Compositor.hs

module Graphics.LambdaCube.Compositor where

import Data.IntMap (IntMap)
import Data.Word

import Graphics.LambdaCube.Common
import Graphics.LambdaCube.GpuProgram
import Graphics.LambdaCube.Material
import Graphics.LambdaCube.PixelFormat
import Graphics.LambdaCube.RenderSystem
import Graphics.LambdaCube.Texture
import Graphics.LambdaCube.Types

data PassType
    = PT_CLEAR          -- ^ Clear target to one colour
    | PT_STENCIL        -- ^ Set stencil operation
    | PT_RENDERSCENE    -- ^ Render the scene or part of it
    | PT_RENDERQUAD     -- ^ Render a full screen quad

-- | Input mode of a TargetPass
data InputMode
    = IM_NONE       -- ^ No input
    | IM_PREVIOUS   -- ^ Output of previous Composition in chain
    deriving Eq

data (Texture t, LinkedGpuProgram lp) => Compositor t lp
    = Compositor
    { cmpName                   :: String
    , cmpTechniques             :: [CompositionTechnique t lp]
    , cmpSupportedTechniques    :: Maybe [CompositionTechnique t lp]
	}

data Texture t => TextureDefinition t
    = TextureDefinition
    { tdName            :: String
    , tdWidth           :: Maybe Int        -- ^ Nothing means adapt to target width
    , tdHeight          :: Maybe Int        -- ^ Nothing means adapt to target height
    , tdWidthFactor     :: FloatType        -- ^ multiple of target width to use (if width = Nothing)
    , tdHeightFactor    :: FloatType        -- ^ multiple of target height to use (if height = Nothing)
    , tdFormatList      :: [PixelFormat]    -- ^ more than one means MRT
    , tdFsaa            :: Bool             -- ^ FSAA enabled; true = determine from main target (if render_scene), false = disable
    , tdHwGammaWrite    :: Bool             -- ^ Do sRGB gamma correction on write (only 8-bit per channel formats)
    , tdShared          :: Bool             -- ^ whether to use shared textures for this one
    , tdTexture         :: Maybe t
    }

data InputTex
    = InputTex
    { itName        :: String   -- ^ Name (local) of the input texture
    , itMrtIndex    :: Int      -- ^ MRT surface index if applicable
    }

data (Texture t, LinkedGpuProgram lp) => CompositionTechnique t lp
    = CompositionTechnique
    { ctTextureDefinitions  :: [TextureDefinition t]        -- ^ Local texture definitions
    , ctTargetPasses        :: [CompositionTargetPass t lp] -- ^ Intermediate target passes
    , ctOutputTarget        :: CompositionTargetPass t lp   -- ^ Output target pass (can be only one)
    , ctSchemeName          :: String                       -- ^ Optional scheme name
    }

data (Texture t, LinkedGpuProgram lp) => CompositionTargetPass t lp
    = CompositionTargetPass
    { ctpInputMode      :: InputMode                    -- ^ Input name
    , ctpOutputName     :: String                       -- ^ (local) output texture
    , ctpOutput         :: Maybe (TextureDefinition t)
    , ctpPasses         :: [CompositionPass t lp]       -- ^ Passes
    , ctpOnlyInitial    :: Bool                         -- ^ This target pass is only executed initially after the effect has been enabled.
    , ctpVisibilityMask :: Word32                       -- ^ Visibility mask for this render
    , ctpLodBias        :: FloatType                    -- ^ LOD bias of this render
    , ctpMaterialScheme :: String                       -- ^ Material scheme name
    , ctpShadowsEnabled :: Bool                         -- ^ Shadows option
    }

data (Texture t, LinkedGpuProgram lp) => CompositionPass t lp
    = CompositionPass
    { cpType                        :: PassType         -- ^ Type of composition pass
    , cpIdentifier                  :: Word32           -- ^ Identifier for this pass
    , cpMaterialName                :: String           -- ^ Material used for rendering
    , cpMaterial                    :: Maybe (Material t lp)
    , cpFirstRenderQueue            :: Int              -- ^ [first,last] render queue to render this pass (in case of PT_RENDERSCENE)
    , cpLastRenderQueue             :: Int
    , cpClearBuffers                :: (Bool,Bool,Bool) -- ^ Clear buffers (in case of PT_CLEAR), hint: [colour] [depth] [stencil]
    , cpClearColour                 :: ColourValue      -- ^ Clear colour (in case of PT_CLEAR)
    , cpClearDepth                  :: FloatType        -- ^ Clear depth (in case of PT_CLEAR)
    , cpClearStencil                :: Word32           -- ^ Clear stencil value (in case of PT_CLEAR)
    , cpInputs                      :: IntMap InputTex  -- ^ Inputs (for material used for rendering the quad)
    , cpStencilCheck                :: Bool             -- ^ Stencil operation parameters
    , cpStencilFunc                 :: CompareFunction
    , cpStencilRefValue             :: Word32
    , cpStencilMask                 :: Word32
    , cpStencilFailOp               :: StencilOperation
    , cpStencilDepthFailOp          :: StencilOperation
    , cpStencilPassOp               :: StencilOperation
    , cpStencilTwoSidedOperation    :: Bool
    , cpQuadCornerModified          :: Bool             -- ^ true if quad should not cover whole screen
    , cpQuadLeft                    :: FloatType        -- ^ quad positions in normalised coordinates [-1;1]x[-1;1] (in case of PT_RENDERQUAD)
    , cpQuadTop                     :: FloatType
    , cpQuadRight                   :: FloatType
    , cpQuadBottom                  :: FloatType
    , cpQuadFarCorners              :: Bool
    , cpQuadFarCornersViewSpace     :: Bool
    }