Updated.

it is only built if it doesn't already exist on the user's platform.
gdbm is a set of database routines that use extendible hashing and works
similar to the standard UNIX dbm routines.  This guarantees the availability
of gdbm to any application that uses SimGear.

Makefile.am

@@ -1,6 +1,14 @@
-EXTRA_DIST = mksymlinks.sh acsite.m4 acconfig.h
+EXTRA_DIST	= mksymlinks.sh acsite.m4 acconfig.h
+
+SUBDIRS		= simgear
+
+#
+# Rule to build RPM distribution package
+#
+rpm: dist
+	cp $(PACKAGE)-$(VERSION).tar.gz /usr/src/packages/SOURCES
+	rpm -ba @PACKAGE@.spec
 
 dist-hook:
 	tar cf - simgear/metar | (cd $(distdir); tar xvf -)
 
-SUBDIRS = simgear

NEWS

@@ -1,3 +1,15 @@
+New in 0.0.7
+* March 29, 2000
+* Added support for RedHat package building contributed by Habibie 
+  <habibie@MailandNews.com>
+* Added gdbm to SimGear.  Many systems will already have gdbm installed so
+  it is only built if it doesn't already exist on the user's platform.
+  gdbm is a set of database routines that use extendible hashing and works
+  similar to the standard UNIX dbm routines.  This guarantees the availability
+  of gdbm to any application that uses SimGear.
+* Optimizations and bullet proofing of magnetic variation code by Norman 
+  Vine and Ed Williams
+
 New in 0.0.6
 * March 27, 2000
 * Added Nima World Magnetic Model 2000 contributed by Ed Williams

SimGear.spec.in

@@ -0,0 +1,76 @@
+%define ver	@VERSION@
+%define rel	1
+%define prefix	/usr
+
+Summary:	Simulator Construction Gear.
+Name:		@PACKAGE@
+Version:	%ver
+Release:	%rel
+Copyright:	LGPL
+Group:		Libraries/Graphics
+Source:		%{name}-%{version}.tar.gz
+#URL:		
+BuildRoot:	/tmp/%{name}-%{version}-%{rel}-root
+Packager:	Fill In As You Wish
+Docdir:		%{prefix}/doc
+
+%description
+This package contains a tools and libraries useful for constructing 
+simulation and visualization applications such as FlightGear or TerraGear. 
+
+Authors:
+	N/A
+
+%prep
+%setup -n %{name}-%{version}
+
+
+%build
+# Needed for snapshot releases.
+if [ ! -f configure ]; then
+	CFLAGS="$RPM_OPT_FLAGS" ./autogen.sh --prefix=%prefix
+else
+	CFLAGS="$RPM_OPT_FLAGS" ./configure --prefix=%prefix
+fi
+
+if [ "$SMP" != "" ]; then
+	JSMP	= '"MAKE=make -k -j $SMP"'
+fi
+
+make ${JSMP};
+
+
+%install
+[ -d ${RPM_BUILD_ROOT} ] && rm -rf ${RPM_BUILD_ROOT}
+
+make prefix=${RPM_BUILD_ROOT}%{prefix} install
+
+#
+# Generating file lists and store them in file-lists
+# Starting with the directory listings
+#
+find ${RPM_BUILD_ROOT}%{prefix}/{bin,include,lib} -type d | sed "s#^${RPM_BUILD_ROOT}#\%attr (-\,root\,root) \%dir #" > file-lists
+%{?ETCDR:find ${RPM_BUILD_ROOT}%{!?SYSCF:%{prefix}}/etc -type d | sed "s#^${RPM_BUILD_ROOT}#\%attr (-\,root\,root) \%dir #" >> file-lists}
+
+#
+# Then, the file listings
+#
+echo "%defattr (-, root, root)" >> file-lists
+%{?ETCDR:find ${RPM_BUILD_ROOT}%{!?SYSCF:%{prefix}}/etc/%{name}.conf -type f | sed -e "s#^${RPM_BUILD_ROOT}#%config #g" >> file-lists}
+find ${RPM_BUILD_ROOT}%{prefix} -type f | sed -e "s#^${RPM_BUILD_ROOT}##g" >> file-lists
+
+
+%clean
+(cd ..; rm -rf %{name}-%{version} ${RPM_BUILD_ROOT})
+
+
+%files -f file-lists
+%defattr (-, root, root)
+%doc AUTHORS
+%doc COPYING
+%doc ChangeLog
+%doc INSTALL
+%doc NEWS
+%doc README
+%doc %{name}.spec.in
+

