Ryan C. Gordon - Thu, 7 Jun 2001 13:15:51

* Added Mix_ChannelFinished() and Mix_GetChunk()
libsdl-org · Jun 10, 2001 · 3309045 · 3309045
1 parent f762ee5
commit 3309045
Show file tree

Hide file tree

Showing 4 changed files with 69 additions and 1 deletion.
diff --git a/CHANGES b/CHANGES
@@ -1,5 +1,7 @@
 
 1.2.1:
+Ryan C. Gordon - Thu, 7 Jun 2001 13:15:51
+ * Added Mix_ChannelFinished() and Mix_GetChunk()
 Ryan C. Gordon - Tue, 5 Jun 2001 11:01:51
  * Added VOC sound file support
 Guillaume Cottenceau - Thu May 10 11:17:55 PDT 2001

diff --git a/SDL_mixer.h b/SDL_mixer.h
@@ -123,6 +123,11 @@ extern DECLSPEC void Mix_HookMusicFinished(void (*music_finished)(void));
 /* Get a pointer to the user data for the current music hook */
 extern DECLSPEC void *Mix_GetMusicHookData(void);
 
+/* Add your own callback when a channel has finished playing. NULL
+ * to disable callback.
+ */
+extern DECLSPEC void Mix_ChannelFinished(void (*channel_finished)(int channel));
+
 /* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
    them dynamically to the next sample if requested with a -1 value below.
    Returns the number of reserved channels.
@@ -219,6 +224,11 @@ extern DECLSPEC int Mix_PlayingMusic(void);
 /* Stop music and set external music playback command */
 extern DECLSPEC int Mix_SetMusicCMD(const char *command);
 
+/* Get the Mix_Chunk currently associated with a mixer channel
+    Returns NULL if it's an invalid channel, or there's no chunk associated.
+*/
+extern DECLSPEC Mix_Chunk *Mix_GetChunk(int channel);
+
 /* Close the mixer, halting all playing audio */
 extern DECLSPEC void Mix_CloseAudio(void);
 

diff --git a/mixer.c b/mixer.c
@@ -61,6 +61,9 @@ static int reserved_channels = 0;
 static void (*mix_postmix)(void *udata, Uint8 *stream, int len) = NULL;
 static void *mix_postmix_data = NULL;
 
+/* rcg07062001 callback to alert when channels are done playing. */
+static void (*channel_done_callback)(int channel) = NULL;
+
 /* Music function declarations */
 extern int open_music(SDL_AudioSpec *mixer);
 extern void close_music(void);
@@ -139,6 +142,11 @@ static void mix_channels(void *udata, Uint8 *stream, int len)
 						mix_channel[i].playing = mix_channel[i].chunk->alen;
 					}
 				}
+
+				/* rcg06072001 Alert app if channel is done playing. */
+				if ( (!mix_channel[i].playing) && (channel_done_callback) ) {
+					channel_done_callback(i);
+				}
 			}
 		}
 	}
@@ -464,6 +472,14 @@ void *Mix_GetMusicHookData(void)
 	return(music_data);
 }
 
+void Mix_ChannelFinished(void (*channel_finished)(int channel))
+{
+    SDL_LockAudio();
+    channel_done_callback = channel_finished;
+    SDL_UnlockAudio();
+}
+
+
 /* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
    them dynamically to the next sample if requested with a -1 value below.
    Returns the number of reserved channels.
@@ -739,6 +755,18 @@ int Mix_Playing(int which)
 	return(status);
 }
 
+/* rcg06072001 Get the chunk associated with a channel. */
+Mix_Chunk *Mix_GetChunk(int channel)
+{
+	Mix_Chunk *retval = NULL;
+
+	if ((channel >= 0) && (channel < num_channels)) {
+		retval = mix_channel[channel].chunk;
+	}
+
+	return(retval);
+}
+
 /* Close the mixer, halting all playing audio */
 void Mix_CloseAudio(void)
 {

diff --git a/playwave.c b/playwave.c
@@ -54,7 +54,22 @@ void Usage(char *argv0)
 {
 	fprintf(stderr, "Usage: %s [-8] [-r rate] [-l] [-m] <wavefile>\n", argv0);
 }
-
+
+
+/*#define TEST_MIX_CHANNELFINISHED*/
+#ifdef TEST_MIX_CHANNELFINISHED  /* rcg06072001 */
+static volatile int channel_is_done = 0;
+static void channel_complete_callback(int chan)
+{
+	Mix_Chunk *done_chunk = Mix_GetChunk(chan);
+	printf("We were just alerted that Mixer channel #%d is done.\n", chan);
+	printf("Channel's chunk pointer is (%p).\n", done_chunk);
+	printf(" Which %s correct.\n", (wave == done_chunk) ? "is" : "is NOT");
+	channel_is_done = 1;
+}
+#endif
+
+
 main(int argc, char *argv[])
 {
 	int audio_rate;
@@ -126,10 +141,23 @@ main(int argc, char *argv[])
 		return(2);
 	}
 
+#ifdef TEST_MIX_CHANNELFINISHED  /* rcg06072001 */
+	setbuf(stdout, NULL);
+	Mix_ChannelFinished(channel_complete_callback);
+#endif
+
 	/* Play and then exit */
 	Mix_PlayChannel(0, wave, loops);
+
+#ifdef TEST_MIX_CHANNELFINISHED  /* rcg06072001 */
+	while (!channel_is_done) {
+		SDL_Delay(100);
+	}
+#else
 	while ( Mix_Playing(0) ) {
 		SDL_Delay(100);
 	}
+#endif
+
 	return(0);
 }