Implementing Syncker Logic for a Custom Project

First of all, you should initialize Syncker. To do so you can simply add the following code to the AppSystemLogic class for both Master and Slave applications.

Insert the following Syncker initialization code to the AppSystemLogic::init() method:

#include "AppSystemLogic.h"
#include <plugins/Unigine/Syncker/UnigineSyncker.h>

 /* .. */

using namespace Unigine;
using namespace Plugins;

/* .. */

int AppSystemLogic::init()
{
	// update application even if focus was lost
	Engine::get()->setBackgroundUpdate(Engine::BACKGROUND_UPDATE_RENDER_NON_MINIMIZED);

	// get the Syncker manager interface
	Syncker::Manager* syncker_manager = Syncker::Manager::get();

	// initialize the Syncker using command line arguments
	// or you can initialize Syncker as Master or Slave directly
	//	via initMaster() or initSlave() methods without using command-line arguments
	syncker_manager->initSyncker();

	// enable debug information in right bottom corner
	syncker_manager->getSyncker()->setDebug(true);

	return 1;
}

In the AppWorldLogic.cpp file add the code to get the pointer to the manager and Master interface for further use in the AppWorldLogic::init() method:

#include "AppWorldLogic.h"
#include <plugins/Unigine/Syncker/UnigineSyncker.h>
#include <UnigineWorld.h>
#include <UnigineGame.h>

using namespace Unigine;
using namespace Plugins;
using namespace Math;

int AppWorldLogic::init()
{

	Syncker::Manager *syncker_manager = Syncker::Manager::get();
	if (syncker_manager && syncker_manager->isMasterInitialized())
		syncker_master = syncker_manager->getMaster();

	return 1;
}

Objects of the following types are synchronized automatically: ObjectWaterGlobal, ObjectCloudLayer, ObjectParticles, WorldLight if they present in the *.world file on all computers.

Synchronization of transformations is supported for all types of nodes. As for other type-specific parameters synchronization is available only for the following ones:

To start synchronizing other nodes or materials (the logic is the same for both), that exist in the world, you just need to tell Syncker which of them you want. To do so you can add the following code to the AppWorldLogic::init() method of your master application:

int AppWorldLogic::init()
{

/* ... */

	// checking if we have a Master interface
	if (syncker_master)
	{
		// getting a pointer for the node named "material_ball"
		NodePtr my_node = World::getNodeByName("material_ball");

		// add the existing node to synchronization
		syncker_master->addSyncNode(my_node, Syncker::Master::SYNC_MASK::TRANSFORM);
	}

	return 1;
}

Now, you can implement your logic for synchronized nodes in the AppWorldLogic::update() method for Master:

int AppWorldLogic::update()
{

	/* ... */

	// checking if we have a Master interface
	if (syncker_master)
	{
		// getting a pointer for the node named "material_ball"
		NodePtr my_node = World::getNodeByName("material_ball");

		// changing node's rotation
		my_node->setRotation(my_node->getRotation() * Math::quat(0, 0, Game::getIFps()));
	}

	return 1;
}

You can create and delete nodes at run time. To synchronize creation of a node on all connected Slave PCs, use the createNode() function.

/* ... */
int cube_created = 0;

int AppWorldLogic::update()
{

	/* ... */

	// checking if we have a Master interface and cube is not yet created
	if (syncker_master && !cube_created)
	{
		// creating a dynamic cube and set up its transformation
		ObjectMeshStaticPtr dynamic_cube = ObjectMeshStatic::create("core/meshes/box.mesh");
		dynamic_cube->setPosition(Math::Vec3(Game::getRandomFloat(-50, 50), Game::getRandomFloat(-50, 50), Game::getRandomFloat(0, 50)));
		dynamic_cube->setRotation(Math::quat(Game::getRandomFloat(0, 360), Game::getRandomFloat(0, 360), Game::getRandomFloat(0, 360)));

		// commanding Slaves to create a dynamic node and adding it to synchronization
		syncker_master->createNode(dynamic_cube);

		cube_created = 1;
	}

	return 1;
}

To synchronize node loading from a *.node file on all connected Slave PCs, use the loadNode() or loadNodereference() methods. This approach is recommended as it allows adding nodes of all types, unlike the createNode() method that supports only a limited number of them.

