-----------------------------------------------------------------------------
-- |
-- Module      :  Graphics.Rendering.OpenGL.GL.Shaders.ProgramObjects
-- Copyright   :  (c) Sven Panne 2006-2019
-- License     :  BSD3
--
-- Maintainer  :  Sven Panne <svenpanne@gmail.com>
-- Stability   :  stable
-- Portability :  portable
--
-- This module corresponds to section 7.3 (Program Objects) of the OpenGL 4.4
-- spec.
--
-----------------------------------------------------------------------------

module Graphics.Rendering.OpenGL.GL.Shaders.ProgramObjects (
   -- * Program Objects
   Program, createProgram, programDeleteStatus,
   attachShader, detachShader, attachedShaders,
   linkProgram, linkStatus,
   validateProgram, validateStatus,
   programInfoLog,
   currentProgram,
   programSeparable, programBinaryRetrievableHint,

   -- TODOs:
   --    glCreateShaderProgramv
   --    ProgramInterface type (from 7.3.1)
   --    glGetProgramInterfaceiv
   --    glGetProgramResourceIndex
   --    glGetProgramResourceName
   --    glGetProgramResourceiv
   --    glGetProgramResourceLocation
   --    glGetProgramResourceLocationIndex

   -- * Fragment Data
   bindFragDataLocation, getFragDataLocation
) where

import Data.List
import Data.Maybe
import Data.StateVar
import Foreign.Marshal.Array
import Foreign.Ptr
import Graphics.Rendering.OpenGL.GL.ByteString
import Graphics.Rendering.OpenGL.GL.Framebuffer
import Graphics.Rendering.OpenGL.GL.GLboolean
import Graphics.Rendering.OpenGL.GL.QueryUtils
import Graphics.Rendering.OpenGL.GL.Shaders.Program
import Graphics.Rendering.OpenGL.GL.Shaders.Shader
import Graphics.GL

--------------------------------------------------------------------------------

createProgram :: IO Program
createProgram :: IO Program
createProgram = (GLuint -> Program) -> IO GLuint -> IO Program
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap GLuint -> Program
Program IO GLuint
forall (m :: * -> *). MonadIO m => m GLuint
glCreateProgram

--------------------------------------------------------------------------------

attachShader :: Program -> Shader -> IO ()
attachShader :: Program -> Shader -> IO ()
attachShader Program
p Shader
s = GLuint -> GLuint -> IO ()
forall (m :: * -> *). MonadIO m => GLuint -> GLuint -> m ()
glAttachShader (Program -> GLuint
programID Program
p) (Shader -> GLuint
shaderID Shader
s)

detachShader :: Program -> Shader -> IO ()
detachShader :: Program -> Shader -> IO ()
detachShader Program
p Shader
s = GLuint -> GLuint -> IO ()
forall (m :: * -> *). MonadIO m => GLuint -> GLuint -> m ()
glDetachShader (Program -> GLuint
programID Program
p) (Shader -> GLuint
shaderID Shader
s)

attachedShaders :: Program -> StateVar [Shader]
attachedShaders :: Program -> StateVar [Shader]
attachedShaders Program
program =
   IO [Shader] -> ([Shader] -> IO ()) -> StateVar [Shader]
forall a. IO a -> (a -> IO ()) -> StateVar a
makeStateVar (Program -> IO [Shader]
getAttachedShaders Program
program) (Program -> [Shader] -> IO ()
setAttachedShaders Program
program)

getAttachedShaders :: Program -> IO [Shader]
getAttachedShaders :: Program -> IO [Shader]
getAttachedShaders Program
program = do
   Int32
numShaders <- GettableStateVar Int32 -> GettableStateVar Int32
forall t a (m :: * -> *). (HasGetter t a, MonadIO m) => t -> m a
get (Program -> GettableStateVar Int32
numAttachedShaders Program
program)
   [GLuint]
ids <- Int -> (Ptr GLuint -> IO [GLuint]) -> IO [GLuint]
forall a b. Storable a => Int -> (Ptr a -> IO b) -> IO b
allocaArray (Int32 -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int32
numShaders) ((Ptr GLuint -> IO [GLuint]) -> IO [GLuint])
-> (Ptr GLuint -> IO [GLuint]) -> IO [GLuint]
forall a b. (a -> b) -> a -> b
$ \Ptr GLuint
buf -> do
      GLuint -> Int32 -> Ptr Int32 -> Ptr GLuint -> IO ()
forall (m :: * -> *).
MonadIO m =>
GLuint -> Int32 -> Ptr Int32 -> Ptr GLuint -> m ()
glGetAttachedShaders (Program -> GLuint
programID Program
program) Int32
numShaders Ptr Int32
forall a. Ptr a
nullPtr Ptr GLuint
buf
      Int -> Ptr GLuint -> IO [GLuint]
forall a. Storable a => Int -> Ptr a -> IO [a]
peekArray (Int32 -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int32
numShaders) Ptr GLuint
buf
   [Shader] -> IO [Shader]
forall (m :: * -> *) a. Monad m => a -> m a
return ([Shader] -> IO [Shader]) -> [Shader] -> IO [Shader]
forall a b. (a -> b) -> a -> b
$ (GLuint -> Shader) -> [GLuint] -> [Shader]
forall a b. (a -> b) -> [a] -> [b]
map GLuint -> Shader
Shader [GLuint]
ids

