Class: Retrograph::Easy::Logo

Inherits:
Object
  • Object
show all
Defined in:
lib/retrograph/easy/logo.rb

Constant Summary collapse

START_PATTERN = 
1
LETTER_NAME_DATA = 
(0...n_letter_patterns).map { |i|
  [ i + letter_pattern_offset, 0 ]
}.flatten.pack("C*")
PATTERN_DATA = 
[letter_patterns, led_patterns].flatten.inject("") { |a, b| a + b }
CHARACTERS = 
[
  0b00100010, # r
  0b01111110, # e
  0b00111010, # t
  0b00100010, # r
  0b00110011, # o
  0b01111101, # g
  0b00100010, # r
  0b01110111, # a
  0b01101110, # P
  0b00101011  # h
]
CHAR_BIT_MAPPINGS = 
[
  [0, corner_pattern_offset, [[0b01000000, 5], [0b00001000, 3]]],
  [2, corner_pattern_offset, [[0b01000000, 5], [0b00000100, 2]]],
  [64, middle_pattern_offset, [[0b00100000, 3], [0b00001000, 2], [0b00000010, 1]]],
  [66, middle_pattern_offset, [[0b00100000, 3], [0b00000100, 1], [0b00000001, 0]]],
  [128, corner_pattern_offset, [[0b00010000, 3], [0b00000010, 1]]],
  [130, corner_pattern_offset, [[0b00010000, 3], [0b00000001, 0]]]
]

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Logo

Returns a new instance of Logo.



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# File 'lib/retrograph/easy/logo.rb', line 28

def initialize(app)
  @app = app
end

Instance Method Details

#prepare_led_character(name_base) ⇒ Object 



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# File 'lib/retrograph/easy/logo.rb', line 75

def prepare_led_character(name_base)
  @app.write_vdu_byte(0x0800 + name_base + 3, 0b00100000)
  @app.write_vdu_byte(0x0800 + name_base + 67, 0b00100000)
  @app.write_vdu_byte(0x0800 + name_base + 129, 0b00010000)
  @app.write_vdu_byte(0x0800 + name_base + 131, 0b00110000)
end

#prepare_led_characters(name_base, count) ⇒ Object 



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# File 'lib/retrograph/easy/logo.rb', line 68

def prepare_led_characters(name_base, count)
  count.times do
    prepare_led_character(name_base)
    name_base += 4
  end
end

#show ⇒ Object 



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# File 'lib/retrograph/easy/logo.rb', line 32

def show
  @app.reset_vdu

  @app.vdu_mode 0x7

  # setup palette
  @app.palette_entry_rgb 0, 0, 0, 0
  @app.palette_entry_rgb 1, 255, 0, 0

  # setup patterns
  @app.tile_pattern_4bit(0x0000, START_PATTERN, PATTERN_DATA)

  num_characters = CHARACTERS.size

  start_row = (28 - 4) / 2 - 2
  start_col = (32 - (num_characters * 2)) / 2
  name_base = (start_col + start_row * 32) * 2

  # setup name table
  @app.write_vdu(0x0800 + name_base, LETTER_NAME_DATA)
  name_base += 64
  prepare_led_characters(name_base, num_characters)

  # start display loop
  characters = [0] * num_characters
  delay = 9
  for revealed in 0..num_characters
    @app.each_of_n_frames(delay) do
      characters.map! { rand(127) + 1 }
      characters[0, revealed] = CHARACTERS[0, revealed]
      show_led_characters(name_base, characters)
    end
    delay = 1
  end
end

#show_led_character(name_base, c) ⇒ Object 



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# File 'lib/retrograph/easy/logo.rb', line 89

def show_led_character(name_base, c)
  for (name_offset, index, mappings) in CHAR_BIT_MAPPINGS
    for (mask, shift) in mappings
      index += (c & mask) >> shift
    end
    @app.write_vdu_byte(0x0800 + name_base + name_offset, index)
  end
end

#show_led_characters(name_base, cs) ⇒ Object 



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# File 'lib/retrograph/easy/logo.rb', line 82

def show_led_characters(name_base, cs)
  cs.each do |c|
    show_led_character(name_base, c)
    name_base += 4
  end
end