From: curt <curt>
Date: Wed, 22 Apr 1998 13:24:04 +0000 (+0000)
Subject: C++ - ifiing the code a bit.
X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=73ed3c180edbb2e65e76342faa2f30aff5ed1186;p=flightgear.git

C++ - ifiing the code a bit.
Starting to reorginize some of the lighting calcs to use a table lookup.
---

diff --git a/Time/Makefile.am b/Time/Makefile.am
index e2ab01cc8..11a9e2976 100644
--- a/Time/Makefile.am
+++ b/Time/Makefile.am
@@ -6,6 +6,7 @@ libTime_la_SOURCES = \
 	event.c event.h \
 	fg_time.c fg_time.h \
 	fg_timer.c fg_timer.h \
-	sunpos.c sunpos.h
+	light.cxx light.hxx \
+	sunpos.cxx sunpos.hxx
 
 INCLUDES += -I$(top_builddir) -I$(top_builddir)/Lib -I$(top_builddir)/Simulator
diff --git a/Time/Makefile.in b/Time/Makefile.in
index c7a427186..1ae8bef1d 100644
--- a/Time/Makefile.in
+++ b/Time/Makefile.in
@@ -78,7 +78,8 @@ libTime_la_SOURCES = \
 	event.c event.h \
 	fg_time.c fg_time.h \
 	fg_timer.c fg_timer.h \
-	sunpos.c sunpos.h
+	light.cxx light.hxx \
+	sunpos.cxx sunpos.hxx
 mkinstalldirs = $(SHELL) $(top_srcdir)/mkinstalldirs
 CONFIG_HEADER = ../../Include/config.h
 CONFIG_CLEAN_FILES = 
@@ -95,7 +96,11 @@ X_EXTRA_LIBS = @X_EXTRA_LIBS@
 X_PRE_LIBS = @X_PRE_LIBS@
 libTime_la_LDFLAGS = 
 libTime_la_LIBADD = 
-libTime_la_OBJECTS =  event.lo fg_time.lo fg_timer.lo sunpos.lo
+libTime_la_OBJECTS =  event.lo fg_time.lo fg_timer.lo light.lo sunpos.lo
+CXXFLAGS = @CXXFLAGS@
+CXXCOMPILE = $(CXX) $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CXXFLAGS)
+LTCXXCOMPILE = $(LIBTOOL) --mode=compile $(CXX) $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CXXFLAGS)
+CXXLINK = $(LIBTOOL) --mode=link $(CXX) $(CXXFLAGS) $(LDFLAGS) -o $@
 CFLAGS = @CFLAGS@
 COMPILE = $(CC) $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CFLAGS)
 LTCOMPILE = $(LIBTOOL) --mode=compile $(CC) $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CFLAGS)
@@ -108,14 +113,15 @@ DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) $(TEXINFOS) $(EXTRA_DIST)
 TAR = tar
 GZIP = --best
 DEP_FILES =  .deps/event.P .deps/fg_time.P .deps/fg_timer.P \
-.deps/sunpos.P
+.deps/light.P .deps/sunpos.P
+CXXMKDEP = $(CXX) -M $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CXXFLAGS)
 SOURCES = $(libTime_la_SOURCES)
 OBJECTS = $(libTime_la_OBJECTS)
 
 all: Makefile $(LTLIBRARIES)
 
 .SUFFIXES:
-.SUFFIXES: .S .c .lo .o .s
+.SUFFIXES: .S .c .cxx .lo .o .s
 $(srcdir)/Makefile.in: @MAINT@ Makefile.am $(top_srcdir)/configure.in $(ACLOCAL_M4)
 	cd $(top_srcdir) && $(AUTOMAKE) --gnu Simulator/Time/Makefile
 
@@ -182,7 +188,11 @@ distclean-libtool:
 maintainer-clean-libtool:
 
 libTime.la: $(libTime_la_OBJECTS) $(libTime_la_DEPENDENCIES)
-	$(LINK) -rpath $(libdir) $(libTime_la_LDFLAGS) $(libTime_la_OBJECTS) $(libTime_la_LIBADD) $(LIBS)
+	$(CXXLINK) -rpath $(libdir) $(libTime_la_LDFLAGS) $(libTime_la_OBJECTS) $(libTime_la_LIBADD) $(LIBS)
+.cxx.o:
+	$(CXXCOMPILE) -c $<
+.cxx.lo:
+	$(LTCXXCOMPILE) -c $<
 
 tags: TAGS
 
@@ -249,6 +259,17 @@ maintainer-clean-depend:
 	@-sed -e 's/^\([^:]*\)\.o:/\1.lo \1.o:/' \
 	  < .deps/$(*F).p > .deps/$(*F).P
 	@-rm -f .deps/$(*F).p
+
+%.o: %.cxx
+	@echo '$(CXXCOMPILE) -c $<'; \
+	$(CXXCOMPILE) -Wp,-MD,.deps/$(*F).P -c $<
+
+%.lo: %.cxx
+	@echo '$(LTCXXCOMPILE) -c $<'; \
+	$(LTCXXCOMPILE) -Wp,-MD,.deps/$(*F).p -c $<
+	@-sed -e 's/^\([^:]*\)\.o:/\1.lo \1.o:/' \
+	  < .deps/$(*F).p > .deps/$(*F).P
+	@-rm -f .deps/$(*F).p
 info:
 dvi:
 check: all
diff --git a/Time/fg_time.c b/Time/fg_time.c
index fdc510df9..e4e186867 100644
--- a/Time/fg_time.c
+++ b/Time/fg_time.c
@@ -44,14 +44,15 @@
 #include <Debug/fg_debug.h>
 #include <Flight/flight.h>
 #include <Include/fg_constants.h>
-#include <Time/fg_time.h>
+
+#include "fg_time.h"
 
 
 #define DEGHR(x)        ((x)/15.)
 #define RADHR(x)        DEGHR(x*RAD_TO_DEG)
 
+
 struct fgTIME cur_time_params;
-struct fgLIGHT cur_light_params;
 
 
 /* Initialize the time dependent variables */
@@ -367,9 +368,13 @@ void fgTimeUpdate(fgFLIGHT *f, struct fgTIME *t) {
 
 
 /* $Log$
-/* Revision 1.40  1998/04/18 04:14:09  curt
-/* Moved fg_debug.c to it's own library.
+/* Revision 1.41  1998/04/22 13:24:05  curt
+/* C++ - ifiing the code a bit.
+/* Starting to reorginize some of the lighting calcs to use a table lookup.
 /*
+ * Revision 1.40  1998/04/18 04:14:09  curt
+ * Moved fg_debug.c to it's own library.
+ *
  * Revision 1.39  1998/04/09 18:40:14  curt
  * We had unified some of the platform disparate time handling code, and
  * there was a bug in timesum() which calculated a new time stamp based on
diff --git a/Time/fg_time.h b/Time/fg_time.h
index 4cc905142..43a580ea3 100644
--- a/Time/fg_time.h
+++ b/Time/fg_time.h
@@ -28,11 +28,6 @@
 #define _FG_TIME_H
 