setAttachedShaders :: Program -> [Shader] -> IO ()
setAttachedShaders :: Program -> [Shader] -> IO ()
setAttachedShaders Program
program [Shader]
newShaders = do
   [Shader]
currentShaders <- Program -> IO [Shader]
getAttachedShaders Program
program
   (Shader -> IO ()) -> [Shader] -> IO ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ (Program -> Shader -> IO ()
attachShader Program
program) ([Shader]
newShaders [Shader] -> [Shader] -> [Shader]
forall a. Eq a => [a] -> [a] -> [a]
\\ [Shader]
currentShaders)
   (Shader -> IO ()) -> [Shader] -> IO ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ (Program -> Shader -> IO ()
detachShader Program
program) ([Shader]
currentShaders [Shader] -> [Shader] -> [Shader]
forall a. Eq a => [a] -> [a] -> [a]
\\ [Shader]
newShaders)

--------------------------------------------------------------------------------

linkProgram :: Program -> IO ()
linkProgram :: Program -> IO ()
linkProgram = GLuint -> IO ()
forall (m :: * -> *). MonadIO m => GLuint -> m ()
glLinkProgram (GLuint -> IO ()) -> (Program -> GLuint) -> Program -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Program -> GLuint
programID

currentProgram :: StateVar (Maybe Program)
currentProgram :: StateVar (Maybe Program)
currentProgram =
   IO (Maybe Program)
-> (Maybe Program -> IO ()) -> StateVar (Maybe Program)
forall a. IO a -> (a -> IO ()) -> StateVar a
makeStateVar
      (do Program
p <- (GLuint -> Program) -> IO GLuint -> IO Program
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap GLuint -> Program
Program (IO GLuint -> IO Program) -> IO GLuint -> IO Program
forall a b. (a -> b) -> a -> b
$ (Int32 -> GLuint) -> PName1I -> IO GLuint
forall p a. GetPName1I p => (Int32 -> a) -> p -> IO a
getInteger1 Int32 -> GLuint
forall a b. (Integral a, Num b) => a -> b
fromIntegral PName1I
GetCurrentProgram
          Maybe Program -> IO (Maybe Program)
forall (m :: * -> *) a. Monad m => a -> m a
return (Maybe Program -> IO (Maybe Program))
-> Maybe Program -> IO (Maybe Program)
forall a b. (a -> b) -> a -> b
$ if Program
p Program -> Program -> Bool
forall a. Eq a => a -> a -> Bool
== Program
noProgram then Maybe Program
forall a. Maybe a
Nothing else Program -> Maybe Program
forall a. a -> Maybe a
Just Program
p)
      (GLuint -> IO ()
forall (m :: * -> *). MonadIO m => GLuint -> m ()
glUseProgram (GLuint -> IO ())
-> (Maybe Program -> GLuint) -> Maybe Program -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Program -> GLuint
programID (Program -> GLuint)
-> (Maybe Program -> Program) -> Maybe Program -> GLuint
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Program -> Maybe Program -> Program
forall a. a -> Maybe a -> a
fromMaybe Program
noProgram)

noProgram :: Program
noProgram :: Program
noProgram = GLuint -> Program
Program GLuint
0

validateProgram :: Program -> IO ()
validateProgram :: Program -> IO ()
validateProgram = GLuint -> IO ()
forall (m :: * -> *). MonadIO m => GLuint -> m ()
glValidateProgram (GLuint -> IO ()) -> (Program -> GLuint) -> Program -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Program -> GLuint
programID