acconfig.h

@@ -181,6 +181,9 @@
 /* Define if you have the wait3 system call.  */
 #undef HAVE_WAIT3
 
+/* Define if you have gdbm installed system wide.  */
+#undef HAVE_GDBM
+
 /* Define if you have zlib installed system wide.  */
 #undef HAVE_ZLIB
 

configure.in

@@ -6,7 +6,7 @@ dnl $Id$
 AC_INIT(simgear/bucket/newbucket.cxx)
 
 dnl Initialize the automake stuff
-AM_INIT_AUTOMAKE(SimGear, 0.0.6)
+AM_INIT_AUTOMAKE(SimGear, 0.0.7)
 
 dnl Checks for programs.
 AC_PROG_MAKE_SET
@@ -24,6 +24,10 @@ else
 fi
 
 
+dnl Run configure in the gdbm subdir
+dnl AC_CONFIG_SUBDIRS( simgear/gdbm )
+
+
 dnl Specify if we want logging (testing build) or not (release build)
 # set logging default value
 # with_logging=yes
@@ -196,6 +200,15 @@ if test "x$ac_cv_header_plib_pu_h" != "xyes"; then
     exit
 fi
 
+dnl Check for system installed gdbm
+AC_CHECK_HEADER(gdbm.h)
+if test "x$ac_cv_header_gdbm_h" = "xyes"; then
+    AC_DEFINE( HAVE_GDBM )
+else
+    echo "no gdbm found, configuring and building."
+fi
+AM_CONDITIONAL(HAVE_GDBM, test "x$ac_cv_header_gdbm_h" = "xyes" )
+
 dnl Check for system installed zlib
 AC_CHECK_HEADER(zlib.h)
 if test "x$ac_cv_header_zlib_h" = "xyes"; then
@@ -227,10 +240,12 @@ AM_CONFIG_HEADER(simgear/config.h)
 
 AC_OUTPUT( \
 	Makefile \
+	SimGear.spec \
 	simgear/Makefile \
 	simgear/version.h \
 	simgear/bucket/Makefile \
 	simgear/debug/Makefile \
+	simgear/gdbm/Makefile \
 	simgear/magvar/Makefile \
 	simgear/math/Makefile \
 	simgear/misc/Makefile \
@@ -259,3 +274,11 @@ if test "x$with_efence" != "x"; then
 else
     echo "Electric fence: no"
 fi
+
+if test "x$ac_cv_header_gdbm_h" != "xyes"; then
+   echo "Building gdbm"
+fi
+
+if test "x$ac_cv_header_zlib_h" != "xyes"; then
+   echo "Building zlib"
+fi

simgear/Makefile.am

@@ -4,6 +4,12 @@ else
 SERIAL_DIRS =
 endif
 
+if HAVE_GDBM
+GDBM_DIRS =
+else
+GDBM_DIRS = gdbm
+endif
+
 if HAVE_ZLIB
 ZLIB_DIRS =
 else
@@ -20,6 +26,7 @@ include_HEADERS = compiler.h constants.h fg_traits.hxx fg_zlib.h version.h
 SUBDIRS = \
 	bucket \
 	debug \
+	$(GDBM_DIRS) \
 	magvar \
 	math \
 	$(METAR_DIRS) \

simgear/config.h

@@ -1,5 +1,5 @@
 /* simgear/config.h.  Generated automatically by configure.  */
-/* simgear/include/config.h.in.  Generated automatically from configure.in by autoheader.  */
+/* simgear/config.h.in.  Generated automatically from configure.in by autoheader.  */
 
