synchronized time between clients

OpenGL/src/interface/MonCraftScene.cpp

@@ -63,6 +63,8 @@ MonCraftScene::MonCraftScene(Viewport* vp)
       sunSpeed(0.0075f),
       lastClock(SDL_GetTicks())
 {
+    World::getInst().t = (uint32_t)(8.f * dayDuration / 24.f);
+
     auto const& serverConf = Config::getServerConfig();
     camera.setFar(16.0f * (float)sqrt(2 * pow(serverConf.renderDistH, 2) + pow(serverConf.renderDistV, 2)));
     camera.setFovY(config.fov);
@@ -132,7 +134,7 @@ MonCraftScene::MonCraftScene(Viewport* vp)
 
     player->setCurrentBlock(overlay->getCurrentBlock());
 
-    World::getInst().t = (uint32_t)(8.f * dayDuration / 24.f);
+
 }
 
 MonCraftScene::~MonCraftScene() {

OpenGL/src/multiplayer/client/RealServer.cpp

@@ -170,6 +170,12 @@ bool RealServer::on_packet_recv(sf::Packet& packet) {
   serverAck = true;
 
   if(type == PacketType::ACK_LOGIN) {
+    uint32_t time;
+    uint32_t start;
+    auto now = std::chrono::steady_clock::now().time_since_epoch();
+    uint32_t end = std::chrono::duration_cast<std::chrono::milliseconds>(now).count();
+    packet >> time >> start;
+    world.t = time + (uint32_t)(end - start);
     state = ServerState::CONNECTED;
     spdlog::info("Logged into the server");
   } 

OpenGL/src/multiplayer/client/RealServer.hpp

@@ -77,6 +77,8 @@ class RealServer: public Server {
   Identifier playerUid;
   PendingChunks pendingChunks;
 
+  uint32_t worldTime;
+
   bool serverAck;
   sf::Time lastServerUpdate;
   const sf::Time timeout = sf::seconds(10);

OpenGL/src/multiplayer/server/Server.cpp

@@ -11,6 +11,7 @@
 #include <memory>
 #include <utility>
 #include <vector>
+#include <chrono>
 
 #include "entity/Entity.hpp"
 #include "multiplayer/Packet.hpp"
@@ -33,6 +34,9 @@ Server::Server(unsigned short port)
   auto& config = Config::getServerConfig();
   renderDistH = config.renderDistH;
   renderDistV = config.renderDistV;
+  World::getInst().t = (uint32_t)(8.f * dayDuration / 24.f);
+  auto now = std::chrono::steady_clock::now().time_since_epoch();
+  lastClock = std::chrono::duration_cast<std::chrono::milliseconds>(now).count();
 }
 
 Server::~Server()
@@ -71,6 +75,13 @@ void Server::on_packet_recv(sf::Packet& packet, ClientID client) {
 }
 
 void Server::on_server_tick() {
+  auto now = std::chrono::steady_clock::now().time_since_epoch();
+  uint32_t time = std::chrono::duration_cast<std::chrono::milliseconds>(now).count();
+  World::getInst().dt = time - lastClock; 
+  World::getInst().t += World::getInst().dt;
+  World::getInst().t = World::getInst().t % dayDuration;
+  lastClock = time;
+
   std::lock_guard<std::mutex> lck(mutex);
   packet_entity_tick();
   packet_chunks();
@@ -121,7 +132,9 @@ void Server::packet_blocks(Identifier uid, BlockArray changedBlocks) {
 void Server::packet_ack_login(ClientID client, Identifier uid) {
   sf::Packet packet;
   PacketHeader header(PacketType::ACK_LOGIN);
-  packet << header << uid;
+  auto now = std::chrono::steady_clock::now().time_since_epoch();
+  uint32_t start = std::chrono::duration_cast<std::chrono::milliseconds>(now).count();
+  packet << header << world.t << start;
   send(packet, client);
 }
 

OpenGL/src/multiplayer/server/Server.hpp

@@ -57,6 +57,8 @@ class Server {
   int renderDistH, renderDistV;
   static const unsigned int maxChunks = 50;
 
+  uint32_t lastClock;
+
   sf::Clock clock;
   const sf::Time timeout = sf::seconds(10);
   const sf::Time tickAckLimit = sf::milliseconds(1000);