Changed Game Link to use libretros Netplay/Netpacket

Netplay is now enabled on all platforms
Required libretro is now 1.17.0
Updated libretro.h to latest version

Makefile.common

@@ -49,7 +49,7 @@ SOURCES_CXX := \
 
 ifeq ($(HAVE_NETWORK),1)
 	SOURCES_CXX += \
-		$(CORE_DIR)/../libretro/net_serial.cpp
+		$(CORE_DIR)/../libretro/netplay_serial.cpp
 endif
 
 ifneq ($(STATIC_LINKING), 1)

Makefile.libretro

@@ -1,5 +1,5 @@
 DEBUG = 0
-HAVE_NETWORK = 0
+HAVE_NETWORK = 1
 VIDEO_RGB565 = 1
 
 SPACE :=

libgambatte/include/gambatte.h

@@ -24,135 +24,160 @@
 #include "serial_io.h"
 #endif
 #include "gbint.h"
-#include <string>
 #include <cstddef>
+#include <string>
 
-namespace gambatte {
+namespace gambatte
+{
 #if defined(VIDEO_RGB565) || defined(VIDEO_ABGR1555)
-typedef uint16_t video_pixel_t;
+  typedef uint16_t video_pixel_t;
 #else
-typedef uint_least32_t video_pixel_t;
+  typedef uint_least32_t video_pixel_t;
 #endif
-enum { BG_PALETTE = 0, SP1_PALETTE = 1, SP2_PALETTE = 2 };
+  enum
+  {
+    BG_PALETTE = 0,
+    SP1_PALETTE = 1,
+    SP2_PALETTE = 2
+  };
 
-class GB {
+  class GB
-public:
+  {
-	GB();
+  public:
-	~GB();
+    GB();
-	
+    ~GB();
-	enum LoadFlag {
-      FORCE_DMG        = 1, /**< Treat the ROM as not having CGB support regardless of what its header advertises. */
-      GBA_CGB          = 2, /**< Use GBA intial CPU register values when in CGB mode. */
-      MULTICART_COMPAT = 4,  /**< Use heuristics to detect and support some multicart MBCs disguised as MBC1. */
-      FORCE_CGB        = 8
-	};
-	
-   int load(const void *romdata, unsigned size, unsigned flags = 0);
-	
-	/** Emulates until at least 'samples' stereo sound samples are produced in the supplied buffer,
-	  * or until a video frame has been drawn.
-	  *
-	  * There are 35112 stereo sound samples in a video frame.
-	  * May run for uptil 2064 stereo samples too long.
-	  * EDIT: Due to internal emulator bugs, may in fact run for
-	  *       an arbitrary number of samples...
-	  * A stereo sample consists of two native endian 2s complement 16-bit PCM samples,
-	  * with the left sample preceding the right one. Usually casting soundBuf to/from
-	  * short* is OK and recommended. The reason for not using a short* in the interface
-	  * is to avoid implementation-defined behaviour without compromising performance.
-	  *
-	  * Returns early when a new video frame has finished drawing in the video buffer,
-	  * such that the caller may update the video output before the frame is overwritten.
-	  * The return value indicates whether a new video frame has been drawn, and the
-	  * exact time (in number of samples) at which it was drawn.
-	  *
-	  * @param videoBuf 160x144 RGB32 (native endian) video frame buffer or 0
-	  * @param pitch distance in number of pixels (not bytes) from the start of one line to the next in videoBuf.
-	  * @param soundBuf buffer with space >= samples + 2064
-	  * @param soundBufSize actual size of soundBuf buffer
-	  * @param samples in: number of stereo samples to produce, out: actual number of samples produced
-	  * @return sample number at which the video frame was produced. -1 means no frame was produced.
-	  */
-	long runFor(gambatte::video_pixel_t *videoBuf, int pitch,
-			gambatte::uint_least32_t *soundBuf, std::size_t soundBufSize, unsigned &samples);
-	
-	/** Reset to initial state.
-	  * Equivalent to reloading a ROM image, or turning a Game Boy Color off and on again.
-	  */
-	void reset();
-	
-	/** @param palNum 0 <= palNum < 3. One of BG_PALETTE, SP1_PALETTE and SP2_PALETTE.
-	  * @param colorNum 0 <= colorNum < 4
-	  */
-	void setDmgPaletteColor(unsigned palNum, unsigned colorNum, unsigned rgb32);
 
