client-side frame interpolation: frames and timers

10 files changed, 138 insertions, 37 deletions

diff --git a/src/core/Makefile.am b/src/core/Makefile.am
index 7c18362..efa4e7b 100644
--- a/src/core/Makefile.am
+++ b/src/core/Makefile.am
@@ -1,7 +1,7 @@
 METASOURCES = AUTO
 INCLUDES = -I$(top_srcdir)/src
 
-libcore_la_SOURCES = application.cc commandbuffer.cc core.cc cvar.cc entity.cc \
+libcore_la_SOURCES = application.cc commandbuffer.cc clientstate.cc core.cc cvar.cc entity.cc \
 	func.cc gameconnection.cc gameinterface.cc gameserver.cc module.cc netclient.cc \
 	netconnection.cc netserver.cc player.cc stats.cc
 libcore_la_LDFLAGS = -avoid-version -no-undefined
@@ -9,7 +9,7 @@ libcore_la_LIBADD = $(top_builddir)/src/filesystem/libfilesystem.la \
 	$(top_builddir)/src/math/libmath.la $(top_builddir)/src/sys/libsys.la $(top_builddir)/src/model/libmodel.la
 
 noinst_LTLIBRARIES = libcore.la
-noinst_HEADERS = application.h commandbuffer.h core.h cvar.h entity.h func.h \
+noinst_HEADERS = application.h commandbuffer.h clientstate.h core.h cvar.h entity.h func.h \
 	gameconnection.h gameinterface.h gameserver.h module.h net.h \
 	netclient.h netconnection.h netserver.cc player.h stats.h
 
diff --git a/src/core/entity.cc b/src/core/entity.cc
index d2fef43..cc956b0 100644
--- a/src/core/entity.cc
+++ b/src/core/entity.cc
@@ -7,13 +7,9 @@
 #include <vector>
 #include <iomanip>
 
-namespace core
-{
-	class Entity;
-}
-
 #include "sys/sys.h"
 #include "core/entity.h"
+#include "core/cvar.h"
 
 namespace core
 {
@@ -101,8 +97,7 @@ Entity::Entity(unsigned int flags) :
 	entity_modelname.clear();
 	entity_name.clear();
 
-	entity_renderstate = 0;
-	entity_renderfuzz = math::randomf();
+	entity_clientstate = 0;
 
 	add(this);
 }
@@ -140,14 +135,15 @@ Entity::Entity(std::istream & is)
 	entity_destroyed = false;	
 	entity_dirty = false;
 
-	entity_renderstate = 0;
-	entity_renderfuzz = math::randomf();
+	entity_clientstate = 0;
 
 	add(this, entity_id);
 }
 
 Entity::~Entity()
 {
+	if (entity_clientstate)
+		delete entity_clientstate;
 }
 
 void Entity::serialize(std::ostream & os) const
diff --git a/src/core/entity.h b/src/core/entity.h
index 1e80435..287157b 100644
--- a/src/core/entity.h
+++ b/src/core/entity.h
@@ -7,6 +7,10 @@
 #ifndef __INCLUDED_CORE_ENTITY_H__
 #define __INCLUDED_CORE_ENTITY_H__
 
+#include <iostream>
+#include <string>
+#include <map>
+
 #include "model/model.h"
 #include "math/axis.h"
 #include "math/mathlib.h"
@@ -19,12 +23,9 @@ class EntityControlable;
 
 }
 
+#include "core/clientstate.h"
 #include "core/player.h"
 
-#include <iostream>
-#include <string>
-#include <map>
-
 namespace core
 {
 
@@ -33,11 +34,11 @@ class Entity
 {
 public:
 	/// Entity flags
+	/**
+ 	 * entities with the Static flag set will not get client-side interpolation
+	 */
 	enum Flags {Static=1, Solid=2, Bright=4};
 
-	/// Entity render state flags
-	enum State {InRange=1, InCloseRange=2};
-
 	/// Entity type constants
 	enum Type {Default=0, Dynamic=1, Controlable=2, Globe=3};
 
@@ -64,12 +65,6 @@ public:
 	///  core type id
 	virtual inline unsigned int type() const { return Default; }
 
-	/// client state
-	inline unsigned int state() const { return entity_renderstate; }
-
-	/// client render fuzz factor
-	inline float fuzz() const { return entity_renderfuzz; };
-
 	/// entity flags
 	inline unsigned int flags() const { return entity_flags; }
 
