diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c) 2020 Oleg Grenrus, 2015 Liam O'Connor + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Liam O'Connor nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/filter/Main.hs b/filter/Main.hs new file mode 100644 --- /dev/null +++ b/filter/Main.hs @@ -0,0 +1,7 @@ +import Image.LaTeX.Render.Pandoc +import Image.LaTeX.Render +import Text.Pandoc.JSON + +main :: IO () +main = toJSONFilter $ convertFormulaSVG defaultEnv defaultPandocFormulaOptions + diff --git a/latex-svg-pandoc.cabal b/latex-svg-pandoc.cabal new file mode 100644 --- /dev/null +++ b/latex-svg-pandoc.cabal @@ -0,0 +1,57 @@ +cabal-version: 2.2 +name: latex-svg-pandoc +version: 0.1 +synopsis: + Render LaTeX formulae in pandoc documents to images with an actual LaTeX + +description: + This library provides utility functions to convert LaTeX equations to images + in Pandoc documents using the @latex-svg-image@ package. It requires an + actual LaTeX installation to work (@latex@, @dvisvgm@). + . + An executable is also provided which can be used as a Pandoc filter from the + commandline, which allows this technique to be used even for standalone Pandoc + jobs. + . + This is a fork of https://github.com/liamoc/latex-formulae + +homepage: http://github.com/phadej/latex-svg#readme +license: BSD-3-Clause +license-file: LICENSE +author: Oleg Grenrus, Liam O'Connor +maintainer: Oleg Grenrus +copyright: 2020 Oleg Grenrus, 2015-2019 Liam O'Connor +category: Image +build-type: Simple +tested-with: GHC ==8.2.2 || ==8.4.4 || ==8.6.5 || ==8.8.3 + +source-repository head + type: git + location: https://github.com/phadej/latex-svg + subdir: latex-svg-pandoc + +library + default-language: Haskell2010 + hs-source-dirs: src + ghc-options: -Wall + exposed-modules: Image.LaTeX.Render.Pandoc + build-depends: + , base >=4.10 && <4.14 + , bytestring ^>=0.10 + , directory ^>=1.3.0.1 + , filepath ^>=1.4.1.2 + , latex-svg-image ^>=0.1 + , pandoc-types ^>=1.17.6.1 || ^>=1.20 + , text ^>=1.2.3.0 + +executable latex-svg-filter + hs-source-dirs: filter + main-is: Main.hs + ghc-options: -Wall + build-depends: + , base + , latex-svg-image + , latex-svg-pandoc + , pandoc-types + + default-language: Haskell2010 diff --git a/src/Image/LaTeX/Render/Pandoc.hs b/src/Image/LaTeX/Render/Pandoc.hs new file mode 100644 --- /dev/null +++ b/src/Image/LaTeX/Render/Pandoc.hs @@ -0,0 +1,192 @@ +{-# LANGUAGE GADTs, OverloadedStrings #-} +module Image.LaTeX.Render.Pandoc ( + -- * SVG + convertFormulaSVG, + convertAllFormulaeSVG, + -- * Separate Files + convertFormulaFiles, + convertAllFormulaeFiles, + -- ** Name Supplies + NameSupply, + newNameSupply, + -- * Options + PandocFormulaOptions(..), + ShrinkSize, + defaultPandocFormulaOptions, + -- ** Error display functions + hideError, + displayError, + -- * Generalised versions + -- ** SVG + convertFormulaSVGWith, + convertAllFormulaeSVGWith, + -- ** Files + convertFormulaFilesWith, + convertAllFormulaeFilesWith, + ) where + +import Data.IORef (IORef, modifyIORef, newIORef, readIORef) +import Data.String (IsString (..)) +import Numeric (showFFloat) +import System.FilePath ((<.>), ()) +import Text.Pandoc.Definition (Format (..), Inline (..), MathType (..), Pandoc, nullAttr) +import Text.Pandoc.Walk (walkM) + +import qualified Data.Text as T + +import Image.LaTeX.Render + +-- | All options pertaining to the actual display of formulae. +data PandocFormulaOptions = PandocFormulaOptions + { errorDisplay :: RenderError -> Inline + -- ^ How to display various errors (such as LaTeX errors). Usually this can just be @displayError@ but you may wish @hideError@ + -- to avoid putting potentially secure information into the output page. + , formulaOptions :: MathType -> FormulaOptions + -- ^ LaTeX environment settings, including the preamble, for each equation type (display and inline) + } + +-- | A set of sensible defaults for formula options. +defaultPandocFormulaOptions :: PandocFormulaOptions +defaultPandocFormulaOptions = PandocFormulaOptions + { errorDisplay = displayError + , formulaOptions = fopts + } + where + fopts DisplayMath = displaymath + fopts InlineMath = math + +-- | Denominator for various dimensions. For high DPI displays, it can be useful to use values of 2 or 4, so that the dimensions +-- of the image are a fraction of the actual image size, and the image appears more crisp. Otherwise, a value of 1 will always +-- produce sensible, if somewhat pixelated results. +type ShrinkSize = Int + +-- | Convert a formula in a pandoc document to an image, embedding the image into the HTML using Data URIs. +convertFormulaSVG + :: EnvironmentOptions -- ^ System environment settings + -> PandocFormulaOptions -- ^ Formula display settings + -> Inline -> IO Inline +convertFormulaSVG = convertFormulaSVGWith . imageForFormula + +-- | Convert all formulae in a pandoc document to images, embedding the images into the HTML using Data URIs. +convertAllFormulaeSVG + :: EnvironmentOptions -- ^ System environment settings + -> PandocFormulaOptions -- ^ Formula display settings + -> Pandoc -> IO Pandoc +convertAllFormulaeSVG e = walkM . convertFormulaSVG e + +-- | A generalisation of 'convertFormulaSVG' which allows the actual image rendering +-- function to be customised, so that (e.g) caching can be added or other image processing. +convertFormulaSVGWith + :: (FormulaOptions -> Formula -> IO (Either