Merge pull request #340 from scarpe-team/mvh-guitar

WIP demo of a guitar fretboard using bloops

examples/skip_ci/guitar_fretboard.rb

@@ -0,0 +1,137 @@
+require 'bloops'
+
+class Fret
+  def initialize(string, fret_idx, note, octave)
+    @string = string
+    @fret_idx = fret_idx
+    @note = note
+    @octave = octave
+  end
+
+  attr_reader :note
+  attr_reader :fret_idx
+  attr_reader :string
+
+  def to_s
+    "#{@note}#{@octave}"
+  end
+end
+
+class GuitarString
+  NOTES = %w{a a# b c c# d d# e f f# g g#}
+  FRET_COUNT = 23
+
+  include Enumerable
+
+  attr_reader :frets
+  attr_reader :fret_radios
+
+  def initialize(idx, open_note, starting_octave)
+    @root_note_index = NOTES.index(open_note)
+    octave = starting_octave
+
+
+    fret_index = 0
+    @frets = NOTES.cycle
+      .take(FRET_COUNT + @root_note_index)
+      .to_a[@root_note_index..-1]
+      .map { |note|
+        if note == NOTES.first
+          octave +=1
+        end
+        Fret.new(idx, fret_index, note, octave)
+      }
+    @fret_radios = {}
+  end
+
+  def render(app)
+    frets = @frets
+    string = self
+
+    app.flow(height: "15%") do
+      frets.each do |f|
+        flow width: "3%" do
+          border black, strokewidth: 1
+          background linen
+          string.fret_radios[f] = radio(f.string)
+          caption f.note
+        end
+      end
+    end
+  end
+end
+
+class Tunings
+  STANDARD  = %w{ e a d g b e }
+  DSTANDARD = %w{ d g c f a d }
+  DADGAD    = %w{ d a d g a d }
+
+  def self.get(constname)
+    tconst = constname.upcase.gsub(" ", "")
+    const_get(tconst).reverse.map.with_index do |n, idx|
+      GuitarString.new(idx, n, 2)
+    end
+  end
+end
+
+def bloops
+  @bloops ||= Bloops.new
+end
+
+def play_chord(notes)
+  bloops.clear
+  sound = bloops.sound Bloops::SQUARE
+  sound.sustain = 0.05
+  sound.decay = 0.35
+
+  notes.each do |n|
+    bloops.tune sound, n
+  end
+
+  bloops.play
+end
+
+Shoes.app(width: 1280, height: 400) do
+  @tuning = "standard"
+  @strings = Tunings::get(@tuning)
+  @fretboard = []
+
+  render_strings = ->(app) {
+    @strings.each do |string|
+      string.render(app)
+    end
+  }
+
+  flow do
+    @current_tuning = title @tuning
+    @fretboard = stack width: "100%", margin: 20, &render_strings
+
+    stack do
+      button "Play" do
+        fretted_notes = @strings.flat_map { |s|
+          s.fret_radios.select { |k, v| v.checked? }.keys
+        }.map(&:to_s)
+
+        play_chord(fretted_notes)
+
+        @strings.map do |s|
+          s.fret_radios.map { |_, r| r.checked = false }
+        end
+      end
+
+      flow do
+        caption "Select a tuning:"
+        @tuning_select = list_box(
+                                  items: ["d standard", "dadgad", "standard"]
+                                 ).change { |tuning| @tuning = tuning }
+
+        button "Change Tuning" do
+          self.instance_variable_set("@strings", Tunings::get(@tuning))
+          @fretboard.clear
+          @fretboard.append(&render_strings)
+          @current_tuning.replace @tuning
+        end
+      end
+    end
+  end
+end