Sha256: cc5b1ca9461351f7f6271f3dc1ff8085759e8098e4d8fda45fa4ff51db658c7e

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Size: 1.44 KB

Versions: 12

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Stored size: 1.44 KB

Contents

class PSD
  module ImageFormat
    # Parses an RLE compressed image
    module RLE
      private

      def parse_rle!
        @byte_counts = parse_byte_counts!
        parse_channel_data!
      end

      def parse_byte_counts!
        byte_counts = []
        (channels * height).times do |i|
          byte_counts << @file.read_short
        end

        return byte_counts
      end

      def parse_channel_data!
        @chan_pos = 0
        @line_index = 0

        channels.times do |i|
          PSD.logger.debug "Parsing RLE channel ##{i}: position = #{@chan_pos}, line = #{@line_index}"
          decode_rle_channel
          @line_index += height
        end
      end

      def decode_rle_channel
        height.times do |j|
          byte_count = @byte_counts[@line_index + j]
          finish = @file.tell + byte_count

          while @file.tell < finish
            len = @file.read(1).bytes.to_a[0]

            if len < 128
              len += 1
              (@chan_pos...@chan_pos+len).each do |k|
                @channel_data[k] = @file.read(1).bytes.to_a[0]
              end

              @chan_pos += len
            elsif len > 128
              len ^= 0xff
              len += 2

              val = @file.read(1).bytes.to_a[0]
              (@chan_pos...@chan_pos+len).each do |k|
                @channel_data[k] = val
              end

              @chan_pos += len
            end
          end
        end
      end
    end
  end
end

Version data entries

12 entries across 12 versions & 1 rubygems

Version Path
psd-1.4.5 lib/psd/image_formats/rle.rb
psd-1.4.4 lib/psd/image_formats/rle.rb
psd-1.4.3 lib/psd/image_formats/rle.rb
psd-1.4.2 lib/psd/image_formats/rle.rb
psd-1.4.1 lib/psd/image_formats/rle.rb
psd-1.4.0 lib/psd/image_formats/rle.rb
psd-1.3.3 lib/psd/image_formats/rle.rb
psd-1.3.2 lib/psd/image_formats/rle.rb
psd-1.3.0 lib/psd/image_formats/rle.rb
psd-1.2.2 lib/psd/image_formats/rle.rb
psd-1.2.1 lib/psd/image_formats/rle.rb
psd-1.2.0 lib/psd/image_formats/rle.rb