branch master updated: * tp/Texinfo/Convert/LaTeX.pm (convert_math_to_images): render math @-commands Texinfo tree elements as images using LaTeX with the preview package and dvipng.

[Patrice Dumas]

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pertusus pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
     new 5815c6a0ac * tp/Texinfo/Convert/LaTeX.pm (convert_math_to_images): 
render math @-commands Texinfo tree elements as images using LaTeX with the 
preview package and dvipng.
5815c6a0ac is described below

commit 5815c6a0acee7c825cf1338937f7c8ad752a7ed9
Author: Patrice Dumas <pertusus@free.fr>
AuthorDate: Thu Oct 31 01:12:34 2024 +0100

    * tp/Texinfo/Convert/LaTeX.pm (convert_math_to_images): render math
    @-commands Texinfo tree elements as images using LaTeX with the
    preview package and dvipng.
    
    * tp/Texinfo/Convert/Info.pm (output): preliminary code for the call
    to convert_math_to_images.
---
 ChangeLog                   |   9 ++
 tp/Texinfo/Convert/Info.pm  |  24 +++++
 tp/Texinfo/Convert/LaTeX.pm | 243 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 276 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 6233ef32d9..81f44122ed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2024-09-01  Patrice Dumas  <pertusus@free.fr>
+
+       * tp/Texinfo/Convert/LaTeX.pm (convert_math_to_images): render math
+       @-commands Texinfo tree elements as images using LaTeX with the
+       preview package and dvipng.
+
+       * tp/Texinfo/Convert/Info.pm (output): preliminary code for the call
+       to convert_math_to_images.
+
 2024-12-24  Patrice Dumas  <pertusus@free.fr>
 
        Remove letter column in printindex HTML formatting, improve formatting
diff --git a/tp/Texinfo/Convert/Info.pm b/tp/Texinfo/Convert/Info.pm
index 2d644754c2..bd1beceb17 100644
--- a/tp/Texinfo/Convert/Info.pm
+++ b/tp/Texinfo/Convert/Info.pm
@@ -30,6 +30,8 @@ use strict;
 
 use Carp qw(cluck);
 
+use File::Spec;
+
 use Texinfo::Common;
 use Texinfo::OutputUnits;
 use Texinfo::Convert::Text;
@@ -121,6 +123,28 @@ sub output($$)
   my $complete_header_bytes = $header_bytes;
   my $output_units = Texinfo::OutputUnits::split_by_node($document);
 
+  my $elements_images;
+  if (0) {
+    require Texinfo::Convert::LaTeX;
+    Texinfo::Convert::LaTeX->import;
+    my $math_images_dir;
+    if (!defined($destination_directory) or $destination_directory =~ /^\s*$/
+        or $destination_directory eq File::Spec->curdir()) {
+      $math_images_dir = $document_name.'_info_images';
+    } else {
+      $math_images_dir = $destination_directory;
+    }
+    $elements_images
+     = Texinfo::Convert::LaTeX::convert_math_to_images($self, $document,
+                                                    $document_name.'_info',
+                                                    $math_images_dir);
+    #if (defined($elements_images)) {
+    #  foreach my $element (%$elements_images) {
+    #    print STDERR "$element $elements_images->{$element}\n";
+    #  }
+    #}
+  }
+
   print STDERR "DOCUMENT\n" if ($self->get_conf('DEBUG'));
 
   my $out_file_nr = 0;
diff --git a/tp/Texinfo/Convert/LaTeX.pm b/tp/Texinfo/Convert/LaTeX.pm
index ae947d1e5e..7d24d82bb2 100644
--- a/tp/Texinfo/Convert/LaTeX.pm
+++ b/tp/Texinfo/Convert/LaTeX.pm
@@ -4492,4 +4492,247 @@ sub _convert($$)
   return $result;
 }
 
