implemented sound for SDL interface. closes #2

CMakeLists.txt

@@ -31,7 +31,7 @@ if(USE_SDL)
   find_package(SDL)
   if(SDL_FOUND AND ${SDL_VERSION_STRING} VERSION_LESS 2)
     include_directories(${SDL_INCLUDE_DIR})
-    list(APPEND LINK_LIBS ${SDL_LIBRARY} ${SDL_MAIN_LIBRARY} SDL_gfx)
+    list(APPEND LINK_LIBS ${SDL_LIBRARY} ${SDL_MAIN_LIBRARY} SDL_gfx asound)
     message("sdl_library:" ${SDL_LIBRARY} ${SDL_MAIN_LIBRARY})
   else()
     # Uncomment below to specify the path to your SDL library. Run "locate libSDL" if unsure.

doc/examples/python_example.py

@@ -26,9 +26,9 @@
   if sys.platform == 'darwin':
     import pygame
     pygame.init()
-#    rle.setBool('sound', False) # Sound doesn't work on OSX
-#  elif sys.platform.startswith('linux'):
-#    rle.setBool('sound', True)
+    rle.setBool('sound', False) # Sound doesn't work on OSX
+  elif sys.platform.startswith('linux'):
+    rle.setBool('sound', True)
   rle.setBool('display_screen', True)
 
 # Load the ROM file

doc/examples/sharedLibraryInterfaceExample.cpp

@@ -43,12 +43,8 @@ int main(int argc, char** argv) {
 
 #ifdef __USE_SDL
     rle.setBool("display_screen", true);
-//    rle.setBool("sound", true);
+    rle.setBool("sound", true);
 #endif
-
-    rle.setString("MK_player1_character", "cage");
-//    rle.setString("MK_player2_character", "scorpion");
-    rle.setInt("MK_opponent_character", 4);
     // Load the ROM file. (Also resets the system for new settings to
     // take effect.)
     rle.loadROM(argv[1], argv[2]);

src/environment/RetroAgent.cpp

@@ -17,11 +17,15 @@
 #include "Serializer.hxx"
 #include "Deserializer.hxx"
 
+#include <alsa/asoundlib.h>
+#include <alsa/control.h>
+
 using namespace rle;
 
 std::atomic_uint RetroAgent::numAgents{0};
 thread_local struct RetroAgent::g_retro_ RetroAgent::g_retro;
 thread_local struct RetroAgent::g_video_ RetroAgent::g_video;
+thread_local static snd_pcm_t *g_pcm = NULL;
 
 struct keymap {
 	unsigned k;
@@ -219,10 +223,32 @@ static void video_refresh(const void *data, unsigned width, unsigned height, uns
 }
 
 static void audio_init(int frequency) {
-}
+	int err;
+
+	if ((err = snd_pcm_open(&g_pcm, "default", SND_PCM_STREAM_PLAYBACK, 0)) < 0)
+		die("Failed to open playback device: %s", snd_strerror(err));
 
+	err = snd_pcm_set_params(g_pcm, SND_PCM_FORMAT_S16, SND_PCM_ACCESS_RW_INTERLEAVED, 2, frequency, 1, 64 * 1000);
+
+	if (err < 0)
+		die("Failed to configure playback device: %s", snd_strerror(err));
+}
 
 static void audio_deinit() {
+	snd_pcm_close(g_pcm);
+}
+
+static size_t audio_write(const void *buf, unsigned frames) {
+	int written = snd_pcm_writei(g_pcm, buf, frames);
+
+	if (written < 0) {
+		printf("Alsa warning/error #%i: ", -written);
+		snd_pcm_recover(g_pcm, written, 0);
+
+		return 0;
+	}
+
+	return written;
 }
 
 static void core_log(enum retro_log_level level, const char *fmt, ...) {
@@ -290,13 +316,11 @@ static bool core_environment(unsigned cmd, void *data) {
 	return true;
 }
 
-
 static void core_video_refresh(const void *data, unsigned width, unsigned height, size_t pitch) {
 	if (data)
 		video_refresh(data, width, height, pitch);
 }
 
-
 static void core_input_poll(void) {
 	int i;
 	for (i = 0; g_binds[i].k || g_binds[i].rk; ++i){
@@ -311,23 +335,29 @@ static void core_input_poll(void) {
 
 }
 
-
 // port == player number
 static int16_t core_input_state(unsigned port, unsigned device, unsigned index, unsigned id) {
 	if (index || device != RETRO_DEVICE_JOYPAD)
 		return 0;
 	return RetroAgent::g_joy[port][id];
 }
 
