From 24fc48a0d5fb862ff35c4aea2a538d8499a2788f Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Wed, 20 Jan 1999 13:42:22 +0000
Subject: [PATCH] Tweaked FDM interface. Testing check sum support for NMEA
 serial output.

---
 FDM/flight.cxx     | 16 +++++++++++++---
 FDM/flight.hxx     | 18 +++++++++++++++---
 Main/GLUTmain.cxx  | 15 ++++++++++-----
 Main/fg_init.cxx   | 12 +++++++++---
 Main/fg_serial.cxx |  8 ++++++--
 5 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/FDM/flight.cxx b/FDM/flight.cxx
index fbe1a048a..7cc2059be 100644
--- a/FDM/flight.cxx
+++ b/FDM/flight.cxx
@@ -70,7 +70,7 @@ void FGState::extrapolate( int time_offset ) {
 
 
 // Initialize the flight model parameters
-int fgFlightModelInit(int model, FGState& f, double dt) {
+int fgFDMInit(int model, FGState& f, double dt) {
     double save_alt = 0.0;
 
     FG_LOG( FG_FLIGHT ,FG_INFO, "Initializing flight model" );
@@ -120,7 +120,7 @@ int fgFlightModelInit(int model, FGState& f, double dt) {
 
 
 // Run multiloop iterations of the flight model
-int fgFlightModelUpdate(int model, FGState& f, int multiloop, int time_offset) {
+int fgFDMUpdate(int model, FGState& f, int multiloop, int time_offset) {
     double time_step, start_elev, end_elev;
 
     // printf("Altitude = %.2f\n", FG_Altitude * 0.3048);
@@ -161,7 +161,7 @@ int fgFlightModelUpdate(int model, FGState& f, int multiloop, int time_offset) {
 
 
 // Set the altitude (force)
-void fgFlightModelSetAltitude(int model, double alt_meters) {
+void fgFDMForceAltitude(int model, double alt_meters) {
     double sea_level_radius_meters;
     double lat_geoc;
 
@@ -181,7 +181,17 @@ void fgFlightModelSetAltitude(int model, double alt_meters) {
 }
 
 
+// Set the local ground elevation
+void fgFDMSetGroundElevation(int model, double ground_meters) {
+    base_fdm_state.set_Runway_altitude( ground_meters * METER_TO_FEET );
+}
+
+
 // $Log$
+// Revision 1.12  1999/01/20 13:42:22  curt
+// Tweaked FDM interface.
+// Testing check sum support for NMEA serial output.
+//
 // Revision 1.11  1999/01/19 17:52:06  curt
 // Working on being able to extrapolate a new position and orientation
 // based on a position, orientation, and time offset.
diff --git a/FDM/flight.hxx b/FDM/flight.hxx
index 6a41775c8..4948bda9f 100644
--- a/FDM/flight.hxx
+++ b/FDM/flight.hxx
@@ -84,6 +84,11 @@
 
 #include <Time/timestamp.hxx>
 
+#ifndef __cplusplus                                                          
+# error This library requires C++
+#endif                                   
+
+
 typedef double FG_VECTOR_3[3];
 
 
@@ -793,19 +798,26 @@ extern FGState cur_fdm_state;
 // General interface to the flight model routines
 
 // Initialize the flight model parameters
-int fgFlightModelInit(int model, FGState& f, double dt);
+int fgFDMInit(int model, FGState& f, double dt);
 
 // Run multiloop iterations of the flight model
-int fgFlightModelUpdate(int model, FGState& f, int multiloop, int jitter);
+int fgFDMUpdate(int model, FGState& f, int multiloop, int jitter);
 
 // Set the altitude (force)
-void fgFlightModelSetAltitude(int model, double alt_meters);
+void fgFDMForceAltitude(int model, double alt_meters);
+
+// Set the local ground elevation
+void fgFDMSetGroundElevation(int model, double alt_meters);
 
 
 #endif // _FLIGHT_HXX
 
 
 // $Log$
+// Revision 1.12  1999/01/20 13:42:23  curt
+// Tweaked FDM interface.
+// Testing check sum support for NMEA serial output.
+//
 // Revision 1.11  1999/01/19 17:52:07  curt
 // Working on being able to extrapolate a new position and orientation
 // based on a position, orientation, and time offset.
diff --git a/Main/GLUTmain.cxx b/Main/GLUTmain.cxx
index 83a73f42a..c4558cb25 100644
--- a/Main/GLUTmain.cxx
+++ b/Main/GLUTmain.cxx
@@ -386,10 +386,10 @@ void fgUpdateTimeDepCalcs(int multi_loop, int remainder) {
 	fgAPRun();
 
 	// printf("updating flight model x %d\n", multi_loop);
-	fgFlightModelUpdate( current_options.get_flight_model(), 
+	fgFDMUpdate( current_options.get_flight_model(), 
 			     cur_fdm_state, multi_loop, remainder );
     } else {
-	fgFlightModelUpdate( current_options.get_flight_model(), 
+	fgFDMUpdate( current_options.get_flight_model(), 
 			     cur_fdm_state, 0, remainder );
     }
 
