1 files changed, 38 insertions, 4 deletions
diff --git a/src/Vivant/Renderer.hs b/src/Vivant/Renderer.hs
index ca623e7..f66b0d7 100644
--- a/src/Vivant/Renderer.hs
+++ b/src/Vivant/Renderer.hs
@@ -1,15 +1,49 @@
 module Vivant.Renderer
-  (Renderer(..))
+  (Renderer(..), getUniformLocation, destroyRenderer, render, setVertexAttribute)
 where
 
 import qualified Graphics.Rendering.OpenGL as GL
 import Linear
 import Foreign.Ptr
+import qualified Graphics.GL.Functions as GL (glUniformMatrix4fv)
+import Graphics.Rendering.OpenGL (($=))
+import Foreign.Marshal.Alloc (free)
+import Foreign.Storable (sizeOf)
 
 data Renderer = Renderer
   { rendererProgram :: Maybe GL.Program,
     rendererVao :: Maybe GL.VertexArrayObject,
-    rendererModelP :: Ptr (M44 Float)
-  } deriving Show
+    rendererModelP :: Ptr (M44 Float),
+    rendererTriangleNum :: Int
+  } deriving (Show)
 
-draw :: Renderer -> IO ()
+getUniformLocation :: GL.UniformLocation -> GL.GLint
+getUniformLocation (GL.UniformLocation i) = i
+
+render :: Renderer -> IO ()
+render r@(Renderer {rendererProgram = Just p}) = do
+--  GL.currentProgram $= rendererProgram r
+  GL.bindVertexArrayObject $= rendererVao r
+
+  model <- getUniformLocation <$> GL.uniformLocation p "model"
+  GL.glUniformMatrix4fv model 1 1 (castPtr (rendererModelP r))
+
+  GL.drawArrays GL.Triangles 0 (fromIntegral $ rendererTriangleNum r)
+
+destroyRenderer :: Renderer -> IO ()
+destroyRenderer r =
+  free $ rendererModelP r
+
+setVertexAttribute :: GL.Program -> String -> Int -> Int -> Int -> IO ()
+setVertexAttribute program name vertices stride offset = do
+  let floatSize = sizeOf (1.0 :: Float)
+  attrib <- GL.get $ GL.attribLocation program name
+  GL.vertexAttribPointer attrib
+    $= ( GL.ToFloat,
+         GL.VertexArrayDescriptor
+           (fromIntegral vertices)
+           GL.Float
+           (fromIntegral $ stride * floatSize)
+           (plusPtr nullPtr (offset * floatSize))
+       )
+  GL.vertexAttribArray attrib $= GL.Enabled