40 lines
1 KiB
Ruby
40 lines
1 KiB
Ruby
class Pixmap
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def self.read_ppm(ios)
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format = ios.gets.chomp
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width, height = ios.gets.chomp.split.map {|n| n.to_i }
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max_colour = ios.gets.chomp
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if (not PIXMAP_FORMATS.include?(format)) or
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width < 1 or height < 1 or
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max_colour != '255'
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then
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ios.close
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raise StandardError, "file '#{filename}' does not start with the expected header"
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end
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ios.binmode if PIXMAP_BINARY_FORMATS.include?(format)
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bitmap = self.new(width, height)
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height.times do |y|
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width.times do |x|
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# read 3 bytes
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red, green, blue = case format
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when 'P3' then ios.gets.chomp.split
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when 'P6' then ios.read(3).unpack('C3')
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end
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bitmap[x,y] = RGBColour.new(red, green, blue)
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end
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end
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ios.close
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bitmap
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end
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def self.open(filename)
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read_ppm(File.open(filename, 'r'))
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end
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def self.open_from_jpeg(filename)
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read_ppm(IO.popen("convert jpg:#{filename} ppm:-", 'r'))
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end
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end
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bitmap = Pixmap.open_from_jpeg('file.jpg')
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