 
-#ifdef __cplusplus                                                          
-extern "C" {                            
-#endif                                   
-
-
 #include <config.h>
 
 #ifdef HAVE_WINDOWS_H
@@ -46,6 +41,11 @@ extern "C" {
 #include <Flight/flight.h>
 
 
+#ifdef __cplusplus                                                          
+extern "C" {                            
+#endif                                   
+
+
 /* Define a structure containing global time parameters */
 struct fgTIME {
     /* the date/time in various forms */
@@ -74,26 +74,6 @@ struct fgTIME {
 extern struct fgTIME cur_time_params;
 
 
-/* Lighting is time dependent so it shows up here */
-/* Define a structure containing the global lighting parameters */
-struct fgLIGHT {
-    /* position of the sun in various forms */
-    double sun_lon, sun_gc_lat;         /* in geocentric coordinates */
-    struct fgCartesianPoint fg_sunpos;  /* in cartesian coordiantes */
-    GLfloat sun_vec[4];                 /* (in view coordinates) */
-    GLfloat sun_vec_inv[4];             /* inverse (in view coordinates) */
-    double sun_angle;                   /* the angle between the sun and the 
-					   local horizontal */
-
-    /* Derived lighting values */
-    GLfloat scene_ambient[3];           /* ambient component */
-    GLfloat scene_diffuse[3];           /* diffuse component */
-    GLfloat fog_color[4];               /* fog color */
-    GLfloat sky_color[4];               /* clear screen color */
-};
-
-extern struct fgLIGHT cur_light_params;
-
 typedef struct fg_timestamp_t {
     long seconds;
     long millis;
@@ -125,13 +105,17 @@ void fgTimeUpdate(fgFLIGHT *f, struct fgTIME *t);
 
