Basic LaTeX example.

README.md

@@ -157,3 +157,17 @@ scaling = adjustSpeed 2 $ syncAll
 ## Valentine's Day
 
 ![Valentine's Day](gifs/valentine.gif)
+
+## Basic LaTeX
+
+```
+latex_basic :: Ani ()
+latex_basic = proc () -> do
+  duration 1 -< ()
+  emit -< do
+    rect_ [width_ "100%", height_ "100%", fill_ "black"]
+    g_ [transform_ $ translate 5 50] $
+      g_ [transform_ $ scale 4 4, fill_ "white"] $
+        latex "$\\sum_{k=1}^\\infty {1 \\over k^2} = {\\pi^2 \\over 6}$"
+```
+![Basic LaTeX](gifs/latex_basic.gif)

reanimate.cabal

@@ -20,6 +20,7 @@ library
                       Reanimate.Render
                       Reanimate.Examples
                       Reanimate.Combinators
+                      Reanimate.LaTeX
   build-depends:       base >=4.12 && <4.13,
                        lucid-svg, time, text, unix, lucid, filepath, process, directory
 

src/Reanimate/Examples.hs

@@ -10,8 +10,7 @@ import Numeric
 
 import Reanimate.Arrow
 import Reanimate.Combinators
-
+import Reanimate.LaTeX
-import Debug.Trace
 
 sinewave :: Ani ()
 sinewave = proc () -> do
@@ -326,3 +325,13 @@ frequencies = proc () -> do
       (idx*width, 0)
     wave1 n = approxFnData 1000 $ \idx ->
       (idx*width, sum [ sin ((idx+n)*pi*2*freq) * 20 | freq <- freqs ])
+
+
+latex_basic :: Ani ()
+latex_basic = proc () -> do
+  duration 1 -< ()
+  emit -< do
+    rect_ [width_ "100%", height_ "100%", fill_ "black"]
+    g_ [transform_ $ translate 5 50] $
+      g_ [transform_ $ scale 4 4, fill_ "white"] $
+        latex "$\\sum_{k=1}^\\infty {1 \\over k^2} = {\\pi^2 \\over 6}$"

src/Reanimate/LaTeX.hs

@@ -0,0 +1,98 @@
+{-# LANGUAGE ScopedTypeVariables, OverloadedStrings #-}
+module Reanimate.LaTeX where
+
+import System.Process
+import System.Exit
+import System.IO
+import System.IO.Unsafe
+import System.FilePath
+import System.Directory
+import Control.Exception
+import Lucid (toHtmlRaw, toHtml)
+import Lucid.Svg (Svg, text_, font_size_, fill_)
+--toHtmlRaw svgFile
+
+--latex -interaction=batchmode -halt-on-error
+--dvisvgm {file} -n -v 0 -o out
+
+latex :: String -> Svg ()
+latex = unsafePerformIO . latexToSVG
+
+latexToSVG :: String -> IO (Svg ())
+latexToSVG tex = handle (\(e::SomeException) -> return (failedSvg tex)) $ do
+  latex <- requireExecutable "latex"
+  dvisvgm <- requireExecutable "dvisvgm"
+  withTempDir $ \tmp_dir -> withTempFile "tex" $ \tex_file -> withTempFile "svg" $ \svg_file -> do
+    let dvi_file = tmp_dir </> replaceExtension (takeFileName tex_file) "dvi"
+    writeFile tex_file tex_prologue
+    appendFile tex_file tex
+    appendFile tex_file tex_epilogue
+    runCmd latex ["-interaction=batchmode", "-halt-on-error", "-output-directory="++tmp_dir, tex_file]
+    runCmd dvisvgm [dvi_file, "-n","-v", "0", "-o",svg_file]
+    svg_data <- readFile svg_file
+    evaluate (length svg_data)
+    return $ toHtmlRaw $ unlines $ drop 1 $ lines svg_data
+
+failedSvg :: String -> Svg ()
+failedSvg tex =
+  text_ [ font_size_ "20"
+        , fill_ "white"] (toHtml $ "bad latex: "++tex)
+
+runCmd exec args = do
+  (ret, stdout, stderr) <- readProcessWithExitCode exec args ""
+  evaluate (length stdout + length stderr)
+  case ret of
+    ExitSuccess -> return ()
+    ExitFailure err -> do
+      putStrLn $
+        "Failed to run: " ++ showCommandForUser exec args ++ "\n" ++
+        "Error code: " ++ show err ++ "\n" ++
+        "stderr: " ++ show stderr
+      throwIO (ExitFailure err)
+
+withTempDir action = do
+  dir <- getTemporaryDirectory
+  (path, handle) <- openTempFile dir "reanimate-XXXXXX"
+  hClose handle
+  removeFile path
+  createDirectory (dir </> path)
+  action (dir </> path) `finally` removeDirectoryRecursive (dir </> path)
+
+withTempFile ext action = do
+  dir <- getTemporaryDirectory
+  (path, handle) <- openTempFile dir ("reanimate-XXXXXX" <.> ext)
+  hClose handle
+  action path `finally` removeFile path
+
+requireExecutable :: String -> IO FilePath
+requireExecutable exec = do
+  mbPath <- findExecutable exec
+  case mbPath of
+    Nothing -> error $ "Couldn't find executable: " ++ exec
+    Just path -> return path
+
+
+tex_prologue =
+  "\\documentclass[preview]{standalone}\n\
+  \\\usepackage[english]{babel}\n\
+  \\\usepackage{amsmath}\n\
+  \\\usepackage{amssymb}\n\
+  \\\usepackage{dsfont}\n\
+  \\\usepackage{setspace}\n\
+  \\\usepackage{tipa}\n\
+  \\\usepackage{relsize}\n\
+  \\\usepackage{textcomp}\n\
+  \\\usepackage{mathrsfs}\n\
+  \\\usepackage{calligra}\n\
+  \\\usepackage{wasysym}\n\
+  \\\usepackage{ragged2e}\n\
+  \\\usepackage{physics}\n\
+  \\\usepackage{xcolor}\n\
+  \\\usepackage{textcomp}\n\
+  \\\usepackage{microtype}\n\
+  \\\DisableLigatures{encoding = *, family = * }\n\
+  \%\\usepackage[UTF8]{ctex}\n\
+  \\\linespread{1}\n\
+  \\\begin{document}\n"
+
+tex_epilogue = "\n\\end{document}"