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-- |
-- Copyright   : (c) 2006-2016, alpheccar.org
-- License     : BSD-style
--
-- Maintainer  : misc@NOSPAMalpheccar.org
-- Stability   : experimental
-- Portability : portable
--
-- PDF shading
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module Graphics.PDF.Shading(
  -- * Shading
  -- ** Type
    PDFShading(..)
  , paintWithShading
  , applyShading
 ) where
     
import Graphics.PDF.Draw
import Graphics.PDF.LowLevel.Types
import Control.Monad.State(gets)
import Graphics.PDF.Shapes(setAsClipPath)
import Control.Monad.Writer
import Graphics.PDF.LowLevel.Serializer

-- | Fill clipping region with a shading
applyShading :: PDFShading -> Draw ()
applyShading :: PDFShading -> Draw ()
applyShading PDFShading
shade = do
    Map PDFShading String
shadingMap <- forall s (m :: * -> *) a. MonadState s m => (s -> a) -> m a
gets DrawState -> Map PDFShading String
shadings
    (String
newName,Map PDFShading String
newMap) <- forall a.
(Ord a, PdfResourceObject a) =>
String -> a -> Map a String -> Draw (String, Map a String)
setResource String
"Shading" PDFShading
shade Map PDFShading String
shadingMap
    forall s (m :: * -> *). MonadState s m => (s -> s) -> m ()
modifyStrict forall a b. (a -> b) -> a -> b
$ \DrawState
s -> DrawState
s { shadings :: Map PDFShading String
shadings = Map PDFShading String
newMap }
    forall w (m :: * -> *). MonadWriter w m => w -> m ()
tell forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Monoid a => [a] -> a
mconcat forall a b. (a -> b) -> a -> b
$ [ forall s a. SerializeValue s a => a -> s
serialize String
"\n/" 
                     , forall s a. SerializeValue s a => a -> s
serialize String
newName
                     , forall s a. SerializeValue s a => a -> s
serialize String
" sh"
                     ]
    
paintWithShading :: PDFShading -- ^ Shading
                 -> Draw a -- ^ Shape to paint
                 -> Draw ()
paintWithShading :: forall a. PDFShading -> Draw a -> Draw ()
paintWithShading PDFShading
shade Draw a
d = do
    forall a. Draw a -> Draw a
withNewContext forall a b. (a -> b) -> a -> b
$ do
      a
_ <- Draw a
d
      Draw ()
setAsClipPath
      PDFShading -> Draw ()
applyShading PDFShading
shade