedSize v)
+  , Block v
+  ) => Block (Point v)
 
 type instance Element (Point v) = Element v
 
diff --git a/src/Geomancy/Quaternion.hs b/src/Geomancy/Quaternion.hs
--- a/src/Geomancy/Quaternion.hs
+++ b/src/Geomancy/Quaternion.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeFamilies #-}
 
 -- | Specialized and inlined @Quaternion Float@.
 
@@ -29,7 +31,7 @@
 import Foreign (Storable(..), castPtr)
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
 
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Vec3 (Vec3, vec3, withVec3)
 
 import qualified Geomancy.Vec3 as Vec3
@@ -267,7 +269,7 @@
     fixedUp = Vec3.cross (Vec3.cross dir3 up) dir3
 
 instance Block Quaternion where
-  sizeOfPacked _  = 16
+  type PackedSize Quaternion = 16
   alignment140 _  = 16
   sizeOf140       = sizeOfPacked
   alignment430    = alignment140
@@ -279,7 +281,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
diff --git a/src/Geomancy/Transform.hs b/src/Geomancy/Transform.hs
--- a/src/Geomancy/Transform.hs
+++ b/src/Geomancy/Transform.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE GeneralisedNewtypeDeriving #-}
+{-# LANGUAGE TypeFamilies #-}
 
 module Geomancy.Transform
   ( Transform(..)
@@ -36,13 +38,13 @@
 import Geomancy.Vec4 (fromVec3, withVec4)
 
 import qualified Geomancy.Mat4 as Mat4
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 newtype Transform = Transform { unTransform :: Mat4 }
   deriving newtype (Show, Semigroup, Monoid, Storable)
 
 instance Block Transform where
-  sizeOfPacked _  = 64
+  type PackedSize Transform = 64
   alignment140 _  = 16
   sizeOf140       = sizeOfPacked
   alignment430    = alignment140
@@ -54,7 +56,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
diff --git a/src/Geomancy/UVec2.hs b/src/Geomancy/UVec2.hs
--- a/src/Geomancy/UVec2.hs
+++ b/src/Geomancy/UVec2.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -10,17 +12,21 @@
   , uvec2
   , withUVec2
   , pattern WithUVec2
+  , convert
   , fromTuple
+  , dot
   ) where
 
 import Control.DeepSeq (NFData(rnf))
-import Data.Word (Word32)
+import Data.Coerce (Coercible, coerce)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
+import Data.Word (Word32)
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data UVec2 = UVec2
   {-# UNPACK #-} !Word32
@@ -42,6 +48,12 @@
 pattern WithUVec2 a b <- ((`withUVec2` (,)) -> (a, b))
 {-# COMPLETE WithUVec2 #-}
 
+{-# INLINE convert #-}
+convert :: Coercible v UVec2 => (Word32 -> a) -> (a -> a -> r) -> v -> r
+convert f t v =
+  withUVec2 (coerce v) \a b ->
+    t (f a) (f b)
+
 {-# INLINE fromTuple #-}
 fromTuple :: (Word32, Word32) -> UVec2
 fromTuple (x, y) = uvec2 x y
@@ -133,6 +145,11 @@
     where
       x' = fromInteger x
 
+{-# INLINE dot #-}
+dot :: UVec2 -> UVec2 -> Word32
+dot (UVec2 l1 l2) (UVec2 r1 r2) =
+  l1 * r1 + l2 * r2
+
 instance Storable UVec2 where
   {-# INLINE sizeOf #-}
   sizeOf _ = 8
@@ -152,7 +169,7 @@
     <*> peekByteOff ptr 4
 