 /* Define to empty if the keyword does not work.  */
 /* #undef const */
@@ -48,8 +48,11 @@
 /* Define if you have the vprintf function.  */
 #define HAVE_VPRINTF 1
 
+/* Define if you have gdbm installed system wide.  */
+#define HAVE_GDBM 1
+
 /* Define if you have zlib installed system wide.  */
-/* #undef HAVE_ZLIB */
+#define HAVE_ZLIB 1
 
 /* Define as the return type of signal handlers (int or void).  */
 #define RETSIGTYPE void
@@ -205,5 +208,5 @@
 #define PACKAGE "SimGear"
 
 /* Version number of package */
-#define VERSION "0.0.6"
+#define VERSION "0.0.7"
 

simgear/config.h.in

@@ -1,4 +1,4 @@
-/* simgear/include/config.h.in.  Generated automatically from configure.in by autoheader.  */
+/* simgear/config.h.in.  Generated automatically from configure.in by autoheader.  */
 
 /* Define to empty if the keyword does not work.  */
 #undef const
@@ -47,6 +47,9 @@
 /* Define if you have the vprintf function.  */
 #undef HAVE_VPRINTF
 
+/* Define if you have gdbm installed system wide.  */
+#undef HAVE_GDBM
+
 /* Define if you have zlib installed system wide.  */
 #undef HAVE_ZLIB
 

simgear/magvar/magvar.cxx

@@ -1,7 +1,7 @@
 // magvar.cxx -- compute local magnetic variation given position,
 //               altitude, and date
 //
-// This is an implimentation of the NIMA WMM 2000
+// This is an implementation of the NIMA (formerly DMA) WMM2000
 //
 //    http://www.nima.mil/GandG/ngdc-wmm2000.html
 //
@@ -15,6 +15,37 @@
 // WMM2000 IGR2000 added 2/00 EAW
 // Released under GPL 3/26/00 EAW
 // Adaptions and modifications for the SimGear project  3/27/2000 CLO
+//
+// Removed all pow() calls and made static roots[][] arrays to
+// save many sqrt() calls on subsequent invocations
+// left old code as SGMagVarOrig() for testing purposes
+// 3/28/2000  Norman Vine -- nhv@yahoo.com
+//
+// Put in some bullet-proofing to handle magnetic and geographic poles.
+// 3/28/2000 EAW
+
+//  The routine uses a spherical harmonic expansion of the magnetic
+// potential up to twelfth order, together with its time variation, as
+// described in Chapter 4 of "Geomagnetism, Vol 1, Ed. J.A.Jacobs,
+// Academic Press (London 1987)". The program first converts geodetic
+// coordinates (lat/long on elliptic earth and altitude) to spherical
+// geocentric (spherical lat/long and radius) coordinates. Using this,
+// the spherical (B_r, B_theta, B_phi) magnetic field components are
+// computed from the model. These are finally referred to surface (X, Y,
+// Z) coordinates.
+//
+//   Fields are accurate to better than 200nT, variation and dip to
+// better than 0.5 degrees, with the exception of the declination near
+// the magnetic poles (where it is ill-defined) where the error may reach
+// 4 degrees or more.
+//
+//   Variation is undefined at both the geographic and  
+// magnetic poles, even though the field itself is well-behaved. To
+// avoid the routine blowing up, latitude entries corresponding to
+// the geographic poles are slightly offset. At the magnetic poles,
+// the routine returns zero variation.
+
+
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License as
@@ -126,6 +157,8 @@ static double hnm[13][13];
 static double sm[13];
 static double cm[13];
 
+static double root[13];
+static double roots[13][13][2];
 
 /* Convert date to Julian day    1950-2049 */
 unsigned long int yymmdd_to_julian_days( int yy, int mm, int dd )
@@ -156,9 +189,10 @@ double rad_to_deg( double rad )
 }
 	     
