1998-01-07 03:16:15 +00:00
|
|
|
/**************************************************************************
|
|
|
|
* moon.c
|
|
|
|
* Written by Durk Talsma. Started October 1997, for the flight gear project.
|
|
|
|
*
|
|
|
|
* 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.
|
|
|
|
*
|
|
|
|
* $Id$
|
|
|
|
* (Log is kept at end of this file)
|
|
|
|
**************************************************************************/
|
|
|
|
|
|
|
|
|
1998-04-03 21:50:53 +00:00
|
|
|
#include <config.h>
|
|
|
|
|
|
|
|
#ifdef HAVE_WINDOWS_H
|
|
|
|
# include <windows.h>
|
|
|
|
#endif
|
|
|
|
|
1998-01-07 03:16:15 +00:00
|
|
|
#include <math.h>
|
|
|
|
#include <GL/glut.h>
|
1998-01-19 19:26:51 +00:00
|
|
|
#include <XGL/xgl.h>
|
1998-01-07 03:16:15 +00:00
|
|
|
|
1998-01-19 19:26:51 +00:00
|
|
|
#include <Astro/orbits.h>
|
|
|
|
#include <Astro/moon.h>
|
1998-01-07 03:16:15 +00:00
|
|
|
|
1998-01-19 19:26:51 +00:00
|
|
|
#include <Aircraft/aircraft.h>
|
1998-01-27 00:47:41 +00:00
|
|
|
#include <Include/fg_constants.h>
|
1998-01-19 19:26:51 +00:00
|
|
|
#include <Include/general.h>
|
|
|
|
#include <Main/views.h>
|
|
|
|
#include <Time/fg_time.h>
|
1998-01-27 00:47:41 +00:00
|
|
|
#include <Main/fg_debug.h>
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
struct CelestialCoord moonPos;
|
|
|
|
|
|
|
|
static float xMoon, yMoon, zMoon;
|
1998-02-23 19:07:49 +00:00
|
|
|
static GLint moon = 0;
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* --------------------------------------------------------------
|
|
|
|
This section contains the code that calculates the actual
|
|
|
|
position of the moon in the night sky.
|
|
|
|
----------------------------------------------------------------*/
|
|
|
|
struct CelestialCoord fgCalculateMoon(struct OrbElements params,
|
|
|
|
struct OrbElements sunParams,
|
|
|
|
struct fgTIME t)
|
|
|
|
{
|
|
|
|
struct CelestialCoord
|
|
|
|
geocCoord, topocCoord;
|
|
|
|
|
|
|
|
double
|
|
|
|
eccAnom, ecl, lonecl, latecl, actTime,
|
|
|
|
xv, yv, v, r, xh, yh, zh, xg, yg, zg, xe, ye, ze,
|
|
|
|
Ls, Lm, D, F, mpar, gclat, rho, HA, g;
|
|
|
|
|
1998-02-07 15:29:31 +00:00
|
|
|
fgAIRCRAFT *a;
|
|
|
|
fgFLIGHT *f;
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
a = ¤t_aircraft;
|
1998-02-07 15:29:31 +00:00
|
|
|
f = a->flight;
|
1998-01-07 03:16:15 +00:00
|
|
|
|
1998-02-02 20:52:20 +00:00
|
|
|
/* calculate the angle between ecliptic and equatorial coordinate
|
|
|
|
* system, in Radians */
|
1998-01-07 03:16:15 +00:00
|
|
|
actTime = fgCalcActTime(t);
|
1998-02-23 19:07:49 +00:00
|
|
|
ecl = ((DEG_TO_RAD * 23.4393) - (DEG_TO_RAD * 3.563E-7) * actTime);
|
|
|
|
/*ecl = 0.409093 - 6.2186E-9 * actTime; */
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
/* calculate the eccentric anomaly */
|
|
|
|
eccAnom = fgCalcEccAnom(params.M, params.e);
|
|
|
|
|
1998-02-02 20:52:20 +00:00
|
|
|
/* calculate the moon's distance (r) and true anomaly (v) */
|
1998-01-07 03:16:15 +00:00
|
|
|
xv = params.a * ( cos(eccAnom) - params.e);
|
|
|
|
yv = params.a * ( sqrt(1.0 - params.e*params.e) * sin(eccAnom));
|
|
|
|
v =atan2(yv, xv);
|
|
|
|
r = sqrt(xv*xv + yv*yv);
|
|
|
|
|
|
|
|
/* estimate the geocentric rectangular coordinates here */
|
1998-02-23 19:07:49 +00:00
|
|
|
xh = r * (cos (params.N) * cos (v + params.w) -
|
|
|
|
sin (params.N) * sin (v + params.w) * cos (params.i));
|
|
|
|
yh = r * (sin (params.N) * cos (v + params.w) +
|
|
|
|
cos (params.N) * sin (v + params.w) * cos (params.i));
