finished episode14

src/BufferClass.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE TypeFamilies #-}
 module BufferClass where
 
 import qualified Graphics.Rendering.OpenGL as GL
@@ -9,19 +10,21 @@ import SDL (($=), get)
 -- think of it as some kind of interface in the object oriented context
 class Buffer a where
 
+  type ObjName a :: *
+
   -- what buffer target does te buffer bind to
   target :: a -> GL.BufferTarget
 
   -- what ID does the buffer have
-  glId :: a -> GL.BufferObject
+  glId :: a -> ObjName a
 
   -- bind the buffer object and fill it with data
   initialize :: a -> IO ()
 
   -- bind the buffer
   bind :: a -> IO ()
-  bind buf = GL.bindBuffer (target buf) $= Just (glId buf)
+  -- bind buf = GL.bindBuffer (target buf) $= Just (glId buf)
 
   -- unbind the buffer
   unbind :: a -> IO ()
-  unbind buf = GL.bindBuffer (target buf) $= Nothing
+  -- unbind buf = GL.bindBuffer (target buf) $= Nothing

src/IndexBuffer.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE TypeFamilies #-}
 module IndexBuffer where
 
 import qualified Graphics.Rendering.OpenGL as GL
@@ -21,6 +22,8 @@ data IndexBuffer a = IndexBuffer
 -- instanciate typeclass from BufferClass and fill in missing implementations
 instance Buffer (IndexBuffer a) where
 
+  type ObjName (IndexBuffer a) = GL.BufferObject
+
   target _ = GL.ElementArrayBuffer
 
   glId = iBufId
@@ -37,6 +40,12 @@ instance Buffer (IndexBuffer a) where
     -- release the buffer using the default implementation of the typeclass
     unbind buf
 
+  -- bind the buffer
+  bind buf = GL.bindBuffer (target buf) $= Just (glId buf)
+
+  -- unbind the buffer
+  unbind buf = GL.bindBuffer (target buf) $= Nothing
+
 newIndexBuffer ::
   (Storable a) =>      -- we have to be able to get a pointer to provided data
   [a] ->               -- list of data elements

src/Main.hs

@@ -32,6 +32,7 @@ import System.Random (randomRIO)
 -- internal imports
 
 import BufferClass
+import VertexArray
 import VertexBuffer
 import IndexBuffer
 
@@ -88,25 +89,31 @@ main = do
       indices = [0, 1, 2, 2, 3, 0] :: [GL.GLuint]
 
   -- construct new VertexBuffer and fill it with data
+  vao <- newVertexArray
   vbo <- newVertexBuffer vertexPositions
 
   -- rebind the vertex buffer
   bind vbo
   
   -- enable and specify data layout of the in-memory vertices
-  GL.vertexAttribPointer (GL.AttribLocation 0) $=
-    ( GL.ToFloat
-    , GL.VertexArrayDescriptor
-      -- There are 2 components (Floats) to our attribute
-      2
-      -- They are Floats
-      GL.Float
-      -- ???
-      0
-      -- our attribute is directly at the beginning of each vertex
-      (plusPtr nullPtr 0)
-    )
-  GL.vertexAttribArray (GL.AttribLocation 0) $= GL.Enabled
+  layout <- newVertexBufferLayout
+  pushElements layout GL.Float 2
+
+  addBuffer vao vbo layout
+
+  -- GL.vertexAttribPointer (GL.AttribLocation 0) $=
+  --   ( GL.ToFloat
+  --   , GL.VertexArrayDescriptor
+  --     -- There are 2 components (Floats) to our attribute
+  --     2
+  --     -- They are Floats
+  --     GL.Float
+  --     -- ???
+  --     0
+  --     -- our attribute is directly at the beginning of each vertex
+  --     (plusPtr nullPtr 0)
+  --   )
+  -- GL.vertexAttribArray (GL.AttribLocation 0) $= GL.Enabled
 
   -- construct new IndexBuffer and fill it with data
   ibo <- newIndexBuffer indices
@@ -166,7 +173,7 @@ main = do
       GL.clear [GL.ColorBuffer]
       
       -- rebind everything neccessary for draw call
-      GL.bindVertexArrayObject $= Just vao
+      bind vao
         -- (note the missing bindings to the vertex buffer and the attrib pointer)
       bind ibo
       GL.currentProgram $= Just sp

src/VertexBuffer.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE TypeFamilies #-}
 module VertexBuffer where
 
 import qualified Graphics.Rendering.OpenGL as GL
@@ -20,6 +21,8 @@ data VertexBuffer a = VertexBuffer
 -- instanciate typeclass from BufferClass and fill in missing implementations
 instance Buffer (VertexBuffer a) where
 
+  type ObjName (VertexBuffer a) = GL.BufferObject
+
   target _ = GL.ArrayBuffer
 
   glId = vBufId
@@ -36,6 +39,12 @@ instance Buffer (VertexBuffer a) where
     -- release the buffer using the default implementation of the typeclass
     unbind buf
 
+  -- bind the buffer
+  bind buf = GL.bindBuffer (target buf) $= Just (glId buf)
+
+  -- unbind the buffer
+  unbind buf = GL.bindBuffer (target buf) $= Nothing
+
 newVertexBuffer ::
   (Storable a) =>      -- we have to be able to get a pointer to provided data
   [a] ->               -- list of data elements