 instance Block UVec2 where
-  sizeOfPacked _  = 8
+  type PackedSize UVec2 = 8
   alignment140 _  = 8
   sizeOf140 _     = 8
   alignment430    = alignment140
@@ -164,7 +181,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -176,3 +192,28 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix UVec2 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withUVec2 l \l1 l2 ->
+      withUVec2 u \u1 u2 ->
+        uvec2
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withUVec2 l \l1 l2 ->
+      withUVec2 u \u1 u2 ->
+        withUVec2 i \i1 i2 ->
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) *
+          unsafeIndex (l1, u1) i1
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withUVec2 l \l1 l2 ->
+      withUVec2 u \u1 u2 ->
+        withUVec2 i \i1 i2 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2
diff --git a/src/Geomancy/UVec3.hs b/src/Geomancy/UVec3.hs
--- a/src/Geomancy/UVec3.hs
+++ b/src/Geomancy/UVec3.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -11,20 +13,24 @@
   , uvec3
   , withUVec3
   , pattern WithUVec3
+  , convert
   , fromTuple
+  , dot
 
   , Packed(..)
   , packed
   ) where
 
 import Control.DeepSeq (NFData(rnf))
-import Data.Word (Word32)
+import Data.Coerce (Coercible, coerce)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
+import Data.Word (Word32)
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data UVec3 = UVec3
   {-# UNPACK #-} !Word32
@@ -47,10 +53,21 @@
 pattern WithUVec3 a b c <- ((`withUVec3` (,,)) -> (a, b, c))
 {-# COMPLETE WithUVec3 #-}
 
+{-# INLINE convert #-}
+convert :: Coercible v UVec3 => (Word32 -> a) -> (a -> a -> a -> r) -> v -> r
+convert f t v =
+  withUVec3 (coerce v) \a b c ->
+    t (f a) (f b) (f c)
+
 {-# INLINE fromTuple #-}
 fromTuple :: (Word32, Word32, Word32) -> UVec3
 fromTuple (a, b, c) = uvec3 a b c
 
+{-# INLINE dot #-}
+dot :: UVec3 -> UVec3 -> Word32
+dot (UVec3 l1 l2 l3) (UVec3 r1 r2 r3) =
+  l1 * r1 + l2 * r2 + l3 * r3
+
 instance NFData UVec3 where
   rnf UVec3{} = ()
 
@@ -192,7 +209,7 @@
     <*> peekByteOff ptr 8
 
 instance Block UVec3 where
-  sizeOfPacked _  = 12
+  type PackedSize UVec3 = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -204,7 +221,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -218,7 +234,7 @@
   {-# INLINE writePacked #-}
 
 instance Block Packed where
-  sizeOfPacked _  = 12
+  type PackedSize Packed = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -230,7 +246,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -242,3 +257,31 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix UVec3 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withUVec3 l \l1 l2 l3 ->
+      withUVec3 u \u1 u2 u3 ->
+        uvec3
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+          <*> range (l3, u3)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withUVec3 l \l1 l2 l3 ->
+      withUVec3 u \u1 u2 u3 ->
+        withUVec3 i \i1 i2 i3 ->
+          unsafeIndex (l3, u3) i3 + unsafeRangeSize (l3, u3) * (
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) * (
+          unsafeIndex (l1, u1) i1))
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withUVec3 l \l1 l2 l3 ->
+      withUVec3 u \u1 u2 u3 ->
+        withUVec3 i \i1 i2 i3 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2 &&
+          inRange (l3, u3) i3
diff --git a/src/Geomancy/UVec4.hs b/src/Geomancy/UVec4.hs
--- a/src/Geomancy/UVec4.hs
+++ b/src/Geomancy/UVec4.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -10,17 +12,21 @@
   , uvec4
   , withUVec4
   , pattern WithUVec4
+  , convert
   , fromTuple
+  , dot
   ) where
 
 import Control.DeepSeq (NFData(rnf))
-import Data.Word (Word32)
+import Data.Coerce (Coercible, coerce)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
+import Data.Word (Word32)
 import Foreign (Storable(..))
 import Foreign.Ptr.Diff (peekDiffOff, pokeDiffOff)
+import GHC.Ix (Ix(..))
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 
 data UVec4 = UVec4
   {-# UNPACK #-} !Word32
@@ -44,6 +50,12 @@
 pattern WithUVec4 a b c d <- ((`withUVec4` (,,,)) -> (a, b, c, d))
 {-# COMPLETE WithUVec4 #-}
 
