feat(server) Implement binary messaging protocol.

libbettola/include/bettola/network/message.h

@@ -0,0 +1,16 @@
+#pragma once
+
+namespace BettolaLib {
+namespace Network {
+
+enum class MessageType : unsigned char {
+  PlayerPosition,
+};
+
+struct MessageHeader {
+  MessageType type;
+  unsigned short size;
+};
+
+} /* namespace Network. */
+} /* namespace BettolaLib. */

libbettola/include/bettola/network/player_pos_message.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "message.h"
+
+namespace BettolaLib {
+namespace Network {
+
+struct PlayerPosMessage {
+  float x;
+  float y;
+};
+
+} /* namespace Network. */
+} /* namespace BettolaLib. */

libbettola/src/bettola/network/socket.cpp

@@ -88,12 +88,16 @@ bool Socket::connect(const std::string& ip_address, unsigned short port) {
   _address.sin_family = AF_INET;
   _address.sin_port = htons(port);
 
-  if(inet_pton(AF_INET, ip_address.c_str(), &_address.sin_addr) <= 0) {
+  int pton_ret = inet_pton(AF_INET, ip_address.c_str(), &_address.sin_addr);
-    perror("Invalid address / Address not supported.");
+  if(pton_ret == 0) {
+    fprintf(stderr, "Invalid address format\n");
+    return false;
+  } else if(pton_ret == -1) {
+    perror("inet_pton failed");
     return false;
   }
 
-  if(::connect(_sockfd, (struct sockaddr*)&_address, sizeof(_address)) <= 0) {
+  if(::connect(_sockfd, (struct sockaddr*)&_address, sizeof(_address)) == -1) {
     fprintf(stderr, "Socket::connect() failed for sockfd %d with errno %d: %s\n", _sockfd,
             errno, strerror(errno));
     perror("Connection failed.");

src/bettola.cpp

@@ -11,6 +11,8 @@
 #include "bettola.h"
 #include "bettola/network/socket.h"
 #include "bettola/network/net_common.h"
+#include "network/message.h"
+#include "network/player_pos_message.h"
 
 /* Dacav's resolution ;) */
 const int SCREEN_WIDTH  = 800;
@@ -82,10 +84,16 @@ int Bettola::run(void) {
     network_time += delta_time;
     if(network_time > 2.0) {
       /* Send/receive every 2 seconds. */
-      send_data("Player position: " + std::to_string(_player.get_x()) + "," +
+      BettolaLib::Network::MessageHeader header;
-                std::to_string(_player.get_y()));
+      header.type = BettolaLib::Network::MessageType::PlayerPosition;
-      std::string response = receive_data();
+      header.size = sizeof(BettolaLib::Network::PlayerPosMessage);
-      printf("Bettola Client (in game loop): Received: '%s'\n", response.c_str());
+      _client_socket.send(&header, sizeof(header));
+
+      BettolaLib::Network::PlayerPosMessage msg;
+      msg.x = _player.get_x();
+      msg.y = _player.get_y();
+      _client_socket.send(&msg, sizeof(msg));
+
       network_time = 0.0;
     }
 
@@ -237,6 +245,7 @@ void Bettola::setup_quad(void) {
 }
 
 bool Bettola::init_client_connection(void) {
+  SDL_Delay(1000); /* Wait a second before trying to connect. */
   if(!_client_socket.create()) {
     printf("Bettola client: Failed to create socket.\n");
     return false;
@@ -252,28 +261,3 @@ bool Bettola::init_client_connection(void) {
   return true;
 }
 
-void Bettola::send_data(const std::string& data) {
-  ssize_t bytes_sent = _client_socket.send(data.c_str(), data.length());
-  if(bytes_sent == -1) {
-    perror("Bettola Client: Failed to send data.");
-  } else {
-    printf("Bettola Client: Sent %zd bytes: '%s'\n", bytes_sent, data.c_str());
-  }
-}
-
-std::string Bettola::receive_data(void) {
-  char buffer[256]; /* Just a small buffer currently. */
-  ssize_t bytes_received = _client_socket.recv(buffer, sizeof(buffer) - 1);
-  if(bytes_received == -1) {
-    perror("Bettola Client: Failed to receive data.");
-    return "";
-  } else if(bytes_received == 0) {
-    printf("Bettola Client: Server disconnected.\n");
-    /* Attempt to reconnect. */
-    _client_socket.close(); /* Close the old socket. */
-    return "";
-  }
-  buffer[bytes_received] = '\0';
-  return std::string(buffer);
-}
-

src/bettola.h

@@ -25,8 +25,6 @@ private:
   bool create_gl_context(void);
 
   bool init_client_connection(void);
-  void send_data(const std::string& data);
-  std::string receive_data(void);
 
   void setup_quad(void);
 

srv/main.cpp

@@ -2,6 +2,8 @@
 
 #include "bettola/network/socket.h"
 #include "bettola/network/net_common.h"
+#include "bettola/network/message.h"
+#include "bettola/network/player_pos_message.h"
 
 int main(void) {
   printf("=== Bettola Server: Starting ===\n");
@@ -39,23 +41,23 @@ int main(void) {
 
     printf("Bettola Server: Client connected!\n");
 
-    char buffer[256]; /* Small buffer for echo. */
+    while(true) {
-    ssize_t bytes_received;
+      BettolaLib::Network::MessageHeader header;
-    do {
+      ssize_t bytes_received = client_socket->recv(&header, sizeof(header));
-      bytes_received = client_socket->recv(buffer, sizeof(buffer) - 1);
-      if(bytes_received > 0) {
-        buffer[bytes_received] = '\n';
-        printf("Bettola Server: Received from client: '%s'\n", buffer);
-        client_socket->send(buffer, bytes_received); /* Echo back. */
-      } else if(bytes_received == -1) {
-        perror("Bettola Server: Error receiving from client.");
-      }
-    } while(bytes_received > 0);
 
-    /* Let's just keep it connected for now. */
+      if(bytes_received <= 0) {
-    // printf("Bettola Server: Client disconnected.\n");
+        break;
-    // client_socket->close();
+      }
-    // delete client_socket;
+
+      if(header.type == BettolaLib::Network::MessageType::PlayerPosition) {
+        BettolaLib::Network::PlayerPosMessage msg;
+        bytes_received = client_socket->recv(&msg, sizeof(msg));
+        if(bytes_received > 0) {
+          printf("Bettola Server: Received PlayerPosition messgae: x=%.2f, y=%.2f\n",
+                 msg.x, msg.y);
+        }
+      }
+    }
   }
 
   server_socket.close(); /* Shouldn't reach here. */