lib/mml2wav/wave.rb in mml2wav-0.0.1 vs lib/mml2wav/wave.rb in mml2wav-0.0.2

@@ -6,28 +6,55 @@
     class << self
       include WaveFile
 
       def write(sounds, options={})
         output_path = options[:output] || "doremi.wav"
-        sampling_rate = options[:sampling_rate] || 8000
+        sampling_rate = options[:sampling_rate] || 22050
+        bpm = options[:bpm] || 60
+        velocity = 5
+        octave = 4
+        default_length = 4.0
 
         format = Format.new(:mono, :pcm_8, sampling_rate)
-        @sine_waves = {}
         Writer.new(output_path, format) do |writer|
           buffer_format = Format.new(:mono, :float, sampling_rate)
-          sounds.split(//).each do |sound|
-            frequency = Scale::FREQUENCIES[sound.downcase.to_sym]
+          sounds.scan(/T\d+|V\d+|L\d+|[A-G][#+]?(?:\d+|\.)?|O\d+|[><]|./i).each do |sound|
+            base_sec = 60.0
+            length = default_length
+            case sound
+            when /\AT(\d+)/i
+              bpm = $1.to_i
+            when /\AV(\d+)/i
+              velocity = $1.to_i
+            when /\AL(\d+)/i
+              default_length = $1.to_f
+            when /\A([A-G][#+]?)(\d+)/i
+              length = $2.to_f
+              sound = $1
+            when /\A([A-G][#+]?)(\.)/i
+              length = default_length / 1.5
+              sound = $1
+            when /\AO(\d+)/i
+              octave = $1.to_i
+            when "<"
+              octave += 1
+            when ">"
+              octave -= 1
+            end
+            sec = base_sec / length / bpm
+            amplitude = velocity.to_f / 10
+            frequency = Scale::FREQUENCIES[sound.downcase]
             next unless frequency
-            @sine_waves[sound] ||= sine_wave(frequency, sampling_rate)
-            samples = @sine_waves[sound]
+            frequency *= (2 ** octave)
+            samples = sine_wave(frequency, sampling_rate, sec, amplitude)
             buffer = Buffer.new(samples, buffer_format)
             writer.write(buffer)
           end
         end
       end
 
       private
-      def sine_wave(frequency, sampling_rate, sec=0.1, amplitude=0.5)
+      def sine_wave(frequency, sampling_rate, sec, amplitude=0.5)
         max = sampling_rate * sec
         if frequency == 0
           return Array.new(max) { 0.0 }
         end
         base_x = 2.0 * Math::PI * frequency / sampling_rate