+
+
+# math commands to images
+#
+# render math @-commands Texinfo tree elements as images.
+# Requires LaTeX with some math modules and the preview package.
+# Use dvipng to generate the images.
+
+sub convert_math_to_images($$$;$)
+{
+  my $self = shift;
+  my $document = shift;
+  my $prefix = shift;
+  my $destination_directory = shift;
+
+  my $document_root = $document->tree();
+
+  my @math_at_commands = ('math', 'displaymath');
+
+  my $math2img_out_dir = $destination_directory;
+  if (!defined($math2img_out_dir) or $math2img_out_dir =~ /^\s*$/) {
+    $math2img_out_dir = File::Spec->curdir();
+  } else {
+    my ($encoded_math2img_out_dir, $math2img_out_dir_encoding)
+      = $self->encoded_output_file_name($math2img_out_dir);
+    $self->create_destination_directory($encoded_math2img_out_dir,
+                                        $math2img_out_dir);
+  }
+
+  my $math2img_basename = "${prefix}_math2img";
+
+  my $collected_commands = Texinfo::Common::collect_commands_list_in_tree(
+                                        $document_root, \@math_at_commands);
+
+  if (scalar(@$collected_commands) == 0) {
+    return undef;
+  }
+
+  my $math2img_latex_basefile = $math2img_basename.'.tex';
+
+  my ($encoded_math2img_latex_basefile, $latex_basefile_name_encoding)
+     = $self->encoded_output_file_name($math2img_latex_basefile);
+
+  my $math2img_latex_file_path_name = File::Spec->catfile($math2img_out_dir,
+                                                   $math2img_latex_basefile);
+
+  my ($encoded_math2img_latex_file_path_name, $math2img_latex_path_encoding)
+     = $self->encoded_output_file_name($math2img_latex_file_path_name);
+
+  my %options_latex_math = copy_options_for_convert_to_latex_math($self);
+
+  my $latex_converter
+     = Texinfo::Convert::LaTeX->converter(\%options_latex_math);
+
+  my $fh;
+  my $counter = 0;
+  my $result = {};
+  foreach my $element (@$collected_commands) {
+    my $cmdname = $element->{'cmdname'};
+    my $tree;
+    if ($cmdname eq 'math') {
+      $tree = $element->{'args'}->[0];
+    } elsif ($element->{'contents'}) {
+      $tree = {'contents' => [@{$element->{'contents'}}]};
+      if (scalar(@{$tree->{'contents'}})
+          and $tree->{'contents'}->[0]->{'type'}
+          and ($tree->{'contents'}->[0]->{'type'} eq 'empty_line_after_command'
+               or $tree->{'contents'}->[0]->{'type'} eq 
'elided_brace_command_arg'
+               or $tree->{'contents'}->[0]->{'type'} eq 
'elided_rawpreformatted')) {
+        shift @{$tree->{'contents'}};
+      }
+      if ($tree->{'contents'}->[-1]->{'cmdname'}
+          and $tree->{'contents'}->[-1]->{'cmdname'} eq 'end') {
+        pop @{$tree->{'contents'}};
+      }
+    } else {
+      next;
+    }
+    if (scalar(@{$tree->{'contents'}}) == 0) {
+      # should correspond to an ignored block
+      next;
+    }
+
+    $counter++;
+    if ($counter == 1) {
+      local *MATH2IMG_TEXFILE;
+      unless (open(*MATH2IMG_TEXFILE,
+              ">$encoded_math2img_latex_file_path_name")) {
+        $self->converter_document_error(
+                sprintf(__("math to images: could not open %s: %s"),
+                                   $math2img_latex_file_path_name, $!));
+        return undef;
+      }
+      $fh = *MATH2IMG_TEXFILE;
+
+      print $fh "% Automatically generated by Texinfo math to image code\n";
+
+      # TODO customization of the packages loaded
+      # The following unused list from
+      # https://orgmode.org/worg/org-tutorials/org-latex-preview.html
+      my $unused_more_packages = '
+\usepackage[usenames]{color}
+\usepackage{amsmath}
+\usepackage[mathscr]{eucal}
+\usepackage[utf8]{inputenc}
+\usepackage[T1]{fontenc}
+% Package fixltx2e omitted
+\usepackage{graphicx}
+% Package longtable omitted
+% Package float omitted
+% Package wrapfig omitted
+\usepackage[normalem]{ulem}
+\usepackage{textcomp}
+\usepackage{marvosym}
+\usepackage{wasysym}
+\usepackage{latexsym}
+\usepackage{amssymb}
+% Package amstext omitted
+% Package hyperref omitted
+';
