Move load_audio into loading.c for consistency

source/loading.c

@@ -28,6 +28,7 @@
 #include "pp2d/pp2d/pp2d.h"
 #include "fs.h"
 #include "unicode.h"
+#include "music.h"
 #include "draw.h"
 
 void delete_entry(Entry_s * entry, bool is_file)
@@ -458,3 +459,42 @@ bool load_preview(Entry_List_s list, int * preview_offset)
 
     return ret;
 }
+
+// Initialize the audio struct
+Result load_audio(Entry_s entry, audio_s *audio) 
+{
+    audio->filesize = load_data("/bgm.ogg", entry, &audio->filebuf);
+
+    audio->mix[0] = audio->mix[1] = 1.0f; // Determines volume for the 12 (?) different outputs. See http://smealum.github.io/ctrulib/channel_8h.html#a30eb26f1972cc3ec28370263796c0444
+
+    ndspChnSetInterp(0, NDSP_INTERP_LINEAR); 
+    ndspChnSetRate(0, 44100);
+    ndspChnSetFormat(0, NDSP_FORMAT_STEREO_PCM16); // Tremor outputs ogg files in 16 bit PCM stereo
+	ndspChnSetMix(0, audio->mix); // See mix comment above
+
+    FILE *file = fmemopen(audio->filebuf, audio->filesize, "rb");
+    if(file != NULL) 
+    {
+        int e = ov_open(file, &audio->vf, NULL, 0);
+        if (e < 0) 
+        {
+            char error[50];
+            sprintf(error, "Vorbis: %d\n", e);
+            DEBUG(error);
+            return MAKERESULT(RL_FATAL, RS_INVALIDARG, RM_APPLICATION, RD_NO_DATA);
+        }
+
+        vorbis_info *vi = ov_info(&audio->vf, -1);
+        ndspChnSetRate(0, vi->rate);// Set sample rate to what's read from the ogg file
+
+        audio->wave_buf[0].nsamples = audio->wave_buf[1].nsamples = vi->rate / 4; // 4 bytes per sample, samples = rate (bytes) / 4
+        audio->wave_buf[0].status = audio->wave_buf[1].status = NDSP_WBUF_DONE; // Used in play to stop from writing to current buffer
+        audio->wave_buf[0].data_vaddr = linearAlloc(BUF_TO_READ); // Most vorbis packets should only be 4 KB at most (?) Possibly dangerous assumption
+        audio->wave_buf[1].data_vaddr = linearAlloc(BUF_TO_READ);
+        DEBUG("Success!");
+        return MAKERESULT(RL_SUCCESS, RS_SUCCESS, RM_APPLICATION, RD_SUCCESS);
+    } else {
+        DEBUG("File not found!\n");
+        return MAKERESULT(RL_FATAL, RS_NOTFOUND, RM_APPLICATION, RD_NOT_FOUND);
+    }
+}