RenderError SVG)) + -- ^ Function that renders a formula, such as @imageForFormula defaultEnv@ + -> PandocFormulaOptions -- ^ Formula display settings + -> Inline -> IO Inline +convertFormulaSVGWith f o (Math t s) = do + res <- f (formulaOptions o t) (toString s) + case res of + Left e -> return $ errorDisplay o e + Right svg -> return $ RawInline (Format "html") $ fromString $ alterForHTML svg +convertFormulaSVGWith _ _ x = return x + +-- | A generalisation of 'convertAllFormulaeSVG' which allows the actual image rendering +-- function to be customised, so that (e.g) caching can be added or other image processing. +convertAllFormulaeSVGWith + :: (FormulaOptions -> Formula -> IO (Either RenderError SVG)) + -- ^ Function that renders a formula, such as @imageForFormula defaultEnv@ + -> PandocFormulaOptions -- ^ Formula display settings + -> Pandoc -> IO Pandoc +convertAllFormulaeSVGWith f = walkM . convertFormulaSVGWith f + +-- | If we use files for the images, we need some way of naming the image files we produce +-- A NameSupply provides us with a source of unique names via an ever-increasing integer. +-- It's important that any invocation of 'convertFormulaFiles' or 'convertAllFormulaeFiles' +-- that shares the same image storage directory will also use the same name supply, or they +-- will overwrite each others images. +-- +-- TODO: remove +type NameSupply = IORef Int + +-- | Create a new name supply. +newNameSupply :: IO NameSupply +newNameSupply = newIORef 0 + +-- | A generalisation of 'convertFormulaFiles' which allows the actual image rendering +-- function to be customised, so that (e.g) caching can be added or other image processing. +convertFormulaFilesWith + :: (FormulaOptions -> Formula -> IO (Either RenderError SVG)) + -- ^ Function that renders a formula, such as @imageForFormula defaultEnv@ + -> NameSupply -- ^ Unique file name supply. Reuse this for every invocation that shares the same image directory. + -> FilePath -- ^ Name of image directory where images will be stored + -> PandocFormulaOptions -- ^ Formula display settings + -> Inline -> IO Inline +convertFormulaFilesWith f ns bn o (Math t s) = f (formulaOptions o t) (toString s) >>= \res -> case res of + Left e -> return $ errorDisplay o e + Right svg -> do + let baseline = getBaseline svg + fn <- readIORef ns + modifyIORef ns (+1) + let uri = bn show fn <.> "svg" + writeFile uri svg + return $ RawInline (Format "html") $ fromString $ + " "display-math") ++ + " style=\"margin:0; vertical-align:-" ++ showFFloat (Just 6) baseline "" ++ "pt;\"/>" + +convertFormulaFilesWith _ _ _ _ x = return x + +-- | Convert a formula in a pandoc document to an image, storing the images in a separate directory. +convertFormulaFiles + :: EnvironmentOptions -- ^ System environment settings + -> NameSupply -- ^ Unique file name supply. Reuse this for every invocation that shares the same image directory. + -> FilePath -- ^ Name of image directory where images will be stored + -> PandocFormulaOptions -- ^ Formula display settings + -> Inline -> IO Inline +convertFormulaFiles = convertFormulaFilesWith . imageForFormula + +-- | Convert every formula in a pandoc document to an image, storing the images in a separate directory. +convertAllFormulaeFiles + :: EnvironmentOptions -- ^ System environment settings + -> NameSupply -- ^ Unique file name supply. Reuse this for every invocation that shares the same image directory. + -> FilePath -- ^ Name of image directory where images will be stored + -> PandocFormulaOptions -- ^ Formula display settings + -> Pandoc -> IO Pandoc +convertAllFormulaeFiles eo ns fp = walkM . convertFormulaFiles eo ns fp + +-- | A generalisation of 'convertAllFormulaeFiles' which allows the actual image rendering +-- function to be customised, so that (e.g) caching can be added or other image processing. +convertAllFormulaeFilesWith + :: (FormulaOptions -> Formula -> IO (Either RenderError SVG)) + -- ^ Function that renders a formula, such as @imageForFormula defaultEnv@ + -> NameSupply -- ^ Unique file name supply. Reuse this for every invocation that shares the same image directory. + -> FilePath -- ^ Name of image directory where images will be stored + -> PandocFormulaOptions -- ^ Formula display settings + -> Pandoc -> IO Pandoc +convertAllFormulaeFilesWith x y a = walkM . convertFormulaFilesWith x y a + +-- | Render all errors simply as "Error" +hideError :: RenderError -> Inline +hideError = const $ Str blank + where + blank = "Error" + +-- | Render errors nicely, in order to show any problems clearly, with all information intact. +displayError :: RenderError -> Inline +displayError (LaTeXFailure str) = pandocError [Str "LaTeX failed:", LineBreak, Code nullAttr $ fromString str] +displayError (DVISVGMFailure str) = pandocError [Str "DVIPS failed:", LineBreak, Code nullAttr $ fromString str] +displayError (IOException e) = pandocError [Str "IO Exception:", LineBreak, Code nullAttr $ fromString $ show e] + +pandocError :: [Inline] -> Inline +pandocError = Strong . (Emph [Str "Error:"] :) + +------------------------------------------------------------------------------- +-- compat +------------------------------------------------------------------------------- + +class IsString s => ToString s where + toString :: s -> String + +instance Char ~ c => ToString [c] where + toString = id + +instance ToString T.Text where + toString = T.unpack