-	/** Sets the callback used for getting input state. */
+    enum LoadFlag
-	void setInputGetter(InputGetter *getInput);
+    {
-   
+      FORCE_DMG = 1,        /**< Treat the ROM as not having CGB support regardless of
-   /** Sets the callback used for getting the bootloader data. */
+                                what its header advertises. */
-   void setBootloaderGetter(bool (*getter)(void *userdata, bool isgbc, uint8_t *data, uint32_t buf_size));
+      GBA_CGB = 2,          /**< Use GBA intial CPU register values when in CGB mode. */
+      MULTICART_COMPAT = 4, /**< Use heuristics to detect and support some
+                               multicart MBCs disguised as MBC1. */
+      FORCE_CGB = 8
+    };
+
+    int load(const void *romdata, unsigned size, unsigned flags = 0);
+
+    /** Emulates until at least 'samples' stereo sound samples are produced in
+     * the supplied buffer, or until a video frame has been drawn.
+     *
+     * There are 35112 stereo sound samples in a video frame.
+     * May run for uptil 2064 stereo samples too long.
+     * EDIT: Due to internal emulator bugs, may in fact run for
+     *       an arbitrary number of samples...
+     * A stereo sample consists of two native endian 2s complement 16-bit PCM
+     * samples, with the left sample preceding the right one. Usually casting
+     * soundBuf to/from short* is OK and recommended. The reason for not using a
+     * short* in the interface is to avoid implementation-defined behaviour
+     * without compromising performance.
+     *
+     * Returns early when a new video frame has finished drawing in the video
+     * buffer, such that the caller may update the video output before the frame
+     * is overwritten. The return value indicates whether a new video frame has
+     * been drawn, and the exact time (in number of samples) at which it was
+     * drawn.
+     *
+     * @param videoBuf 160x144 RGB32 (native endian) video frame buffer or 0
+     * @param pitch distance in number of pixels (not bytes) from the start of
+     * one line to the next in videoBuf.
+     * @param soundBuf buffer with space >= samples + 2064
+     * @param soundBufSize actual size of soundBuf buffer
+     * @param samples in: number of stereo samples to produce, out: actual number
+     * of samples produced
+     * @return sample number at which the video frame was produced. -1 means no
+     * frame was produced.
+     */
+    long runFor(gambatte::video_pixel_t *videoBuf, int pitch,
+                gambatte::uint_least32_t *soundBuf, std::size_t soundBufSize,
+                unsigned &samples);
+
+    /** Reset to initial state.
+     * Equivalent to reloading a ROM image, or turning a Game Boy Color off and
+     * on again.
+     */
+    void reset();
+
+    /** @param palNum 0 <= palNum < 3. One of BG_PALETTE, SP1_PALETTE and
+     * SP2_PALETTE.
+     * @param colorNum 0 <= colorNum < 4
+     */
+    void setDmgPaletteColor(unsigned palNum, unsigned colorNum, unsigned rgb32);
+
+    /** Sets the callback used for getting input state. */
+    void setInputGetter(InputGetter *getInput);
+
+    /** Sets the callback used for getting the bootloader data. */
+    void setBootloaderGetter(bool (*getter)(void *userdata, bool isgbc,
+                                            uint8_t *data, uint32_t buf_size));
 
 #ifdef HAVE_NETWORK
-	/** Sets the callback used for transferring serial data. */
+    /** Sets the callback used for transferring serial data. */
-	void setSerialIO(SerialIO *serial_io);
+    void setSerialIO(SerialIO *serial_io);
 #endif
-	
-	/** Sets the directory used for storing save data. The default is the same directory as the ROM Image file. */
-	void setSaveDir(const std::string &sdir);
 
