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Incorporated Durk's Astro/ tweaks. Includes unifying the sun position

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calculation code between sun display, and other FG sections that use this
for things like lighting.
This commit is contained in:
curt
2009-09-15 18:31:29 +02:00
committed by Tim Moore
parent 3e386f51a1
commit 20cf326fec
7 changed files with 186 additions and 210 deletions
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Astro/planets.c
+48 -43
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@@ -43,46 +43,37 @@ struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
struct OrbElements theSun,
struct fgTIME t, int idx)
{
struct CelestialCoord
result;
struct CelestialCoord result;
struct SunPos
SolarPosition;
fgSUNPOS SolarPosition;
double
eccAnom, r, v, ecl, actTime, R, s, ir, Nr, B, FV, ring_magn,
double eccAnom, r, v, ecl, actTime, R, s, ir, Nr, B, FV, ring_magn,
xv, yv, xh, yh, zh, xg, yg, zg, xe, ye, ze;
actTime = fgCalcActTime(t);
/* calculate the angle between ecliptic and equatorial coordinate system */
/* ecl = DEG_TO_RAD * (23.4393 - 3.563E-7 * actTime); */
ecl = 0.409093 - 6.2186E-9 * actTime;
actTime = fgCalcActTime(t);
/*calculate the angle between ecliptic and equatorial coordinate system */
ecl = DEG_TO_RAD * (23.4393 - 3.563E-7 * actTime);
/* calculate the eccentric anomaly */
eccAnom = fgCalcEccAnom(planet.M, planet.e);
eccAnom = fgCalcEccAnom(planet.M, planet.e);
/* calculate the planets distance (r) and true anomaly (v) */
xv = planet.a * (cos(eccAnom) - planet.e);
yv = planet.a * (sqrt(1.0 - planet.e*planet.e) * sin(eccAnom));
v = atan2(yv, xv);
r = sqrt ( xv*xv + yv*yv);
/* calculate the planets position in 3-dimensional space */
xh = r * ( cos(planet.N) * cos(v+planet.w) - sin(planet.N) * sin(v+planet.w) * cos(planet.i));
yh = r * ( sin(planet.N) * cos(v+planet.w) + cos(planet.N) * sin(v+planet.w) * cos(planet.i));
xh = r * (cos (planet.N) * cos (v + planet.w) -
sin (planet.N) * sin (v + planet.w) * cos (planet.i));
yh = r * (sin (planet.N) * cos (v + planet.w) +
cos (planet.N) * sin (v + planet.w) * cos (planet.i));
zh = r * ( sin(v+planet.w) * sin(planet.i));
/* calculate the ecliptic longitude and latitude */
/*
lonecl = atan2(yh, xh);
latecl = atan2(zh, sqrt ( xh*xh + yh*yh));
*/
/* calculate the solar position */
SolarPosition = fgCalcSunPos(theSun);
xg = xh + SolarPosition.xs;
yg = yh + SolarPosition.ys;
xg = xh + solarPosition.xs;
yg = yh + solarPosition.ys;
zg = zh;
xe = xg;
@@ -91,7 +82,6 @@ struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
result.RightAscension = atan2(ye,xe);
result.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
/* Let's calculate the brightness of the planet */
R = sqrt ( xg*xg + yg*yg + zg*zg);
@@ -117,7 +107,9 @@ struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
ir = 0.4897394;
Nr = 2.9585076 + 6.6672E-7*actTime;
B = asin ( sin (result.Declination) * cos(ir) - cos(result.Declination) * sin (ir) * sin (result.RightAscension - Nr));
B = asin (sin (result.Declination) * cos (ir) -
cos (result.Declination) * sin (ir) *
sin (result.RightAscension - Nr));
ring_magn = -2.6 * sin (fabs(B)) + 1.2 * pow(sin(B),2);
result.magnitude = -9.0 + 5*log10( r*R ) + 0.044 * FV + ring_magn;
break;
@@ -145,15 +137,18 @@ struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
void fgPlanetsInit( void )
{
struct fgLIGHT *l;
int i;
struct CelestialCoord pltPos;
double magnitude;
l = &cur_light_params;
/* if the display list was already built during a previous init,
recycle it */
then recycle it */
if (planets)
if (planets) {
xglDeleteLists(planets, 1);
}
planets = xglGenLists(1);
xglNewList( planets, GL_COMPILE );
@@ -166,10 +161,6 @@ void fgPlanetsInit( void )
pltPos = fgCalculatePlanet(pltOrbElements[i],
pltOrbElements[0], cur_time_params, i);
/* give the planets a temporary color, for testing purposes */
/* xglColor3f( 1.0, 0.0, 0.0); */
/* scale magnitudes to (0.0 - 1.0) */
magnitude = (0.0 - pltPos.magnitude) / 5.0 + 1.0;
/* scale magnitudes again so they look ok */
@@ -182,15 +173,24 @@ void fgPlanetsInit( void )
if ( magnitude > 1.0 ) { magnitude = 1.0; }
if ( magnitude < 0.0 ) { magnitude = 0.0; }
xglColor3f(magnitude, magnitude, magnitude);
/* xglColor3f(1.0, 1.0,1.0); */
xglVertex3f( 50000.0 * cos(pltPos.RightAscension) *
cos(pltPos.Declination),
50000.0 * sin(pltPos.RightAscension) *
cos(pltPos.Declination),
50000.0 * sin(pltPos.Declination) );
/* Add planets to the display list, based on sun_angle and current
magnitude It's pretty experimental... */
if ((double) (l->sun_angle - FG_PI_2) >
((magnitude - 1.0) * -20 * DEG_TO_RAD))
{
xglColor3f (magnitude, magnitude, magnitude);
printf ("Sun Angle to Horizon (in Rads) = %f\n",
(double) (l->sun_angle - FG_PI_2));
printf ("Transformed Magnitude is :%f %f\n",
magnitude, (magnitude - 1.0) * -20 * DEG_TO_RAD);
xglVertex3f (50000.0 * cos (pltPos.RightAscension) *
cos (pltPos.Declination),
50000.0 * sin (pltPos.RightAscension) *
cos (pltPos.Declination),
50000.0 * sin (pltPos.Declination));
}
}
xglEnd();
xglEndList();
@@ -204,10 +204,15 @@ void fgPlanetsRender( void ) {
/* $Log$
/* Revision 1.6 1998/02/12 21:59:36 curt
/* Incorporated code changes contributed by Charlie Hotchkiss
/* <chotchkiss@namg.us.anritsu.com>
/* Revision 1.7 1998/02/23 19:07:55 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 1.6 1998/02/12 21:59:36 curt
* Incorporated code changes contributed by Charlie Hotchkiss
* <chotchkiss@namg.us.anritsu.com>
*
* Revision 1.5 1998/02/03 23:20:12 curt
* Lots of little tweaks to fix various consistency problems discovered by
* Solaris' CC. Fixed a bug in fg_debug.c with how the fgPrintf() wrapper