 
 /* $Log$
-/* Revision 1.19  1998/04/21 17:01:44  curt
-/* Fixed a problems where a pointer to a function was being passed around.  In
-/* one place this functions arguments were defined as ( void ) while in another
-/* place they were defined as ( int ).  The correct answer was ( int ).
-/*
-/* Prepairing for C++ integration.
+/* Revision 1.20  1998/04/22 13:24:05  curt
+/* C++ - ifiing the code a bit.
+/* Starting to reorginize some of the lighting calcs to use a table lookup.
 /*
+ * Revision 1.19  1998/04/21 17:01:44  curt
+ * Fixed a problems where a pointer to a function was being passed around.  In
+ * one place this functions arguments were defined as ( void ) while in another
+ * place they were defined as ( int ).  The correct answer was ( int ).
+ *
+ * Prepairing for C++ integration.
+ *
  * Revision 1.18  1998/04/08 23:35:40  curt
  * Tweaks to Gnu automake/autoconf system.
  *
diff --git a/Time/light.cxx b/Time/light.cxx
new file mode 100644
index 000000000..697cc56a3
--- /dev/null
+++ b/Time/light.cxx
@@ -0,0 +1,158 @@
+//
+// light.hxx -- lighting routines
+//
+// Written by Curtis Olson, started April 1998.
+//
+// Copyright (C) 1998  Curtis L. Olson  - curt@me.umn.edu
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#include <config.h>
+
+#ifdef HAVE_WINDOWS_H
+#  include <windows.h>
+#endif
+
+#include <GL/glut.h>
+#include <XGL/xgl.h>
+#include <string.h>
+
+#include <Debug/fg_debug.h>
+#include <Include/fg_constants.h>
+#include <Include/general.h>
+#include <Main/views.hxx>
+#include <Math/fg_geodesy.h>
+#include <Math/interpolater.hxx>
+#include <Math/mat3.h>
+#include <Math/polar.h>
+
+#include "fg_time.h"
+#include "light.hxx"
+#include "sunpos.hxx"
+
+
+fgLIGHT cur_light_params;
+
+static fgINTERPTABLE *ambient_tbl;
+static fgINTERPTABLE *diffuse_tbl;
+static fgINTERPTABLE *sky_tbl;
+
+
+// initialize lighting tables
+void fgLightInit( void ) {
+    fgGENERAL *g;
+    char path[256];
+
+    fgPrintf( FG_EVENT, FG_INFO, 
+	     "Initializing Lighting interpolation tables.\n" );
+
+    g = &general;
+
+    // build the path name to the ambient lookup table
+    path[0] = '\0';
+    strcat(path, g->root_dir);
+    strcat(path, "/Scenery/");
+    strcat(path, "Ambient.table");
+    // initialize ambient table
+    ambient_tbl = new fgINTERPTABLE(path);
+
+    // build the path name to the diffuse lookup table
+    path[0] = '\0';
+    strcat(path, g->root_dir);
+    strcat(path, "/Scenery/");
+    strcat(path, "Diffuse.table");
+    // initialize diffuse table
+    diffuse_tbl = new fgINTERPTABLE(path);
+    
+    // build the path name to the sky lookup table
+    path[0] = '\0';
+    strcat(path, g->root_dir);
+    strcat(path, "/Scenery/");
+    strcat(path, "Sky.table");
+    // initialize sky table
+    sky_tbl = new fgINTERPTABLE(path);
+}
+
+
+// update lighting parameters based on current sun position
+void fgLightUpdate( void ) {
+    struct fgLIGHT *l;
+    struct fgTIME *t;
+    struct fgVIEW *v;
+    /* if the 4th field is 0.0, this specifies a direction ... */
+    GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
+    /* base sky color */
+    GLfloat base_sky_color[4] =        {0.60, 0.60, 0.90, 1.0};
+    /* base fog color */
+    GLfloat base_fog_color[4] = {0.70, 0.70, 0.70, 1.0};
+    double deg, ambient, diffuse, sky_brightness;
+
+    l = &cur_light_params;
+    t = &cur_time_params;
+    v = &current_view;
+
+    fgPrintf( FG_EVENT, FG_INFO, "Updating light parameters.\n" );
+
+    /* calculate lighting parameters based on sun's relative angle to
+     * local up */
+
+    deg = l->sun_angle * 180.0 / FG_PI;
+    fgPrintf( FG_EVENT, FG_INFO, "  Sun angle = %.2f.\n", deg );
+
+    ambient = ambient_tbl->interpolate( deg );
+    diffuse = diffuse_tbl->interpolate( deg );
+    sky_brightness = sky_tbl->interpolate( deg );
+
+    fgPrintf( FG_EVENT, FG_INFO, 
+	      "  ambient = %.2f  diffuse = %.2f  sky = %.2f\n", 
+	      ambient, diffuse, sky_brightness );
+
+    // sky_brightness = 0.15;  // used to force a dark sky (when testing)
+
+    // if ( ambient < 0.02 ) { ambient = 0.02; }
+    // if ( diffuse < 0.0 ) { diffuse = 0.0; }
+    // if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
+
+    l->scene_ambient[0] = white[0] * ambient;
+    l->scene_ambient[1] = white[1] * ambient;
+    l->scene_ambient[2] = white[2] * ambient;
+
+    l->scene_diffuse[0] = white[0] * diffuse;
+    l->scene_diffuse[1] = white[1] * diffuse;
+    l->scene_diffuse[2] = white[2] * diffuse;
+
+    /* set fog color */
+    l->fog_color[0] = base_fog_color[0] * (ambient + diffuse);
+    l->fog_color[1] = base_fog_color[1] * (ambient + diffuse);
+    l->fog_color[2] = base_fog_color[2] * (ambient + diffuse);
+    l->fog_color[3] = base_fog_color[3];
+
+    /* set sky color */
+    l->sky_color[0] = base_sky_color[0] * sky_brightness;
+    l->sky_color[1] = base_sky_color[1] * sky_brightness;
+    l->sky_color[2] = base_sky_color[2] * sky_brightness;
+    l->sky_color[3] = base_sky_color[3];
+}
+
+
+// $Log$
+// Revision 1.1  1998/04/22 13:24:06  curt
+// C++ - ifiing the code a bit.
+// Starting to reorginize some of the lighting calcs to use a table lookup.
+//
+//
diff --git a/Time/light.hxx b/Time/light.hxx
new file mode 100644
index 000000000..d926fac47
--- /dev/null
+++ b/Time/light.hxx
@@ -0,0 +1,103 @@
+//
+// light.hxx -- lighting routines
+//
+// Written by Curtis Olson, started April 1998.
+//
+// Copyright (C) 1998  Curtis L. Olson  - curt@me.umn.edu
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifndef _LIGHT_HXX
+#define _LIGHT_HXX
+
+
+#ifndef __cplusplus                                                          
+# error This library requires C++
+#endif                                   
+
+
+#include <config.h>
+
+#ifdef HAVE_WINDOWS_H
+#  include <windows.h>
+#endif
+
+#include <GL/glut.h>
+#include <XGL/xgl.h>
+
+#include <Include/fg_types.h>
+
+
+// Define a structure containing the global lighting parameters
+typedef struct {
+
+    ///////////////////////////////////////////////////////////
+    // position of the sun in various forms
+
+    // in geocentric coordinates
+    double sun_lon, sun_gc_lat;
+
+    // in cartesian coordiantes
+    struct fgCartesianPoint fg_sunpos;
+
+    // (in view coordinates)
+    GLfloat sun_vec[4];
+
+    // inverse (in view coordinates)
+    GLfloat sun_vec_inv[4];
+
+    // the angle between the sun and the local horizontal
+    double sun_angle;
+
+    ///////////////////////////////////////////////////////////
+    // Derived lighting values
+
+    // ambient component
+    GLfloat scene_ambient[3];
+
+    // diffuse component
+    GLfloat scene_diffuse[3];
+
+    // fog color