-   void *savedata_ptr();
+    /** Sets the directory used for storing save data. The default is the same
-   unsigned savedata_size();
+     * directory as the ROM Image file. */
-   void *rtcdata_ptr();
+    void setSaveDir(const std::string &sdir);
-   unsigned rtcdata_size();
-	
-	/** Returns true if the currently loaded ROM image is treated as having CGB support. */
-	bool isCgb() const;
-	
-	/** Returns true if a ROM image is loaded. */
-	bool isLoaded() const;
-	
-   void saveState(void *data);
-   void loadState(const void *data);
-   size_t stateSize() const;
 
-   void setColorCorrection(bool enable);
+    void *savedata_ptr();
-   void setColorCorrectionMode(unsigned colorCorrectionMode);
+    unsigned savedata_size();
-   void setColorCorrectionBrightness(float colorCorrectionBrightness);
+    void *rtcdata_ptr();
-   void setDarkFilterLevel(unsigned darkFilterLevel);
+    unsigned rtcdata_size();
-   video_pixel_t gbcToRgb32(const unsigned bgr15);
 
-   /** Set Game Genie codes to apply to currently loaded ROM image. Cleared on ROM load.
+    /** Returns true if the currently loaded ROM image is treated as having CGB
-    * @param codes Game Genie codes in format HHH-HHH-HHH;HHH-HHH-HHH;... where H is [0-9]|[A-F]
+     * support. */
-    */
+    bool isCgb() const;
-   void setGameGenie(const std::string &codes);
 
-   /** Set Game Shark codes to apply to currently loaded ROM image. Cleared on ROM load.
+    /** Returns true if a ROM image is loaded. */
-    * @param codes Game Shark codes in format 01HHHHHH;01HHHHHH;... where H is [0-9]|[A-F]
+    bool isLoaded() const;
-    */
+
-   void setGameShark(const std::string &codes);
+    void saveState(void *data);
+    void loadState(const void *data);
+    size_t stateSize() const;
+
+    void setColorCorrection(bool enable);
+    void setColorCorrectionMode(unsigned colorCorrectionMode);
+    void setColorCorrectionBrightness(float colorCorrectionBrightness);
+    void setDarkFilterLevel(unsigned darkFilterLevel);
+    video_pixel_t gbcToRgb32(const unsigned bgr15);
+
+    /** Set Game Genie codes to apply to currently loaded ROM image. Cleared on
+     * ROM load.
+     * @param codes Game Genie codes in format HHH-HHH-HHH;HHH-HHH-HHH;... where
+     * H is [0-9]|[A-F]
+     */
+    void setGameGenie(const std::string &codes);
+
+    /** Set Game Shark codes to apply to currently loaded ROM image. Cleared on
+     * ROM load.
+     * @param codes Game Shark codes in format 01HHHHHH;01HHHHHH;... where H is
+     * [0-9]|[A-F]
+     */
+    void setGameShark(const std::string &codes);
+
+    void clearCheats();
 
-   void clearCheats();
-   
 #ifdef __LIBRETRO__
-   void *vram_ptr() const;
+    void *vram_ptr() const;
-   void *rambank0_ptr() const;
+    void *rambank0_ptr() const;
-   void *rambank1_ptr() const;
+    void *rambank1_ptr() const;
-   void *rambank2_ptr() const;
+    void *rambank2_ptr() const;
-   void *bankedram_ptr() const;
+    void *bankedram_ptr() const;
-   void *rombank0_ptr() const;
+    void *rombank0_ptr() const;
-   void *rombank1_ptr() const;
+    void *rombank1_ptr() const;
-   void *zeropage_ptr() const;
+    void *zeropage_ptr() const;
-   void *oamram_ptr() const;
+    void *oamram_ptr() const;
 #endif
 
-private:
+  private:
-	struct Priv;
+    struct Priv;
-	Priv *const p_;
+    Priv *const p_;
 
-	void loadState(const std::string &filepath, bool osdMessage);
+    void loadState(const std::string &filepath, bool osdMessage);
-	GB(const GB &);
+    GB(const GB &);
-	GB & operator=(const GB &);
+    GB &operator=(const GB &);
-};
+  };
-}
+} // namespace gambatte
 
