Class: Doom::Wad::Patch

Inherits:
Object
  • Object
show all
Defined in:
lib/doom/wad/patch.rb

Defined Under Namespace

Classes: Post

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, width, height, left_offset, top_offset, columns) ⇒ Patch

Returns a new instance of Patch.



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# File 'lib/doom/wad/patch.rb', line 10

def initialize(name, width, height, left_offset, top_offset, columns)
  @name = name
  @width = width
  @height = height
  @left_offset = left_offset
  @top_offset = top_offset
  @columns = columns
end

Instance Attribute Details

#columns ⇒ Object (readonly)

Returns the value of attribute columns.



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# File 'lib/doom/wad/patch.rb', line 8

def columns
  @columns
end

#height ⇒ Object (readonly)

Returns the value of attribute height.



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# File 'lib/doom/wad/patch.rb', line 8

def height
  @height
end

#left_offset ⇒ Object (readonly)

Returns the value of attribute left_offset.



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# File 'lib/doom/wad/patch.rb', line 8

def left_offset
  @left_offset
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/doom/wad/patch.rb', line 8

def name
  @name
end

#top_offset ⇒ Object (readonly)

Returns the value of attribute top_offset.



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# File 'lib/doom/wad/patch.rb', line 8

def top_offset
  @top_offset
end

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/doom/wad/patch.rb', line 8

def width
  @width
end

Class Method Details

.load(wad, name) ⇒ Object 



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# File 'lib/doom/wad/patch.rb', line 19

def self.load(wad, name)
  data = wad.read_lump(name)
  return nil unless data

  parse(name, data)
end

.parse(name, data) ⇒ Object 



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# File 'lib/doom/wad/patch.rb', line 26

def self.parse(name, data)
  width = data[0, 2].unpack1('v')
  height = data[2, 2].unpack1('v')
  left_offset = data[4, 2].unpack1('s<')
  top_offset = data[6, 2].unpack1('s<')

  column_offsets = width.times.map do |i|
    data[8 + i * 4, 4].unpack1('V')
  end

  columns = column_offsets.map do |offset|
    read_column(data, offset)
  end

  new(name, width, height, left_offset, top_offset, columns)
end

.read_column(data, offset) ⇒ Object 



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# File 'lib/doom/wad/patch.rb', line 43

def self.read_column(data, offset)
  posts = []
  pos = offset

  loop do
    top_delta = data[pos].ord
    break if top_delta == 0xFF

    length = data[pos + 1].ord
    pixels = data[pos + 3, length].bytes
    posts << Post.new(top_delta, pixels)
    pos += length + 4
  end

  posts
end