 
-/* return variation (in degrees) given geodetic latitude (radians), longitude
-(radians) ,height (km) and (Julian) date
-N and E lat and long are positive, S and W negative
+/*
+ * return variation (in radians) given geodetic latitude (radians),
+ * longitude(radians), height (km) and (Julian) date
+ * N and E lat and long are positive, S and W negative
 */
 
 double SGMagVar( double lat, double lon, double h, long dat, double* field )
@@ -168,6 +202,159 @@ double SGMagVar( double lat, double lon, double h, long dat, double* field )
     /* reference dates */
     long date0_wmm2000 = yymmdd_to_julian_days(0,1,1);
 
+    double yearfrac,sr,r,theta,c,s,psi,fn,fn_0,B_r,B_theta,B_phi,X,Y,Z;
+    double sinpsi, cospsi, inv_s;
+
+    static int been_here = 0;
+
+    double sinlat = sin(lat);
+    double coslat = cos(lat);
+
+    /* convert to geocentric coords: */
+    // sr = sqrt(pow(a*coslat,2.0)+pow(b*sinlat,2.0));
+    sr = sqrt(a*a*coslat*coslat + b*b*sinlat*sinlat);
+    /* sr is effective radius */
+    theta = atan2(coslat * (h*sr + a*a),
+		  sinlat * (h*sr + b*b));
+    /* theta is geocentric co-latitude */
+
+    r = h*h + 2.0*h * sr +
+	(a*a*a*a - ( a*a*a*a - b*b*b*b ) * sinlat*sinlat ) / 
+	(a*a - (a*a - b*b) * sinlat*sinlat );
+
+    r = sqrt(r);
+
+    /* r is geocentric radial distance */
+    c = cos(theta);
+    s = sin(theta);
+    /* protect against zero divide at geographic poles */
+    inv_s =  1.0 / (s + (s == 0.)*1.0e-8); 
+
+    /* zero out arrays */
+    for ( n = 0; n <= nmax; n++ ) {
+	for ( m = 0; m <= n; m++ ) {
+	    P[n][m] = 0;
+	    DP[n][m] = 0;
+	}
+    }
+
+    /* diagonal elements */
+    P[0][0] = 1;
+    P[1][1] = s;
+    DP[0][0] = 0;
+    DP[1][1] = c;
+    P[1][0] = c ;
+    DP[1][0] = -s;
+
+    // these values will not change for subsequent function calls
+    if( !been_here ) {
+	for ( n = 2; n <= nmax; n++ ) {
+	    root[n] = sqrt((2.0*n-1) / (2.0*n));
+	}
+
+	for ( m = 0; m <= nmax; m++ ) {
+	    double mm = m*m;
+	    for ( n = max(m + 1, 2); n <= nmax; n++ ) {
+		roots[m][n][0] = sqrt((n-1)*(n-1) - mm);
+		roots[m][n][1] = 1.0 / sqrt( n*n - mm);
+	    }
+	}
+	been_here = 1;
+    }
+
+    for ( n=2; n <= nmax; n++ ) {
+	// double root = sqrt((2.0*n-1) / (2.0*n));
+	P[n][n] = P[n-1][n-1] * s * root[n];
+	DP[n][n] = (DP[n-1][n-1] * s + P[n-1][n-1] * c) *
+	    root[n];
+    }
+
+    /* lower triangle */
+    for ( m = 0; m <= nmax; m++ ) {
+	// double mm = m*m;
+	for ( n = max(m + 1, 2); n <= nmax; n++ ) {
+	    // double root1 = sqrt((n-1)*(n-1) - mm);
+	    // double root2 = 1.0 / sqrt( n*n - mm);
+	    P[n][m] = (P[n-1][m] * c * (2.0*n-1) -
+		       P[n-2][m] * roots[m][n][0]) *