 #endif

libgambatte/libretro/net_serial.cpp

@@ -1,296 +0,0 @@
-#include "net_serial.h"
-#include "libretro.h"
-#include "gambatte_log.h"
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <errno.h>
-#include <sys/types.h>
-#ifdef _WIN32
-#include <winsock2.h>
-#include <ws2tcpip.h>
-#else
-#include <sys/socket.h>
-#include <sys/ioctl.h>
-#include <netinet/in.h>
-#include <netdb.h>
-#endif
-
-NetSerial::NetSerial()
-: is_stopped_(true)
-, is_server_(false)
-, port_(12345)
-, hostname_()
-, server_fd_(-1)
-, sockfd_(-1)
-, lastConnectAttempt_(0)
-{
-}
-
-NetSerial::~NetSerial()
-{
-	stop();
-}
-
-bool NetSerial::start(bool is_server, int port, const std::string& hostname)
-{
-	stop();
-
-	gambatte_log(RETRO_LOG_INFO, "Starting GameLink network %s on %s:%d\n",
-			is_server ? "server" : "client", hostname.c_str(), port);
-	is_server_ = is_server;
-	port_ = port;
-	hostname_ = hostname;
-	is_stopped_ = false;
-
-	return checkAndRestoreConnection(false);
-}
-void NetSerial::stop()
-{
-	if (!is_stopped_) {
-		gambatte_log(RETRO_LOG_INFO, "Stopping GameLink network\n");
-		is_stopped_ = true;
-		if (sockfd_ >= 0) {
-			close(sockfd_);
-			sockfd_ = -1;
-		}
-		if (server_fd_ >= 0) {
-			close(server_fd_);
-			server_fd_ = -1;
-		}
-	}
-}
-
-bool NetSerial::checkAndRestoreConnection(bool throttle)
-{
-	if (is_stopped_) {
-		return false;
-	}
-	if (sockfd_ < 0 && throttle) {
-		clock_t now = clock();
-		// Only attempt to establish the connection every 5 seconds
-		if (((now - lastConnectAttempt_) / CLOCKS_PER_SEC) < 5) {
-			return false;
-		}
-	}
-	lastConnectAttempt_ = clock();
-	if (is_server_) {
-		if (!startServerSocket()) {
-			return false;
-		}
-		if (!acceptClient()) {
-			return false;
-		}
-	} else {
-		if (!startClientSocket()) {
-			return false;
-		}
-	}
-	return true;
-}
-bool NetSerial::startServerSocket()
-{
-	int fd;
-	struct sockaddr_in server_addr;
-
-	if (server_fd_ < 0) {
-		memset((char *)&server_addr, '\0', sizeof(server_addr));
-		server_addr.sin_family = AF_INET;
-		server_addr.sin_port = htons(port_);
-		server_addr.sin_addr.s_addr = INADDR_ANY;
-
-		int fd = socket(AF_INET, SOCK_STREAM, 0);
-		if (fd < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error opening socket: %s\n", strerror(errno));
-			return false;
-		}
-
-		if (bind(fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error on binding: %s\n", strerror(errno));
-			close(fd);
-			return false;
-		}
-
-		if (listen(fd, 1) < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error listening: %s\n", strerror(errno));
-			close(fd);
-			return false;
-		}
-		server_fd_ = fd;
-		gambatte_log(RETRO_LOG_INFO, "GameLink network server started!\n");
-	}
-
-	return true;
-}
-bool NetSerial::acceptClient()
-{
-	struct sockaddr_in client_addr;
-	struct timeval tv;
-	fd_set rfds;
-
-	if (server_fd_ < 0) {
-		return false;
-	}
-	if (sockfd_ < 0) {
-		int retval;
-
-		FD_ZERO(&rfds);
-		FD_SET(server_fd_, &rfds);
-		tv.tv_sec = 0;
-		tv.tv_usec = 0;
-
-		if (select(server_fd_ + 1, &rfds, NULL, NULL, &tv) <= 0) {
-			return false;
-		}
-
-		socklen_t client_len = sizeof(client_addr);
-		sockfd_ = accept(server_fd_, (struct sockaddr*)&client_addr, &client_len);
-		if (sockfd_ < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error on accept: %s\n", strerror(errno));
-			return false;
-		}