+    GLfloat fog_color[4];
+
+    // clear screen color
+    GLfloat sky_color[4];
+} fgLIGHT;
+
+
+extern fgLIGHT cur_light_params;
+
+
+// initialize lighting tables
+void fgLightInit( void );
+
+
+// update lighting parameters based on current sun position
+void fgLightUpdate( void);
+
+
+#endif // _LIGHT_HXX
+
+
+// $Log$
+// Revision 1.1  1998/04/22 13:24:06  curt
+// C++ - ifiing the code a bit.
+// Starting to reorginize some of the lighting calcs to use a table lookup.
+//
+//
diff --git a/Time/sunpos.c b/Time/sunpos.c
deleted file mode 100644
index 040df051d..000000000
--- a/Time/sunpos.c
+++ /dev/null
@@ -1,474 +0,0 @@
-/*
- * sunpos.c
- * kirk johnson
- * july 1993
- *
- * code for calculating the position on the earth's surface for which
- * the sun is directly overhead (adapted from _practical astronomy
- * with your calculator, third edition_, peter duffett-smith,
- * cambridge university press, 1988.)
- *
- * RCS $Id$
- *
- * Copyright (C) 1989, 1990, 1993, 1994, 1995 Kirk Lauritz Johnson
- *
- * Parts of the source code (as marked) are:
- *   Copyright (C) 1989, 1990, 1991 by Jim Frost
- *   Copyright (C) 1992 by Jamie Zawinski <jwz@lucid.com>
- *
- * Permission to use, copy, modify and freely distribute xearth for
- * non-commercial and not-for-profit purposes is hereby granted
- * without fee, provided that both the above copyright notice and this
- * permission notice appear in all copies and in supporting
- * documentation.
- *
- * The author makes no representations about the suitability of this
- * software for any purpose. It is provided "as is" without express or
- * implied warranty.
- *
- * THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
- * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
- * OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * $Id$
- * (Log is kept at end of this file)
- */
-
-
-#include <math.h>
-#include <stdio.h>
-#include <time.h>
-
-#include <Astro/orbits.h>
-#include <Include/fg_constants.h>
-#include <Main/views.h>
-#include <Math/fg_geodesy.h>
-#include <Math/mat3.h>
-#include <Math/polar.h>
-#include <Time/fg_time.h>
-#include <Time/sunpos.h>
-
-
-#undef E
-
-
-/*
- * the epoch upon which these astronomical calculations are based is
- * 1990 january 0.0, 631065600 seconds since the beginning of the
- * "unix epoch" (00:00:00 GMT, Jan. 1, 1970)
- *
- * given a number of seconds since the start of the unix epoch,
- * DaysSinceEpoch() computes the number of days since the start of the
- * astronomical epoch (1990 january 0.0)
- */
-
-#define EpochStart           (631065600)
-#define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
-
-/*
- * assuming the apparent orbit of the sun about the earth is circular,
- * the rate at which the orbit progresses is given by RadsPerDay --
- * FG_2PI radians per orbit divided by 365.242191 days per year:
- */
-
-#define RadsPerDay (FG_2PI/365.242191)
-
-/*
- * details of sun's apparent orbit at epoch 1990.0 (after
- * duffett-smith, table 6, section 46)
- *
- * Epsilon_g    (ecliptic longitude at epoch 1990.0) 279.403303 degrees
- * OmegaBar_g   (ecliptic longitude of perigee)      282.768422 degrees
- * Eccentricity (eccentricity of orbit)                0.016713
- */
-
-#define Epsilon_g    (279.403303*(FG_2PI/360))
-#define OmegaBar_g   (282.768422*(FG_2PI/360))
-#define Eccentricity (0.016713)
-
-/*
- * MeanObliquity gives the mean obliquity of the earth's axis at epoch
- * 1990.0 (computed as 23.440592 degrees according to the method given
- * in duffett-smith, section 27)
- */
-#define MeanObliquity (23.440592*(FG_2PI/360))
-
-/* static double solve_keplers_equation(double); */
-/* static double sun_ecliptic_longitude(time_t); */
-static void   ecliptic_to_equatorial(double, double, double *, double *);
-static double julian_date(int, int, int);
-static double GST(time_t);
-
-/*
- * solve Kepler's equation via Newton's method
- * (after duffett-smith, section 47)
- */
-/*
-static double solve_keplers_equation(double M) {
-    double E;
-    double delta;
-
-    E = M;
-    while (1) {
-	delta = E - Eccentricity*sin(E) - M;
-	if (fabs(delta) <= 1e-10) break;
-	E -= delta / (1 - Eccentricity*cos(E));
-    }
-
-    return E;
-}
-*/
-
-
-/* compute ecliptic longitude of sun (in radians) (after
- * duffett-smith, section 47) */
-/*
-static double sun_ecliptic_longitude(time_t ssue) {
-    // time_t ssue;              //  seconds since unix epoch
-    double D, N;
-    double M_sun, E;
-    double v;
-
-    D = DaysSinceEpoch(ssue);
-
-    N = RadsPerDay * D;
-    N = fmod(N, FG_2PI);
-    if (N < 0) N += FG_2PI;
-
-    M_sun = N + Epsilon_g - OmegaBar_g;
-    if (M_sun < 0) M_sun += FG_2PI;
-
-    E = solve_keplers_equation(M_sun);
-    v = 2 * atan(sqrt((1+Eccentricity)/(1-Eccentricity)) * tan(E/2));
-
-    return (v + OmegaBar_g);
-}
-*/
-
-
-/* convert from ecliptic to equatorial coordinates (after
- * duffett-smith, section 27) */
-
-static void ecliptic_to_equatorial(double lambda, double beta, 
-				   double *alpha, double *delta) {
-    /* double  lambda;            ecliptic longitude       */
-    /* double  beta;              ecliptic latitude        */
-    /* double *alpha;             (return) right ascension */
-    /* double *delta;             (return) declination     */
-
-    double sin_e, cos_e;
-
-    sin_e = sin(MeanObliquity);
-    cos_e = cos(MeanObliquity);
-
-    *alpha = atan2(sin(lambda)*cos_e - tan(beta)*sin_e, cos(lambda));
-    *delta = asin(sin(beta)*cos_e + cos(beta)*sin_e*sin(lambda));
-}
-
-
-/* computing julian dates (assuming gregorian calendar, thus this is
- * only valid for dates of 1582 oct 15 or later) (after duffett-smith,
- * section 4) */
-
-static double julian_date(int y, int m, int d) {
-    /* int y;                    year (e.g. 19xx)          */
-    /* int m;                    month (jan=1, feb=2, ...) */
-    /* int d;                    day of month              */
-
-    int    A, B, C, D;
-    double JD;
-
-    /* lazy test to ensure gregorian calendar */
-    if (y < 1583) {
-	printf("WHOOPS! Julian dates only valid for 1582 oct 15 or later\n");
-    }
-
-    if ((m == 1) || (m == 2)) {
-	y -= 1;
-	m += 12;
-    }
-
-    A = y / 100;
-    B = 2 - A + (A / 4);
-    C = (int)(365.25 * y);
-    D = (int)(30.6001 * (m + 1));
-
-    JD = B + C + D + d + 1720994.5;
-
-    return JD;
-}
-
-
-/* compute greenwich mean sidereal time (GST) corresponding to a given
- * number of seconds since the unix epoch (after duffett-smith,
- * section 12) */
-static double GST(time_t ssue) {
-    /* time_t ssue;           seconds since unix epoch */
-
-    double     JD;
-    double     T, T0;
-    double     UT;
-    struct tm *tm;
-