@@ -79,6 +74,9 @@ public:
 	/// entity model name
 	inline std::string const & modelname() { return entity_modelname; }
 
+	/// entity client render state
+	inline ClientState * state() { return entity_clientstate; }
+
 	/// pointer to the model, is used client-side
 	inline model::Model * model() { return entity_model; }
 
@@ -158,8 +156,10 @@ public:
 	bool 			entity_created;
 	bool			entity_destroyed;
 
-	unsigned int		entity_renderstate;
-	float			entity_renderfuzz;
+	/// timestamp when entity data was received from the server
+	float			entity_servertimestamp;
+
+	ClientState		*entity_clientstate;
 
 private:
 	/// add an entity to the registry
diff --git a/src/core/gameconnection.cc b/src/core/gameconnection.cc
index 4f410d5..baf0967 100644
--- a/src/core/gameconnection.cc
+++ b/src/core/gameconnection.cc
@@ -88,6 +88,10 @@ void GameConnection::frame(float seconds)
 		return;
 	}
 
+	if (!Cvar::sv_dedicated->value()) {
+		update_clientstate();
+	}
+
 	connection_frametime += seconds;
 
 	float f = 0;
diff --git a/src/core/gameinterface.cc b/src/core/gameinterface.cc
index 5789592..8d351a0 100644
--- a/src/core/gameinterface.cc
+++ b/src/core/gameinterface.cc
@@ -91,7 +91,53 @@ void GameInterface::clear()
 
 	// remove all models
 	model::Model::clear();
+
+	game_previousframetime = 0;
+	game_serverframetime = 0;
+	game_clientframetime = 0;
+	game_timestep = 0;
+	game_frames = 0;
 }
 
+void GameInterface::reset_clientstate(float servertime)
+{
+	game_timestep =  (servertime - game_serverframetime);
+
+	if (game_timestep < 0)
+		game_timestep = 0;
+
+	game_previousframetime = game_serverframetime;
+	game_serverframetime = servertime;
+	game_clientframetime = game_previousframetime;
+
+	std::map<unsigned int, core::Entity *>::iterator it;
+	for (it=core::Entity::registry.begin(); it != core::Entity::registry.end(); it++) {
+		
+		core::Entity *entity = (*it).second;
+
+		if (entity->state() && !(entity->flags() & Entity::Static))
+			entity->state()->assign(entity);
+	}
+	
+	game_frames = 0;
+}
 
-} // namespace core
+void GameInterface::update_clientstate()
+{
+	game_frames++;
+	game_clientframetime += game_timestep;
+
+	if (game_clientframetime > game_serverframetime)
+		game_clientframetime = game_serverframetime;
+}
+
+float GameInterface::timeoffset() {
+	float d = game_serverframetime - game_previousframetime;
+	if (d < 0)
+		d = 1;
+	float t = game_serverframetime - game_clientframetime;
+
+	return t/d;
+}
+
+}
diff --git a/src/core/gameinterface.h b/src/core/gameinterface.h
index e38c061..2324bb5 100644
--- a/src/core/gameinterface.h
+++ b/src/core/gameinterface.h
@@ -27,6 +27,20 @@ public:
 	/// return the local player
 	inline Player *localplayer() { return &game_localplayer; }
 
+	/// return the server time of the last received server frame
+	inline float serverframetime() const { return game_serverframetime; }
+
+	/// return the server time of the previous received server frame
+	inline float previousframetime() const { return game_serverframetime; }
+
+	/// return the server time of the previous received server frame
+	inline float clientframetime() const { return game_clientframetime; }
+
+	/// client frame time between previousframetime and serverframetime, from 0 - 1
+	float timeoffset();
+
+	inline float timestep() const { return game_timestep; }
+
 /*----- virtual inspectors --------------------------------------- */
 
 	/// returns true if the game server can run a time frime
@@ -37,6 +51,12 @@ public:
 	/// clear all game variables, game functions and entities
 	void clear();
 
+	/// reset the client state
+	void reset_clientstate(float servertime);
+
+	/// update the client state timers
+	void update_clientstate();
+
 /*----- virtual mutators ------------------------------------------ */
 	
 	/// run one game time frame
@@ -46,6 +66,14 @@ public:
 protected:
 	/// the local player
 	static Player 			game_localplayer;
+	
+	float				game_serverframetime;
+	float				game_previousframetime;
+
+	float				game_timestep;
+	float				game_clientframetime;
+
+	unsigned int			game_frames;
 };
 