-		gambatte_log(RETRO_LOG_INFO, "GameLink network server connected to client!\n");
-	}
-	return true;
-}
-bool NetSerial::startClientSocket()
-{
-	int fd;
-	struct sockaddr_in server_addr;
-
-	if (sockfd_ < 0) {
-		memset((char *)&server_addr, '\0', sizeof(server_addr));
-		server_addr.sin_family = AF_INET;
-		server_addr.sin_port = htons(port_);
-
-		int fd = socket(AF_INET, SOCK_STREAM, 0);
-		if (fd < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error opening socket: %s\n", strerror(errno));
-			return false;
-		}
-
-		struct hostent* server_hostname = gethostbyname(hostname_.c_str());
-		if (server_hostname == NULL) {
-			gambatte_log(RETRO_LOG_ERROR, "Error, no such host: %s\n", hostname_.c_str());
-			close(fd);
-			return false;
-		}
-
-		memmove((char*)&server_addr.sin_addr.s_addr, (char*)server_hostname->h_addr, server_hostname->h_length);
-		if (connect(fd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
-			gambatte_log(RETRO_LOG_ERROR, "Error connecting to server: %s\n", strerror(errno));
-			close(fd);
-			return false;
-		}
-		sockfd_ = fd;
-		gambatte_log(RETRO_LOG_INFO, "GameLink network client connected to server!\n");
-	}
-	return true;
-}
-
-unsigned char NetSerial::send(unsigned char data, bool fastCgb)
-{
-	unsigned char buffer[2];
-
-	if (is_stopped_) {
-		return 0xFF;
-	}
-	if (sockfd_ < 0) {
-		if (!checkAndRestoreConnection(true)) {
-			return 0xFF;
-		}
-	}
-
-	buffer[0] = data;
-	buffer[1] = fastCgb;
-#ifdef _WIN32
-   if (::send(sockfd_, (char*) buffer, 2, 0) <= 0)
-#else
-	if (write(sockfd_, buffer, 2) <= 0)
-#endif
-   {
-		gambatte_log(RETRO_LOG_ERROR, "Error writing to socket: %s\n", strerror(errno));
-		close(sockfd_);
-		sockfd_ = -1;
-		return 0xFF;
-	}
-
-#ifdef _WIN32
-	if (recv(sockfd_, (char*) buffer, 2, 0) <= 0) 
-#else
-   if (read(sockfd_, buffer, 2) <= 0) 
-#endif
-   {
-		gambatte_log(RETRO_LOG_ERROR, "Error reading from socket: %s\n", strerror(errno));
-		close(sockfd_);
-		sockfd_ = -1;
-		return 0xFF;
-	}
-
-	return buffer[0];
-}
-
-bool NetSerial::check(unsigned char out, unsigned char& in, bool& fastCgb)
-{
-	unsigned char buffer[2];
-#ifdef _WIN32
-	u_long bytes_avail = 0;
-#else
-	int bytes_avail = 0;
-#endif
-	if (is_stopped_) {
-		return false;
-	}
-	if (sockfd_ < 0) {
-		if (!checkAndRestoreConnection(true)) {
-			return false;
-		}
-	}
-#ifdef _WIN32
-   if (ioctlsocket(sockfd_, FIONREAD, &bytes_avail) < 0)
-#else
-	if (ioctl(sockfd_, FIONREAD, &bytes_avail) < 0)
-#endif
-   {
-		gambatte_log(RETRO_LOG_ERROR, "IOCTL Failed: %s\n", strerror(errno));
-		return false;
-	}
-
-	// No data available yet
-	if (bytes_avail < 2) {
-		return false;
-	}
-
-#ifdef _WIN32
-	if (recv(sockfd_, (char*) buffer, 2, 0) <= 0) 
-#else
-   if (read(sockfd_, buffer, 2) <= 0) 
-#endif
-   {
-		gambatte_log(RETRO_LOG_ERROR, "Error reading from socket: %s\n", strerror(errno));
-		close(sockfd_);
-		sockfd_ = -1;
-		return false;
-	}
-
-//	slave_txn_cnt++;
-
-	in = buffer[0];
-	fastCgb = buffer[1];
-
-	buffer[0] = out;
-	buffer[1] = 128;
-   #ifdef _WIN32
-      if (::send(sockfd_, (char*) buffer, 2, 0) <= 0)
-   #else
-   	if (write(sockfd_, buffer, 2) <= 0)
-   #endif
-   {
-		gambatte_log(RETRO_LOG_ERROR, "Error writing to socket: %s\n", strerror(errno));
-		close(sockfd_);
-		sockfd_ = -1;
-		return false;
-	}
-
-	return true;
-}