@@ -492,14 +492,15 @@ static void fgMainLoop( void ) {
 		   f->get_Altitude() * FEET_TO_METER,
 		   scenery.cur_elev + alt_adjust_m - 3.0,
 		   scenery.cur_elev + alt_adjust_m );
-	    fgFlightModelSetAltitude( current_options.get_flight_model(), 
-				      scenery.cur_elev + alt_adjust_m );
+	    fgFDMForceAltitude( current_options.get_flight_model(), 
+				scenery.cur_elev + alt_adjust_m );
 
 	    FG_LOG( FG_ALL, FG_DEBUG, 
 		    "<*> resetting altitude to " 
 		    << f->get_Altitude() * FEET_TO_METER << " meters" );
 	}
-	f->set_Runway_altitude( scenery.cur_elev * METER_TO_FEET );
+	fgFDMSetGroundElevation( current_options.get_flight_model(),
+				 scenery.cur_elev );  // meters
     }
 
     /* printf("Adjustment - ground = %.2f  runway = %.2f  alt = %.2f\n",
@@ -1002,6 +1003,10 @@ int main( int argc, char **argv ) {
 
 
 // $Log$
+// Revision 1.82  1999/01/20 13:42:24  curt
+// Tweaked FDM interface.
+// Testing check sum support for NMEA serial output.
+//
 // Revision 1.81  1999/01/19 20:57:03  curt
 // MacOS portability changes contributed by "Robert Puyol" <puyol@abvent.fr>
 //
diff --git a/Main/fg_init.cxx b/Main/fg_init.cxx
index 58ebc1a57..45f00f274 100644
--- a/Main/fg_init.cxx
+++ b/Main/fg_init.cxx
@@ -107,7 +107,8 @@ int fgInitPosition( void ) {
 	    "starting altitude is = " << current_options.get_altitude() );
 
     f->set_Altitude( current_options.get_altitude() * METER_TO_FEET );
-    f->set_Runway_altitude( f->get_Altitude() - 3.758099 );
+    fgFDMSetGroundElevation( current_options.get_flight_model(),
+			     (f->get_Altitude() - 3.758099) * FEET_TO_METER );
 
     FG_LOG( FG_GENERAL, FG_INFO,
 	    "Initial position is: ("
@@ -208,7 +209,8 @@ int fgInitSubsystems( void )
 			     tmp_abs_view_pos );
     FG_LOG( FG_GENERAL, FG_DEBUG, 
 	    "Altitude after update " << scenery.cur_elev );
-    f->set_Runway_altitude( scenery.cur_elev * METER_TO_FEET );
+    fgFDMSetGroundElevation( current_options.get_flight_model(), 
+			     scenery.cur_elev );
 
     // Reset our altitude if we are below ground
     if ( f->get_Altitude() < f->get_Runway_altitude() + 3.758099) {
@@ -341,7 +343,7 @@ int fgInitSubsystems( void )
     // Initialize the flight model subsystem data structures base on
     // above values
 
-    fgFlightModelInit( current_options.get_flight_model(), cur_fdm_state, 
+    fgFDMInit( current_options.get_flight_model(), cur_fdm_state, 
 		       1.0 / DEFAULT_MODEL_HZ );
 
     // I'm just sticking this here for now, it should probably move
@@ -379,6 +381,10 @@ int fgInitSubsystems( void )
 
 
 // $Log$
+// Revision 1.62  1999/01/20 13:42:25  curt
+// Tweaked FDM interface.
+// Testing check sum support for NMEA serial output.
+//
 // Revision 1.61  1999/01/08 03:23:57  curt
 // Beginning work on compensating for sim time vs. real world time "jitter".
 //
diff --git a/Main/fg_serial.cxx b/Main/fg_serial.cxx
index cfa7d6868..1516e85af 100644
--- a/Main/fg_serial.cxx
+++ b/Main/fg_serial.cxx
@@ -294,11 +294,11 @@ static void send_nmea_out( fgIOCHANNEL& p ) {
     // $GPRMC,HHMMSS,A,DDMM.MMM,N,DDDMM.MMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E*XX
     sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,0.000,E",
 	     utc, lat, lon, speed, heading, date );
-    sprintf( rmc_sum, "%02X", 0 /*calc_nmea_cksum(rmc)*/ );
+    sprintf( rmc_sum, "%02X", calc_nmea_cksum(rmc) );
 
     sprintf( gga, "GPGGA,%s,%s,%s,1,,,%s,F,,,,",
 	     utc, lat, lon, altitude_ft );
-    sprintf( gga_sum, "%02X", 0 /*calc_nmea_cksum(gga)*/ );
+    sprintf( gga_sum, "%02X", calc_nmea_cksum(gga) );
 
 
     FG_LOG( FG_SERIAL, FG_DEBUG, rmc );
@@ -456,6 +456,10 @@ void fgSerialProcess() {
 
 
 // $Log$
+// Revision 1.9  1999/01/20 13:42:26  curt
+// Tweaked FDM interface.
+// Testing check sum support for NMEA serial output.
+//
 // Revision 1.8  1999/01/19 20:57:04  curt
 // MacOS portability changes contributed by "Robert Puyol" <puyol@abvent.fr>
 //
-- 
2.39.2