|
1998-01-07 03:16:15 +00:00
|
|
|
zh = r * (sin(v + params.w) * sin(params.i));
|
|
|
|
|
|
|
|
/* calculate the ecliptic latitude and longitude here */
|
|
|
|
lonecl = atan2( yh, xh);
|
|
|
|
latecl = atan2( zh, sqrt( xh*xh + yh*yh));
|
|
|
|
|
1998-02-02 20:52:20 +00:00
|
|
|
/* calculate a number of perturbations, i.e. disturbances caused by
|
|
|
|
* the gravitational influence of the sun and the other mayor
|
1998-02-23 19:07:49 +00:00
|
|
|
* planets. The largest of these even have their own names */
|
1998-01-07 03:16:15 +00:00
|
|
|
Ls = sunParams.M + sunParams.w;
|
|
|
|
Lm = params.M + params.w + params.N;
|
|
|
|
D = Lm - Ls;
|
|
|
|
F = Lm - params.N;
|
|
|
|
|
1998-02-02 20:52:20 +00:00
|
|
|
lonecl += DEG_TO_RAD * (
|
|
|
|
- 1.274 * sin (params.M - 2*D) /* the Evection */
|
|
|
|
+ 0.658 * sin (2 * D) /* the Variation */
|
|
|
|
- 0.186 * sin (sunParams.M) /* the yearly variation */
|
|
|
|
- 0.059 * sin (2*params.M - 2*D)
|
|
|
|
- 0.057 * sin (params.M - 2*D + sunParams.M)
|
|
|
|
+ 0.053 * sin (params.M + 2*D)
|
|
|
|
+ 0.046 * sin (2*D - sunParams.M)
|
|
|
|
+ 0.041 * sin (params.M - sunParams.M)
|
|
|
|
- 0.035 * sin (D) /* the Parallactic Equation */
|
|
|
|
- 0.031 * sin (params.M + sunParams.M)
|
|
|
|
- 0.015 * sin (2*F - 2*D)
|
|
|
|
+ 0.011 * sin (params.M - 4*D)
|
|
|
|
);
|
|
|
|
latecl += DEG_TO_RAD * (
|
|
|
|
- 0.173 * sin (F - 2*D)
|
|
|
|
- 0.055 * sin (params.M - F - 2*D)
|
|
|
|
- 0.046 * sin (params.M + F - 2*D)
|
|
|
|
+ 0.033 * sin (F + 2*D)
|
|
|
|
+ 0.017 * sin (2 * params.M + F)
|
|
|
|
);
|
|
|
|
|
1998-01-07 03:16:15 +00:00
|
|
|
r += (
|
|
|
|
- 0.58 * cos(params.M - 2*D)
|
|
|
|
- 0.46 * cos(2*D)
|
1998-02-02 20:52:20 +00:00
|
|
|
);
|
|
|
|
|
1998-01-07 03:16:15 +00:00
|
|
|
xg = r * cos(lonecl) * cos(latecl);
|
|
|
|
yg = r * sin(lonecl) * cos(latecl);
|
|
|
|
zg = r * sin(latecl);
|
|
|
|
|
|
|
|
xe = xg;
|
|
|
|
ye = yg * cos(ecl) - zg * sin(ecl);
|
|
|
|
ze = yg * sin(ecl) + zg * cos(ecl);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
geocCoord.RightAscension = atan2(ye, xe);
|
|
|
|
geocCoord.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
|
|
|
|
|
|
|
|
/* New since 25 december 1997 */
|
|
|
|
/* Calculate the moon's topocentric position instead of it's geocentric! */
|
|
|
|
|
1998-02-02 20:52:20 +00:00
|
|
|
/* calculate the moon's parrallax, i.e. the apparent size of the
|
|
|
|
* (equatorial) radius of the Earth, as seen from the moon */
|
|
|
|
mpar = asin( 1 / r);
|
|
|
|
gclat = FG_Latitude - 0.083358 * sin (2 * DEG_TO_RAD * FG_Latitude);
|
|
|
|
rho = 0.99883 + 0.00167 * cos(2 * DEG_TO_RAD * FG_Latitude);
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
if (geocCoord.RightAscension < 0)
|
|
|
|
geocCoord.RightAscension += (2*FG_PI);
|
|
|
|
|
|
|
|
HA = t.lst - (3.8197186 * geocCoord.RightAscension);
|
|
|
|
|
|
|
|
g = atan (tan(gclat) / cos( (HA / 3.8197186)));
|
|
|
|
|
|
|
|
|
|
|
|
|
1998-02-23 19:07:49 +00:00
|
|
|
topocCoord.RightAscension = geocCoord.RightAscension -
|
|
|
|
mpar * rho * cos (gclat) * sin (HA) / cos (geocCoord.Declination);
|
|
|
|
topocCoord.Declination = geocCoord.Declination -
|
|
|
|
mpar * rho * sin (gclat) * sin (g - geocCoord.Declination) / sin (g);
|
1998-01-07 03:16:15 +00:00
|
|
|
return topocCoord;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
1998-01-19 18:40:15 +00:00
|
|
|
void fgMoonInit( void ) {
|
1998-02-23 19:07:49 +00:00
|
|
|
GLfloat moonColor[4] = {0.85, 0.75, 0.35, 1.0};
|
