{-#  LANGUAGE ForeignFunctionInterface #-}
-- | DirectX9.D3D.Perf - d3d performance profiling helpers
module DirectX9.D3D.Perf
where
import DirectX9.Types
import DirectX9.D3D.Raw

import Control.Exception    ( bracket_ )
import Foreign.C.String     ( withCWString )
import System.IO.Unsafe     ( unsafePerformIO )

d3dPerfEnable :: Bool -> IO ()
d3dPerfEnable cond =
    c_D3DPERF_SetOptions (if cond then 0 else 1)

-- | d3dPerfGroup creates an user-defined event for performance profiler.
d3dPerfGroup :: Bool -> D3DCOLOR -> String -> IO b -> IO b
d3dPerfGroup cond col msg act
    | not cond  = act
    | otherwise = bracket_
        (withCWString msg $ c_D3DPERF_BeginEvent col)
        (c_D3DPERF_EnvEvent)
        act

-- | d3dPerfMarker creates a marker for performance profiler
d3dPerfMarker :: Bool -> D3DCOLOR -> String -> IO ()
d3dPerfMarker cond col msg
    | not cond  = return ()
    | otherwise = (withCWString msg $ c_D3DPERF_SetMarker col) >> return ()

-- | d3dPerfPrint creates a marker for performance profiler
d3dPerfPrint :: (Show a) => Bool -> D3DCOLOR -> a -> IO ()
d3dPerfPrint cond col msg
    | not cond  = return ()
    | otherwise = (withCWString (show msg) $ c_D3DPERF_SetMarker col) >> return ()

-- | d3dPerfTrace creates a marker for performance profiler, but it is pure unlike
-- d3dPerfMarker.  It makes use of unsafePerformIO and has same disadvantages as
-- Debug.Trace.trace.
d3dPerfTrace :: Bool -> D3DCOLOR -> String -> a -> a
d3dPerfTrace cond col msg val
    | not cond  = val
    | otherwise = unsafePerformIO $
        (withCWString msg $ c_D3DPERF_SetMarker col) >> return val

foreign import stdcall "fake.h D3DPERF_SetOptions" c_D3DPERF_SetOptions :: DWORD -> IO ()
foreign import stdcall "fake.h D3DPERF_GetStatus" c_D3DPERF_GetStatus :: IO ()
foreign import stdcall "fake.h D3DPERF_BeginEvent"
    c_D3DPERF_BeginEvent :: D3DCOLOR -> LPCWSTR -> IO Int
foreign import stdcall "fake.h D3DPERF_EndEvent"
    c_D3DPERF_EnvEvent :: IO Int
foreign import stdcall "fake.h D3DPERF_SetMarker"
    c_D3DPERF_SetMarker :: D3DCOLOR -> LPCWSTR -> IO ()