[GTK3] Use the audio abstraction of the SDL UI

Makefile

@@ -120,7 +120,13 @@ ifneq ($(findstring gtk3,$(MAKECMDGOALS)),)
 $(error The gtk3 target requires pkg-config)
 endif
 else
-GTK3_CFLAGS  := $(shell $(PKG_CONFIG) --cflags gio-2.0 gtk+-3.0 epoxy sdl2) -DGTK_DISABLE_DEPRECATED=1 -DG_DISABLE_DEPRECATED=1 -DG_LOG_DOMAIN=\"SameBoy\" -DRESOURCE_PREFIX=\"/io/github/sameboy/\" -DAPP_ID=\"io.github.sameboy\"
+GTK_OPTIONS  := -DGTK_DISABLE_DEPRECATED=1 -DG_DISABLE_DEPRECATED=1 -DG_LOG_DOMAIN=\"SameBoy\" -DRESOURCE_PREFIX=\"/io/github/sameboy/\" -DAPP_ID=\"io.github.sameboy\"
+
+ifeq ($(SDL_AUDIO_DRIVER),sdl)
+GTK_OPTIONS  += -DUSE_SDL_AUDIO
+endif
+
+GTK3_CFLAGS  := $(shell $(PKG_CONFIG) --cflags gio-2.0 gtk+-3.0 epoxy sdl2) $(GTK_OPTIONS)
 GTK3_LDFLAGS := $(shell $(PKG_CONFIG) --libs gio-2.0 gtk+-3.0 epoxy sdl2)
 
 # TODO: REMOVE DISABLE UNUSED WARNINGS
@@ -198,7 +204,7 @@ all: cocoa sdl tester libretro
 
 CORE_SOURCES := $(shell ls Core/*.c)
 SDL_SOURCES := $(shell ls SDL/*.c) $(OPEN_DIALOG) SDL/audio/$(SDL_AUDIO_DRIVER).c
-GTK3_SOURCES := $(shell ls gtk3/*.c) gtk3/sameboy-gtk3-resources.c
+GTK3_SOURCES := $(shell ls gtk3/*.c) gtk3/sameboy-gtk3-resources.c SDL/audio/$(SDL_AUDIO_DRIVER).c
 TESTER_SOURCES := $(shell ls Tester/*.c)
 
 ifeq ($(PLATFORM),Darwin)

SDL/audio/audio.h

@@ -5,12 +5,14 @@
 #include <stddef.h>
 #include <Core/gb.h>
 
+unsigned GB_audio_default_sample_rate(void);
 bool GB_audio_is_playing(void);
 void GB_audio_set_paused(bool paused);
 void GB_audio_clear_queue(void);
-unsigned GB_audio_get_frequency(void);
+unsigned GB_audio_get_sample_rate(void);
 size_t GB_audio_get_queue_length(void);
 void GB_audio_queue_sample(GB_sample_t *sample);
-void GB_audio_init(void);
+void GB_audio_init(unsigned sample_rate);
+void GB_audio_destroy(void);
 
 #endif /* sdl_audio_h */

SDL/audio/sdl.c

@@ -29,6 +29,11 @@ static SDL_AudioSpec want_aspec, have_aspec;
 static unsigned buffer_pos = 0;
 static GB_sample_t audio_buffer[AUDIO_BUFFER_SIZE];
 
+unsigned GB_audio_default_sample_rate(void)
+{
+    return AUDIO_FREQUENCY;
+}
+
 bool GB_audio_is_playing(void)
 {
     return SDL_GetAudioDeviceStatus(device_id) == SDL_AUDIO_PLAYING;
@@ -45,7 +50,7 @@ void GB_audio_clear_queue(void)
     SDL_ClearQueuedAudio(device_id);
 }
 
-unsigned GB_audio_get_frequency(void)
+unsigned GB_audio_get_sample_rate(void)
 {
     return have_aspec.freq;
 }
@@ -65,11 +70,11 @@ void GB_audio_queue_sample(GB_sample_t *sample)
     }
 }
 
-void GB_audio_init(void)
+void GB_audio_init(unsigned sample_rate)
 {
     /* Configure Audio */
     memset(&want_aspec, 0, sizeof(want_aspec));
-    want_aspec.freq = AUDIO_FREQUENCY;
+    want_aspec.freq = sample_rate == 0 ? GB_audio_default_sample_rate() : sample_rate;
     want_aspec.format = AUDIO_S16SYS;
     want_aspec.channels = 2;
     want_aspec.samples = 512;
@@ -94,3 +99,9 @@ void GB_audio_init(void)
     
     device_id = SDL_OpenAudioDevice(0, 0, &want_aspec, &have_aspec, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE | SDL_AUDIO_ALLOW_SAMPLES_CHANGE);
 }
+
+void GB_audio_destroy() {
+    GB_audio_set_paused(true);
+
+    SDL_CloseAudioDevice(device_id);
+}

