+++ /dev/null
-// 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.
-//
-// $Id$
-
-
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <simgear/compiler.h>
-
-#ifdef SG_HAVE_STD_INCLUDES
-# include <cmath>
-# include <cstdio>
-# include <ctime>
-# ifdef macintosh
- SG_USING_STD(time_t);
-# endif
-#else
-# include <math.h>
-# include <stdio.h>
-# include <time.h>
-#endif
-
-#include <simgear/constants.h>
-#include <simgear/debug/logstream.hxx>
-#include <simgear/ephemeris/ephemeris.hxx>
-#include <simgear/math/point3d.hxx>
-#include <simgear/math/polar3d.hxx>
-#include <simgear/math/sg_geodesy.hxx>
-#include <simgear/math/vector.hxx>
-#include <simgear/timing/sg_time.hxx>
-
-#include <Main/globals.hxx>
-#include <Main/viewer.hxx>
-#include <Scenery/scenery.hxx>
-#include <Time/light.hxx>
-
-#include "sunpos.hxx"
-
-// #undef E // should no longer be needed
-#define MeanObliquity (23.440592*(SGD_2PI/360))
-
-static void ecliptic_to_equatorial(double, double, double *, double *);
-static double julian_date(int, int, int);
-static double GST(time_t);
-
-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;
- double sin_l, cos_l;
-
- sin_e = sin(MeanObliquity);
- cos_e = cos(MeanObliquity);
- sin_l = sin(lambda);
- cos_l = cos(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);
-}
-
-
-/* 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) {
- SG_LOG( SG_EVENT, SG_ALERT,
- "WHOOPS! Julian dates only valid for 1582 oct 15 or later" );
- }
-
- 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);
-
- /* **********************************************************************
- * 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( globals->get_ephem()->get_sun()->getLon(),
- 0.0, &alpha, &delta );
- tmp = alpha - (SGD_2PI/24)*GST(ssue);
- if (tmp < -SGD_PI) {
- do tmp += SGD_2PI;
- while (tmp < -SGD_PI);
- } else if (tmp > SGD_PI) {
- do tmp -= SGD_2PI;
- while (tmp < -SGD_PI);
- }
-
- *lon = tmp;
- *lat = delta;
-}
-
-
-/* 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 */
-
-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( globals->get_ephem()->get_sun()->getLon(),
- globals->get_ephem()->get_sun()->getLat(),
- &alpha, &delta );
-
- // tmp = alpha - (SGD_2PI/24)*GST(ssue);
- tmp = alpha - (SGD_2PI/24)*gst;
- if (tmp < -SGD_PI) {
- do tmp += SGD_2PI;
- while (tmp < -SGD_PI);
- } else if (tmp > SGD_PI) {
- do tmp -= SGD_2PI;
- while (tmp < -SGD_PI);
- }
-
- *lon = tmp;
- *lat = delta;
-}
-
-
-// update the cur_time_params structure with the current sun position
-void fgUpdateSunPos( void ) {
- sgVec3 nup, nsun;
- Point3D rel_sunpos;
- double dot, east_dot;
- double sun_gd_lat, sl_radius;
-
- // vector in cartesian coordinates from current position to the
- // postion on the earth's surface the sun is directly over
- sgVec3 to_sun;
-
- // surface direction to go to head towards sun
- sgVec3 surface_to_sun;
-
- FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
- SGTime *t = globals->get_time_params();
- FGViewer *v = globals->get_current_view();
-
- SG_LOG( SG_EVENT, SG_DEBUG, " Updating Sun position" );
- SG_LOG( SG_EVENT, SG_DEBUG, " Gst = " << t->getGst() );
-
- double sun_l;
- fgSunPositionGST(t->getGst(), &sun_l, &sun_gd_lat);
- l->set_sun_lon(sun_l);
-
- sgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &sun_l);
- l->set_sun_gc_lat(sun_l);
-
- Point3D p = Point3D( l->get_sun_lon(), l->get_sun_gc_lat(), sl_radius );
- l->set_sunpos( sgPolarToCart3d(p) );
-
- SG_LOG( SG_EVENT, SG_DEBUG, " t->cur_time = " << t->get_cur_time() );
- SG_LOG( SG_EVENT, SG_DEBUG,
- " Sun Geodetic lat = " << sun_gd_lat
