pituicat/src/Types/Graphics/VertexArray.hs

75 lines
1.7 KiB
Haskell

{-# LANGUAGE TypeFamilies #-}
module Types.Graphics.VertexArray where
import qualified Graphics.Rendering.OpenGL as GL
import SDL (($=), get)
import qualified Data.Vector as V
import Foreign (sizeOf)
import Foreign.Ptr
import Control.Concurrent.STM
import Control.Monad (void)
-- internal imports
import Classes.Graphics.Bindable
import Classes.Graphics.Buffer
import Classes.Graphics.VertexLayout
import Types.Graphics.VertexBuffer
newtype VertexArray = VertexArray
{ vArrId :: GL.VertexArrayObject
}
deriving (Eq, Show)
instance Bindable VertexArray where
bind va = GL.bindVertexArrayObject $= Just (vArrId va)
unbind va = GL.bindVertexArrayObject $= Nothing
newVertexArray :: IO VertexArray
newVertexArray = VertexArray
<$> GL.genObjectName
instance VertexLayout Vertex where
type VertArray Vertex = VertexArray
layoutElements vert =
foldr
(\a@(index, count) acc ->
( index
, GL.VertexArrayDescriptor
count
GL.Float
(fromIntegral $ sizeOf (undefined :: Vertex))
(nullPtr `plusPtr` (sizeOf (undefined :: GL.GLfloat) * fromIntegral
(sum (map ((\(GL.VertexArrayDescriptor c _ _ _) -> c) . snd) acc))))
) : acc
)
[]
(zip [0 ..] [3, 4, 2, 1])
addBuffer vert va vb = do
-- bind vertex array and vertex buffer ot associate them
bind va
bind vb
-- enable and fill vertex attrib pointer(s)
let list = layoutElements vert
mapM_
(\(index, descriptor) -> do
GL.vertexAttribArray (GL.AttribLocation index) $= GL.Enabled
GL.vertexAttribPointer (GL.AttribLocation index) $=
( GL.ToNormalizedFloat
, descriptor
)
)
list
unbind va
unbind vb