Starting to reorginize some of the lighting calcs to use a table lookup.
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
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 =
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)
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
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
@-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
#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 */
/* $Log$
-/* 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
#define _FG_TIME_H
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
#include <config.h>
#ifdef HAVE_WINDOWS_H
#include <Flight/flight.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
/* Define a structure containing global time parameters */
struct fgTIME {
/* the date/time in various forms */
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;
/* $Log$
-/* 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.
*
--- /dev/null
+//
+// 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 = ¤t_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.
+//
+//
--- /dev/null
+//
+// 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.
+//
+//
+++ /dev/null
-/*
- * 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 = ¤t_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.
- *
- */
--- /dev/null
+/*
+ * 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 = ¤t_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.
+ *
+ */
+++ /dev/null
-/*
- * 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 */
--- /dev/null
+/*
+ * 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 */
projects / flightgear.git / commitdiff