-    tm = gmtime(&ssue);
-
-    JD = julian_date(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday);
-    T  = (JD - 2451545) / 36525;
-
-    T0 = ((T + 2.5862e-5) * T + 2400.051336) * T + 6.697374558;
-
-    T0 = fmod(T0, 24.0);
-    if (T0 < 0) T0 += 24;
-
-    UT = tm->tm_hour + (tm->tm_min + tm->tm_sec / 60.0) / 60.0;
-
-    T0 += UT * 1.002737909;
-    T0 = fmod(T0, 24.0);
-    if (T0 < 0) T0 += 24;
-
-    return T0;
-}
-
-
-/* given a particular time (expressed in seconds since the unix
- * epoch), compute position on the earth (lat, lon) such that sun is
- * directly overhead.  (lat, lon are reported in radians */
-
-void fgSunPosition(time_t ssue, double *lon, double *lat) {
-    /* time_t  ssue;           seconds since unix epoch */
-    /* double *lat;            (return) latitude        */
-    /* double *lon;            (return) longitude       */
-
-    /* double lambda; */
-    double alpha, delta;
-    double tmp;
-
-    /* lambda = sun_ecliptic_longitude(ssue); */
-    /* ecliptic_to_equatorial(lambda, 0.0, &alpha, &delta); */
-    ecliptic_to_equatorial (solarPosition.lonSun, 0.0, &alpha, &delta);
-
-    tmp = alpha - (FG_2PI/24)*GST(ssue);
-    if (tmp < -FG_PI) {
-	do tmp += FG_2PI;
-	while (tmp < -FG_PI);
-    } else if (tmp > FG_PI) {
-	do tmp -= FG_2PI;
-	while (tmp < -FG_PI);
-    }
-
-    *lon = tmp;
-    *lat = delta;
-}
-
-
-/* update the cur_time_params structure with the current sun position */
-void fgUpdateSunPos( void ) {
-    struct fgLIGHT *l;
-    struct fgTIME *t;
-    struct fgVIEW *v;
-    MAT3vec nup, nsun;
-    /* if the 4th field is 0.0, this specifies a direction ... */
-    GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
-    /* base sky color */
-    GLfloat base_sky_color[4] =        {0.60, 0.60, 0.90, 1.0};
-    /* base fog color */
-    GLfloat base_fog_color[4] = {0.70, 0.70, 0.70, 1.0};
-    double sun_gd_lat, sl_radius, temp;
-    double x_2, x_4, x_8, x_10;
-    double light, ambient, diffuse, sky_brightness;
-    static int time_warp = 0;
-
-    l = &cur_light_params;
-    t = &cur_time_params;
-    v = &current_view;
-
-    printf("  Updating Sun position\n");
-
-    time_warp += 0; /* increase this to make the world spin real fast */
-
-    fgSunPosition(t->cur_time + time_warp, &l->sun_lon, &sun_gd_lat);
-
-    fgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &l->sun_gc_lat);
-
-    l->fg_sunpos = fgPolarToCart(l->sun_lon, l->sun_gc_lat, sl_radius);
-
-    /* printf("  Geodetic lat = %.5f Geocentric lat = %.5f\n", sun_gd_lat,
-       t->sun_gc_lat); */
-
-    /* FALSE! (?> the sun position has to be translated just like
-     * everything else */
-    /* l->sun_vec_inv[0] = l->fg_sunpos.x - scenery_center.x;  */
-    /* l->sun_vec_inv[1] = l->fg_sunpos.y - scenery_center.y; */
-    /* l->sun_vec_inv[2] = l->fg_sunpos.z - scenery_center.z; */
-    /* MAT3_SCALE_VEC(l->sun_vec, l->sun_vec_inv, -1.0); */
-
-    /* I think this will work better for generating the sun light vector */
-    l->sun_vec[0] = l->fg_sunpos.x;
-    l->sun_vec[1] = l->fg_sunpos.y;
-    l->sun_vec[2] = l->fg_sunpos.z;
-    MAT3_NORMALIZE_VEC(l->sun_vec, temp);
-    MAT3_SCALE_VEC(l->sun_vec_inv, l->sun_vec, -1.0);
-
-    /* make these are directional light sources only */
-    l->sun_vec[3] = 0.0;
-    l->sun_vec_inv[3] = 0.0;
-
-    printf("  l->sun_vec = %.2f %.2f %.2f\n", l->sun_vec[0], l->sun_vec[1],
-	   l->sun_vec[2]);
-
-    /* calculate the sun's relative angle to local up */
-    MAT3_COPY_VEC(nup, v->local_up);
-    nsun[0] = l->fg_sunpos.x; 
-    nsun[1] = l->fg_sunpos.y;
-    nsun[2] = l->fg_sunpos.z;
-    MAT3_NORMALIZE_VEC(nup, temp);
-    MAT3_NORMALIZE_VEC(nsun, temp);
-
-    l->sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
-    printf("  SUN ANGLE relative to current location = %.3f rads.\n", 
-	   l->sun_angle);
-
-    /* calculate lighting parameters based on sun's relative angle to
-     * local up */
-    /* ya kind'a have to plot this to see how it works */
-
-    /* x = t->sun_angle^8 */
-    x_2 = l->sun_angle * l->sun_angle;
-    x_4 = x_2 * x_2;
-    x_8 = x_4 * x_4;
-    x_10 = x_8 * x_2;
-
-    light = pow(1.1, -x_10 / 30.0);
-    ambient = 0.2 * light;
-    diffuse = 1.0 * light;
-
-    sky_brightness = 0.85 * pow(1.2, -x_8 / 20.0) + 0.15;
-
-    /* sky_brightness = 0.15; */ /* to force a dark sky (for testing) */
-
-    if ( ambient < 0.02 ) { ambient = 0.02; }
-    if ( diffuse < 0.0 ) { diffuse = 0.0; }
-
-    if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
-
-    l->scene_ambient[0] = white[0] * ambient;
-    l->scene_ambient[1] = white[1] * ambient;
-    l->scene_ambient[2] = white[2] * ambient;
-
-    l->scene_diffuse[0] = white[0] * diffuse;
-    l->scene_diffuse[1] = white[1] * diffuse;
-    l->scene_diffuse[2] = white[2] * diffuse;
-
-    /* set fog color */
-    l->fog_color[0] = base_fog_color[0] * (ambient + diffuse);
-    l->fog_color[1] = base_fog_color[1] * (ambient + diffuse);
-    l->fog_color[2] = base_fog_color[2] * (ambient + diffuse);
-    l->fog_color[3] = base_fog_color[3];
-
-    /* set sky color */
-    l->sky_color[0] = base_sky_color[0] * sky_brightness;
-    l->sky_color[1] = base_sky_color[1] * sky_brightness;
-    l->sky_color[2] = base_sky_color[2] * sky_brightness;
-    l->sky_color[3] = base_sky_color[3];
-}
-
-
-/* $Log$
-/* Revision 1.27  1998/04/03 22:12:57  curt
-/* Converting to Gnu autoconf system.
-/* Centralized time handling differences.
-/*
- * Revision 1.26  1998/02/23 19:08:00  curt
- * Incorporated Durk's Astro/ tweaks.  Includes unifying the sun position
- * calculation code between sun display, and other FG sections that use this
- * for things like lighting.
- *
- * Revision 1.25  1998/02/09 15:07:53  curt
- * Minor tweaks.
- *
- * Revision 1.24  1998/01/27 00:48:07  curt
- * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
- * system and commandline/config file processing code.
- *
- * Revision 1.23  1998/01/19 19:27:21  curt
- * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
- * This should simplify things tremendously.
- *
- * Revision 1.22  1998/01/19 18:40:40  curt
- * Tons of little changes to clean up the code and to remove fatal errors
- * when building with the c++ compiler.
- *
- * Revision 1.21  1997/12/30 23:10:19  curt
- * Calculate lighting parameters here.
- *
- * Revision 1.20  1997/12/30 22:22:43  curt
- * Further integration of event manager.
- *
- * Revision 1.19  1997/12/30 20:47:59  curt
- * Integrated new event manager with subsystem initializations.
- *
- * Revision 1.18  1997/12/23 04:58:40  curt
- * Tweaked the sky coloring a bit to build in structures to allow finer rgb
- * control.
- *
