gamnit: implement app::audio for desktop using SDL2 mixer

[nit.git] / lib / linux / audio.nit

diff --git a/lib/linux/audio.nit b/lib/linux/audio.nit
index 85f572a..a3bfb4f 100644 (file)
--- a/lib/linux/audio.nit
+++ b/lib/linux/audio.nit
@@ -14,23 +14,112 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Linux audio implementation
+# `app::audio` implementation for GNU/Linux using SDL2 mixer
 module audio
 
 import app::audio
+import sdl2::mixer
 import linux
 
 redef class PlayableAudio
+       redef var error = null
 
-       redef fun play do
-               if path.has_suffix(".wav") then
-                       sys.system "aplay -q {app.assets_dir}{path} &"
-               else if path.has_suffix(".mp3") then
-                       sys.system "mpg123 -q {app.assets_dir}{path} &"
+       # Real file system path to this asset
+       private fun fs_path: String do return app.assets_dir / path
+
+       # Does `fs_path` exist?
+       private fun fs_path_exists: Bool
+       do
+               if not fs_path.file_exists then
+                       error = new Error("Failed to load audio '{path}': file not found")
+                       return false
+               end
+               return true
+       end
+end
+
+redef class Sound
+
+       private var native: nullable MixChunk = null
+
+       redef fun load
+       do
+               if not fs_path_exists then return
+
+               # SDL2 mixer load
+               var native = mix.load_wav(fs_path.to_cstring)
+               if native.address_is_null then
+                       error = new Error("Failed to load sound '{path}': {mix.error}")
+                       return
+               end
+
+               self.native = native
+       end
+
+       redef fun play
+       do
+               var native = native
+
+               if native == null and error == null then
+                       # Lazy load
+                       load
+
+                       # Auto print errors on lazy loading only
+                       var error = error
+                       if error != null then print_error error
+               end
+
+               # If there's an error, silently skip
+               if error != null then return
+               native = self.native
+               assert native != null
+
+               # Play on any available channel
+               mix.play_channel(-1, native, 0)
+       end
+end
+
+redef class Music
+
+       private var native: nullable MixMusic = null
+
+       redef fun load
+       do
+               if not fs_path_exists then return
+
+               # SDL2 mixer load
+               var native = mix.load_mus(fs_path.to_cstring)
+               if native.address_is_null then
+                       error = new Error("Failed to load music '{path}': {mix.error}")
+                       return
+               end
+
+               self.native = native
+       end
+
+       redef fun play
+       do
+               var native = native
+
+               if native == null and error == null then
+                       # Lazy load
+                       load
+
+                       # Auto print errors on lazy loading only
+                       var error = error
+                       if error != null then print_error error
                end
+
+               # If there's an error, silently skip
+               if error != null then return
+               native = self.native
+               assert native != null
+
+               # Play looping
+               mix.play_music(native, -1)
        end
 
-       redef fun load do end
-       redef fun pause do end
-       redef fun resume do end
+       redef fun pause do mix.pause_music
+
+       redef fun resume do mix.resume_music
 end