instiki/lib/maruku/ext/math/mathml_engines/blahtex.rb
2007-01-22 11:34:51 -06:00

109 lines
2.6 KiB
Ruby

require 'tempfile'
require 'fileutils'
require 'digest/md5'
require 'pstore'
module MaRuKu; module Out; module HTML
PNG = Struct.new(:src,:depth,:height)
def convert_to_png_blahtex(kind, tex)
begin
FileUtils::mkdir_p MaRuKu::Globals[:html_png_dir]
# first, we check whether this image has already been processed
md5sum = Digest::MD5.hexdigest(tex+" params: ")
result_file = File.join(MaRuKu::Globals[:html_png_dir], md5sum+".txt")
if not File.exists?(result_file)
tmp_in = Tempfile.new('maruku_blahtex')
f = tmp_in.open
f.write tex
f.close
resolution = get_setting(:html_png_resolution)
options = "--png --use-preview-package --shell-dvipng 'dvipng -D #{resolution}' "
options += ("--png-directory '%s'" % MaRuKu::Globals[:html_png_dir])
cmd = "blahtex #{options} < #{tmp_in.path} > #{result_file}"
$stderr.puts "$ #{cmd}"
system cmd
tmp_in.delete
end
result = nil
f = File.open(result_file)
result = f.read
f.close
doc = Document.new(result, {:respect_whitespace =>:all})
png = doc.root.elements[1]
if png.name != 'png'
maruku_error "Blahtex error: \n#{doc}"
return nil
end
depth = png.elements['depth'] || (raise "No depth element in:\n #{doc}")
height = png.elements['height'] || (raise "No height element in:\n #{doc}")
md5 = png.elements['md5'] || (raise "No md5 element in:\n #{doc}")
depth = depth.text.to_f
height = height.text.to_f # XXX check != 0
md5 = md5.text
dir_url = MaRuKu::Globals[:html_png_url]
return PNG.new("#{dir_url}#{md5}.png", depth, height)
rescue Exception => e
maruku_error "Error: #{e}"
end
nil
end
BlahtexCache = PStore.new("blahtex_cache.pstore")
def convert_to_mathml_blahtex(kind, tex)
begin
BlahtexCache.transaction do
if BlahtexCache[tex].nil?
tmp_in = Tempfile.new('maruku_blahtex')
f = tmp_in.open
f.write tex
f.close
tmp_out = Tempfile.new('maruku_blahtex')
options = "--mathml"
cmd = "blahtex #{options} < #{tmp_in.path} > #{tmp_out.path}"
$stderr.puts "$ #{cmd}"
system cmd
tmp_in.delete
result = nil
File.open(tmp_out.path) do |f| result=f.read end
puts result
BlahtexCache[tex] = result
end
blahtex = BlahtexCache[tex]
doc = Document.new(blahtex, {:respect_whitespace =>:all})
mathml = doc.root.elements['mathml']
if not mathml
maruku_error "Blahtex error: \n#{doc}"
return nil
else
return mathml
end
end
rescue Exception => e
maruku_error "Error: #{e}"
end
nil
end
end end end