+		roots[m][n][1];
+
+	    DP[n][m] = ((DP[n-1][m] * c - P[n-1][m] * s) *
+			(2.0*n-1) - DP[n-2][m] * roots[m][n][0]) *
+		roots[m][n][1];
+	}
+    }
+
+    /* compute gnm, hnm at dat */
+    /* WMM2000 */
+    yearfrac = (dat - date0_wmm2000) / 365.25;
+    for ( n = 1; n <= nmax; n++ ) {
+	for ( m = 0; m <= nmax; m++ ) {
+	    gnm[n][m] = gnm_wmm2000[n][m] + yearfrac * gtnm_wmm2000[n][m];
+	    hnm[n][m] = hnm_wmm2000[n][m] + yearfrac * htnm_wmm2000[n][m];
+	}
+    }
+
+    /* compute sm (sin(m lon) and cm (cos(m lon)) */
+    for ( m = 0; m <= nmax; m++ ) {
+	sm[m] = sin(m * lon);
+	cm[m] = cos(m * lon);
+    }
+
+    /* compute B fields */
+    B_r = 0.0;
+    B_theta = 0.0;
+    B_phi = 0.0;
+    fn_0 = r_0/r;
+    fn = fn_0 * fn_0;
+
+    for ( n = 1; n <= nmax; n++ ) {
+	double c1_n=0;
+	double c2_n=0;
+	double c3_n=0;
+	for ( m = 0; m <= n; m++ ) {
+	    double tmp = (gnm[n][m] * cm[m] + hnm[n][m] * sm[m]); 
+	    c1_n=c1_n + tmp * P[n][m];
+	    c2_n=c2_n + tmp * DP[n][m];
+	    c3_n=c3_n + m * (gnm[n][m] * sm[m] - hnm[n][m] * cm[m]) * P[n][m];
+	}
+	// fn=pow(r_0/r,n+2.0);
+	fn *= fn_0;
+	B_r = B_r + (n + 1) * c1_n * fn;
+	B_theta = B_theta - c2_n * fn;
+	B_phi = B_phi + c3_n * fn * inv_s;
+    }
+
+    /* Find geodetic field components: */
+    psi = theta - ((pi / 2.0) - lat);
+    sinpsi = sin(psi);
+    cospsi = cos(psi);
+    X = -B_theta * cospsi - B_r * sinpsi;
+    Y = B_phi;
+    Z = B_theta * sinpsi - B_r * cospsi;
+
+    field[0]=B_r;
+    field[1]=B_theta;
+    field[2]=B_phi;
+    field[3]=X;
+    field[4]=Y;
+    field[5]=Z;   /* output fields */
+
+    /* find variation in radians */
+    /* return zero variation at magnetic pole X=Y=0. */
+    /* E is positive */
+    return (X != 0. || Y != 0.) ? atan2(Y, X) : (double) 0.;  
+}
+
+
+#ifdef TEST_NHV_HACKS
+double SGMagVarOrig( double lat, double lon, double h, long dat, double* field )
+{
+    /* output field B_r,B_th,B_phi,B_x,B_y,B_z */
+    int n,m;
+    /* reference dates */
+    long date0_wmm2000 = yymmdd_to_julian_days(0,1,1);
+
     double yearfrac,sr,r,theta,c,s,psi,fn,B_r,B_theta,B_phi,X,Y,Z;
 
     /* convert to geocentric coords: */
@@ -187,7 +374,7 @@ double SGMagVar( double lat, double lon, double h, long dat, double* field )
     c = cos(theta);
     s = sin(theta);
 
-    /*zero out arrays */
+    /* zero out arrays */
     for ( n = 0; n <= nmax; n++ ) {
 	for ( m = 0; m <= n; m++ ) {
 	    P[n][m] = 0;
@@ -274,4 +461,4 @@ double SGMagVar( double lat, double lon, double h, long dat, double* field )
     /* find variation, leave in radians! */
     return atan2(Y, X);  /* E is positive */
 }
-
+#endif // TEST_NHV_HACKS