SDL/main.c

@@ -383,15 +383,15 @@ static void gb_audio_callback(GB_gameboy_t *gb, GB_sample_t *sample)
     if (turbo_down) {
         static unsigned skip = 0;
         skip++;
-        if (skip == GB_audio_get_frequency() / 8) {
+        if (skip == GB_audio_get_sample_rate() / 8) {
             skip = 0;
         }
-        if (skip > GB_audio_get_frequency() / 16) {
+        if (skip > GB_audio_get_sample_rate() / 16) {
             return;
         }
     }
     
-    if (GB_audio_get_queue_length() / sizeof(*sample) > GB_audio_get_frequency() / 4) {
+    if (GB_audio_get_queue_length() / sizeof(*sample) > GB_audio_get_sample_rate() / 4) {
         return;
     }
     
@@ -488,7 +488,7 @@ restart:
         GB_set_vblank_callback(&gb, (GB_vblank_callback_t) vblank);
         GB_set_pixels_output(&gb, active_pixel_buffer);
         GB_set_rgb_encode_callback(&gb, rgb_encode);
-        GB_set_sample_rate(&gb, GB_audio_get_frequency());
+        GB_set_sample_rate(&gb, GB_audio_get_sample_rate());
         GB_set_color_correction_mode(&gb, configuration.color_correction_mode);
         update_palette();
         if ((unsigned)configuration.border_mode <= GB_BORDER_ALWAYS) {
@@ -649,7 +649,7 @@ int main(int argc, char **argv)
         pixel_format = SDL_AllocFormat(SDL_PIXELFORMAT_ABGR8888);
     }
     
-    GB_audio_init();
+    GB_audio_init(GB_audio_default_sample_rate());
 
     SDL_EventState(SDL_DROPFILE, SDL_ENABLE);
     

gtk3/main.c

@@ -1,27 +1,7 @@
 #include "main.h"
-
+#include "../SDL/audio/audio.h"
-#ifndef _WIN32
-#define DEFAULT_AUDIO_SAMPLE_RATE 96000
-#else
-/* Windows (well, at least my VM) can't handle 96KHz sound well :( */
-
-/* felsqualle says: For SDL 2.0.6+ using the WASAPI driver, the highest freq.
-   we can get is 48000. 96000 also works, but always has some faint crackling in
-   the audio, no matter how high or low I set the buffer length...
-   Not quite satisfied with that solution, because acc. to SDL2 docs,
-   96k + WASAPI *should* work. */
-
-#define DEFAULT_AUDIO_SAMPLE_RATE 48000
-#endif
-
-/* Compatibility with older SDL versions */
-#ifndef SDL_AUDIO_ALLOW_SAMPLES_CHANGE
-#define SDL_AUDIO_ALLOW_SAMPLES_CHANGE 0
-#endif
 
 static SDL_GameController *controller = NULL;
-static SDL_AudioSpec want_aspec, have_aspec;
-static SDL_AudioDeviceID device_id;
 
 static const GThread *main_thread;
 
@@ -324,49 +304,28 @@ static gboolean init_controllers() {
 	return true;
 }
 
+static bool audio_initialized = false;
 static gboolean init_audio() {
-	bool audio_playing = SDL_GetAudioDeviceStatus(device_id) == SDL_AUDIO_PLAYING;
+	bool audio_playing = GB_audio_is_playing();
-	SDL_PauseAudioDevice(device_id, 1);
-	SDL_ClearQueuedAudio(device_id);
-	SDL_QuitSubSystem(SDL_INIT_AUDIO);
 
+	if (audio_initialized) {
+		GB_audio_destroy();
+	}
+
+#ifdef USE_SDL_AUDIO
 	if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
 		g_warning("Failed to initialize audio: %s", SDL_GetError());
 		return false;
 	}
-
-	memset(&want_aspec, 0, sizeof(want_aspec));
-	want_aspec.freq = gui_data.sample_rate;
-	want_aspec.format = AUDIO_S16SYS;
-	want_aspec.channels = 2;
-	want_aspec.samples = 512;
-
-	SDL_version _sdl_version;
-	SDL_GetVersion(&_sdl_version);
-	unsigned sdl_version = _sdl_version.major * 1000 + _sdl_version.minor * 100 + _sdl_version.patch;
-
-#ifndef _WIN32
-	/* SDL 2.0.5 on macOS and Linux introduced a bug where certain combinations of buffer lengths and frequencies
-	fail to produce audio correctly. */
-	if (sdl_version >= 2005) {
-		want_aspec.samples = 2048;
-	}
-#else
-	if (sdl_version < 2006) {
-		/* Since WASAPI audio was introduced in SDL 2.0.6, we have to lower the audio frequency
-		to 44100 because otherwise we would get garbled audio output.*/
-		want_aspec.freq = 44100;
-	}
 #endif
 
-	device_id = SDL_OpenAudioDevice(0, 0, &want_aspec, &have_aspec, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE | SDL_AUDIO_ALLOW_SAMPLES_CHANGE);
+	GB_audio_init(gui_data.sample_rate);
+	GB_set_sample_rate(&gb, GB_audio_get_sample_rate());
+	
+	// restore playing state
+	GB_audio_set_paused(!audio_playing);
 