- * Revision 1.17  1997/12/15 23:55:08  curt
- * Add xgl wrappers for debugging.
- * Generate terrain normals on the fly.
- *
- * Revision 1.16  1997/12/11 04:43:57  curt
- * Fixed sun vector and lighting problems.  I thing the moon is now lit
- * correctly.
- *
- * Revision 1.15  1997/12/10 22:37:55  curt
- * Prepended "fg" on the name of all global structures that didn't have it yet.
- * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
- *
- * Revision 1.14  1997/12/09 04:25:39  curt
- * Working on adding a global lighting params structure.
- *
- * Revision 1.13  1997/11/25 19:25:42  curt
- * Changes to integrate Durk's moon/sun code updates + clean up.
- *
- * Revision 1.12  1997/11/15 18:15:39  curt
- * Reverse direction of sun vector, so object normals can be more normal.
- *
- * Revision 1.11  1997/10/28 21:07:21  curt
- * Changed GLUT/ -> Main/
- *
- * Revision 1.10  1997/09/13 02:00:09  curt
- * Mostly working on stars and generating sidereal time for accurate star
- * placement.
- *
- * Revision 1.9  1997/09/05 14:17:31  curt
- * More tweaking with stars.
- *
- * Revision 1.8  1997/09/05 01:36:04  curt
- * Working on getting stars right.
- *
- * Revision 1.7  1997/09/04 02:17:40  curt
- * Shufflin' stuff.
- *
- * Revision 1.6  1997/08/27 03:30:37  curt
- * Changed naming scheme of basic shared structures.
- *
- * Revision 1.5  1997/08/22 21:34:41  curt
- * Doing a bit of reorganizing and house cleaning.
- *
- * Revision 1.4  1997/08/19 23:55:09  curt
- * Worked on better simulating real lighting.
- *
- * Revision 1.3  1997/08/13 20:23:49  curt
- * The interface to sunpos now updates a global structure rather than returning
- * current sun position.
- *
- * Revision 1.2  1997/08/06 00:24:32  curt
- * Working on correct real time sun lighting.
- *
- * Revision 1.1  1997/08/01 15:27:56  curt
- * Initial revision.
- *
- */
diff --git a/Time/sunpos.cxx b/Time/sunpos.cxx
new file mode 100644
index 000000000..dcfe41541
--- /dev/null
+++ b/Time/sunpos.cxx
@@ -0,0 +1,479 @@
+/*
+ * sunpos.c
+ * kirk johnson
+ * july 1993
+ *
+ * code for calculating the position on the earth's surface for which
+ * the sun is directly overhead (adapted from _practical astronomy
+ * with your calculator, third edition_, peter duffett-smith,
+ * cambridge university press, 1988.)
+ *
+ * RCS $Id$
+ *
+ * Copyright (C) 1989, 1990, 1993, 1994, 1995 Kirk Lauritz Johnson
+ *
+ * Parts of the source code (as marked) are:
+ *   Copyright (C) 1989, 1990, 1991 by Jim Frost
+ *   Copyright (C) 1992 by Jamie Zawinski <jwz@lucid.com>
+ *
+ * Permission to use, copy, modify and freely distribute xearth for
+ * non-commercial and not-for-profit purposes is hereby granted
+ * without fee, provided that both the above copyright notice and this
+ * permission notice appear in all copies and in supporting
+ * documentation.
+ *
+ * The author makes no representations about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ *
+ * THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
+ * OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * $Id$
+ * (Log is kept at end of this file)
+ */
+
+
+#include <math.h>
+#include <stdio.h>
+#include <time.h>
+
+#include <Astro/orbits.hxx>
+#include <Include/fg_constants.h>
+#include <Main/views.hxx>
+#include <Math/fg_geodesy.h>
+#include <Math/mat3.h>
+#include <Math/polar.h>
+
+#include "fg_time.h"
+#include "sunpos.hxx"
+
+
+#undef E
+
+
+/*
+ * the epoch upon which these astronomical calculations are based is
+ * 1990 january 0.0, 631065600 seconds since the beginning of the
+ * "unix epoch" (00:00:00 GMT, Jan. 1, 1970)
+ *
+ * given a number of seconds since the start of the unix epoch,
+ * DaysSinceEpoch() computes the number of days since the start of the
+ * astronomical epoch (1990 january 0.0)
+ */
+
+#define EpochStart           (631065600)
+#define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
+
+/*
+ * assuming the apparent orbit of the sun about the earth is circular,
+ * the rate at which the orbit progresses is given by RadsPerDay --
+ * FG_2PI radians per orbit divided by 365.242191 days per year:
+ */
+
+#define RadsPerDay (FG_2PI/365.242191)
+
+/*
+ * details of sun's apparent orbit at epoch 1990.0 (after
+ * duffett-smith, table 6, section 46)
+ *
+ * Epsilon_g    (ecliptic longitude at epoch 1990.0) 279.403303 degrees
+ * OmegaBar_g   (ecliptic longitude of perigee)      282.768422 degrees
+ * Eccentricity (eccentricity of orbit)                0.016713
+ */
+
+#define Epsilon_g    (279.403303*(FG_2PI/360))
+#define OmegaBar_g   (282.768422*(FG_2PI/360))
+#define Eccentricity (0.016713)
+
+/*
+ * MeanObliquity gives the mean obliquity of the earth's axis at epoch
+ * 1990.0 (computed as 23.440592 degrees according to the method given
+ * in duffett-smith, section 27)
+ */
+#define MeanObliquity (23.440592*(FG_2PI/360))
+
+/* static double solve_keplers_equation(double); */
+/* static double sun_ecliptic_longitude(time_t); */
+static void   ecliptic_to_equatorial(double, double, double *, double *);
+static double julian_date(int, int, int);
+static double GST(time_t);
+
+/*
+ * solve Kepler's equation via Newton's method
+ * (after duffett-smith, section 47)
+ */
+/*
+static double solve_keplers_equation(double M) {
+    double E;
+    double delta;
+
+    E = M;
+    while (1) {
+	delta = E - Eccentricity*sin(E) - M;
+	if (fabs(delta) <= 1e-10) break;
+	E -= delta / (1 - Eccentricity*cos(E));
+    }
+
+    return E;
+}
+*/
+
+
+/* compute ecliptic longitude of sun (in radians) (after
+ * duffett-smith, section 47) */
+/*
+static double sun_ecliptic_longitude(time_t ssue) {
+    // time_t ssue;              //  seconds since unix epoch
+    double D, N;
+    double M_sun, E;
+    double v;
+
+    D = DaysSinceEpoch(ssue);
+
+    N = RadsPerDay * D;
+    N = fmod(N, FG_2PI);
+    if (N < 0) N += FG_2PI;
+
+    M_sun = N + Epsilon_g - OmegaBar_g;
+    if (M_sun < 0) M_sun += FG_2PI;
+
+    E = solve_keplers_equation(M_sun);
+    v = 2 * atan(sqrt((1+Eccentricity)/(1-Eccentricity)) * tan(E/2));
+
+    return (v + OmegaBar_g);
+}
+*/
+
+
+/* convert from ecliptic to equatorial coordinates (after
+ * duffett-smith, section 27) */
+
+static void ecliptic_to_equatorial(double lambda, double beta, 
+				   double *alpha, double *delta) {
+    /* double  lambda;            ecliptic longitude       */
+    /* double  beta;              ecliptic latitude        */
+    /* double *alpha;             (return) right ascension */
+    /* double *delta;             (return) declination     */
+
+    double sin_e, cos_e;
+
+    sin_e = sin(MeanObliquity);
+    cos_e = cos(MeanObliquity);
+
+    *alpha = atan2(sin(lambda)*cos_e - tan(beta)*sin_e, cos(lambda));
