Input.hs

{-# LANGUAGE FlexibleContexts      #-}

-----------------------------------------------------------------------------
-- |
-- Module      :  Diagrams.TwoD.Input
-- Copyright   :  (c) 2015 Tillmann Vogt
-- License     :  BSD-style (see LICENSE)
-- Maintainer  :  diagrams-discuss@googlegroups.com
--
-- Importing external images into diagrams.
-----------------------------------------------------------------------------

module Diagrams.TwoD.Input
    ( loadImageEmbedded
    , loadImageExternal
    ) where

import           Control.Monad (msum)
import           Codec.Picture
import           Codec.Picture.Types  (dynamicMap)

import           Data.Semigroup
import           Data.Typeable        (Typeable)

import           Diagrams.Core
import           Diagrams.TwoD.Image
import           Diagrams.TwoD.Size
import           Diagrams.TwoD.Types
import           Diagrams.SVG.ReadSVG (readSVGFile, InputConstraints)

import           Filesystem.Path.CurrentOS (decodeString)

-- | Load 2d formats given by a filepath and embed them
loadImageEmbedded :: InputConstraints b n => FilePath -> IO (Either String (QDiagram b V2 n Any))
loadImageEmbedded path = do
  dImg <- readImage path
  svgImg <- readSVGFile (decodeString path)
  return $ msum  [ svgImg,
                   fmap (image.rasterImage) dImg ] -- skip "Left"s and use the first "Right" image
  where
    rasterImage img = DImage (ImageRaster img) (dynamicMap imageWidth img) (dynamicMap imageHeight img) mempty

-- | Load 2d formats given by a filepath and make a reference
loadImageExternal :: (InputConstraints b n, Renderable (DImage n External) b) => FilePath -> IO (Either String (QDiagram b V2 n Any))
loadImageExternal path = do
  dImg <- readImage path
--  svgImg <- readSVGFile path
  return $ msum [ fmap (image.rasterPath) dImg ]
--                svgImg ] -- skip "Left"s and use the first "Right" image
  where
    rasterPath img = DImage (ImageRef path) (dynamicMap imageWidth img) (dynamicMap imageHeight img) mempty