- << " Geocentric lat = " << l->get_sun_gc_lat() );
-
- // update the sun light vector
- sgSetVec4( l->sun_vec(), l->get_sunpos().x(),
- l->get_sunpos().y(), l->get_sunpos().z(), 0.0 );
- sgNormalizeVec4( l->sun_vec() );
- sgCopyVec4( l->sun_vec_inv(), l->sun_vec() );
- sgNegateVec4( l->sun_vec_inv() );
-
- // make sure these are directional light sources only
- l->sun_vec()[3] = l->sun_vec_inv()[3] = 0.0;
- // cout << " l->sun_vec = " << l->sun_vec[0] << "," << l->sun_vec[1]
- // << ","<< l->sun_vec[2] << endl;
-
- // calculate the sun's relative angle to local up
- sgCopyVec3( nup, v->get_world_up() );
- sgSetVec3( nsun, l->get_sunpos().x(),
- l->get_sunpos().y(), l->get_sunpos().z() );
- sgNormalizeVec3(nup);
- sgNormalizeVec3(nsun);
- // cout << "nup = " << nup[0] << "," << nup[1] << ","
- // << nup[2] << endl;
- // cout << "nsun = " << nsun[0] << "," << nsun[1] << ","
- // << nsun[2] << endl;
-
- l->set_sun_angle( acos( sgScalarProductVec3 ( nup, nsun ) ) );
- SG_LOG( SG_EVENT, SG_DEBUG, "sun angle relative to current location = "
- << l->get_sun_angle() );
-
- // calculate vector to sun's position on the earth's surface
- Point3D vp( v->get_view_pos()[0],
- v->get_view_pos()[1],
- v->get_view_pos()[2] );
- rel_sunpos = l->get_sunpos() - (vp + globals->get_scenery()->get_center());
- sgSetVec3( 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]);
-
- // 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".
-
- sgmap_vec_onto_cur_surface_plane( v->get_world_up(), v->get_view_pos(),
- to_sun, surface_to_sun );
- sgNormalizeVec3(surface_to_sun);
- // cout << "(sg) Surface direction to sun is "
- // << surface_to_sun[0] << ","
- // << surface_to_sun[1] << ","
- // << surface_to_sun[2] << endl;
- // cout << "Should be close to zero = "
- // << sgScalarProductVec3(nup, surface_to_sun) << endl;
-
- // calculate the angle between surface_to_sun and
- // v->get_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 = sgScalarProductVec3( surface_to_sun, v->get_surface_east() );
- // cout << " East dot product = " << east_dot << endl;
-
- // 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 = sgScalarProductVec3( surface_to_sun, v->get_surface_south() );
- // cout << " Dot product = " << dot << endl;
-
- if (dot > 1.0) {
- SG_LOG( SG_ASTRO, SG_INFO,
- "Dot product = " << dot << " is greater than 1.0" );
- dot = 1.0;
- }
- else if (dot < -1.0) {
- SG_LOG( SG_ASTRO, SG_INFO,
- "Dot product = " << dot << " is less than -1.0" );
- dot = -1.0;
- }
-
- if ( east_dot >= 0 ) {
- l->set_sun_rotation( acos(dot) );
- } else {
- l->set_sun_rotation( -acos(dot) );
- }
- // cout << " Sky needs to rotate = " << angle << " rads = "
- // << angle * SGD_RADIANS_TO_DEGREES << " degrees." << endl;
-}
-
-
# include <config.h>
#endif
+#include <simgear/math/vector.hxx>
+#include <simgear/math/polar3d.hxx>
+#include <simgear/math/sg_geodesy.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/magvar/magvar.hxx>
#include <simgear/timing/sg_time.hxx>
#include <FDM/flight.hxx>
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
+#include <Main/viewer.hxx>
+#include <Scenery/scenery.hxx>
#include "light.hxx"
-#include "sunpos.hxx"
+#include "sunsolver.hxx"
#include "tmp.hxx"
zone.str() );
}
+
+// update the cur_time_params structure with the current sun position
+void fgUpdateSunPos( void ) {
+ sgVec3 nup, nsun;
+ Point3D rel_sunpos;
+ double dot, east_dot;
+ double sun_gd_lat, sl_radius;
+
+ // vector in cartesian coordinates from current position to the
+ // postion on the earth's surface the sun is directly over