/* ... */
int node_loaded = 0;

int AppWorldLogic::update()
{

	/* ... */

	// checking if we have a Master interface and our node is not yet loaded
	if (syncker_master && !node_loaded)
	{

		// commanding Slaves to load a node and adding it to synchronization
		syncker_master->loadNode("my_node.node", Syncker::Master::SYNC_MASK::NODE_FLAGS | Syncker::Master::SYNC_MASK::TRANSFORM);

		node_loaded = 1;
	}

	return 1;
}

Let us consider the following simple example: we can set transformation for a node, by simply sending rotation and position via a user message.

1. First step is to create an object on Master and on all Slave PCs as a static one (without adding it to synchronization).

2. Next, we implement a callback function:

   • on_message_received — to be called on receiving a user message. Here we extract the parameters from the received message and use them (in this case to change node's transformation).

3. And the last step is to set this callback using the setMessageReceivedCallback() method in AppWorldLogic::init()

   Source code (C++)

   // declaring and initializing pointers for the Master, Slave, and Syncker instances
   Unigine::Plugins::Syncker::Master* master = nullptr;
   Unigine::Plugins::Syncker::Slave* slave = nullptr;
   Unigine::Plugins::Syncker::Syncker* syncker = nullptr;
   
   // declaring a node, that we are going to transform via user messages
   NodePtr node;
   
   // declaring a blob to store our messages
   Unigine::BlobPtr blob = Unigine::Blob::create();
   
   // declaring message types to be used
   enum MESSAGE_TYPE
   {
   	REPORT,
   	TRANSFORM,
   };
   
   /* ... */
   
   /// callback function to be fired on receiving a user message
   void AppWorldLogic::on_message_received(const Unigine::BlobPtr& message)
   {
   	// reading an unsigned char from the blob defining message type (REPORT or TRANSFORM)
   	unsigned char type = message->readUChar();
   	switch (type)
   	{
   	case REPORT:
   	{
   		// printing to the console that we have received a message
   		Log::message("REPORT Message received!");
   	}
   	break;
   
   	case TRANSFORM:
   	{
   		// reading position and rotation from the message and using them to update node's transformation
   		Vec3 pos = Vec3(message->readDVec3());
   		quat rot = message->readQuat();
   		node->setTransform(translate(pos) * Mat4(rotate(rot)));
   	}
   	break;
   	}
   }
   
   int AppWorldLogic::init()
   {
   
      /* ... */
   	
   	// trying to get a Manager interface
   	auto manager = Syncker::Manager::get();
   	if (manager)
   	{
   		// checking if we have a Master interface
   		if (manager->isMasterInitialized())
   			master = manager->getMaster();
   		else if (manager->isSlaveInitialized())
   			slave = manager->getSlave();
   
   		// getting a pointer to Master/Slave base class
   		syncker = manager->getSyncker();
   	}
   
   	// subscribing to network messages
   	if (syncker)
   		syncker->setMessageReceivedCallback("net", MakeCallback(this, &AppWorldLogic::on_message_received));
   
   	/* ... */
   
   	// somewhere in code... sending a REPORT message
   	blob->clear();
   	blob->writeUChar(REPORT);
   	syncker->sendMessage("net", blob);
   
   	return 1;
   }
   
   int AppWorldLogic::update()
   {
   
   	/* ... */
   
   	// sending a message with object's transform to all peers
   	if (master)
   	{
   		Vec3 pos = node->getPosition();
   		quat rot = node->getRotation();
   		blob->clear();
   		blob->writeUChar(TRANSFORM);
   		blob->writeDVec3(dvec3(pos));
   		blob->writeQuat(rot);
   		syncker->sendMessage("net", blob);
   	}
   