1998-02-02 20:52:20 +00:00
|
|
|
GLfloat black[4] = { 0.0, 0.0, 0.0, 1.0 };
|
1998-01-07 03:16:15 +00:00
|
|
|
|
1998-01-27 00:47:41 +00:00
|
|
|
fgPrintf( FG_ASTRO, FG_INFO, "Initializing the Moon\n");
|
1998-01-07 03:16:15 +00:00
|
|
|
fgSolarSystemUpdate(&(pltOrbElements[1]), cur_time_params);
|
|
|
|
moonPos = fgCalculateMoon(pltOrbElements[1], pltOrbElements[0],
|
|
|
|
cur_time_params);
|
1998-01-27 00:47:41 +00:00
|
|
|
fgPrintf( FG_ASTRO, FG_DEBUG,
|
|
|
|
"Moon found at %f (ra), %f (dec)\n", moonPos.RightAscension,
|
|
|
|
moonPos.Declination);
|
1998-01-07 03:16:15 +00:00
|
|
|
|
|
|
|
xMoon = 60000.0 * cos(moonPos.RightAscension) * cos(moonPos.Declination);
|
|
|
|
yMoon = 60000.0 * sin(moonPos.RightAscension) * cos(moonPos.Declination);
|
|
|
|
zMoon = 60000.0 * sin(moonPos.Declination);
|
|
|
|
|
1998-02-23 19:07:49 +00:00
|
|
|
if (moon) {
|
|
|
|
xglDeleteLists (moon, 1);
|
1998-01-07 03:16:15 +00:00
|
|
|
}
|
1998-02-23 19:07:49 +00:00
|
|
|
|
|
|
|
moon = xglGenLists (1);
|
|
|
|
xglNewList (moon, GL_COMPILE);
|
|
|
|
|
|
|
|
xglMaterialfv (GL_FRONT, GL_AMBIENT, black);
|
|
|
|
xglMaterialfv (GL_FRONT, GL_DIFFUSE, moonColor);
|
|
|
|
xglPushMatrix ();
|
|
|
|
xglTranslatef (xMoon, yMoon, zMoon);
|
|
|
|
xglScalef (1400, 1400, 1400);
|
|
|
|
|
|
|
|
glutSolidSphere (1.0, 10, 10);
|
|
|
|
xglPopMatrix ();
|
|
|
|
xglEndList ();
|
1998-01-07 03:16:15 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Draw the moon */
|
1998-01-19 18:40:15 +00:00
|
|
|
void fgMoonRender( void ) {
|
1998-01-07 03:16:15 +00:00
|
|
|
xglCallList(moon);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* $Log$
|
1998-04-03 21:50:53 +00:00
|
|
|
/* Revision 1.8 1998/04/03 21:52:49 curt
|
|
|
|
/* Converting to Gnu autoconf system.
|
1998-01-07 03:16:15 +00:00
|
|
|
/*
|
1998-04-03 21:50:53 +00:00
|
|
|
* Revision 1.7 1998/02/23 19:07:54 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.
|
|
|
|
*
|
1998-02-23 19:07:49 +00:00
|
|
|
* Revision 1.6 1998/02/07 15:29:32 curt
|
|
|
|
* Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
|
|
|
|
* <chotchkiss@namg.us.anritsu.com>
|
|
|
|
*
|
1998-02-07 15:29:31 +00:00
|
|
|
* Revision 1.5 1998/02/02 20:53:21 curt
|
|
|
|
* To version 0.29
|
|
|
|
*
|
1998-02-02 20:52:20 +00:00
|
|
|
* Revision 1.4 1998/01/27 00:47:46 curt
|
|
|
|
* Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
|
|
|
|
* system and commandline/config file processing code.
|
|
|
|
*
|
1998-01-27 00:47:41 +00:00
|
|
|
* Revision 1.3 1998/01/19 19:26:57 curt
|
|
|
|
* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
|
|
|
|
* This should simplify things tremendously.
|
|
|
|
*
|
1998-01-19 19:26:51 +00:00
|
|
|
* Revision 1.2 1998/01/19 18:40:16 curt
|
|
|
|
* Tons of little changes to clean up the code and to remove fatal errors
|
|
|
|
* when building with the c++ compiler.
|
|
|
|
*
|
1998-01-19 18:40:15 +00:00
|
|
|
* Revision 1.1 1998/01/07 03:16:16 curt
|
|
|
|
* Moved from .../Src/Scenery/ to .../Src/Astro/
|
|
|
|
*
|
1998-01-07 03:16:15 +00:00
|
|
|
* Revision 1.16 1998/01/06 01:20:24 curt
|
|
|
|
* Tweaks to help building with MSVC++
|
|
|
|
*
|
|
|
|
* Revision 1.15 1998/01/05 18:44:35 curt
|
|
|
|
* Add an option to advance/decrease time from keyboard.
|
|
|
|
*
|
|
|
|
* Revision 1.14 1997/12/30 20:47:50 curt
|
|
|
|
* Integrated new event manager with subsystem initializations.
|
|
|
|
*
|
|
|
|
* Revision 1.13 1997/12/30 16:41:00 curt
|
|
|
|
* Added log at end of file.
|
|
|
|
*
|
|
|
|
*/
|