+ sgVec3 to_sun;
+
+ // surface direction to go to head towards sun
+ sgVec3 surface_to_sun;
+
+ FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
+ SGTime *t = globals->get_time_params();
+ FGViewer *v = globals->get_current_view();
+
+ SG_LOG( SG_EVENT, SG_DEBUG, " Updating Sun position" );
+ SG_LOG( SG_EVENT, SG_DEBUG, " Gst = " << t->getGst() );
+
+ double sun_l;
+ fgSunPositionGST(t->getGst(), &sun_l, &sun_gd_lat);
+ l->set_sun_lon(sun_l);
+
+ sgGeodToGeoc(sun_gd_lat, 0.0, &sl_radius, &sun_l);
+ l->set_sun_gc_lat(sun_l);
+
+ Point3D p = Point3D( l->get_sun_lon(), l->get_sun_gc_lat(), sl_radius );
+ l->set_sunpos( sgPolarToCart3d(p) );
+
+ SG_LOG( SG_EVENT, SG_DEBUG, " t->cur_time = " << t->get_cur_time() );
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Sun Geodetic lat = " << sun_gd_lat
+ << " Geocentric lat = " << l->get_sun_gc_lat() );
+
+ // update the sun light vector
+ sgSetVec4( l->sun_vec(), l->get_sunpos().x(),
+ l->get_sunpos().y(), l->get_sunpos().z(), 0.0 );
+ sgNormalizeVec4( l->sun_vec() );
+ sgCopyVec4( l->sun_vec_inv(), l->sun_vec() );
+ sgNegateVec4( l->sun_vec_inv() );
+
+ // make sure these are directional light sources only
+ l->sun_vec()[3] = l->sun_vec_inv()[3] = 0.0;
+ // cout << " l->sun_vec = " << l->sun_vec[0] << "," << l->sun_vec[1]
+ // << ","<< l->sun_vec[2] << endl;
+
+ // calculate the sun's relative angle to local up
+ sgCopyVec3( nup, v->get_world_up() );
+ sgSetVec3( nsun, l->get_sunpos().x(),
+ l->get_sunpos().y(), l->get_sunpos().z() );
+ sgNormalizeVec3(nup);
+ sgNormalizeVec3(nsun);
+ // cout << "nup = " << nup[0] << "," << nup[1] << ","
+ // << nup[2] << endl;
+ // cout << "nsun = " << nsun[0] << "," << nsun[1] << ","
+ // << nsun[2] << endl;
+
+ l->set_sun_angle( acos( sgScalarProductVec3 ( nup, nsun ) ) );
+ SG_LOG( SG_EVENT, SG_DEBUG, "sun angle relative to current location = "
+ << l->get_sun_angle() );
+
+ // calculate vector to sun's position on the earth's surface
+ Point3D vp( v->get_view_pos()[0],
+ v->get_view_pos()[1],
+ v->get_view_pos()[2] );
+ rel_sunpos = l->get_sunpos() - (vp + globals->get_scenery()->get_center());
+ sgSetVec3( 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]);
+
+ // 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".
+
+ sgmap_vec_onto_cur_surface_plane( v->get_world_up(), v->get_view_pos(),
+ to_sun, surface_to_sun );
+ sgNormalizeVec3(surface_to_sun);
+ // cout << "(sg) Surface direction to sun is "
+ // << surface_to_sun[0] << ","
+ // << surface_to_sun[1] << ","
+ // << surface_to_sun[2] << endl;
+ // cout << "Should be close to zero = "
+ // << sgScalarProductVec3(nup, surface_to_sun) << endl;
+
+ // calculate the angle between surface_to_sun and
+ // v->get_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 = sgScalarProductVec3( surface_to_sun, v->get_surface_east() );
+ // cout << " East dot product = " << east_dot << endl;
+
+ // 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 = sgScalarProductVec3( surface_to_sun, v->get_surface_south() );
+ // cout << " Dot product = " << dot << endl;
+
+ if (dot > 1.0) {
+ SG_LOG( SG_ASTRO, SG_INFO,
+ "Dot product = " << dot << " is greater than 1.0" );
+ dot = 1.0;
+ }
+ else if (dot < -1.0) {
+ SG_LOG( SG_ASTRO, SG_INFO,
+ "Dot product = " << dot << " is less than -1.0" );
+ dot = -1.0;
+ }
+
+ if ( east_dot >= 0 ) {
+ l->set_sun_rotation( acos(dot) );
+ } else {
+ l->set_sun_rotation( -acos(dot) );
+ }
+ // cout << " Sky needs to rotate = " << angle << " rads = "
+ // << angle * SGD_RADIANS_TO_DEGREES << " degrees." << endl;
+}
+
projects / flightgear.git / commitdiff