programInfoLog :: Program -> GettableStateVar String
programInfoLog :: Program -> GettableStateVar String
programInfoLog =
   GettableStateVar String -> GettableStateVar String
forall a. IO a -> IO a
makeGettableStateVar (GettableStateVar String -> GettableStateVar String)
-> (Program -> GettableStateVar String)
-> Program
-> GettableStateVar String
forall b c a. (b -> c) -> (a -> b) -> a -> c
.
      (ByteString -> String) -> IO ByteString -> GettableStateVar String
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ByteString -> String
unpackUtf8 (IO ByteString -> GettableStateVar String)
-> (Program -> IO ByteString) -> Program -> GettableStateVar String
forall b c a. (b -> c) -> (a -> b) -> a -> c
.
         (Program -> GettableStateVar Int32)
-> (Program -> Int32 -> Ptr Int32 -> Ptr GLchar -> IO ())
-> Program
-> IO ByteString
forall a.
(a -> GettableStateVar Int32)
-> (a -> Int32 -> Ptr Int32 -> Ptr GLchar -> IO ())
-> a
-> IO ByteString
stringQuery Program -> GettableStateVar Int32
programInfoLogLength (GLuint -> Int32 -> Ptr Int32 -> Ptr GLchar -> IO ()
forall (m :: * -> *).
MonadIO m =>
GLuint -> Int32 -> Ptr Int32 -> Ptr GLchar -> m ()
glGetProgramInfoLog (GLuint -> Int32 -> Ptr Int32 -> Ptr GLchar -> IO ())
-> (Program -> GLuint)
-> Program
-> Int32
-> Ptr Int32
-> Ptr GLchar
-> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Program -> GLuint
programID)

--------------------------------------------------------------------------------

programSeparable :: Program -> StateVar Bool
programSeparable :: Program -> StateVar Bool
programSeparable = GetProgramPName -> Program -> StateVar Bool
programStateVarBool GetProgramPName
ProgramSeparable

programBinaryRetrievableHint :: Program -> StateVar Bool
programBinaryRetrievableHint :: Program -> StateVar Bool
programBinaryRetrievableHint = GetProgramPName -> Program -> StateVar Bool
programStateVarBool GetProgramPName
ProgramBinaryRetrievableHint

programStateVarBool :: GetProgramPName -> Program -> StateVar Bool
programStateVarBool :: GetProgramPName -> Program -> StateVar Bool
programStateVarBool GetProgramPName
pname Program
program =
   IO Bool -> (Bool -> IO ()) -> StateVar Bool
forall a. IO a -> (a -> IO ()) -> StateVar a
makeStateVar
      (IO Bool -> IO Bool
forall t a (m :: * -> *). (HasGetter t a, MonadIO m) => t -> m a
get ((Int32 -> Bool) -> GetProgramPName -> Program -> IO Bool
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Bool
forall a. (Eq a, Num a) => a -> Bool
unmarshalGLboolean GetProgramPName
pname Program
program))
      (GLuint -> GLuint -> Int32 -> IO ()
forall (m :: * -> *).
MonadIO m =>
GLuint -> GLuint -> Int32 -> m ()
glProgramParameteri (Program -> GLuint
programID Program
program)
                           (GetProgramPName -> GLuint
marshalGetProgramPName GetProgramPName
pname) (Int32 -> IO ()) -> (Bool -> Int32) -> Bool -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Bool -> Int32
forall a. Num a => Bool -> a
marshalGLboolean)

--------------------------------------------------------------------------------

programDeleteStatus :: Program -> GettableStateVar Bool
programDeleteStatus :: Program -> IO Bool
programDeleteStatus = (Int32 -> Bool) -> GetProgramPName -> Program -> IO Bool
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Bool
forall a. (Eq a, Num a) => a -> Bool
unmarshalGLboolean GetProgramPName
ProgramDeleteStatus

linkStatus :: Program -> GettableStateVar Bool
linkStatus :: Program -> IO Bool
linkStatus = (Int32 -> Bool) -> GetProgramPName -> Program -> IO Bool
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Bool
forall a. (Eq a, Num a) => a -> Bool
unmarshalGLboolean GetProgramPName
LinkStatus

validateStatus :: Program -> GettableStateVar Bool
validateStatus :: Program -> IO Bool
validateStatus = (Int32 -> Bool) -> GetProgramPName -> Program -> IO Bool
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Bool
forall a. (Eq a, Num a) => a -> Bool
unmarshalGLboolean GetProgramPName
ValidateStatus

