[Csp-commits] APPLICATIONS/CSPFlightSim/Source CSPFlightSim.cpp,1.6,1.7

[<mk...@us...>]

Update of /cvsroot/csp/APPLICATIONS/CSPFlightSim/Source
In directory sc8-pr-cvs1:/tmp/cvs-serv22143

Modified Files:
	CSPFlightSim.cpp 
Log Message:
Initial time fix.  (prevents extra long first frame)
Long timestep fix.  (could cause physics instability/segfaults)
Frame rate buffer overflow fix.

Index: CSPFlightSim.cpp
===================================================================
RCS file: /cvsroot/csp/APPLICATIONS/CSPFlightSim/Source/CSPFlightSim.cpp,v
retrieving revision 1.6
retrieving revision 1.7
diff -C2 -d -r1.6 -r1.7
*** CSPFlightSim.cpp	18 Dec 2002 01:38:47 -0000	1.6
--- CSPFlightSim.cpp	19 Dec 2002 08:56:37 -0000	1.7
***************
*** 57,60 ****
--- 57,61 ----
  osg::Timer _timer;
  osg::Timer_t _initialTick, _lastFrameTick, _frameTick;
+ double _timeStep, _frameTime, _timeLag = 0.0;
  
  osg::Timer_t clockTick()
***************
*** 69,76 ****
--- 70,94 ----
  
  // update time from the current frame update and the previous one.
+ // the timestep for updates is restricted to 1 second max.  greater
+ // delays will accumulate in _timeLag to be made up in subsequent 
+ // frames.  this prevents long delays from destabilizing the update
+ // computations.
  osg::Timer_t updateFrameTick()
  {
      _lastFrameTick = _frameTick;
      _frameTick = _timer.tick();
+     _frameTime = _timer.delta_s(_lastFrameTick,_frameTick);
+     _timeStep = _frameTime + _timeLag;
+     if (_timeStep > 1.0) {
+     	_timeLag = _timeStep - 1.0;
+ 	_timeStep = 1.0;
+     } 
+     if (_timeStep < 0.01) {
+     	// todo: microsleep
+     	_timeStep = 0.01;
+     	_timeLag = 0.0;
+     } else {
+     	_timeLag = 0.0;
+     }
      return _frameTick;
  }
***************
*** 78,87 ****
  double frameSeconds() 
  { 
! 	return _timer.delta_s(_lastFrameTick,_frameTick); 
  }
  
  double frameRate() 
  { 
! 	return 1.0/frameSeconds(); 
  }
  
--- 96,106 ----
  double frameSeconds() 
  { 
! 	return _frameTime; //_timer.delta_s(_lastFrameTick,_frameTick); 
  }
  
  double frameRate() 
  { 
! 	if (_frameTime < 0.005) return 200.0;
! 	return 1.0/_frameTime; //frameSeconds(); 
  }
  
***************
*** 193,196 ****
--- 212,221 ----
      CSP_LOG(CSP_APP, CSP_DEBUG, "CSPFlightSim::Run..." );
      m_bFreezeSim = false;
+     
+     // reset to frame time so we don't jump in one frame through
+     // all the time it took to initialize.  just a hack for now.
+ 	_initialTick = _timer.tick();
+ 	_frameTick = _initialTick;
+ 	_lastFrameTick = _initialTick;
  	
      try
***************
*** 199,203 ****
  		{
  			updateFrameTick();
! 			float dt = frameSeconds();
  
  			g_pSimTime->updateSimTime(dt);    
--- 224,228 ----
  		{
  			updateFrameTick();
! 			float dt = _timeStep; //frameSeconds();
  
  			g_pSimTime->updateSimTime(dt);    
***************
*** 529,533 ****
  {
  	int width = m_SDLScreen->w;
! 	char buffer[128];
  	StandardVector3 direction = g_pPlayerObject->getDirection();
  	StandardVector3 upVector = g_pPlayerObject->getUpDirection();
--- 554,558 ----
  {
  	int width = m_SDLScreen->w;
! 	char buffer[256];
  	StandardVector3 direction = g_pPlayerObject->getDirection();
  	StandardVector3 upVector = g_pPlayerObject->getUpDirection();
***************
*** 551,556 ****
  void CSPFlightSim::ShowStats(float fps)
  {
!     char framerate[30];
!     char buffer[128];
      static float maxFps = 0.0, minFps = 500.0;
  
--- 576,581 ----
  void CSPFlightSim::ShowStats(float fps)
  {
!     char framerate[64];
!     char buffer[256];
      static float maxFps = 0.0, minFps = 500.0;