+{-# INLINE convert #-}
+convert :: Coercible v UVec4 => (Word32 -> a) -> (a -> a -> a -> a -> r) -> v -> r
+convert f t v =
+  withUVec4 (coerce v) \a b c d ->
+    t (f a) (f b) (f c) (f d)
+
 {-# INLINE fromTuple #-}
 fromTuple :: (Word32, Word32, Word32, Word32) -> UVec4
 fromTuple (x, y, z, w) = uvec4 x y z w
@@ -171,7 +183,7 @@
     <*> peekByteOff ptr 12
 
 instance Block UVec4 where
-  sizeOfPacked _  = 16
+  type PackedSize UVec4 = 16
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -183,7 +195,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -195,3 +206,39 @@
   {-# INLINE write430 #-}
   {-# INLINE readPacked #-}
   {-# INLINE writePacked #-}
+
+instance Ix UVec4 where
+  {-# INLINE range #-}
+  range (l, u) =
+    withUVec4 l \l1 l2 l3 l4 ->
+      withUVec4 u \u1 u2 u3 u4 ->
+        uvec4
+          <$> range (l1, u1)
+          <*> range (l2, u2)
+          <*> range (l3, u3)
+          <*> range (l4, u4)
+
+  {-# INLINE unsafeIndex #-}
+  unsafeIndex (l, u) i =
+    withUVec4 l \l1 l2 l3 l4 ->
+      withUVec4 u \u1 u2 u3 u4 ->
+        withUVec4 i \i1 i2 i3 i4 ->
+          unsafeIndex (l4, u4) i4 + unsafeRangeSize (l4, u4) * (
+          unsafeIndex (l3, u3) i3 + unsafeRangeSize (l3, u3) * (
+          unsafeIndex (l2, u2) i2 + unsafeRangeSize (l2, u2) * (
+          unsafeIndex (l1, u1) i1)))
+
+  {-# INLINE inRange #-}
+  inRange (l, u) i =
+    withUVec4 l \l1 l2 l3 l4 ->
+      withUVec4 u \u1 u2 u3 u4 ->
+        withUVec4 i \i1 i2 i3 i4 ->
+          inRange (l1, u1) i1 &&
+          inRange (l2, u2) i2 &&
+          inRange (l3, u3) i3 &&
+          inRange (l4, u4) i4
+
+{-# INLINE dot #-}
+dot :: UVec4 -> UVec4 -> Word32
+dot (UVec4 l1 l2 l3 l4) (UVec4 r1 r2 r3 r4) =
+  l1 * r1 + l2 * r2 + l3 * r3 + l4 * r4
diff --git a/src/Geomancy/Vec2.hs b/src/Geomancy/Vec2.hs
--- a/src/Geomancy/Vec2.hs
+++ b/src/Geomancy/Vec2.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -12,6 +14,7 @@
   , withVec2
   , pattern WithVec2
   , fromTuple
+  , convert
 
   , (^*)
   , (^/)
@@ -22,6 +25,7 @@
   ) where
 
 import Control.DeepSeq (NFData(rnf))
+import Data.Coerce (Coercible, coerce)
 import Data.MonoTraversable (Element, MonoFunctor(..), MonoPointed(..))
 import Data.VectorSpace (VectorSpace)
 import Foreign (Storable(..))
@@ -29,7 +33,7 @@
 import qualified Data.VectorSpace as VectorSpace
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Gl.Funs (GlModf(..), GlNearest)
 
 data Vec2 = Vec2
@@ -48,6 +52,12 @@
   -> r
 withVec2 (Vec2 a b) f = f a b
 
+{-# INLINE convert #-}
+convert :: Coercible v Vec2 => (Float -> a) -> (a -> a -> r) -> v -> r
+convert f t v =
+  withVec2 (coerce v) \a b ->
+    t (f a) (f b)
+
 pattern WithVec2 :: Float -> Float -> Vec2
 pattern WithVec2 a b <- ((`withVec2` (,)) -> (a, b))
 {-# COMPLETE WithVec2 #-}
@@ -233,7 +243,7 @@
     <*> peekByteOff ptr 4
 