libgambatte/libretro/net_serial.h

@@ -1,41 +0,0 @@
-#ifndef _NET_SERIAL_H
-#define _NET_SERIAL_H
-
-#if defined(__HAIKU__)
-#include <sys/socket.h>
-#include <sys/select.h>
-#endif
-
-#include <gambatte.h>
-#include <time.h>
-
-class NetSerial : public gambatte::SerialIO
-{
-	public:
-		NetSerial();
-		~NetSerial();
-
-		bool start(bool is_server, int port, const std::string& hostname);
-		void stop();
-
-		virtual bool check(unsigned char out, unsigned char& in, bool& fastCgb);
-		virtual unsigned char send(unsigned char data, bool fastCgb);
-
-	private:
-		bool startServerSocket();
-		bool startClientSocket();
-		bool acceptClient();
-		bool checkAndRestoreConnection(bool throttle);
-
-		bool is_stopped_;
-		bool is_server_;
-		int  port_;
-		std::string hostname_;
-
-		int server_fd_;
-		int sockfd_;
-
-		clock_t lastConnectAttempt_;
-};
-
-#endif

libgambatte/libretro/netplay_serial.cpp

@@ -0,0 +1,128 @@
+#include "netplay_serial.h"
+#include "gambatte_log.h"
+#include <string.h>
+#include <math.h>
+
+NetplaySerial::NetplaySerial() : dataAvailable_(0), hasPeer_(false)
+{
+}
+
+NetplaySerial::~NetplaySerial()
+{
+}
+
+void NetplaySerial::netplayStart(uint16_t clientId, retro_netpacket_send_t sendCallback, retro_netpacket_poll_receive_t pollCallback)
+{
+    gambatte_log(RETRO_LOG_DEBUG, "Starting netplay!\n");
+    send_cb_ = sendCallback;
+    poll_cb_ = pollCallback;
+}
+
+void NetplaySerial::netplayStop()
+{
+    gambatte_log(RETRO_LOG_DEBUG, "Stopping netplay!\n");
+    send_cb_ = NULL;
+    poll_cb_ = NULL;
+    hasPeer_ = false;
+    dataAvailable_ = 0;
+}
+
+bool NetplaySerial::netplayConnect(uint16_t clientId)
+{
+    if (hasPeer_)
+    {
+        gambatte_log(RETRO_LOG_DEBUG, "Client tried to connect but we already have a peer\n");
+        return false;
+    }
+    else
+    {
+        gambatte_log(RETRO_LOG_DEBUG, "Client connected\n");
+        hasPeer_ = true;
+        return true;
+    }
+}
+
+void NetplaySerial::netplayDisconnect(uint16_t clientId)
+{
+    gambatte_log(RETRO_LOG_DEBUG, "Client disconnected\n");
+    hasPeer_ = false;
+}
+
+void NetplaySerial::netplayReceive(const void *buf, size_t len, uint16_t client_id)
+{
+    if (dataAvailable_ + len > NETPLAY_SERIAL_BUFFER_SIZE)
+    {
+        gambatte_log(RETRO_LOG_WARN, "[receive] buffer full, dropping packets...\n");
+        return;
+    }
+    memcpy(&buffer_[dataAvailable_], buf, len);
+    dataAvailable_ += len;
+}
+
+bool NetplaySerial::check(unsigned char out, unsigned char &in, bool &fastCgb)
+{
+    if (!isAvailable_() || dataAvailable_ < 2)
+    {
+        return false;
+    }
+    int read;
+    unsigned char buffer[2];
+    if ((read = getData_(&buffer, 2)) <= 0)
+    {
