Rendering a texture on screen - haskell

Question

I'm new to both Haskell and OpenGL and I'm trying to render a texture on the screen.
Here's what I've got so far:
makeTexture :: FilePath -> IO GL.TextureObject
makeTexture f = do
t <- either error id <$> GLU.readTexture f
GL.textureFilter GL.Texture2D GL.$= ((GL.Linear', Nothing), GL.Linear')
GLU.texture2DWrap GL.$= (GL.Mirrored, GL.ClampToEdge)
return t
renderEntity :: Entity -> IO ()
renderEntity e = do
GL.activeTexture GL.$= GL.TextureUnit 0
GL.textureBinding GL.Texture2D GL.$= Just (texture $ model e)
-- I see a white triangle on the screen.
renderTriangle $ fmap (vadd $ position e) (points $ model e :: [Vector2])
-- I do not see this. Nor is the triangle textured either.
GL.renderPrimitive GL.Quads $ do
n 0 1 0
t 0 1 >> v 10 (-10) 10
t 1 1 >> v 10 (-10) (-10)
t 1 0 >> v (-10) (-10) (-10)
t 0 0 >> v (-10) (-10) 10
where v x y z = GL.vertex (GL.Vertex3 x y z :: GL.Vertex3 GL.GLfloat)
n x y z = GL.normal (GL.Normal3 x y z :: GL.Normal3 GL.GLfloat)
t u v = GL.texCoord (GL.TexCoord2 u v :: GL.TexCoord2 GL.GLfloat)
Where Entity looks like:
texMetal <- makeTexture "texture/metal.jpg"
let
entity = Entity
{ angle = 0
, position = (0, 0) :: Vector2
, velocity = (5, 5) :: Vector2
, model = Model
{ points = [(-60, -40), (60, -40), (0, 60)] :: [Vector2]
, texture = texMetal
}
}
And when I'm initializing I have these:
GL.viewport GL.$= (pos, size)
GL.matrixMode GL.$= GL.Projection
GL.texture GL.Texture2D GL.$= GL.Enabled
GL.normalize GL.$= GL.Enabled
GL.loadIdentity
GL.ortho2D (-fromIntegral width / 2)
(fromIntegral width / 2)
(-fromIntegral height / 2)
(fromIntegral height / 2)
GL.matrixMode GL.$= GL.Modelview 0
GL.loadIdentity
And the resulting picture:
It has two triangles because I have two 'entities' set in my code. But I don't see my quad nor do I see any sign of texturing.

Answer 1

It seems I had incorrect coordinates, because this works well:
renderEntity :: Entity -> IO ()
renderEntity e = do
GL.activeTexture GL.$= GL.TextureUnit 0
GL.textureBinding GL.Texture2D GL.$= Just (texture $ model e)
GL.renderPrimitive GL.Quads $ do
v 100 100
t 0 1
v 100 (-100)
t 1 1
v (-100) (-100)
t 1 0
v (-100) 100
t 0 0
where v x y = GL.vertex (GL.Vertex2 x y :: GL.Vertex2 GL.GLfloat)
t u v = GL.texCoord (GL.TexCoord2 u v :: GL.TexCoord2 GL.GLfloat)