programInfoLogLength :: Program -> GettableStateVar GLsizei
programInfoLogLength :: Program -> GettableStateVar Int32
programInfoLogLength = (Int32 -> Int32)
-> GetProgramPName -> Program -> GettableStateVar Int32
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Int32
forall a b. (Integral a, Num b) => a -> b
fromIntegral GetProgramPName
ProgramInfoLogLength

numAttachedShaders :: Program -> GettableStateVar GLsizei
numAttachedShaders :: Program -> GettableStateVar Int32
numAttachedShaders = (Int32 -> Int32)
-> GetProgramPName -> Program -> GettableStateVar Int32
forall a.
(Int32 -> a) -> GetProgramPName -> Program -> GettableStateVar a
programVar1 Int32 -> Int32
forall a b. (Integral a, Num b) => a -> b
fromIntegral GetProgramPName
AttachedShaders

--------------------------------------------------------------------------------

-- | 'bindFragDataLocation' binds a varying variable, specified by program and name, to a
-- drawbuffer. The effects only take place after succesfull linking of the program.
-- invalid arguments and conditions are
-- - an index larger than maxDrawBufferIndex
-- - names starting with 'gl_'
-- linking failure will ocure when
-- - one of the arguments was invalid
-- - more than one varying varuable name is bound to the same index
-- It's not an error to specify unused variables, those will be ingored.
bindFragDataLocation :: Program -> String -> SettableStateVar DrawBufferIndex
bindFragDataLocation :: Program -> String -> SettableStateVar GLuint
bindFragDataLocation (Program GLuint
program) String
varName = (GLuint -> IO ()) -> SettableStateVar GLuint
forall a. (a -> IO ()) -> SettableStateVar a
makeSettableStateVar ((GLuint -> IO ()) -> SettableStateVar GLuint)
-> (GLuint -> IO ()) -> SettableStateVar GLuint
forall a b. (a -> b) -> a -> b
$ \GLuint
ind ->
   String -> (Ptr GLchar -> IO ()) -> IO ()
forall a. String -> (Ptr GLchar -> IO a) -> IO a
withGLstring String
varName ((Ptr GLchar -> IO ()) -> IO ()) -> (Ptr GLchar -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ GLuint -> GLuint -> Ptr GLchar -> IO ()
forall (m :: * -> *).
MonadIO m =>
GLuint -> GLuint -> Ptr GLchar -> m ()
glBindFragDataLocation GLuint
program GLuint
ind

-- | query the binding of a given variable, specified by program and name. The program has to be
-- linked. The result is Nothing if an error occures or the name is not a name of a varying
-- variable. If the program hasn't been linked an 'InvalidOperation' error is generated.
getFragDataLocation :: Program -> String -> IO (Maybe DrawBufferIndex)
getFragDataLocation :: Program -> String -> IO (Maybe GLuint)
getFragDataLocation (Program GLuint
program) String
varName = do
   Int32
r <- String
-> (Ptr GLchar -> GettableStateVar Int32) -> GettableStateVar Int32
forall a. String -> (Ptr GLchar -> IO a) -> IO a
withGLstring String
varName ((Ptr GLchar -> GettableStateVar Int32) -> GettableStateVar Int32)
-> (Ptr GLchar -> GettableStateVar Int32) -> GettableStateVar Int32
forall a b. (a -> b) -> a -> b
$ GLuint -> Ptr GLchar -> GettableStateVar Int32
forall (m :: * -> *). MonadIO m => GLuint -> Ptr GLchar -> m Int32
glGetFragDataLocation GLuint
program
   if Int32
r Int32 -> Int32 -> Bool
forall a. Ord a => a -> a -> Bool
< Int32
0
    then Maybe GLuint -> IO (Maybe GLuint)
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe GLuint
forall a. Maybe a
Nothing
    else Maybe GLuint -> IO (Maybe GLuint)
forall (m :: * -> *) a. Monad m => a -> m a
return (Maybe GLuint -> IO (Maybe GLuint))
-> (GLuint -> Maybe GLuint) -> GLuint -> IO (Maybe GLuint)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GLuint -> Maybe GLuint
forall a. a -> Maybe a
Just (GLuint -> IO (Maybe GLuint)) -> GLuint -> IO (Maybe GLuint)
forall a b. (a -> b) -> a -> b
$ Int32 -> GLuint
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int32
r