   	/* ... */
   
   	return 1;
   }

Synchronizing Terrain Modifications#

Plugins::Syncker::Manager* syncker_manager = nullptr;

ObjectTerrainGlobalPtr terrain;

/// Method updating the Terrain
void AppWorldLogic::update_terrain(int detail, float threshold, float width, float contrast)
{
	// apply parameters to terrain
	terrain->getDetail(detail)->setMaskThreshold(threshold);
	terrain->getDetail(detail)->setMaskWidth(width);
	terrain->getDetail(detail)->setMaskContrast(contrast);

	if (syncker_manager)
	{
		auto master = syncker_manager->getMaster();
		if (master)
		{
			// send the "terrain_update" message with parameters
			BlobPtr blob = Blob::create();
			blob->writeInt(detail);
			blob->writeFloat(threshold);
			blob->writeFloat(width);
			blob->writeFloat(contrast);

			master->sendMessage("terrain_update", blob);
		}
	}
}

void AppWorldLogic::on_terrain_update(const Unigine::BlobPtr& message)
{
	// read parameters from the message in the same order
	int detail = message->readInt();
	float threshold = message->readFloat();
	float width = message->readFloat();
	float contrast = message->readFloat();
	// invoke update_terrain to apply parameters
	update_terrain(detail, threshold, width, contrast);
}

int AppWorldLogic::init()
{

	// getting the terrain object (this operation is performed once, so it should be in the init() method)
	terrain = checked_ptr_cast<ObjectTerrainGlobal>(World::getNodeByType(Node::OBJECT_TERRAIN_GLOBAL));

	// for Slave
	syncker_manager = Plugins::Syncker::Manager::get();
	if (syncker_manager)
	{
		auto slave = syncker_manager->getSlave();
		if (slave)
		{
			// set the on_terrain_update() method to be called on receiving the "terrain_update" message by a Slave.
			slave->setMessageReceivedCallback("terrain_update", MakeCallback(this, &AppWorldLogic::on_terrain_update));
		}
	}

	return 1;
}

int AppWorldLogic::update()
{

	 // for the Master
	if (Input::isKeyPressed(Input::KEY_T))
	{
		update_terrain(1, 2.0, 3.0f, 4.0f);
	}

	return 1;
}

You can change the viewport on the Master or Slave side. For this purpose you can use the following code (example):

Plugins::Syncker::Manager* syncker_manager = nullptr;

	/* ...

	perform checks if the Syncker plugin is loaded
	and get the Syncker manager interface (Manager)

	 ... */

	// if syncker is initialized, assigning the config settings for the specified computer named "MyPC_1"
	if (syncker_manager->isSynckerInitialized())
		syncker_manager->getSyncker()->setComputerName("MyPC_1");

	/* ... */

You can also tell Slave to use another camera. To do so, you can use the following code (example):

/* ... */

PlayerSpectatorPtr aux_player = nullptr;

/* ... */

int AppWorldLogic::update()
{

	/* ... */

	// checking if we have a Master interface
	if (syncker_master && !aux_player)
	{
		// creating a new auxiliary player (on Master and Slaves)
		aux_player = PlayerSpectator::create();
		aux_player->setPosition(Vec3(0.0f, -40.0f, 200.0f));
		aux_player->setDirection(vec3(0.0f, 1.0f, 0.0f), vec3_up);
		aux_player->setMinVelocity(10);
		aux_player->setMaxVelocity(aux_player->getMinVelocity() * 2);

		// commanding Slaves to create a new player and adding it to synchronization
		syncker_master->createNode(aux_player, ~0);

		// setting a new created player for the computer named "MyPC_1"
		syncker_master->setCustomPlayer("MyPC_1", aux_player);
	}

	/* ... */

	return 1;
}