SF.net SVN: alleg:[10564] allegro/branches/4.9/addons/kcm_audio

[<mm...@us...>]

Revision: 10564
          http://alleg.svn.sourceforge.net/alleg/?rev=10564&view=rev
Author:   mmimica
Date:     2008-08-26 11:05:16 +0000 (Tue, 26 Aug 2008)

Log Message:
-----------
* Support all three loop modes when playing samples attached to voices in ALSA driver.
* Allow setting loop mode of an unattached ALLEGRO_SAMPLE.

Modified Paths:
--------------
    allegro/branches/4.9/addons/kcm_audio/alsa.c
    allegro/branches/4.9/addons/kcm_audio/kcm_sample.c

Modified: allegro/branches/4.9/addons/kcm_audio/alsa.c
===================================================================
--- allegro/branches/4.9/addons/kcm_audio/alsa.c	2008-08-26 05:13:09 UTC (rev 10563)
+++ allegro/branches/4.9/addons/kcm_audio/alsa.c	2008-08-26 11:05:16 UTC (rev 10564)
@@ -51,6 +51,7 @@
    unsigned int pos; /* in frames */
    unsigned int len; /* in frames */
    snd_pcm_uframes_t frag_len; /* in frames */
+   bool reversed; /* true if playing reversed ATM. */
 
    volatile bool stop;
    volatile bool stopped;
@@ -105,6 +106,15 @@
 }
 
 
+/*
+ * Updates the supplied non-streaming voice.
+ * buf   - Returns a pointer to the buffer containing sample data.
+ * bytes - The requested size of the sample data buffer. Returns the actual
+ *         size of returned the buffer.
+ * Updates 'stop', 'pos' and 'reversed' fields of the supplied voice.
+ * If the voice is played backwards, 'buf' will point to the end of the buffer
+ * and 'bytes' is the size that can be read towards the beginning.
+ */
 static int alsa_update_nonstream_voice(ALLEGRO_VOICE *voice, void **buf, int *bytes)
 {
    ALSA_VOICE *alsa_voice = (ALSA_VOICE*)voice->extra;
@@ -113,16 +123,40 @@
 
    *buf = voice->attached_stream->buffer.ptr + bpos;
 
-   if (bpos + *bytes > blen) {
-      *bytes = blen - bpos;
-      if (voice->attached_stream->loop == ALLEGRO_PLAYMODE_ONEDIR)
-         alsa_voice->stop = true;
+   if (!alsa_voice->reversed) {
+      if (bpos + *bytes > blen) {
+         *bytes = blen - bpos;
+         if (voice->attached_stream->loop == ALLEGRO_PLAYMODE_ONCE) {
+            alsa_voice->stop = true;
+            alsa_voice->pos = 0;
+         }
+         if (voice->attached_stream->loop == ALLEGRO_PLAYMODE_ONEDIR) {
+            alsa_voice->pos = 0;
+         }
+         else if (voice->attached_stream->loop == ALLEGRO_PLAYMODE_BIDIR) {
+            alsa_voice->reversed = true;
+            alsa_voice->pos = alsa_voice->len;
+         }
+         return 1;
+      }
+      else
+         alsa_voice->pos += *bytes / alsa_voice->frame_size;
+   }
+   else {
+      if (bpos - *bytes < 0) {
+         *bytes = bpos;
+         /* loop will be ALLEGRO_PLAYMODE_BIDIR, other playing modes that play
+            backwards are not currently supported by the API */
+         /*if (voice->attached_stream->loop != ALLEGRO_PLAYMODE_BIDIR)
+            alsa_voice->stop = true;*/
 
-      alsa_voice->pos = 0;
-      return 1;
+         alsa_voice->pos = 0;
+         alsa_voice->reversed = false;
+         return 1;
+      }
+      else
+         alsa_voice->pos -= *bytes / alsa_voice->frame_size;
    }
-   else
-      alsa_voice->pos += *bytes / alsa_voice->frame_size;
 
    return 0;
 }
@@ -216,10 +250,21 @@
       /* Read sample data into the buffer. */
       if (!voice->is_streaming && !alsa_voice->stopped) {
          void *buf;
+         bool reverse = alsa_voice->reversed;
          int bytes = frames * alsa_voice->frame_size;
+
          alsa_update_nonstream_voice(voice, &buf, &bytes);
-         memcpy(mmap, buf, bytes);
          frames = bytes / alsa_voice->frame_size;
+         if (!reverse) {
+            memcpy(mmap, buf, bytes);
+         }
+         else {
+            /* Put a reversed copy in the driver's buffer. */
+            unsigned int i;
+            int fs = alsa_voice->frame_size;
+            for (i = 1; i <= frames; i++)
+               memcpy(mmap + i * fs, buf - i * fs, fs);
+         }
       }
       else if (voice->is_streaming && !alsa_voice->stopped) {
          const void *data = _al_voice_update(voice, frames);
@@ -257,11 +302,6 @@
 {
    ALSA_VOICE *ex_data = voice->extra;
 
-   if (voice->attached_stream->loop == ALLEGRO_PLAYMODE_BIDIR) {
-      TRACE(PREFIX_N "ALLEGRO_PLAYMODE_BIDIR is not supported by the driver.\n");
-      return 1;
-   }
-
    ex_data->pos = 0;
    ex_data->len = voice->attached_stream->len >> MIXER_FRAC_SHIFT;
 
@@ -340,6 +380,7 @@
 
    ex_data->stop = true;
    ex_data->stopped = true;
+   ex_data->reversed = false;
    /* ALSA usually overrides this, but set it just in case. */
    ex_data->frag_len = 256;
 

Modified: allegro/branches/4.9/addons/kcm_audio/kcm_sample.c
===================================================================
--- allegro/branches/4.9/addons/kcm_audio/kcm_sample.c	2008-08-26 05:13:09 UTC (rev 10563)
+++ allegro/branches/4.9/addons/kcm_audio/kcm_sample.c	2008-08-26 11:05:16 UTC (rev 10564)
@@ -473,7 +473,9 @@
             return 1;
          }
 
-         al_lock_mutex(spl->mutex);
+         if (spl->parent.u.ptr)
+            al_lock_mutex(spl->mutex);
+
          spl->loop = val;
          if (spl->loop != ALLEGRO_PLAYMODE_ONCE) {
             if (spl->pos < spl->loop_start)
@@ -481,7 +483,10 @@
             else if (spl->pos > spl->loop_end-MIXER_FRAC_ONE)
                spl->pos = spl->loop_end-MIXER_FRAC_ONE;
          }
-         al_unlock_mutex(spl->mutex);
+
+         if (spl->parent.u.ptr)
+            al_unlock_mutex(spl->mutex);
+
          return 0;
 
       default:


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