From c24e18e0fc7c5dc064f8dffae27e2664304c5626 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Tue, 17 Jun 1997 03:41:10 +0000
Subject: [PATCH] Nonsignal based interval timing is now working. This would be
 a good time to look at cleaning up the code structure a bit.

---
 Main/GLmain.c   | 57 ++++++++++++++++++++++++++++++++++++++-----------
 Time/fg_timer.c | 16 +++++++++-----
 2 files changed, 55 insertions(+), 18 deletions(-)

diff --git a/Main/GLmain.c b/Main/GLmain.c
index c3244a8e6..26c56120b 100644
--- a/Main/GLmain.c
+++ b/Main/GLmain.c
@@ -70,10 +70,15 @@ double view_offset = 0.0;
 double goal_view_offset = 0.0;
 
 /* Another hack */
-#define DEFAULT_MODEL_HZ 20
+#define DEFAULT_TIMER_HZ 20
 #define DEFAULT_MULTILOOP 6
+#define DEFAULT_MODEL_HZ (DEFAULT_TIMER_HZ * DEFAULT_MULTILOOP)
+
 double Simtime;
 
+/* Another hack */
+int use_signals = 0;
+
 
 /**************************************************************************
  * fgInitVisuals() -- Initialize various GL/view parameters
@@ -208,13 +213,19 @@ static void fgUpdateVisuals( void ) {
  * Update internal time dependent calculations (i.e. flight model)
  **************************************************************************/
 
-void fgUpdateTimeDepCalcs() {
+void fgUpdateTimeDepCalcs(int multi_loop) {
     struct flight_params *f;
 
     f = &current_aircraft.flight;
 
     /* update the flight model */
-    fgFlightModelUpdate(FG_LARCSIM, f, DEFAULT_MULTILOOP);
+    if ( multi_loop < 0 ) {
+	printf("updating flight model with default = %d\n", DEFAULT_MULTILOOP);
+	fgFlightModelUpdate(FG_LARCSIM, f, DEFAULT_MULTILOOP);
+    } else {
+	printf("updating flight model with dynamic = %d\n", multi_loop);
+	fgFlightModelUpdate(FG_LARCSIM, f, multi_loop);
+    }
 
     if ( fabs(goal_view_offset - view_offset) < 0.09 ) {
 	view_offset = goal_view_offset;
@@ -244,7 +255,7 @@ void fgUpdateTimeDepCalcs() {
 
 void fgInitTimeDepCalcs() {
     /* initialize timer */
-    fgTimerInit( 1.0 / DEFAULT_MODEL_HZ, fgUpdateTimeDepCalcs );
+    fgTimerInit( 1.0 / DEFAULT_TIMER_HZ, fgUpdateTimeDepCalcs );
 }
 
 
@@ -276,11 +287,25 @@ static void fgSceneryDraw() {
 
 /* What should we do when we have nothing else to do?  How about get
  * ready for the next move?*/
-static void fgMainLoop( void )
-{
-    printf("Time interval is = %d\n", fgGetTimeInterval());
+static void fgMainLoop( void ) {
+    static int remainder = 0;
+    int elapsed, multi_loop;
+
+    elapsed = fgGetTimeInterval();
+    printf("Time interval is = %d, previous remainder is = %d\n", elapsed, 
+	   remainder);
+
+    multi_loop = ((float)elapsed * 0.001) * DEFAULT_MODEL_HZ;
+    remainder = elapsed - ((multi_loop*1000) / DEFAULT_MODEL_HZ);
+    printf("Model iterations needed = %d, new remainder = %d\n", multi_loop, 
+	   remainder);
+
     aircraft_debug(1);
     fgUpdateVisuals();
+
+    if ( ! use_signals ) {
+	fgUpdateTimeDepCalcs(multi_loop);
+    }
 }
 
 
@@ -393,11 +418,13 @@ int main( int argc, char *argv[] ) {
     /* fgSlewInit(-335340,162540, 15, 4.38); */
     /* fgSlewInit(-398673.28,120625.64, 53, 4.38); */
 
-    fgFlightModelInit(FG_LARCSIM, f, 1.0/(DEFAULT_MODEL_HZ*DEFAULT_MULTILOOP));
+    fgFlightModelInit( FG_LARCSIM, f, 1.0 / DEFAULT_MODEL_HZ );
 
-    printf("Ready to initialize timer\n");
-    /* init timer routines, signals, etc. */
-    fgInitTimeDepCalcs();
+    if ( use_signals ) {
+	/* init timer routines, signals, etc.  Arrange for an alarm
+	   signal to be generated, etc. */
+	fgInitTimeDepCalcs();
+    }
 
     /* build all objects */
     fgSceneryInit();
@@ -443,9 +470,13 @@ int main( int argc, char *argv[] ) {
 
 
 /* $Log$
-/* Revision 1.14  1997/06/16 19:32:51  curt
-/* Starting to add general timer support.
+/* Revision 1.15  1997/06/17 03:41:10  curt
+/* Nonsignal based interval timing is now working.
+/* This would be a good time to look at cleaning up the code structure a bit.
 /*
+ * Revision 1.14  1997/06/16 19:32:51  curt
+ * Starting to add general timer support.
+ *
  * Revision 1.13  1997/06/02 03:40:06  curt
  * A tiny bit more view tweaking.
  *
diff --git a/Time/fg_timer.c b/Time/fg_timer.c
index 84b3038e8..5b478b78e 100644
--- a/Time/fg_timer.c
+++ b/Time/fg_timer.c
@@ -35,7 +35,7 @@
 
 unsigned long int fgSimTime;
 static struct itimerval t, ot;
-static void (*callbackfunc)();
+static void (*callbackfunc)(int multi_loop);
 
 
 /* This routine catches the SIGALRM */
@@ -45,7 +45,9 @@ void fgTimerCatch() {
 
     /* printf("In fgTimerCatch()\n"); */
 
-    callbackfunc();
+    /* -1 tells the routine to use default interval rather than something
+       dynamically calculated based on frame rate */
+    callbackfunc(-1); 
 
     signal(SIGALRM, fgTimerCatch);
 }
@@ -94,15 +96,19 @@ int fgGetTimeInterval() {
 	ftime(&current);
 	interval = 1000 * (current.time - last.time) + 
 	    (current.millitm - last.millitm);
+	last = current;
     }
 
-    last = current;
     return(interval);
 }
 
 
 /* $Log$
-/* Revision 1.1  1997/06/16 19:24:20  curt
-/* Initial revision.
+/* Revision 1.2  1997/06/17 03:41:10  curt
+/* Nonsignal based interval timing is now working.
+/* This would be a good time to look at cleaning up the code structure a bit.
 /*
+ * Revision 1.1  1997/06/16 19:24:20  curt
+ * Initial revision.
+ *
  */