abstracted some stuff for dealing with the midi interface and generat…

…ing notes

examples/metronome.rb

@@ -2,6 +2,7 @@
 
 tempo = 96
 # comment this out and choose another one below if you want
+# a second metronome is set to run an octave and a half below at 8/8
 signature = [4,4]
 # signature = [3,4]
 # signature = [5,4]
@@ -12,18 +13,24 @@
 require 'rubygems'
 require 'midiator'
 require 'lib/ouroubourus'
+require 'lib/interfaces/midiator'
 require 'lib/sequencers/metronome'
 
-@s = Ouroubourus::Scheduler.new :timekeeper => Ouroubourus::LocalTimer.new(tempo, :resolution => 80)
-@midi = MIDIator::Interface.new
-@midi.autodetect_driver
-@midi.program_change 0, 115 # wood block
+require 'ruby-debug'
+Debugger.start
+
+@s = Ouroubourus::Scheduler.new :timekeeper => Ouroubourus::LocalTimer.new(tempo)
+@midi = Midiator.new
+@midi.interface.autodetect_driver
+@midi.interface.program_change 0, 115 # wood block
 @metronome1 = Metronome.new :interface => @midi, :signature => signature
-@metronome2 = Metronome.new :interface => @midi, :signature => [6,4], :basenote => 67
+@metronome2 = Metronome.new :interface => @midi, :signature => [8,8], :basenote => 53
 @s.subscribers << @metronome1
 @s.subscribers << @metronome2
 
 Signal.trap("INT") { @s.timekeeper.thread.exit!; "Interrupt caught, cancelling..." }
 
+# debugger
+
 @s.start
 @s.timekeeper.thread.join

lib/interfaces/midiator.rb

@@ -0,0 +1,15 @@
+require 'midiator'
+
+class Midiator
+
+  attr_accessor :interface
+
+  def initialize
+    @interface = MIDIator::Interface.new
+  end
+
+  def note(channel, pitch, velocity)
+    @interface.driver.note_on(pitch, channel, velocity)
+  end
+
+end

lib/ouroubourus.rb

@@ -6,5 +6,6 @@ module Ouroubourus
 
 $:.unshift File.dirname(__FILE__)
 %w(scheduler schedulable schedule
+midi midi/note midi/generator
 timekeeper/timekeeper timekeeper/local_timer
 ).each {|r| require "ouroubourus/#{r}.rb" }

lib/ouroubourus/midi.rb

@@ -0,0 +1,5 @@
+module Ouroubourus
+  module Midi
+
+  end
+end

lib/ouroubourus/midi/generator.rb

@@ -0,0 +1,27 @@
+module Ouroubourus
+  module MIDI
+    module Generator
+
+      def play(notes)
+        [notes].flatten.each do |note|
+          if note.start.zero?
+            note_on(note.channel, note.pitch, note.velocity)
+            @schedule.in(note.duration, L{ note_off(note.channel, note.pitch)})
+          else
+            @schedule.in(note.start, L{ note_on(note.channel, note.pitch, note.velocity) })
+            @schedule.in(note.start + note.duration, L{ note_off(note.channel, note.pitch) })
+          end
+        end
+      end
+
+      def note_on(channel, pitch, velocity)
+        @interface.note(channel, pitch, velocity)
+      end
+
+      def note_off(channel, pitch)
+        note_on(channel, pitch, 0)
+      end
+
+    end
+  end
+end

lib/ouroubourus/midi/note.rb

@@ -0,0 +1,45 @@
+module Ouroubourus
+  module MIDI
+    class Note
+
+      attr_reader :pitch, :velocity, :duration, :start, :channel
+
+      def initialize(p, vel, dur, chan=1, s=0)
+        self.pitch = p
+        self.velocity = vel
+        self.channel = chan
+        self.duration = dur
+        self.start = s
+      end
+
+      def pitch=(val)
+        @pitch = seven_bit(val)
+      end
+
+      def velocity=(val)
+        @velocity = seven_bit(val)
+      end
+
+      def channel=(val)
+        val = 1 if val < 1
+        val = 16 if val > 16
+        @channel = val
+      end
+
+      def duration=(val)
+        @duration = [1,val].max
+      end
+
+      def start=(val)
+        @start = [0,val].max
+      end
+
+    protected
+      def seven_bit(val)
+        val = 0 if val < 0
+        val = 127 if val > 127
+        val
+      end
+    end
+  end
+end

lib/ouroubourus/schedule.rb

@@ -11,7 +11,7 @@ def initialize
     def run(now)
       @time = now
       ready, @queue = @queue.partition {|pos, proc| pos <= now }
-      ready.each {|time, proc| Thread.start { proc.call(time) } }
+      ready.each {|time, proc| proc.call(time) }
     end
 
     def at(position, block)

lib/ouroubourus/scheduler.rb

@@ -10,7 +10,7 @@ def initialize(options={})
 
     def start
       return false unless timekeeper.kind_of?(Ouroubourus::Timekeeper)
-      timekeeper.start {|now| @subscribers.each{|s| Thread.start { s.run(now) } }}
+      timekeeper.start {|now| @subscribers.each{|s| s.run(now) }}
     end
 
   end

lib/sequencers/metronome.rb

@@ -1,5 +1,6 @@
 class Metronome
   include Ouroubourus::Schedulable
+  include Ouroubourus::MIDI::Generator
 
   attr_accessor :interface, :signature, :channel #, :schedule
 
@@ -9,30 +10,30 @@ def initialize(options={})
     @interface = options[:interface]
     @channel   = options[:channel] || 1
     @basenote  = options[:basenote] || 72
-    @run       = L{|now| tick(now) }
-    schedule.next 480, @run
-  end
-
-  def tick(now)
-    note = (now % bar_length) == 0 ? one : beat
-    @interface.driver.note_on(note[:pitch], @channel, note[:velocity])
-    @schedule.in(note[:duration], L{ @interface.driver.note_off(note[:pitch], @channel, 0) })
-    @schedule.next note_length, @run
+    @run       = L do |now|
+      play(now % bar_length == 0 ? one : beat)
+      @schedule.next beat_length, @run
+    end
+    schedule.next beat_length, @run
   end
 
   def bar_length
-    @signature.first * note_length
+    @signature.first * beat_length
   end
 
-  def note_length
+  def beat_length
     4.0 / @signature.last * 480
   end
 
   def one
-    {:pitch => @basenote + 12, :velocity => 100, :duration => 180}
+    note(@basenote+12, 100, 180)
   end
 
   def beat
-    {:pitch => @basenote, :velocity => 60, :duration => 90}
+    note(@basenote, 60, 90)
+  end
+
+  def note(pitch, velocity, duration)
+    Ouroubourus::MIDI::Note.new(pitch, velocity, duration, @channel, 0)
   end
 end