Class: DiscreetProxy::Proxy

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

Overview

This class represents a proxy.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(w = DEFAULT_WIDTH, h = DEFAULT_HEIGHT) ⇒ Proxy

Returns a new instance of Proxy.



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# File 'lib/discreet_proxy.rb', line 57

def initialize(w = DEFAULT_WIDTH, h = DEFAULT_HEIGHT)
  @width, @height = w.to_i, h.to_i
  # Blank out the pixel values with black
  generate_black
end

Instance Attribute Details

#height ⇒ Object (readonly)

Image dimensions, standard is 126x92



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# File 'lib/discreet_proxy.rb', line 51

def height
  @height
end

#rows ⇒ Object (readonly)

Array of rows with each row being an array of packed color integers (you can unpack them with ChunkyPNG::Color)



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# File 'lib/discreet_proxy.rb', line 55

def rows
  @rows
end

#width ⇒ Object (readonly)

Image dimensions, standard is 126x92



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# File 'lib/discreet_proxy.rb', line 51

def width
  @width
end

Instance Method Details

#[](left, top) ⇒ Object

Get an array of the [r,g,b] pixel values at the specific coordinate



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# File 'lib/discreet_proxy.rb', line 75

def [](left, top)
  png_color_int = @rows[top][left]
  unpack_rgb(png_color_int)
end

#[]=(x, y, *rgb) ⇒ Object

Set the color value at the specific coordinate. If the passed value is a single integer, it gets interpreted as a PNG color value. If a triplet array with three components is passed it’s interpreted as RGB



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# File 'lib/discreet_proxy.rb', line 83

def []=(x, y, *rgb)
  color = rgb.flatten
  
  # Check for raw pixel value
  if color.length == 1 && color[0].is_a?(Numeric)
    @rows[y][x] = color[0]
  else
    r, g, b = color.map{|e| e.to_i }
    @rows[y][x] = pack_rgb(r, g ,b)
  end
end

#fill_pixbuf(io) ⇒ Object

Once the proxy metadata is known, this method can parse out the actual pixel data from the passed IO



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# File 'lib/discreet_proxy.rb', line 120

def fill_pixbuf(io)
  @rows = []
  
  # Data comes in row per row, starting on bottom left because of endianness
  per_row = (@width.to_i + row_pad) * 3
  total_size = ((per_row + row_pad) * @height) + 1
  blob = StringIO.new(io.read(total_size))
  
  @height.times do
    row = []
    row_data = blob.read(@width.to_i * 3)
    row_data = StringIO.new(row_data.to_s)
    
    # Read 3x8bit for each pixel
    @width.times do
      rgb = (row_data.read(3) || "AAA").unpack("CCC")
      row.push(pack_rgb(*rgb))
    end
    
    # At the end of each row (thus at the beginning byteswap),
    # 2 bytes contain garbage since rows are aligned
    # to start at 8-complement byte offsets. If they are not discarded this disturbs
    # the RGB cadence of the other values.
    blob.seek(blob.pos + row_pad)
    
    # Since the file is actually BE, the rows are ordered top to bottom in the file
    @rows.unshift(row)
  end
end

#save(filename) ⇒ Object

Save out the .p file



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# File 'lib/discreet_proxy.rb', line 151

def save(filename)
  File.open(filename, 'wb') { |io| io.write(to_dotp) }
end

#save_png(filename) ⇒ Object

Save out the PNG version of the file



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# File 'lib/discreet_proxy.rb', line 156

def save_png(filename)
  to_png.save(filename)
end

#to_dotp ⇒ Object

Compose a string with the entire contents of a proxy file



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# File 'lib/discreet_proxy.rb', line 96

def to_dotp
  # Pack the header
  buf = StringIO.new(0xFF.chr * 40)
  byteswap_version = [PROXY_VERSION].pack("e").reverse
  header = [MAGIC, VERSION_BSWAP, width, height, PROXY_DEPTH].pack("na6nnn")
  buf.write(header)
  buf.seek(40)
  
  # Now... all the reverses come in reverse
  (0...@rows.length).each do | row_offset |
    row_idx = (@rows.length - 1) - row_offset
    @rows[row_idx].each do | pix |
      rgb = unpack_rgb(pix).pack("CCC")
      buf.write(rgb) 
    end
    # Then write the padding
    buf.write(0x00.chr * row_pad)
  end
  
  buf.string
end

#to_png ⇒ Object 



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# File 'lib/discreet_proxy.rb', line 63

def to_png
  png = ChunkyPNG::Image.new(@width, @height)
  png.metadata["Software"] = "Ruby DiscreetProxy converter/chunky_png"
  @rows.each_with_index do | row, y |
    png.replace_row!(y, row)
  end
  # Bump it to the default icon size
  png.resample_bilinear!(DEFAULT_WIDTH, DEFAULT_HEIGHT)
  png
end