SDL2_mixer: add support for MID (#16556)

Enable SDL2_mixer to use timidity to provide MIDI support.

To use, you must provide your own sound files. I sourced mine from
https://www.npmjs.com/package/freepats

And mount them here:

--preload-file="../freepats@/etc/timidity"

(that's the default place timidity will look for configuration)

Author: connorjclark

src/settings.js

@@ -1457,7 +1457,7 @@ var USE_MODPLUG = false;
 // [link]
 var SDL2_IMAGE_FORMATS = [];
 
-// Formats to support in SDL2_mixer. Valid values: ogg, mp3
+// Formats to support in SDL2_mixer. Valid values: ogg, mp3, mod, mid
 // [link]
 var SDL2_MIXER_FORMATS = ["ogg"];
 

tests/test_browser.py

@@ -3275,6 +3275,8 @@ def test_sdl2_mixer_wav(self, flags):
     'ogg': (['ogg'],    'MIX_INIT_OGG', 'alarmvictory_1.ogg'),
     'mp3': (['mp3'],    'MIX_INIT_MP3', 'pudinha.mp3'),
     'mod': (['mod'],    'MIX_INIT_MOD', 'bleep.xm'),
+    # TODO: need to source freepats.cfg and a midi file
+    # 'mod': (['mid'],    'MIX_INIT_MID', 'midi.mid'),
   })
   @requires_sound_hardware
   def test_sdl2_mixer_music(self, formats, flags, music_name):

tools/ports/sdl2_mixer.py

@@ -63,6 +63,11 @@ def create(final):
         '-DMUSIC_MOD_MODPLUG',
       ]
 
+    if "mid" in settings.SDL2_MIXER_FORMATS:
+      flags += [
+        '-DMUSIC_MID_TIMIDITY',
+      ]
+
     ports.build_port(
       dest_path,
       final,
@@ -74,7 +79,6 @@ def create(final):
       ],
       exclude_dirs=[
         'native_midi',
-        'timidity',
         'external',
       ]
     )