scale.rb in head_music-0.4.0

- old
+ new

@@ -13,52 +13,57 @@
   def initialize(root_pitch, scale_type)
     @root_pitch = HeadMusic::Pitch.get(root_pitch)
     @scale_type = HeadMusic::ScaleType.get(scale_type)
   end
 
-  def pitches
-    @pitches ||= begin
+  def pitches(direction: :ascending, octaves: 1)
+    @pitches ||= {}
+    @pitches[direction] ||= {}
+    @pitches[direction][octaves] ||= begin
       letter_cycle = root_pitch.letter_cycle
       semitones_from_root = 0
       [root_pitch].tap do |pitches|
-        scale_type.intervals.each_with_index do |semitones, i|
-          semitones_from_root += semitones
-          pitches << pitch_for_step(i+1, semitones_from_root)
+        if [:ascending, :both].include?(direction)
+          (1..octaves).each do |i|
+            scale_type.ascending_intervals.each_with_index do |semitones, i|
+              semitones_from_root += semitones
+              pitches << pitch_for_step(i+1, semitones_from_root, :ascending)
+            end
+          end
         end
+        if [:descending, :both].include?(direction)
+          (1..octaves).each do |i|
+            scale_type.descending_intervals.each_with_index do |semitones, i|
+              semitones_from_root -= semitones
+              pitches << pitch_for_step(i+1, semitones_from_root, :descending)
+            end
+          end
+        end
       end
     end
   end
 
-  def pitch_names
+  def spellings
     pitches.map(&:spelling).map(&:to_s)
   end
 
-  def in(spelling)
-    spelling = HeadMusic::Spelling.get(spelling.to_s)
-    spellings = []
-    letter_index = HeadMusic::Letter::all.index(spelling.letter)
-    starting_pitch_class = spelling.pitch_class
-    pattern.each do |interval_from_tonic|
-      letter = HeadMusic::Letter.all[letter_index]
-      if interval_from_tonic
-        accidental_interval = letter.pitch_class.smallest_interval_to(HeadMusic::PitchClass.get(starting_pitch_class + interval_from_tonic))
-        accidental = HeadMusic::Accidental.for_interval(accidental_interval)
-        spellings << HeadMusic::Spelling.get([letter, accidental].join)
-      end
-      letter_index = (letter_index + 1) % 7
-    end
-    spellings
+  def pitch_names(direction: :ascending, octaves: 1)
+    pitches(direction: direction, octaves: octaves).map(&:name)
   end
 
   def letter_cycle
     @letter_cycle ||= root_pitch.letter_cycle
   end
 
-  def root_pitch_class
-    @root_pitch_class ||= root_pitch.pitch_class
+  def root_pitch_number
+    @root_pitch_number ||= root_pitch.number
   end
 
+  def degree(degree_number)
+    pitches[degree_number - 1]
+  end
+
   private
 
   def parent_scale_pitches
     HeadMusic::Scale.get(root_pitch, scale_type.parent_name).pitches if scale_type.parent
   end
@@ -67,24 +72,24 @@
     parent_scale_pitches.detect { |parent_scale_pitch|
       parent_scale_pitch.pitch_class == (root_pitch + semitones_from_root).to_i % 12
     }
   end
 
-  def letter_for_step(step, semitones_from_root)
+  def letter_for_step(step, semitones_from_root, direction)
     pitch_class_number = (root_pitch.pitch_class.to_i + semitones_from_root) % 12
     if scale_type.intervals.length == 7
-      letter_cycle[step % 7]
+      direction == :ascending ? letter_cycle[step % 7] : letter_cycle[-step % 7]
     elsif scale_type.intervals.length < 7 && parent_scale_pitches
       parent_scale_pitch_for(semitones_from_root).letter
     elsif root_pitch.flat?
       HeadMusic::PitchClass::FLAT_SPELLINGS[pitch_class_number]
     else
       HeadMusic::PitchClass::SHARP_SPELLINGS[pitch_class_number]
     end
   end
 
-  def pitch_for_step(step, semitones_from_root)
-    pitch_number = root_pitch_class.to_i + semitones_from_root
-    letter = letter_for_step(step, semitones_from_root)
+  def pitch_for_step(step, semitones_from_root, direction)
+    pitch_number = root_pitch_number + semitones_from_root
+    letter = letter_for_step(step, semitones_from_root, direction)
     HeadMusic::Pitch.from_number_and_letter(pitch_number, letter)
   end
 end