{- | For initialising framebuffers.
 -}
module Framebuffer.Setup
    ( setupTextureFramebuffer
    , setupFramebufferGivenStencil
    , setupFramebuffer2GivenStencil 
    ) where
import Graphics.Rendering.OpenGL hiding (Point,translate,scale,imageHeight)
import Graphics.GL.Core43

setupTextureFramebuffer 
    :: GLsizei
    -> GLsizei
    -> IO (FramebufferObject, TextureObject)
{-# INLINE setupTextureFramebuffer #-}
setupTextureFramebuffer x y = do
    fboName <- genObjectName
    bindFramebuffer Framebuffer $= fboName

    fboTO <- genObjectName
    textureBinding Texture2D $= Just fboTO
    glTexStorage2D GL_TEXTURE_2D 1 GL_RGBA8 x y
    textureFilter Texture2D $= minMagFilter
    framebufferTexture2D Framebuffer (ColorAttachment 0) Texture2D fboTO 0
    fboStatus <- framebufferStatus Framebuffer
    case fboStatus of
        Complete -> return ()
        _ -> putStrLn $ "Texture framebuffer status: " ++ show fboStatus
    return (fboName, fboTO)

setupFramebufferGivenStencil 
    :: RenderbufferObject 
    -> IO (FramebufferObject, TextureObject)
{-# INLINE setupFramebufferGivenStencil #-}
setupFramebufferGivenStencil rboName = do
    fboName <- genObjectName
    bindFramebuffer Framebuffer $= fboName
    toName <- genObjectName
    framebufferRenderbuffer Framebuffer DepthStencilAttachment Renderbuffer rboName
    fboStatus <- framebufferStatus Framebuffer
    case fboStatus of
        Complete -> return ()
        _ -> putStrLn $ "Framebuffer with given stencil status: " ++ show fboStatus
    return (fboName,toName)
setupFramebuffer2GivenStencil 
    :: RenderbufferObject 
    -> IO (FramebufferObject, (TextureObject,TextureObject))
setupFramebuffer2GivenStencil rboName = do
    fboName <- genObjectName
    bindFramebuffer Framebuffer $= fboName
    toName <- genObjectName
    toName2 <- genObjectName
    framebufferRenderbuffer Framebuffer DepthStencilAttachment Renderbuffer rboName
    fboStatus <- framebufferStatus Framebuffer
    case fboStatus of
        Complete -> return ()
        _ -> putStrLn $ "Framebuffer with given stencil and two texture objects status: " ++ show fboStatus
    return (fboName,(toName,toName2))

minMagFilter :: ((TextureFilter, Maybe TextureFilter),TextureFilter)
minMagFilter = ((Nearest,Nothing),Nearest)