+    *delta = asin(sin(beta)*cos_e + cos(beta)*sin_e*sin(lambda));
+}
+
+
+/* computing julian dates (assuming gregorian calendar, thus this is
+ * only valid for dates of 1582 oct 15 or later) (after duffett-smith,
+ * section 4) */
+
+static double julian_date(int y, int m, int d) {
+    /* int y;                    year (e.g. 19xx)          */
+    /* int m;                    month (jan=1, feb=2, ...) */
+    /* int d;                    day of month              */
+
+    int    A, B, C, D;
+    double JD;
+
+    /* lazy test to ensure gregorian calendar */
+    if (y < 1583) {
+	printf("WHOOPS! Julian dates only valid for 1582 oct 15 or later\n");
+    }
+
+    if ((m == 1) || (m == 2)) {
+	y -= 1;
+	m += 12;
+    }
+
+    A = y / 100;
+    B = 2 - A + (A / 4);
+    C = (int)(365.25 * y);
+    D = (int)(30.6001 * (m + 1));
+
+    JD = B + C + D + d + 1720994.5;
+
+    return JD;
+}
+
+
+/* compute greenwich mean sidereal time (GST) corresponding to a given
+ * number of seconds since the unix epoch (after duffett-smith,
+ * section 12) */
+static double GST(time_t ssue) {
+    /* time_t ssue;           seconds since unix epoch */
+
+    double     JD;
+    double     T, T0;
+    double     UT;
+    struct tm *tm;
+
+    tm = gmtime(&ssue);
+
+    JD = julian_date(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday);
+    T  = (JD - 2451545) / 36525;
+
+    T0 = ((T + 2.5862e-5) * T + 2400.051336) * T + 6.697374558;
+
+    T0 = fmod(T0, 24.0);
+    if (T0 < 0) T0 += 24;
+
+    UT = tm->tm_hour + (tm->tm_min + tm->tm_sec / 60.0) / 60.0;
+
+    T0 += UT * 1.002737909;
+    T0 = fmod(T0, 24.0);
+    if (T0 < 0) T0 += 24;
+
+    return T0;
+}
+
+
+/* given a particular time (expressed in seconds since the unix
+ * epoch), compute position on the earth (lat, lon) such that sun is
+ * directly overhead.  (lat, lon are reported in radians */
+
+void fgSunPosition(time_t ssue, double *lon, double *lat) {
+    /* time_t  ssue;           seconds since unix epoch */
+    /* double *lat;            (return) latitude        */
+    /* double *lon;            (return) longitude       */
+
+    /* double lambda; */
+    double alpha, delta;
+    double tmp;
+
+    /* lambda = sun_ecliptic_longitude(ssue); */
+    /* ecliptic_to_equatorial(lambda, 0.0, &alpha, &delta); */
+    ecliptic_to_equatorial (solarPosition.lonSun, 0.0, &alpha, &delta);
+
+    tmp = alpha - (FG_2PI/24)*GST(ssue);
+    if (tmp < -FG_PI) {
+	do tmp += FG_2PI;
+	while (tmp < -FG_PI);
+    } else if (tmp > FG_PI) {
+	do tmp -= FG_2PI;
+	while (tmp < -FG_PI);
+    }
+
+    *lon = tmp;
+    *lat = delta;
+}
+
+
+/* update the cur_time_params structure with the current sun position */
+void fgUpdateSunPos( void ) {
+    struct fgLIGHT *l;
+    struct fgTIME *t;
+    struct fgVIEW *v;
+    MAT3vec nup, nsun;
+    /* if the 4th field is 0.0, this specifies a direction ... */
+    GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
+    /* base sky color */
+    GLfloat base_sky_color[4] =        {0.60, 0.60, 0.90, 1.0};
+    /* base fog color */
+    GLfloat base_fog_color[4] = {0.70, 0.70, 0.70, 1.0};
+    double sun_gd_lat, sl_radius, temp;
+    double x_2, x_4, x_8, x_10;
+    double light, ambient, diffuse, sky_brightness;
+    static int time_warp = 0;
+
+    l = &cur_light_params;
+    t = &cur_time_params;
+    v = &current_view;
+
+    printf("  Updating Sun position\n");
+
+    time_warp += 0; /* increase this to make the world spin real fast */
+
+    fgSunPosition(t->cur_time + time_warp, &l->sun_lon, &sun_gd_lat);
+
+    fgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &l->sun_gc_lat);
+
+    l->fg_sunpos = fgPolarToCart(l->sun_lon, l->sun_gc_lat, sl_radius);
+
+    /* printf("  Geodetic lat = %.5f Geocentric lat = %.5f\n", sun_gd_lat,
+       t->sun_gc_lat); */
+
+    /* FALSE! (?> the sun position has to be translated just like
+     * everything else */
+    /* l->sun_vec_inv[0] = l->fg_sunpos.x - scenery_center.x;  */
+    /* l->sun_vec_inv[1] = l->fg_sunpos.y - scenery_center.y; */
+    /* l->sun_vec_inv[2] = l->fg_sunpos.z - scenery_center.z; */
+    /* MAT3_SCALE_VEC(l->sun_vec, l->sun_vec_inv, -1.0); */
+
+    /* I think this will work better for generating the sun light vector */
+    l->sun_vec[0] = l->fg_sunpos.x;
+    l->sun_vec[1] = l->fg_sunpos.y;
+    l->sun_vec[2] = l->fg_sunpos.z;
+    MAT3_NORMALIZE_VEC(l->sun_vec, temp);
+    MAT3_SCALE_VEC(l->sun_vec_inv, l->sun_vec, -1.0);
+
+    /* make these are directional light sources only */
+    l->sun_vec[3] = 0.0;
+    l->sun_vec_inv[3] = 0.0;
+
+    printf("  l->sun_vec = %.2f %.2f %.2f\n", l->sun_vec[0], l->sun_vec[1],
+	   l->sun_vec[2]);
+
+    /* calculate the sun's relative angle to local up */
+    MAT3_COPY_VEC(nup, v->local_up);
+    nsun[0] = l->fg_sunpos.x; 
+    nsun[1] = l->fg_sunpos.y;
+    nsun[2] = l->fg_sunpos.z;
+    MAT3_NORMALIZE_VEC(nup, temp);
+    MAT3_NORMALIZE_VEC(nsun, temp);
+
+    l->sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
+    printf("  SUN ANGLE relative to current location = %.3f rads.\n", 
+	   l->sun_angle);
+
+    /* calculate lighting parameters based on sun's relative angle to
+     * local up */
+    /* ya kind'a have to plot this to see how it works */
+
+    /* x = t->sun_angle^8 */
+//     x_2 = l->sun_angle * l->sun_angle;
+//     x_4 = x_2 * x_2;
+//     x_8 = x_4 * x_4;
+//     x_10 = x_8 * x_2;
+
+//     light = pow(1.1, -x_10 / 30.0);
+//     ambient = 0.2 * light;
+//     diffuse = 1.0 * light;
+
+//     sky_brightness = 0.85 * pow(1.2, -x_8 / 20.0) + 0.15;
+
+    /* sky_brightness = 0.15; */ /* to force a dark sky (for testing) */
+
+//     if ( ambient < 0.02 ) { ambient = 0.02; }
+//     if ( diffuse < 0.0 ) { diffuse = 0.0; }
+
+//     if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
+
+//     l->scene_ambient[0] = white[0] * ambient;
+//     l->scene_ambient[1] = white[1] * ambient;
+//     l->scene_ambient[2] = white[2] * ambient;
+
+//     l->scene_diffuse[0] = white[0] * diffuse;
+//     l->scene_diffuse[1] = white[1] * diffuse;
+//     l->scene_diffuse[2] = white[2] * diffuse;
+
+//     /* set fog color */
+//     l->fog_color[0] = base_fog_color[0] * (ambient + diffuse);
+//     l->fog_color[1] = base_fog_color[1] * (ambient + diffuse);
+//     l->fog_color[2] = base_fog_color[2] * (ambient + diffuse);
+//     l->fog_color[3] = base_fog_color[3];
+
+//     /* set sky color */
+//     l->sky_color[0] = base_sky_color[0] * sky_brightness;
+//     l->sky_color[1] = base_sky_color[1] * sky_brightness;
+//     l->sky_color[2] = base_sky_color[2] * sky_brightness;
+//     l->sky_color[3] = base_sky_color[3];
+}
+
+
+/* $Log$
+/* Revision 1.1  1998/04/22 13:24:07  curt
