Implements volume control to Music (#123)

4 files changed, 81 insertions, 7 deletions

diff --git a/ext/ruby2d/ruby2d.c b/ext/ruby2d/ruby2d.c
index 885bf5c..03caf3d 100644
--- a/ext/ruby2d/ruby2d.c
+++ b/ext/ruby2d/ruby2d.c
@@ -65,6 +65,7 @@
   #define r_define_module(name)  mrb_define_module(mrb, name)
   #define r_define_class(module, name)  mrb_define_class_under(mrb, module, name, mrb->object_class)
   #define r_define_method(class, name, function, args)  mrb_define_method(mrb, class, name, function, args)
+  #define r_define_class_method(class, name, function, args)  mrb_define_class_method(mrb, class, name, function, args)
   #define r_args_none  (MRB_ARGS_NONE())
   #define r_args_req(n)  MRB_ARGS_REQ(n)
   // Helpers
@@ -87,6 +88,7 @@
   #define r_define_module(name)  rb_define_module(name)
   #define r_define_class(module, name)  rb_define_class_under(module, name, rb_cObject)
   #define r_define_method(class, name, function, args)  rb_define_method(class, name, function, args)
+  #define r_define_class_method(class, name, function, args)  rb_define_singleton_method(class, name, function, args)
   #define r_args_none  0
   #define r_args_req(n)  n
   // Helpers
@@ -670,6 +672,21 @@ static R_VAL ruby2d_music_ext_stop(R_VAL self) {
 
 
 /*
+ * Ruby2D::Music#ext_volume
+ */
+#if MRUBY
+static R_VAL ruby2d_music_ext_volume(mrb_state* mrb, R_VAL self) {
+  mrb_value vol;
+  mrb_get_args(mrb, "o", &vol);
+#else
+static R_VAL ruby2d_music_ext_volume(R_VAL self, R_VAL vol) {
+#endif
+  int mix_vol = NUM2INT(vol) == -1 ? -1 : MIX_MAX_VOLUME * NUM2INT(vol) / 100.0;
+  return INT2NUM(ceil(Mix_VolumeMusic(mix_vol) * 100.0 / MIX_MAX_VOLUME));
+}
+
+
+/*
  * Ruby2D::Music#ext_fadeout
  */
 #if MRUBY
@@ -1133,6 +1150,9 @@ void Init_ruby2d() {
   // Ruby2D::Music#ext_stop
   r_define_method(ruby2d_music_class, "ext_stop", ruby2d_music_ext_stop, r_args_none);
 
+  // Ruby2D::Music#self.ext_volume
+  r_define_class_method(ruby2d_music_class, "ext_volume", ruby2d_music_ext_volume, r_args_req(1));
+
   // Ruby2D::Music#ext_fadeout
   r_define_method(ruby2d_music_class, "ext_fadeout", ruby2d_music_ext_fadeout, r_args_req(1));
 
diff --git a/lib/ruby2d/music.rb b/lib/ruby2d/music.rb
index 41b8901..5974a8a 100644
--- a/lib/ruby2d/music.rb
+++ b/lib/ruby2d/music.rb
@@ -39,6 +39,22 @@ module Ruby2D
       ext_stop
     end
 
+    # Returns the previous volume setting, in percentage
+    def self.volume
+      self.ext_volume(-1)
+    end
+
+    # Set music volume, 0 to 100%
+    def self.volume=(v)
+      # If a negative value, volume will be 0
+      if v < 0 then v = 0 end
+      self.ext_volume(v)
+    end
+
+    # Alias instance methods to class methods
+    def volume; Music.volume end
+    def volume=(v); Music.volume=(v) end
+
     # Fade out music over provided milliseconds
     def fadeout(ms)
       ext_fadeout(ms)
diff --git a/test/audio.rb b/test/audio.rb
index 7d39569..8a0e8f6 100644
--- a/test/audio.rb
+++ b/test/audio.rb
@@ -11,28 +11,39 @@ set width: 300, height: 200, title: "Ruby 2D — Audio"
 snd = Sound.new("#{media}/sound.wav")
 mus = Music.new("#{media}/music.wav")
 
+volume_bar = Rectangle.new(color: 'green', width: 300, height: 50)
+
+on :mouse_down do |event|
+  Music.volume = event.x / Window.width.to_f * 100
+  volume_bar.width = Music.volume / 100.0 * Window.width
+  puts "Music volume: #{Music.volume}%"
+end
+
 on :key_down do |event|
   case event.key
   when 'p'
-    puts "Playing sound..."
+    puts "Playing sound"
     snd.play
   when 'm'
-    puts "Playing music..."
+    puts "Playing music"
     mus.play
+    mus.volume = 100
+    volume_bar.width = Window.width
+    puts "Music volume: #{mus.volume}"
   when 'l'
-    puts "Loop music true..."
+    puts "Looping music"
     mus.loop = true
   when 'a'
-    puts "Pause music..."
+    puts "Music paused"
     mus.pause
   when 'r'
-    puts "Resume music..."
+    puts "Music resumed"
     mus.resume
   when 's'
-    puts "Stop music..."
+    puts "Music stopped"
     mus.stop
   when 'f'
-    puts "fade out music..."
+    puts "Music fading out"
     mus.fadeout 2000
   when 'escape'
     close
diff --git a/test/music_spec.rb b/test/music_spec.rb
index c3a1173..09b6f1c 100644
--- a/test/music_spec.rb
+++ b/test/music_spec.rb
@@ -6,6 +6,33 @@ RSpec.describe Ruby2D::Music do
     it "raises exception if audio file doesn't exist" do
       expect { Music.new("bad_music.mp3") }.to raise_error(Ruby2D::Error)
     end
+
+    it "creates new music" do
+      Music.new("test/media/music.mp3")
+    end
+  end
+
+  describe "#volume" do
+    it "sets the volume on music instances" do
+      mus = Music.new("test/media/music.mp3")
+      expect(mus.volume).to eq(100)
+      mus.volume = 68
+      expect(mus.volume).to eq(68)
+    end
+
+    it "sets the volume using class methods" do
+      Music.volume = 27
+      expect(Music.volume).to eq(27)
+    end
+
+    it "sets volume to 0 or 100 if outside of range" do
+      Music.volume = 234
+      expect(Music.volume).to eq(100)
+      Music.volume = -312
+      expect(Music.volume).to eq(0)
+      Music.volume = -1
+      expect(Music.volume).to eq(0)
+    end
   end
 
 end