-
 static void core_audio_sample(int16_t left, int16_t right) {
+	int16_t buf[2] = {left, right};
+	if(RetroAgent::g_retro.audioEnabled){
+		audio_write(buf, 1);
+	}
 }
 
 
 static size_t core_audio_sample_batch(const int16_t *data, size_t frames) {
+	if(RetroAgent::g_retro.audioEnabled){
+		return audio_write(data, frames);
+	}else{
+		return 0;
+	}
 }
 
-
 static void core_load(const char *sofile) {
 	void (*set_environment)(retro_environment_t) = NULL;
 	void (*set_video_refresh)(retro_video_refresh_t) = NULL;
@@ -380,7 +410,6 @@ static void core_load(const char *sofile) {
 	puts("Core loaded");
 }
 
-
 static void core_load_game(const char *filename) {
 	struct retro_system_av_info av = {0};
 	struct retro_system_info system = {0};
@@ -419,7 +448,6 @@ static void core_load_game(const char *filename) {
 	die("Failed to load content '%s': %s", filename, strerror(errno));
 }
 
-
 static void core_unload() {
 	if (RetroAgent::g_retro.initialized)
 		RetroAgent::g_retro.retro_deinit();
@@ -435,7 +463,6 @@ RetroAgent::RetroAgent() : coreLoaded(false), romLoaded(false){
 RetroAgent::~RetroAgent(){
 	unloadRom();
 	core_unload();
-//	--numAgents;
 }
 
 static bool replace(std::string& str, const std::string& from, const std::string& to) {
@@ -480,6 +507,7 @@ void RetroAgent::loadCore(const string& coreName){
 
 void RetroAgent::unloadCore(){
 	core_unload();
+	audio_deinit();
 	coreLoaded = false;
 }
 
@@ -504,6 +532,10 @@ void RetroAgent::run(){
 	RetroAgent::g_retro.retro_run();
 }
 
+void RetroAgent::audioEnable(bool audioState){
+	RetroAgent::g_retro.audioEnabled = audioState;
+}
+
 int RetroAgent::getHeight(){
 	return RetroAgent::g_video.rGeom.base_height;
 }
@@ -574,7 +606,6 @@ void RetroAgent::getRgbMask(uint32_t& rmask, uint32_t& gmask, uint32_t& bmask, u
 	amask = RetroAgent::g_video.amask;
 }
 
-
 uint32_t RetroAgent::getBufferSize() const{
 	return RetroAgent::g_video.rGeom.base_width * RetroAgent::g_video.rGeom.base_height;
 

src/environment/RetroAgent.h

@@ -24,6 +24,7 @@ class RetroAgent{
 	void loadCore(const string& corePath);
 	void loadRom(const string& romPath);
 	void run();
+	void audioEnable(bool audioState);
 	void videoRender();
 	void swapBuffers();
 	void videoDeinit();
@@ -76,6 +77,7 @@ class RetroAgent{
 	//	string saveFolder = "/home/administrator/DQN/rle-nano/SNES-Learning-Environment/saves/";
 		string corePath;
 		size_t serializeSize;
+		bool audioEnabled;
 	};
 	thread_local static struct g_retro_ g_retro;
 

src/environment/Settings.cxx

@@ -325,6 +325,7 @@ void Settings::setDefaultSettings() {
 
 	// Display Settings
 	boolSettings.emplace(std::make_pair("display_screen", false));
+	boolSettings.emplace(std::make_pair("sound", false));
 
 	// Game-Specific Settings
 

src/environment/retro_environment.cpp

@@ -102,6 +102,8 @@ void RetroEnvironment::reset() {
 
   // Reset the emulator
   m_rlesystem->getRetroAgent()->reset();
+  bool audio = m_rlesystem->settings()->getBool("sound", true);
+  m_rlesystem->getRetroAgent()->audioEnable(false);
 
   // NOOP for 60 steps in the deterministic environment setting, or some random amount otherwise
   int noopSteps;
@@ -125,6 +127,7 @@ void RetroEnvironment::reset() {
 //  m_rlesystem->p_display_screen->display_screen();
   }
   m_settings->startingOperations(*m_rlesystem);
+  m_rlesystem->getRetroAgent()->audioEnable(audio);
 }
 
 /** Save/restore the environment state. */

src/environment/retro_environment.hpp

@@ -122,7 +122,6 @@ class RetroEnvironment {
     pRleSystem m_rlesystem;
     pRomSettings m_settings;
     PhosphorBlend m_phosphor_blend; // For performing phosphor colour averaging, if so desired
-//    std::string m_cartridge_md5; // Necessary for saving and loading emulator state
 
     std::stack<RLEState> m_saved_states; // States are saved on a stack