+/* C++ - ifiing the code a bit.
+/* Starting to reorginize some of the lighting calcs to use a table lookup.
+/*
+ * Revision 1.27  1998/04/03 22:12:57  curt
+ * Converting to Gnu autoconf system.
+ * Centralized time handling differences.
+ *
+ * Revision 1.26  1998/02/23 19:08:00  curt
+ * Incorporated Durk's Astro/ tweaks.  Includes unifying the sun position
+ * calculation code between sun display, and other FG sections that use this
+ * for things like lighting.
+ *
+ * Revision 1.25  1998/02/09 15:07:53  curt
+ * Minor tweaks.
+ *
+ * Revision 1.24  1998/01/27 00:48:07  curt
+ * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
+ * system and commandline/config file processing code.
+ *
+ * Revision 1.23  1998/01/19 19:27:21  curt
+ * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
+ * This should simplify things tremendously.
+ *
+ * Revision 1.22  1998/01/19 18:40:40  curt
+ * Tons of little changes to clean up the code and to remove fatal errors
+ * when building with the c++ compiler.
+ *
+ * Revision 1.21  1997/12/30 23:10:19  curt
+ * Calculate lighting parameters here.
+ *
+ * Revision 1.20  1997/12/30 22:22:43  curt
+ * Further integration of event manager.
+ *
+ * Revision 1.19  1997/12/30 20:47:59  curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.18  1997/12/23 04:58:40  curt
+ * Tweaked the sky coloring a bit to build in structures to allow finer rgb
+ * control.
+ *
+ * Revision 1.17  1997/12/15 23:55:08  curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.16  1997/12/11 04:43:57  curt
+ * Fixed sun vector and lighting problems.  I thing the moon is now lit
+ * correctly.
+ *
+ * Revision 1.15  1997/12/10 22:37:55  curt
+ * Prepended "fg" on the name of all global structures that didn't have it yet.
+ * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
+ *
+ * Revision 1.14  1997/12/09 04:25:39  curt
+ * Working on adding a global lighting params structure.
+ *
+ * Revision 1.13  1997/11/25 19:25:42  curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.12  1997/11/15 18:15:39  curt
+ * Reverse direction of sun vector, so object normals can be more normal.
+ *
+ * Revision 1.11  1997/10/28 21:07:21  curt
+ * Changed GLUT/ -> Main/
+ *
+ * Revision 1.10  1997/09/13 02:00:09  curt
+ * Mostly working on stars and generating sidereal time for accurate star
+ * placement.
+ *
+ * Revision 1.9  1997/09/05 14:17:31  curt
+ * More tweaking with stars.
+ *
+ * Revision 1.8  1997/09/05 01:36:04  curt
+ * Working on getting stars right.
+ *
+ * Revision 1.7  1997/09/04 02:17:40  curt
+ * Shufflin' stuff.
+ *
+ * Revision 1.6  1997/08/27 03:30:37  curt
+ * Changed naming scheme of basic shared structures.
+ *
+ * Revision 1.5  1997/08/22 21:34:41  curt
+ * Doing a bit of reorganizing and house cleaning.
+ *
+ * Revision 1.4  1997/08/19 23:55:09  curt
+ * Worked on better simulating real lighting.
+ *
+ * Revision 1.3  1997/08/13 20:23:49  curt
+ * The interface to sunpos now updates a global structure rather than returning
+ * current sun position.
+ *
+ * Revision 1.2  1997/08/06 00:24:32  curt
+ * Working on correct real time sun lighting.
+ *
+ * Revision 1.1  1997/08/01 15:27:56  curt
+ * Initial revision.
+ *
+ */
diff --git a/Time/sunpos.h b/Time/sunpos.h
deleted file mode 100644
index a55d80d58..000000000
--- a/Time/sunpos.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * sunpos.h
- * kirk johnson
- * july 1993
- *
- * code for calculating the position on the earth's surface for which
- * the sun is directly overhead (adapted from _practical astronomy
- * with your calculator, third edition_, peter duffett-smith,
- * cambridge university press, 1988.)
- *
- * RCS $Id$
- *
- * Copyright (C) 1989, 1990, 1993, 1994, 1995 Kirk Lauritz Johnson
- *
- * Parts of the source code (as marked) are:
- *   Copyright (C) 1989, 1990, 1991 by Jim Frost
- *   Copyright (C) 1992 by Jamie Zawinski <jwz@lucid.com>
- *
- * Permission to use, copy, modify and freely distribute xearth for
- * non-commercial and not-for-profit purposes is hereby granted
- * without fee, provided that both the above copyright notice and this
- * permission notice appear in all copies and in supporting
- * documentation.
- *
- * The author makes no representations about the suitability of this
- * software for any purpose. It is provided "as is" without express or
- * implied warranty.
- *
- * THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
- * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
- * OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-
-#ifndef _SUNPOS_H
-#define _SUNPOS_H
-
-
-#ifdef __cplusplus                                                          
-extern "C" {                            
-#endif                                   
-
-
-#include <time.h>
-
-#include <Include/fg_types.h>
-
-/* update the cur_time_params structure with the current sun position */
-void fgUpdateSunPos( void );
-
-void fgSunPosition(time_t ssue, double *lon, double *lat);
-
-
-#ifdef __cplusplus
-}
-#endif
-
-
-#endif /* _SUNPOS_H */
diff --git a/Time/sunpos.hxx b/Time/sunpos.hxx
new file mode 100644
index 000000000..8719ef994
--- /dev/null
+++ b/Time/sunpos.hxx
@@ -0,0 +1,58 @@
+/*
+ * sunpos.hxx
+ * kirk johnson
+ * july 1993
+ *
+ * code for calculating the position on the earth's surface for which
+ * the sun is directly overhead (adapted from _practical astronomy
+ * with your calculator, third edition_, peter duffett-smith,
+ * cambridge university press, 1988.)
+ *
+ * RCS $Id$
+ *
+ * Copyright (C) 1989, 1990, 1993, 1994, 1995 Kirk Lauritz Johnson
+ *
+ * Parts of the source code (as marked) are:
+ *   Copyright (C) 1989, 1990, 1991 by Jim Frost
+ *   Copyright (C) 1992 by Jamie Zawinski <jwz@lucid.com>
+ *
+ * Permission to use, copy, modify and freely distribute xearth for
+ * non-commercial and not-for-profit purposes is hereby granted
+ * without fee, provided that both the above copyright notice and this
+ * permission notice appear in all copies and in supporting
+ * documentation.
+ *
+ * The author makes no representations about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ *
+ * THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
+ * OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+
+#ifndef _SUNPOS_HXX
+#define _SUNPOS_HXX
+
+
+#ifndef __cplusplus                                                          
+# error This library requires C++
+#endif                                   
+
+
+#include <time.h>
+
+#include <Include/fg_types.h>
+
+/* update the cur_time_params structure with the current sun position */
+void fgUpdateSunPos( void );
+
+void fgSunPosition(time_t ssue, double *lon, double *lat);
+
+
+#endif /* _SUNPOS_H */