Class: Graphit::BmpFile

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bitmap_drawing) ⇒ BmpFile

Returns a new instance of BmpFile.



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# File 'lib/graphit/bmp_file.rb', line 6

def initialize( bitmap_drawing )
  self.bitmap_drawing = bitmap_drawing
end

Instance Attribute Details

#bitmap_drawing ⇒ Object

Returns the value of attribute bitmap_drawing.



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# File 'lib/graphit/bmp_file.rb', line 4

def bitmap_drawing
  @bitmap_drawing
end

Instance Method Details

#save_to_file(filename) ⇒ Object 



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# File 'lib/graphit/bmp_file.rb', line 10

def save_to_file( filename )
  File.open( filename, 'w') do |f|
  
    start = Time.now.to_f
  
    # if options[:debug]
    #   puts "Generating pixels: #{Time.now.to_f - start}"
    # end
  
    # if options[:debug]
    #   puts data_to_graph.size
    #   puts "Data points ^"
    #   puts "Max: #{@xmax}, Min: #{@xmin}"
    # end
  
  
    height = self.bitmap_drawing.height
    width  = self.bitmap_drawing.width
  
    start = Time.now.to_f

    pixel_data = ""
    self.bitmap_drawing.pixels.reverse.each_with_index do |row, i|
      row_bytes = 0
      row.each do |pixel|
        BinUtils.append_int8!(pixel_data, pixel[0]) 
        BinUtils.append_int8!(pixel_data, pixel[1]) 
        BinUtils.append_int8!(pixel_data, pixel[2]) 
  
        #pixel_data += [pixel[0,2].hex].pack( "C" )
        #pixel_data += [pixel[2,2].hex].pack( "C" )
        #pixel_data += [pixel[4,2].hex].pack( "C" )
  
        row_bytes += 3
      end

      # Padding
      bytes_to_pad = row_bytes % 4

      # puts "Row: #{i}, bytes: #{row_bytes}, padding: #{bytes_to_pad}"

      bytes_to_pad.times do
        BinUtils.append_int8!(pixel_data, 0x00) 
      end
    end
  
    # if options[:debug]
    #   puts "Generating pixel data string: #{Time.now.to_f - start}"
    # end
  
    file_size = 54 + pixel_data.size

    f.print [0x42].pack ("C")
    f.print [0x4D].pack( "C" )
    f.print [file_size].pack( "L" )
  
    f.print [0x00].pack( "C" ) # Unused
    f.print [0x00].pack( "C" )
    f.print [0x00].pack( "C" )
    f.print [0x00].pack( "C" )
  
    f.print [54].pack( "L" ) # Pixel Array Offset
  
    f.print [0x28, 0x00, 0x00, 0x00].pack( "L" )  #Number of bytes in the DIB header (from this point)

    f.print [width].pack( "L" ) #Width of the bitmap in pixels
    f.print [height].pack( "L" ) #Height
  
    f.print [0x01, 0x00].pack( "S" ) # Number of color planes being used
    f.print [0x18, 0x00].pack( "S" ) # Number of bits per pixel
    f.print [0x00].pack( "L" ) # BI_RGB, no pixel array compression used
    f.print [pixel_data.size].pack( "L" ) # Size of the raw bitmap data (including padding)
    f.print [0x130B].pack( "L" ) #2835 pixels/meter horizontal
    f.print [0x130B].pack( "L" ) #2835 pixels/meter vertical
    f.print [0x00].pack( "L" ) # Number of colors in the palette
    f.print [0x00].pack( "L" ) #0 means all colors are important
  
    f.print pixel_data
  end
end