time management

1 files changed, 41 insertions, 18 deletions

diff --git a/src/client/client.cc b/src/client/client.cc
index 9db7f7e..ede6b29 100644
--- a/src/client/client.cc
+++ b/src/client/client.cc
@@ -24,6 +24,8 @@ namespace client
 {
 
 core::Cvar *cl_framerate = 0;
+core::Cvar *cl_frametime = 0;
+
 Client app;
 
 //--- engine functions --------------------------------------------
@@ -87,9 +89,11 @@ void Client::init(int count, char **arguments)
 	cvar = core::Cvar::get("cl_colorsecond", "1.0 1.0 1.0", core::Cvar::Archive | core::Cvar::Info);
 	cvar->set_info("[r g b] player secondary color");
 	
-	cl_framerate = core::Cvar::get("cl_framerate", "120", core::Cvar::Archive);
+	cl_framerate = core::Cvar::get("cl_framerate", "125", core::Cvar::Archive);
 	cl_framerate->set_info("[int] client framerate in frames/sec");
 
+	cl_frametime = core::Cvar::set("cl_frametime", "8", core::Cvar::ReadOnly);
+	cl_frametime->set_info("[int] current minimal length of one frame, in milliseconds (read-only)");
 	// initialize SDL, but do not initialize any subsystems
 	SDL_Init(0);
 
@@ -117,30 +121,49 @@ void Client::run()
 {
 	con_print << "^BRunning client..." << std::endl;
 
-	Uint32 client_framerate =  (Uint32)(1000/120);
-	Uint32 elapsed = 0;
+	// default framerate 125fps, 8 milliseconds
+	Uint32 client_frame_lenght = 8;
+	
+	Uint32 client_previous_timestamp = 0;
+	Uint32 client_current_timestamp = 0;
 	
 	console()->flush();
 	console()->clear_notify();
 
 	while (true) {
-		Uint32 chrono = SDL_GetTicks();
-
-		core::Application::frame((float)elapsed / 1000.0f);
-		video::frame((float)elapsed / 1000.0f);
-		input::frame((float)elapsed / 1000.0f);
+		// elapsed time in microseconds
+		client_current_timestamp = SDL_GetTicks();
+			
+		// calculate the desired frame length
+		if (cl_framerate->value() < 0) {
+			(*cl_framerate) = 0.0f;
+		} else if (cl_framerate->value() > 1000.0f) {
+			(*cl_framerate) = 1000.0f;
+		}
+
+		if (cl_framerate->value()) {			
+			client_frame_lenght = (Uint32) roundf(1000.0f / cl_framerate->value());
+		} else {
+			client_frame_lenght = 0;
+		}
+		(*cl_frametime) = (float) client_frame_lenght;
 		
-		Uint32 current = SDL_GetTicks();
-		elapsed = current - chrono;
-
-		if (cl_framerate->value()) {
-			client_framerate = (Uint32) (1000.0f / cl_framerate->value());
-			if (client_framerate && (elapsed < client_framerate)) {
-				SDL_Delay(client_framerate - elapsed);
-				elapsed = client_framerate;
+		// only advance per microsecond frame
+		Uint32 d = client_current_timestamp - client_previous_timestamp;
+		if ((d > 0)) {
+			if (d >= client_frame_lenght) {
+				float elapsed = (float)(d) / 1000.f;
+				core::Application::frame(elapsed);
+				video::frame(elapsed);
+				input::frame(elapsed);
+
+				client_previous_timestamp = client_current_timestamp;
+			} else {
+				SDL_Delay(client_frame_lenght - d);
 			}
-		};
-
+		} else {
+			SDL_Delay(1);
+		}
 	}
 
 }