+        gambatte_log(RETRO_LOG_ERROR, "[check] Error during receive (read=%d)!\n", read);
+        return false;
+    }
+    in = buffer[0];
+    fastCgb = buffer[1];
+    buffer[0] = out;
+    buffer[1] = 128;
+    send_cb_(NETPLAY_SERIAL_PACKET_FLAGS, buffer, 2, RETRO_NETPACKET_BROADCAST);
+    return true;
+}
+
+unsigned char NetplaySerial::send(unsigned char data, bool fastCgb)
+{
+    if (!isAvailable_())
+    {
+        return 0xFF;
+    }
+    unsigned char buffer[2];
+    buffer[0] = data;
+    buffer[1] = fastCgb;
+    send_cb_(NETPLAY_SERIAL_PACKET_FLAGS, buffer, 2, RETRO_NETPACKET_BROADCAST);
+    // Poll data to wait for response
+    while (!hasData_() && isAvailable_()) // TODO timeout
+    {
+        poll_cb_();
+    }
+    int read;
+    if ((read = getData_(&buffer, 2)) < 0)
+    {
+        gambatte_log(RETRO_LOG_ERROR, "[send] Received invalid data length (%d)\n", read);
+        return 0xFF;
+    }
+    return buffer[0];
+}
+
+bool NetplaySerial::isAvailable_()
+{
+    return send_cb_ != NULL && poll_cb_ != NULL;
+}
+
+bool NetplaySerial::hasData_()
+{
+    return dataAvailable_ > 0;
+}
+
+int NetplaySerial::getData_(void *buf, size_t len)
+{
+    if (len > dataAvailable_ || len <= 0)
+    {
+        return -1;
+    }
+    int avail = len > dataAvailable_ ? dataAvailable_ : len;
+    memcpy(buf, &buffer_, avail);
+    memmove(&buffer_[0], &buffer_[avail], dataAvailable_ - avail);
+    dataAvailable_ -= avail;
+    return avail;
+}

libgambatte/libretro/netplay_serial.h

@@ -0,0 +1,37 @@
+#ifndef _NETPLAY_SERIAL_H
+#define _NETPLAY_SERIAL_H
+
+#include <gambatte.h>
+#include <libretro.h>
+#include <time.h>
+
+#define NETPLAY_SERIAL_PACKET_FLAGS                                            \
+  RETRO_NETPACKET_FLUSH_HINT | RETRO_NETPACKET_RELIABLE
+#define NETPLAY_SERIAL_BUFFER_SIZE 128
+
+class NetplaySerial : public gambatte::SerialIO {
+public:
+  NetplaySerial();
+  ~NetplaySerial();
+  void netplayStart(uint16_t clientId, retro_netpacket_send_t sendCallback,
+                    retro_netpacket_poll_receive_t pollCallback);
+  void netplayStop();
+  bool netplayConnect(uint16_t clientId);
+  void netplayDisconnect(uint16_t clientId);
+  void netplayReceive(const void *buf, size_t len, uint16_t client_id);
+  virtual bool check(unsigned char out, unsigned char &in, bool &fastCgb);
+  virtual unsigned char send(unsigned char data, bool fastCgb);
+
+private:
+  bool isAvailable_();
+  bool hasData_();
+  int getData_(void *buf, size_t len);
+
+  retro_netpacket_send_t send_cb_;
+  retro_netpacket_poll_receive_t poll_cb_;
+  bool hasPeer_;
+  char buffer_[NETPLAY_SERIAL_BUFFER_SIZE]; // Buffer to store received bytes
+  uint16_t dataAvailable_;
+};
+
+#endif