-	g_debug("Requested Sample Rate: %d Hz\nUsed Sample Rate: %d Hz", want_aspec.freq, have_aspec.freq);
+	return audio_initialized = true;
-
-	SDL_PauseAudioDevice(device_id, audio_playing? 0 : 1);
-	GB_set_sample_rate(&gb, have_aspec.freq);
-
-	return true;
 }
 
 static GB_model_t get_model() {
@@ -395,19 +354,21 @@ static void gb_audio_callback(GB_gameboy_t *gb, GB_sample_t *sample) {
 	if (turbo_down) {
 		static unsigned skip = 0;
 		skip++;
-		if (skip == have_aspec.freq / 8) {
+
+		if (skip == GB_audio_get_sample_rate() / 8) {
 			skip = 0;
 		}
-		if (skip > have_aspec.freq / 16) {
+
+		if (skip > GB_audio_get_sample_rate() / 16) {
 			return;
 		}
 	}
 
-	if (SDL_GetQueuedAudioSize(device_id) / sizeof(*sample) > have_aspec.freq / 4) {
+	if (GB_audio_get_queue_length() / sizeof(*sample) > GB_audio_get_sample_rate() / 4) {
 		return;
 	}
 
-	SDL_QueueAudio(device_id, sample, sizeof(*sample));
+	GB_audio_queue_sample(sample);
 }
 
 // Console TODO:
@@ -826,7 +787,7 @@ static void startup(GApplication *app, gpointer gui_data_gptr) {
 	printer = GTK_WINDOW(get_object("printer"));
 
 	if (config.sample_rate == -1) {
-		gui_data->sample_rate = DEFAULT_AUDIO_SAMPLE_RATE;
+		gui_data->sample_rate = GB_audio_default_sample_rate();
 	}
 	else {
 		gui_data->sample_rate = config.sample_rate;
@@ -1058,7 +1019,7 @@ static gboolean on_key_press(GtkWidget *w, GdkEventKey *event, gpointer data) {
 
 		case GDK_KEY_space: {
 			turbo_down = event->type == GDK_KEY_PRESS;
-			SDL_ClearQueuedAudio(device_id);
+			GB_audio_clear_queue();
 			GB_set_turbo_mode(&gb, turbo_down, turbo_down && rewind_down);
 		break; }
 
@@ -1259,14 +1220,7 @@ static void on_model_changed(GSimpleAction *action, GVariant *value, gpointer us
 static void on_mute_changed(GSimpleAction *action, GVariant *value, gpointer user_data) {
 	gboolean do_mute = g_variant_get_boolean(value);
 
-	if (do_mute) {
+	GB_audio_set_paused(do_mute);
-		SDL_PauseAudioDevice(device_id, 1);
-	}
-	else {
-		SDL_ClearQueuedAudio(device_id);
-		SDL_PauseAudioDevice(device_id, 0);
-	}
-
 	g_simple_action_set_state(action, value);
 }
 
@@ -1705,7 +1659,7 @@ G_MODULE_EXPORT void on_sample_rate_changed(GtkWidget *w, gpointer user_data_gpt
 	config.sample_rate = g_ascii_strtoll(gtk_combo_box_get_active_id(box), NULL, 10);
 
 	if (config.sample_rate == -1) {
-		gui_data.sample_rate = DEFAULT_AUDIO_SAMPLE_RATE;
+		gui_data.sample_rate = GB_audio_default_sample_rate();
 	}
 	else {
 		gui_data.sample_rate = config.sample_rate;
@@ -2198,7 +2152,7 @@ static void init(GuiData *gui_data) {
 	GB_set_vblank_callback(&gb, vblank);
 	GB_set_pixels_output(&gb, get_current_buffer());
 	GB_set_rgb_encode_callback(&gb, rgb_encode);
-	GB_set_sample_rate(&gb, gui_data->sample_rate);
+	GB_set_sample_rate(&gb, GB_audio_get_sample_rate());
 	GB_set_color_correction_mode(&gb, get_color_correction_mode());
 	GB_set_highpass_filter_mode(&gb, get_highpass_mode());
 	GB_set_rewind_length(&gb, config.rewind_duration);
@@ -2280,7 +2234,7 @@ static void load_boot_rom(GB_gameboy_t *gb, GB_boot_rom_t type) {
 static void stop(GuiData *gui_data) {
 	if (!running) return;
 
-	SDL_PauseAudioDevice(device_id, 1);
+	GB_audio_set_paused(true);
 	GB_debugger_set_disabled(&gb, true);
 
 	if (GB_debugger_is_stopped(&gb)) {
@@ -2341,8 +2295,8 @@ static void start(GuiData *gui_data) {
 	running = true;
 	gui_data->stopped = false;
 
-	SDL_ClearQueuedAudio(device_id);
+	GB_audio_clear_queue();
-	SDL_PauseAudioDevice(device_id, 0);
+	GB_audio_set_paused(false);
 
 	/* Run emulation */
 	while (running) {