Class: LatexToPng::Convert

Inherits:
Object
  • Object
show all
Defined in:
lib/latex_to_png.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = { filepath: nil, formula: nil, size: nil }) ⇒ Convert

or formula or filepath



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# File 'lib/latex_to_png.rb', line 48

def initialize opts={ filepath: nil, formula: nil, size: nil }

    @filepath = opts[:filepath]  if opts[:filepath]
    @size = (opts[:size] || 10).to_i
    @formula = opts[:formula] if opts[:formula]

end

Instance Attribute Details

#filepath ⇒ Object

Returns the value of attribute filepath.



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# File 'lib/latex_to_png.rb', line 35

def filepath
  @filepath
end

Class Method Details

.template ⇒ Object 



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# File 'lib/latex_to_png.rb', line 39

def template
  return @doc if @doc
  @doc = ERB.new(File.read("#{ File.dirname __FILE__}/templates/equation.erb"))
  @doc
end

Instance Method Details

#convert(filepath, size, name = filepath.split("/").last.split(".").first) ⇒ Object 



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# File 'lib/latex_to_png.rb', line 84

def convert filepath, size,
  name = filepath.split("/").last.split(".").first
  dirname =  File.dirname filepath
  density = ((300/10)*size).to_i
# debugger
    #convert for .dvi
    # dvi to .ps
    # .ps to .png "q*" option is to run quietly
    # %x(
    #   cd #{dirname}; latex  -halt-on-error  -output-format=pdf #{filepath} &&
    #   convert -density #{density}x#{density} #{name}.pdf  -trim  #{name}.png  1>&2 > /dev/null
    #   )
    #
    #   Thread.new {
    #      %x(cd #{dirname}; rm -f  #{name}.log #{name}.pdf #{name}.aux &)
    #   }.run()

     %x(
       cd #{dirname}; latex -halt-on-error  #{filepath} &&
       dvips -q* -E #{name}.dvi &&
       convert -density #{density}x#{density} #{name}.ps #{name}.png  1>&2 > /dev/null
       )

      Thread.new {
         %x(cd #{dirname}; rm -f #{name}.dvi #{name}.log  #{name}.aux  #{name}.ps &)
      }.run()



     png_path = "#{filepath.gsub(/.tex$/,"")}.png"

     if File.exist?(png_path)
       return open(png_path)
     else
       raise StandardError("Image not generated")
     end
end

#from_estatic(filepath, size) ⇒ Object 



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# File 'lib/latex_to_png.rb', line 79

def from_estatic filepath, size

  convert(filepath, size )
end

#from_formula(formula, size) ⇒ Object 



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# File 'lib/latex_to_png.rb', line 61

def from_formula formula, size


  tmp_file = Tempfile.new("formula")
  tmp_file.write  mount_tex(formula)
  tmp_file.close
  # debugger
  filepath = tmp_file.path

  convert(filepath,size )

end

#mount_tex(formula) ⇒ Object 



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# File 'lib/latex_to_png.rb', line 74

def mount_tex formula
   self.class.template.result(Formula.new( formula ).instance_eval { binding })
end

#size_in_points(size_in_pixels) ⇒ Object 



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# File 'lib/latex_to_png.rb', line 56

def size_in_points size_in_pixels
  size = Sizes.invert[size_in_pixels]
  return (size.nil?)? size_in_points("#{size_in_pixels.to_i + 1}px") : size
end

#to_png ⇒ Object 



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# File 'lib/latex_to_png.rb', line 123

def to_png
  if @formula
    from_formula @formula, @size

  else
    from_estatic @filepath, @size
 end
end