Operation.hs

{-# LANGUAGE ExistentialQuantification, RankNTypes #-}

-- | This module contains the image manipulation primitives of GEGL, called Operations.
-- Some of these have defaults, which can be invoked by calling 'Data.Default.def'.
-- Those operations with no defaults are marked accordingly.
module GEGL.Operation
  ( Operation(..)
  , Property(..)
  , PropertyValue(..)
  , loadOperation
  , cropOperation
  , defaultCropOperation
  , textOperation
  , defaultTextOperation
  -- , defaultFractalExplorerOperation
  , pngSaveOperation
  , defaultPNGSaveOperation
  , checkerboardOperation
  , defaultCheckerboardOperation
  , overOperation
  , defaultOverOperation
  , bufferSourceOperation
  , translateOperation
  , FractalType(..)
  , FractalMode(..)
  ) where

import Foreign.C.Types
import Foreign.C.String
import Foreign.Storable(Storable(..))
import Foreign.Ptr (Ptr)

import GEGL.FFI.Color (GeglColor(..))
import GEGL.FFI.Buffer (GeglBuffer(..))
import GEGL.Color (Color(..))

import BABL.Format (PixelFormat)

data Property = Property
  { propertyName :: String
  , propertyValue :: PropertyValue
  }

data PropertyValue
  = PropertyInt Int
  | PropertyString String
  | PropertyDouble Double
  | PropertyColor Color
  | PropertyFormat PixelFormat
  | PropertyBuffer GeglBuffer
  | PropertyPointer (Ptr ())

data Operation = Operation
  { operationName :: String
  , operationParams :: [Property]
  }

-- | Simple Operation to load image files. Is agnostic to image format.
-- This operation has no default.
loadOperation :: [Property] -> Operation
loadOperation = Operation "gegl:load"

-- | Operation for cropping a buffer.
cropOperation :: [Property] -> Operation
cropOperation = Operation "gegl:crop"

defaultCropOperation :: Operation
defaultCropOperation = cropOperation []

-- | A PNG image saving operation.
pngSaveOperation :: [Property] -> Operation
pngSaveOperation = Operation "gegl:png-save"

defaultPNGSaveOperation :: Operation
defaultPNGSaveOperation = pngSaveOperation []

-- | Operation for rendering strings of text.
textOperation :: [Property] -> Operation
textOperation = Operation "gegl:text"

defaultTextOperation :: Operation
defaultTextOperation = textOperation []

-- | Layover operation.
overOperation :: [Property] -> Operation
overOperation = Operation "gegl:over"

defaultOverOperation :: Operation
defaultOverOperation = overOperation []

-- | Create a checkerboard pattern.
checkerboardOperation :: [Property] -> Operation
checkerboardOperation = Operation "gegl:checkerboard"

defaultCheckerboardOperation :: Operation
defaultCheckerboardOperation = checkerboardOperation []

-- | Use an existing 'GeglBuffer' as image source.
--   This operation has no default.
bufferSourceOperation :: [Property] -> Operation
bufferSourceOperation = Operation "gegl:buffer-source"

-- | Translate an existing buffer
translateOperation :: [Property] -> Operation
translateOperation = Operation "gegl:translate"

-- | Type for defining the fractal type in 'FractalExplorerOperation'.
data FractalType
  = Mandelbrot
  | Julia
  | Barnsley1
  | Barnsley2
  | Barnsley3
  | Spider
  | ManOWar
  | Lambda
  | Sierpinsky

-- | Type for defining the color mode in 'FractalExplorerOperation'.
data FractalMode
  = Sine
  | Cosine
  | None