{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TemplateHaskell #-}

-- | Datatypes used to setup and pass data to shaders.
module Shader.Data 
--    (
--    VAO (..),
--    VBO (..),
--    EBO (..),
--    TO (..),
--    FBO (..),
--    Shader (..),
--    PrimitiveMode (..),
--    -- | Lens functions
--    vaoName,
--    shaderUINT,
--    shaderPrimitive,
--    shaderVAO,
--    textureObject,
--    vboName,
--    vboPtr,
--    vboVertexSize,
--    unFBO,
--    unTO,
--    unPrimitiveMode,
--    eboName,
--    eboPtr,
--    -- | Synonyms
--    vert,
--    geom,
--    frag,
--    pmPoints,
--    pmLines,
--    pmLinesAdjacency,
--    pmLineLoop,
--    pmLineStrip,
--    pmTriangles,
--    pmTriangleStrip,
--    pmTriangleFan,
--    pmQuads,
--    pmPatches,
--) 
    where

import Control.Lens
import Foreign
import Graphics.GL.Core45

-- | Datatype containing the necessary information for a single shader.
data Shader = Shader
    { _shaderUINT :: GLuint -- should be shaderID
    , _shaderPrimitive :: PrimitiveMode
    , _shaderVAO :: VAO
    }

newtype FBO = FBO {_unFBO :: GLuint}

newtype TO = TO {_unTO :: GLuint}

{- | Vertex array object: contains the reference to the object,
and its buffer targets.
-}
newtype VAO = VAO { _vaoName :: GLuint }

data VertexAttribute = VertexAttribute
    { _vaCount :: GLint
    , _vaType :: GLenum
    , _vaNormalize :: GLboolean
    , _vaOffset :: GLuint
    }


{- | Vertex buffer object: contains the reference to the object,
a pointer to a location with space that can be written to the buffer,
and a list of attribute pointer sizes.
Vertex attributes are interleaved within the vbo.
-}
data VBO = VBO
    { _vboName :: GLuint
    , _vboPtr :: Ptr Float
    , _vboVertexBytes :: Int
    -- add int for AMOUNT of data poked!
    }

data BOType = WindowPoss

data FloatBO = FloatBO
    { _boName :: GLuint
    , _boPtr :: Ptr Float
    , _boType :: BOType
    }

data EBO = EBO
    { _eboName :: GLuint
    , _eboPtr :: Ptr GLuint
    }

-- | Datatype containing the reference to a texture object.
newtype ShaderTexture = ShaderTexture
    { _textureObject :: GLuint -- DSA style texture, 450
    --    , _textureTarget :: GLenum
    }

newtype PrimitiveMode = PrimitiveMode {_unPrimitiveMode :: GLenum}

-- | Short synonyms for shader types
vert, geom, frag :: GLenum
vert = GL_VERTEX_SHADER
geom = GL_GEOMETRY_SHADER
frag = GL_FRAGMENT_SHADER

pmPoints, pmLines, pmLinesAdjacency, pmLineLoop, pmLineStrip, pmTriangles, pmTriangleStrip, pmTriangleFan, pmQuads, pmPatches :: PrimitiveMode
pmPoints = PrimitiveMode GL_POINTS
pmLines = PrimitiveMode GL_LINES
pmLinesAdjacency = PrimitiveMode GL_LINES_ADJACENCY
pmLineLoop = PrimitiveMode GL_LINE_LOOP
pmLineStrip = PrimitiveMode GL_LINE_STRIP
pmTriangles = PrimitiveMode GL_TRIANGLES
pmTriangleStrip = PrimitiveMode GL_TRIANGLE_STRIP
pmTriangleFan = PrimitiveMode GL_TRIANGLE_FAN
pmQuads = PrimitiveMode GL_QUADS
pmPatches = PrimitiveMode GL_PATCHES

makeLenses ''VAO
makeLenses ''VBO
makeLenses ''EBO
makeLenses ''ShaderTexture
makeLenses ''Shader
makeLenses ''FBO
makeLenses ''TO
makeLenses ''PrimitiveMode
makeLenses ''VertexAttribute