 instance Block Vec2 where
-  sizeOfPacked _  = 8
+  type PackedSize Vec2 = 8
   alignment140 _  = 8
   sizeOf140 _     = 8
   alignment430    = alignment140
@@ -245,7 +255,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
diff --git a/src/Geomancy/Vec3.hs b/src/Geomancy/Vec3.hs
--- a/src/Geomancy/Vec3.hs
+++ b/src/Geomancy/Vec3.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
@@ -15,6 +16,7 @@
   , vec3
   , withVec3
   , pattern WithVec3
+  , convert
   , fromVec2
   , fromTuple
 
@@ -43,7 +45,7 @@
 import qualified Data.VectorSpace as VectorSpace
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Gl.Funs (GlModf(..), GlNearest)
 import Geomancy.Vec2 (Vec2, withVec2)
 
@@ -64,6 +66,12 @@
   -> r
 withVec3 (Vec3 a b c) f = f a b c
 
+{-# INLINE convert #-}
+convert :: Coercible v Vec3 => (Float -> a) -> (a -> a -> a -> r) -> v -> r
+convert f t v =
+  withVec3 (coerce v) \a b c ->
+    t (f a) (f b) (f c)
+
 pattern WithVec3 :: Float -> Float -> Float -> Vec3
 pattern WithVec3 a b c <- ((`withVec3` (,,)) -> (a, b, c))
 {-# COMPLETE WithVec3 #-}
@@ -238,7 +246,7 @@
       ptr' = castPtr ptr
 
 instance Block Vec3 where
-  sizeOfPacked _  = 12
+  type PackedSize Vec3 = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -250,7 +258,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
@@ -382,7 +389,7 @@
       ptr' = castPtr ptr
 
 instance Block Packed where
-  sizeOfPacked _  = 12
+  type PackedSize Packed = 12
   alignment140 _  = 16
   sizeOf140 _     = 16
   alignment430    = alignment140
@@ -394,7 +401,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}
diff --git a/src/Geomancy/Vec4.hs b/src/Geomancy/Vec4.hs
--- a/src/Geomancy/Vec4.hs
+++ b/src/Geomancy/Vec4.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -16,6 +17,7 @@
   , vec4
   , withVec4
   , pattern WithVec4
+  , convert
   , fromVec2
   , fromVec22
   , fromVec3
@@ -43,7 +45,7 @@
 import qualified Data.VectorSpace as VectorSpace
 
 import Geomancy.Elementwise (Elementwise(..))
-import Geomancy.Gl.Block (Block(..))
+import Graphics.Gl.Block (Block(..))
 import Geomancy.Gl.Funs (GlModf(..), GlNearest)
 import Geomancy.Vec2 (Vec2, withVec2)
 import Geomancy.Vec3 (Vec3, withVec3)
@@ -77,6 +79,12 @@
     (F# (indexFloatArray# arr 0x2#))
     (F# (indexFloatArray# arr 0x3#))
 
+{-# INLINE convert #-}
+convert :: Coercible v Vec4 => (Float -> a) -> (a -> a -> a -> a -> r) -> v -> r
+convert f t v =
+  withVec4 (coerce v) \a b c d->
+    t (f a) (f b) (f c) (f d)
+
 {-# INLINE compareVec4 #-}
 compareVec4 :: Vec4 -> Vec4 -> Ordering
 compareVec4 (Vec4 src1) (Vec4 src2) =
@@ -302,7 +310,7 @@
       (# world', Vec4 arr' #)
 
 instance Block Vec4 where
-  sizeOfPacked _  = 16
+  type PackedSize Vec4 = 16
   alignment140 _  = 16
   sizeOf140       = sizeOfPacked
   alignment430    = alignment140
@@ -314,7 +322,6 @@
   write430    = write140
   readPacked  = read140
   writePacked = write140
-  {-# INLINE sizeOfPacked #-}
   {-# INLINE alignment140 #-}
   {-# INLINE sizeOf140 #-}
   {-# INLINE alignment430 #-}