-/*
- * 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>
+// sunpos.cxx (adapted from XEarth)
+// 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.)
+//
+// 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)
+
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <Include/compiler.h>
+
+#ifdef FG_HAVE_STD_INCLUDES
+# include <cmath>
+# include <cstdio>
+# include <ctime>
+#else
+# include <math.h>
+# include <stdio.h>
+# include <time.h>
+#endif
+
+#include <Debug/logstream.hxx>
+#include <Astro/solarsystem.hxx>
#include <Include/fg_constants.h>
#include <Main/views.hxx>
-#include <Math/fg_geodesy.h>
+#include <Math/fg_geodesy.hxx>
#include <Math/mat3.h>
-#include <Math/polar.h>
+#include <Math/point3d.hxx>
+#include <Math/polar3d.hxx>
+#include <Math/vector.hxx>
+#include <Scenery/scenery.hxx>
-#include "fg_time.h"
+#include "fg_time.hxx"
#include "sunpos.hxx"
+extern SolarSystem *solarSystem;
#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 *delta; (return) declination */
double sin_e, cos_e;
+ double sin_l, cos_l;
sin_e = sin(MeanObliquity);
cos_e = cos(MeanObliquity);
+ sin_l = sin(lambda);
+ cos_l = cos(lambda);
- *alpha = atan2(sin(lambda)*cos_e - tan(beta)*sin_e, cos(lambda));
- *delta = asin(sin(beta)*cos_e + cos(beta)*sin_e*sin(lambda));
+ *alpha = atan2(sin_l*cos_e - tan(beta)*sin_e, cos_l);
+ *delta = asin(sin(beta)*cos_e + cos(beta)*sin_e*sin_l);
}
/* lazy test to ensure gregorian calendar */
if (y < 1583) {
- printf("WHOOPS! Julian dates only valid for 1582 oct 15 or later\n");
+ FG_LOG( FG_EVENT, FG_ALERT,
+ "WHOOPS! Julian dates only valid for 1582 oct 15 or later" );
}
if ((m == 1) || (m == 2)) {
/* lambda = sun_ecliptic_longitude(ssue); */
/* ecliptic_to_equatorial(lambda, 0.0, &alpha, &delta); */
- ecliptic_to_equatorial (solarPosition.lonSun, 0.0, &alpha, &delta);
-
+ //ecliptic_to_equatorial (solarPosition.lonSun, 0.0, &alpha, &delta);
+
+ /* **********************************************************************
+ * NOTE: in the next function, each time the sun's position is updated, the
+ * the sun's longitude is returned from solarSystem->sun. Note that the
+ * sun's position is updated at a much higher frequency than the rate at
+ * which the solar system's rebuilds occur. This is not a problem, however,
+ * because the fgSunPosition we're talking about here concerns the changing
+ * position of the sun due to the daily rotation of the earth.
+ * The ecliptic longitude, however, represents the position of the sun with
+ * respect to the stars, and completes just one cycle over the course of a
+ * year. Its therefore pretty safe to update the sun's longitude only once
+ * every ten minutes. (Comment added by Durk Talsma).