+      print $fh '
+\documentclass{minimal}
+\usepackage{amsmath}
+\usepackage{amsthm}
+\usepackage{amssymb}
+\usepackage{bm}
+\usepackage[active,tightpage]{preview}
+\pagestyle{empty}
+\begin{document}
+'
+    }
+    my $text;
+    $text = convert_to_latex_math($latex_converter, $tree, undef);
+    print $fh "\\begin{preview}\n";
+    if ($cmdname eq 'math') {
+      print $fh "\$$text\$\n";
+    } else { #displaymath
+      print $fh "\n\\[" . $text . "\\]\n";
+    }
+    print $fh "\\end{preview}\n\n";
+
+    my $png_file_name = File::Spec->catfile($math2img_out_dir,
+                                        $math2img_basename.$counter.'.png');
+    $result->{$element} = $png_file_name;
+  }
+  if ($counter > 0) {
+    print $fh "\\end{document}\n";
+    # FIXME check close error
+    close ($fh);
+  } else {
+    return undef;
+  }
+
+  # run LaTeX
+  my ($encoded_math2img_out_dir, $math2img_out_dir_encoding)
+    = $self->encoded_output_file_name($math2img_out_dir);
+
+  my $math2img_initial_dir = Cwd::abs_path;
+  unless (chdir $encoded_math2img_out_dir) {
+    $self->converter_document_warn(
+            sprintf(__("math to images: chdir %s failed: %s"),
+                         $math2img_out_dir, $!));
+    return undef;
+  }
+  print STDERR "cwd($encoded_math2img_out_dir): " . Cwd::cwd() ."\n"
+    if ($self->get_conf('VERBOSE'));
+
+  $self->converter_document_warn(
+              sprintf(__("math to images: output file missing: %s"),
+                               $math2img_latex_basefile))
+    unless (-f $encoded_math2img_latex_basefile);
+
+  my $exec = 'latex';
+  my $cmd = "$exec $math2img_latex_basefile";
+  my $encoding = $self->get_conf('MESSAGE_ENCODING');
+
+  my $encoded_exec;
+  if (defined($encoding)) {
+    $encoded_exec = Encode::encode($encoding, $exec);
+  } else {
+    $encoded_exec = $exec;
+  }
+
+  my $encoded_cmd = $encoded_exec . " " . $encoded_math2img_latex_basefile;
+
+  print STDERR "math2img command: $encoded_cmd\n"
+    if ($self->get_conf('VERBOSE'));
+
+  # do not use system in order to be sure that STDIN is not
+  # mixed up with the main script STDIN.  It is important because
+  # if latex fails, it will may from STDIN and the input may trigger
+  # diverse actions.
+  if (not(open(MATH2IMG, "|-", $encoded_cmd))) {
+    $self->converter_document_error(sprintf(__(
+                         "math to images: command failed: %s"), $cmd));
+    return undef;
+  }
+  if (!close(MATH2IMG)) {
+    $self->converter_document_warn(sprintf(__(
+                     "math to images: closing communication failed: %s: %s"),
+                         $cmd, $!));
+    return undef;
+  }
+
+  my $math2img_dvi_basefile = $math2img_basename.'.dvi';
+
+  my ($encoded_math2img_dvi_basefile, $dvi_basefile_name_encoding)
+     = $self->encoded_output_file_name($math2img_dvi_basefile);
+
+  my $math2img_dvi_file_path_name = File::Spec->catfile($math2img_out_dir,
+                                                   $math2img_dvi_basefile);
+
+  my ($encoded_math2img_dvi_file_path_name, $math2img_dvi_path_encoding)
+     = $self->encoded_output_file_name($math2img_dvi_file_path_name);
+
+  $self->converter_document_warn(
+              sprintf(__("math to images: dvi file missing: %s"),
+                               $math2img_dvi_basefile))
+    unless (-f $encoded_math2img_dvi_basefile);
+
+  my @to_images_options = ('-T', 'tight', '-D', '600');
+  my @to_images_args = (@to_images_options, $encoded_math2img_dvi_basefile);
+
+  my $to_image_exec = 'dvipng';
+  my $status = system $to_image_exec, @to_images_args;
+
+  if ($status != 0) {
+    $self->converter_document_warn(sprintf(__(
+     "math to images: system `%s' failed: %d\n"), $to_image_exec . ' ' .
+         join(' ', @to_images_options). ' '.$math2img_dvi_basefile, $?));
+    return undef;
+  }
+
+  unless (chdir $math2img_initial_dir) {
+    $self->converter_document_warn(sprintf(__(
+          "math to images: unable to return to initial directory: %s"), $!));
+    return undef;
+  }
+
+  return $result;
+}
+
+
 1;