Module: TwistyPuzzles::CubeConstants

Includes:
Utils::ArrayHelper
Included in:
CancellationHelper, ColorScheme, CubeState, Part, Part, SkewbCoordinate, SkewbState
Defined in:
lib/twisty_puzzles/cube_constants.rb

Overview

Various constants about the cube.

Constant Summary collapse

FACE_SYMBOLS =

The order determines the priority of the faces.

%i[U F R L B D].freeze
OPPOSITE_FACE_SYMBOLS = 
[%i[U D], %i[F B], %i[R L]].freeze
FACE_NAMES = 
FACE_SYMBOLS.map(&:to_s).freeze
ALPHABET_SIZE = 
24
SKEWB_STICKERS =

Stickers on each Skewb face.

5
CHIRALITY_FACE_SYMBOLS = 
%i[U R F].freeze

Instance Method Summary collapse

Methods included from Utils::ArrayHelper

#apply_permutation, #check_types, #find_only, #only, #replace_once, #rotate_out_nils, #turned_equals?

Instance Method Details

#chirality_canonical_face_symbol(face_symbol) ⇒ Object 



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# File 'lib/twisty_puzzles/cube_constants.rb', line 29

def chirality_canonical_face_symbol(face_symbol)
  if CHIRALITY_FACE_SYMBOLS.include?(face_symbol)
    face_symbol
  else
    opposite_face_symbol(face_symbol)
  end
end

#opposite_face_symbol(face_symbol) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/twisty_puzzles/cube_constants.rb', line 21

def opposite_face_symbol(face_symbol)
  candidates = OPPOSITE_FACE_SYMBOLS.select { |ss| ss.include?(face_symbol) }
  raise if candidates.length > 1
  raise ArgumentError, "Invalid face symbol #{face_symbol}." if candidates.empty?

  only(only(candidates).reject { |s| s == face_symbol })
end

#valid_chirality?(face_symbols) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/twisty_puzzles/cube_constants.rb', line 37

def valid_chirality?(face_symbols)
  # To make it comparable to our CHIRALITY_FACE_SYMBOLS, we switch each face used in c
  # different from the ones used in the CHIRALITY_FACE_SYMBOLS for the opposite face.
  canonical_face_symbols = face_symbols.map { |f| chirality_canonical_face_symbol(f) }

  # Each time we swap a face for the opposite, the chirality direction should be inverted.
  no_swapped_face_symbols = canonical_face_symbols.zip(face_symbols).count { |a, b| a != b }
  inverted = no_swapped_face_symbols.odd?
  inverted_face_symbols = inverted ? canonical_face_symbols.reverse : canonical_face_symbols

  # If the corner is not equal modulo rotation to CHIRALITY_FACE_SYMBOLS after this
  # transformation, the original corner had a bad chirality.
  turned_equals?(inverted_face_symbols, CHIRALITY_FACE_SYMBOLS)
end