Class: Minicomic::BookletLayout

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

Instance Method Summary collapse

Constructor Details

#initialize(stream, *pages) ⇒ BookletLayout

Returns a new instance of BookletLayout.



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# File 'lib/minicomic.rb', line 98

def initialize( stream, *pages )
  @bboxes = {}
  @stream = stream

  pages.push nil if pages.size % 2 != 0 # pad to even number of pages

  # move the back cover to the beginning, to be paired with the front cover
  pages.unshift pages.pop

  # pair up adjacent pages into spreads
  spreads = (0...(pages.size/2)).map { |i| [ pages[i*2], pages[i*2+1] ] }

  # format each spread, breaking spreads back into invdividual pages after
  pages = spreads.inject( [] ) do |acc, spread|
    is_cover = acc.empty?
    acc.push *format_pages( is_cover, *spread )
  end

  # return the back cover to the end
  pages.push pages.shift

  emit_document pages
end

Instance Method Details

#bbox(i, n, document) ⇒ Object 



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# File 'lib/minicomic.rb', line 163

def bbox( i, n, document )
  rx, ry = @bboxes[document] ||= (
    rx, ry = 0.0..(FORMAT_WIDTH.to_f * n), 0.0..(FORMAT_HEIGHT.to_f)
    File.open( document, "r" ) do |stream|
      stream.each_line do |line|
        case line
        when /^%%BoundingBox: (\d+) (\d+) (\d+) (\d+)/
          rx, ry = ($1.to_f)..($3.to_f), ($2.to_f)..($4.to_f)
          break
        when /^%%EndComments/
          break
        end
      end
    end
    [ rx, ry ]
  )
  width = rx.end - rx.begin
  [ ( rx.begin + width * i / n )..( rx.begin + width * ( i + 1 ) / n ), ry ]
end

#bottom_margin(height) ⇒ Object 



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# File 'lib/minicomic.rb', line 183

def bottom_margin( height )
  ( FORMAT_HEIGHT.to_f - height ) / PHI
end

#emit_clip_rect(x0, y0, x1, y1) ⇒ Object 



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# File 'lib/minicomic.rb', line 235

def emit_clip_rect( x0, y0, x1, y1 )
  @stream.puts "newpath"
  @stream.puts "#{ x0 } #{ y0 } moveto"
  @stream.puts "#{ x0 } #{ y1 } lineto"
  @stream.puts "#{ x1 } #{ y1 } lineto"
  @stream.puts "#{ x1 } #{ y0 } lineto"
  @stream.puts "closepath eoclip newpath"
end

#emit_document(pages) ⇒ Object 



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# File 'lib/minicomic.rb', line 216

def emit_document( pages )
  @stream.puts "%!PS-Adobe-3.0"
  emit_dsc 'Creator', 'minicomic'
  emit_dsc 'Pages', pages.size
  #emit_dsc 'Orientation', 'Portrait'
  #bbox = "0 0 #{ FORMAT_WIDTH } #{ FORMAT_HEIGHT }"
  #emit_dsc 'BoundingBox', bbox
  #emit_dsc 'HiResBoundingBox', bbox
  emit_dsc 'EndComments'
  pages.each_with_index do |page, n|
    if page
      emit_page( n, *page )
    else
      emit_empty_page( n )
    end
  end
  emit_dsc 'EOF'
end

#emit_dsc(name, value = nil) ⇒ Object 



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# File 'lib/minicomic.rb', line 208

def emit_dsc( name, value=nil )
  if value
    @stream.puts "%%#{ name }: #{ value }"
  else
    @stream.puts "%%#{ name }"
  end
end

#emit_empty_page(n) ⇒ Object 



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# File 'lib/minicomic.rb', line 270

def emit_empty_page( n )
  emit_dsc 'Page', "#{ n } #{ n }"
  @stream.puts "showpage"
end

#emit_page(n, bbox, translate, document) ⇒ Object 



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# File 'lib/minicomic.rb', line 244

def emit_page( n, bbox, translate, document )
  emit_dsc 'Page', "#{ n } #{ n }"

  @stream.puts "save"

  emit_clip_rect( 0, 0, FORMAT_WIDTH, FORMAT_HEIGHT )

  @stream.puts <<EOS
#{ bbox.map { |r| -r.begin }.join( ' ' ) } translate 
#{ PAGE_SCALE } #{ PAGE_SCALE } scale
#{ translate.join( ' ' ) } translate
EOS

  emit_clip_rect( bbox[0].begin, bbox[1].begin, bbox[0].end, bbox[1].end )

  emit_dsc 'BeginDocument', File.basename( document )
  File.open( document, 'r' ) do |input|
    input.each_line do |line|
      @stream.puts line
    end
  end
  emit_dsc 'EndDocument'
  emit_dsc 'PageTrailer'
  @stream.puts "restore"
end

#format_pages(is_cover, *pages) ⇒ Object 



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# File 'lib/minicomic.rb', line 122

def format_pages( is_cover, *pages )
  spread = pages.map do |page|
    if page
      [ bbox(*page), page[2] ]
    else
      nil
    end
  end.map do |page|
    if page
      bbox, document = page
      dims = (0..1).map { |d| ( bbox[d].end - bbox[d].begin ) * PAGE_SCALE }
      [ bbox, dims, document ]
    else
      nil
    end
  end

  if spread.all? # i.e. both?
    spread_dims = spread.map { |page| page[1] }
    left_document = spread[LEFT][2]
    right_document = spread[RIGHT][2]
    if left_document == right_document
      tx = translate_spread( *spread_dims )
    elsif is_cover
      tx = spread_dims.map { |dims| translate_single( dims ) }
    else
      tx = translate_facing( *spread_dims )
    end
    [ [ spread[LEFT][0], tx[LEFT], left_document ],
      [ spread[RIGHT][0], tx[RIGHT], right_document ] ]
  else
    spread.map do |page|
      if page
        [ page[0], translate_single( page[1] ), page[2] ]
      else
        nil
      end
    end
  end
end

#horizontal_margin(width) ⇒ Object 



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# File 'lib/minicomic.rb', line 187

def horizontal_margin( width )
  ( FORMAT_WIDTH.to_f - width ) / 2
end

#translate_facing(left, right) ⇒ Object 



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# File 'lib/minicomic.rb', line 195

def translate_facing( left, right )
  left_margin = horizontal_margin( left[0] )
  right_margin = horizontal_margin( right[0] )
  gutter = [ [ left_margin, right_margin ].min, 0 ].max
  [ [ left_margin + ( gutter / 3 ), bottom_margin( left[1] ) ],
    [ right_margin - ( gutter / 3 ), bottom_margin( right[1] ) ] ]
end

#translate_single(dims) ⇒ Object 



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# File 'lib/minicomic.rb', line 191

def translate_single( dims )
  [ horizontal_margin( dims[0] ), bottom_margin( dims[1] ) ]
end

#translate_spread(left, right) ⇒ Object 



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# File 'lib/minicomic.rb', line 203

def translate_spread( left, right )
  [ [ FORMAT_WIDTH.to_f - left[0], bottom_margin( left[1] ) ],
    [ 0, bottom_margin( right[1] ) ] ]
end