 /// global local player instance
diff --git a/src/core/gameserver.cc b/src/core/gameserver.cc
index ae2b3a9..3c126fc 100644
--- a/src/core/gameserver.cc
+++ b/src/core/gameserver.cc
@@ -32,6 +32,7 @@ GameServer::GameServer() : GameInterface()
 	con_print << "Initializing game server...\n";
 	server_instance = this;
 	server_network = 0;
+	server_time = 0;
 	server_frametime = 0.0f;
 	server_maxplayerid = 1;
 
@@ -243,6 +244,8 @@ void GameServer::frame(float seconds)
 	if (error())
 		return;
 
+	server_time += seconds;
+
 	// process incoming network messages
 	if (server_network) {
 		server_network->receive();
@@ -256,6 +259,10 @@ void GameServer::frame(float seconds)
 	if (localplayer()->dirty())
 	 	localplayer()->update_info();
 
+	if (!Cvar::sv_dedicated->value()) {
+		update_clientstate();
+	}
+
 	server_frametime += seconds;
 
 	if ((Cvar::sv_dedicated->value() || Cvar::sv_private->value())) {
@@ -266,7 +273,12 @@ void GameServer::frame(float seconds)
 			}
 		}
 	} 
-			
+	
+	// copy the previous entity state to the client state
+	if (!Cvar::sv_dedicated->value()) {
+		reset_clientstate(server_time);
+	}
+
 	// run a time frame on each entity
 	std::map<unsigned int, Entity *>::iterator it;
 	for (it=Entity::registry.begin(); it != Entity::registry.end(); it++) {
@@ -292,6 +304,11 @@ void GameServer::frame(float seconds)
 		server_network->transmit();
 
 		// TODO - start server frame
+		std::ostringstream framehdr;
+		framehdr.str("");
+		framehdr << "frame " << server_time << "\n";
+		server_network->broadcast(framehdr.str());
+
 		std::map<unsigned int, Entity *>::iterator it;
 		for (it=Entity::registry.begin(); it != Entity::registry.end(); it++) {
 			Entity *entity = (*it).second;
diff --git a/src/core/gameserver.h b/src/core/gameserver.h
index 907d69e..4fb9c47 100644
--- a/src/core/gameserver.h
+++ b/src/core/gameserver.h
@@ -75,6 +75,7 @@ private:
 
 	unsigned int		server_maxplayerid;
 	float			server_frametime;
+	float			server_time;
 };
 
 inline GameServer *server() { return GameServer::instance(); }
diff --git a/src/core/netconnection.cc b/src/core/netconnection.cc
index dda339c..55480d2 100644
--- a/src/core/netconnection.cc
+++ b/src/core/netconnection.cc
@@ -267,6 +267,7 @@ void NetConnection::transmit()
  * msg public <name> <text>
  * die
  * ent
+ * frame
  * sup
  * pif
  */
@@ -305,6 +306,12 @@ void NetConnection::parse_incoming_message(const std::string & message)
 
 	} else if (command == "ping") {
 
+	} else if (command == "frame") {
+		float timestamp;
+		if (msgstream >> timestamp) {
+			game()->reset_clientstate(timestamp);
+		}
+
 	} else if (command == "die") {
 		unsigned int id;
 		if (msgstream >> id) {
@@ -339,14 +346,17 @@ void NetConnection::parse_incoming_message(const std::string & message)
 			}
 		}
 	} else if (command == "sup") {
-		unsigned int id;
-		if (msgstream >> id) {
-			//con_debug << "Received update entity id " << id << std::endl;
-			Entity *entity = Entity::find(id);
-			if (!entity) {
-				con_warn << "Update for unknown entity " << id << std::endl;
-			} else 
-				entity->recieve_server_update(msgstream);
+		if (connection_state == Connected) 
+		{
+			unsigned int id;
+			if (msgstream >> id) {
+				//con_debug << "Received update entity id " << id << std::endl;
+				Entity *entity = Entity::find(id);
+				if (!entity) {
+					con_warn << "Update for unknown entity " << id << std::endl;
+				} else 
+					entity->recieve_server_update(msgstream);
+			}
 		}
 
 	} else if (command == "pif") {
diff --git a/src/core/stats.h b/src/core/stats.h
index 44153ec..9d90fdc 100644
--- a/src/core/stats.h
+++ b/src/core/stats.h
@@ -7,7 +7,6 @@
 #ifndef __INCLUDED_CORE_STATS_H__
 #define __INCLUDED_CORE_STATS_H__
 
-/// this namespace contains the network subsystem
 namespace core
 {