+ ************************************************************************/
+
+ ecliptic_to_equatorial( SolarSystem::theSolarSystem->getSun()->getLon(),
+ 0.0, &alpha, &delta );
tmp = alpha - (FG_2PI/24)*GST(ssue);
if (tmp < -FG_PI) {
do tmp += FG_2PI;
}
-/* update the cur_time_params structure with the current sun position */
+/* given a particular time expressed in side real time at prime
+ * meridian (GST), compute position on the earth (lat, lon) such that
+ * sun is directly overhead. (lat, lon are reported in radians */
+
+static void fgSunPositionGST(double gst, 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);
+ ecliptic_to_equatorial( SolarSystem::theSolarSystem->getSun()->getLon(),
+ SolarSystem::theSolarSystem->getSun()->getLat(),
+ &alpha, &delta );
+
+// tmp = alpha - (FG_2PI/24)*GST(ssue);
+ tmp = alpha - (FG_2PI/24)*gst;
+ 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;
+ fgLIGHT *l;
+ fgTIME *t;
+ FGView *v;
+ MAT3vec nup, nsun, v0, surface_to_sun;
+ Point3D p, rel_sunpos;
+ double dot, east_dot;
+ double sun_gd_lat, sl_radius;
+ double ntmp;
l = &cur_light_params;
t = &cur_time_params;
v = ¤t_view;
- printf(" Updating Sun position\n");
+ FG_LOG( FG_EVENT, FG_INFO, " Updating Sun position" );
- time_warp += 0; /* increase this to make the world spin real fast */
-
- fgSunPosition(t->cur_time + time_warp, &l->sun_lon, &sun_gd_lat);
+ // (not sure why there was two)
+ // fgSunPosition(t->cur_time, &l->sun_lon, &sun_gd_lat);
+ fgSunPositionGST(t->gst, &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); */
+ p = Point3D( l->sun_lon, l->sun_gc_lat, sl_radius );
+ l->fg_sunpos = fgPolarToCart3d(p);
- /* 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); */
+ FG_LOG( FG_EVENT, FG_INFO, " t->cur_time = " << t->cur_time );
+ FG_LOG( FG_EVENT, FG_INFO,
+ " Sun Geodetic lat = " << sun_gd_lat
+ << " Geocentric lat = " << l->sun_gc_lat );
- /* 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);
+ // 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, ntmp);
MAT3_SCALE_VEC(l->sun_vec_inv, l->sun_vec, -1.0);
- /* make these are directional light sources only */
+ // make sure 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]);
+ // 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);
+ // calculate the sun's relative angle to local up
+ MAT3_COPY_VEC(nup, v->get_local_up());
+ nsun[0] = l->fg_sunpos.x();
+ nsun[1] = l->fg_sunpos.y();
+ nsun[2] = l->fg_sunpos.z();
+ MAT3_NORMALIZE_VEC(nup, ntmp);
+ MAT3_NORMALIZE_VEC(nsun, ntmp);
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];
+ // printf(" SUN ANGLE relative to current location = %.3f rads.\n",
+ // l->sun_angle);
+
+ // calculate vector to sun's position on the earth's surface
+ rel_sunpos = l->fg_sunpos - (v->get_view_pos() + scenery.center);
+ v->set_to_sun( rel_sunpos.x(), rel_sunpos.y(), rel_sunpos.z() );
+ // printf( "Vector to sun = %.2f %.2f %.2f\n",
+ // v->to_sun[0], v->to_sun[1], v->to_sun[2]);
+
+ // make a vector to the current view position
+ Point3D view_pos = v->get_view_pos();
+ MAT3_SET_VEC(v0, view_pos.x(), view_pos.y(), view_pos.z());
+
+ // Given a vector from the view position to the point on the
+ // earth's surface the sun is directly over, map into onto the
+ // local plane representing "horizontal".
+ map_vec_onto_cur_surface_plane( v->get_local_up(), v0, v->get_to_sun(),
+ surface_to_sun );
+ MAT3_NORMALIZE_VEC(surface_to_sun, ntmp);
+ v->set_surface_to_sun( surface_to_sun[0], surface_to_sun[1],
+ surface_to_sun[2] );
+ // printf("Surface direction to sun is %.2f %.2f %.2f\n",
+ // v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]);
+ // printf("Should be close to zero = %.2f\n",
+ // MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun));
+
+ // calculate the angle between v->surface_to_sun and
+ // v->surface_east. We do this so we can sort out the acos()
+ // ambiguity. I wish I could think of a more efficient way ... :-(
+ east_dot = MAT3_DOT_PRODUCT( surface_to_sun, v->get_surface_east() );
+ // printf(" East dot product = %.2f\n", east_dot);
+
+ // calculate the angle between v->surface_to_sun and
+ // v->surface_south. this is how much we have to rotate the sky
+ // for it to align with the sun
+ dot = MAT3_DOT_PRODUCT( surface_to_sun, v->get_surface_south() );
+ // printf(" Dot product = %.2f\n", dot);
+ if ( east_dot >= 0 ) {
+ l->sun_rotation = acos(dot);
+ } else {
+ l->sun_rotation = -acos(dot);
+ }
+ // printf(" Sky needs to rotate = %.3f rads = %.1f degrees.\n",
+ // angle, angle * RAD_TO_DEG); */
}
-/* $Log$
-/* 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.
- *
- */
+// $Log$
+// Revision 1.21 1999/03/22 02:08:18 curt
+// Changes contributed by Durk Talsma:
+//
+// Here's a few changes I made to fg-0.58 this weekend. Included are the
+// following features:
+// - Sun and moon have a halo
+// - The moon has a light vector, moon_angle, etc. etc. so that we can have
+// some moonlight during the night.
+// - Lot's of small changes tweakes, including some stuff Norman Vine sent
+// me earlier.
+//
+// Revision 1.20 1999/02/26 22:10:11 curt
+// Added initial support for native SGI compilers.
+//
+// Revision 1.19 1999/01/07 20:25:37 curt
+// Portability changes and updates from Bernie Bright.
+//
+// Revision 1.18 1998/12/09 18:50:36 curt
+// Converted "class fgVIEW" to "class FGView" and updated to make data
+// members private and make required accessor functions.
+//
+// Revision 1.17 1998/11/09 23:41:53 curt
+// Log message clean ups.
+//
+// Revision 1.16 1998/11/07 19:07:14 curt
+// Enable release builds using the --without-logging option to the configure
+// script. Also a couple log message cleanups, plus some C to C++ comment
+// conversion.
+//
+// Revision 1.15 1998/10/18 01:17:24 curt
+// Point3D tweaks.
+//
+// Revision 1.14 1998/10/17 01:34:32 curt
+// C++ ifying ...
+//
+// Revision 1.13 1998/10/16 00:56:12 curt
+// Converted to Point3D class.
+//
+// Revision 1.12 1998/09/15 04:27:50 curt
+// Changes for new astro code.
+//
+// Revision 1.11 1998/08/12 21:13:22 curt
+// Optimizations by Norman Vine.
+//
+// Revision 1.10 1998/07/22 21:45:39 curt
+// fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
+// but seems to be triggering a bug.
+// light.cxx: Added code to adjust fog color based on sunrise/sunset effects
+// and view orientation. This is an attempt to match the fog color to the
+// sky color in the center of the screen. You see discrepancies at the
+// edges, but what else can be done?
+// sunpos.cxx: Caculate local direction to sun here. (what compass direction
+// do we need to face to point directly at sun)
+//
+// Revision 1.9 1998/07/08 14:48:39 curt
+// polar3d.h renamed to polar3d.hxx
+//
+// Revision 1.8 1998/05/02 01:53:18 curt
+// Fine tuning mktime() support because of varying behavior on different
+// platforms.
+//
+// Revision 1.7 1998/04/30 12:36:05 curt
+// C++-ifying a couple source files.
+//
+// Revision 1.6 1998/04/28 01:22:18 curt
+// Type-ified fgTIME and fgVIEW.
+//
+// Revision 1.5 1998/04/26 05:10:05 curt
+// "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
+//
+// Revision 1.4 1998/04/25 22:06:34 curt
+// Edited cvs log messages in source files ... bad bad bad!
+//
+// Revision 1.3 1998/04/25 20:24:03 curt
+// Cleaned up initialization sequence to eliminate interdependencies
+// between sun position, lighting, and view position. This creates a
+// valid single pass initialization path.
+//
+// Revision 1.2 1998/04/24 00:52:31 curt
+// Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
+// Fog color fixes.
+// Separated out lighting calcs into their own file.
+//
+// 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 <pbleisch@acm.org> 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.
+//
projects / flightgear.git / blobdiff