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

[simgear.git] / Astro / orbits.c

diff --git a/Astro/orbits.c b/Astro/orbits.c
index 50da74503f6b0075e7125a93fc6342b881c76625..fe5208c4a9c6e8dd2117cb10fc9414fe3feb009b 100644 (file)
--- a/Astro/orbits.c
+++ b/Astro/orbits.c
@@ -36,48 +36,12 @@
 struct OrbElements pltOrbElements[9];
 
 
-//double fgCalcActTime(struct fgTIME t)
-//{
-//   double
-//         actTime, UT;
-//   int year;
-//
-//   /* a hack. This one introduces the 2000 problem into the program */
-//   year = t.gmt->tm_year + 1900;
-//
-//   /* calculate the actual time, remember to add 1 to tm_mon! */
-//   actTime = 367 * year - 7 *
-//               (year + ((t.gmt->tm_mon+1) + 9) / 12) / 4 + 275 *
-//                (t.gmt->tm_mon+1) / 9 + t.gmt->tm_mday - 730530;
-//
-//    UT = t.gmt->tm_hour + ((double) t.gmt->tm_min / 60);
-//    /*printf("UT = %f\n", UT); */
-//    actTime += (UT / 24.0);
-//    #define DEBUG 1
-//    #ifdef DEBUG
-//    /* printf("  Actual Time:\n"); */
-//    /* printf("  current day = %f\t", actTime); */
-//    /* printf("  GMT = %d, %d, %d, %d, %d, %d\n",
-//        year, t.gmt->tm_mon, t.gmt->tm_mday,
-//        t.gmt->tm_hour, t.gmt->tm_min, t.gmt->tm_sec); */
-//    #endif
-//    return actTime;
-//}
-
-
 double fgCalcActTime(struct fgTIME t)
 {
   return (t.mjd - 36523.5);
 }
 
 
-/* convert degrees to radians */
-/*
-double fgDegToRad(double angle)
-{
-       return (angle * PIOVER180);
-}
-*/
 double fgCalcEccAnom(double M, double e)
 {
     double
@@ -101,16 +65,26 @@ double fgCalcEccAnom(double M, double e)
 }
 
 
-// This function assumes that if the FILE ptr is valid that the contents
-// will be valid. Should we check the file for validity?
+/* This function assumes that if the FILE ptr is valid that the
+   contents will be valid. Should we check the file for validity? */
+  
+/* Sounds like a good idea to me. What type of checks are you thinking
+   of, other than feof(FILE*)? That's currently the only check I can
+   think of (Durk) */
 
-void fgReadOrbElements(struct OrbElements *dest, FILE *src)
+int fgReadOrbElements(struct OrbElements *dest, FILE *src)
 {
        char line[256];
     int i,j;
     j = 0;
     do
     {
+       if (feof (src)) {
+           fgPrintf (FG_ASTRO, FG_ALERT,
+                     "End of file found while reading planetary positions:\n");
+           return 0;
+       }
+ 
        fgets(line, 256,src);
         for (i = 0; i < 256; i++)
         {
@@ -127,6 +101,8 @@ void fgReadOrbElements(struct OrbElements *dest, FILE *src)
            &dest->aFirst, &dest->aSec,
            &dest->eFirst, &dest->eSec,
            &dest->MFirst, &dest->MSec);
+
+    return(1);
 }
 
 
@@ -159,7 +135,9 @@ int fgSolarSystemInit(struct fgTIME t)
        for (i = 0; i < 9; i ++)
            {
                /* ...read from the data file ... */
-               fgReadOrbElements(&pltOrbElements[i], data);
+               if (!(fgReadOrbElements (&pltOrbElements[i], data))) {
+                   ret_val = 0;
+               }
                /* ...and calculate the actual values */
                fgSolarSystemUpdate(&pltOrbElements[i], t);
            }
@@ -177,20 +155,25 @@ void fgSolarSystemUpdate(struct OrbElements *planet, struct fgTIME t)
    actTime = fgCalcActTime(t);
 
    /* calculate the actual orbital elements */
-    planet->M = DEG_TO_RAD * (planet->MFirst + (planet->MSec * actTime));      // angle in radians
-    planet->w = DEG_TO_RAD * (planet->wFirst + (planet->wSec * actTime));      // angle in radians
-    planet->N = DEG_TO_RAD * (planet->NFirst + (planet->NSec * actTime));      // angle in radians
-    planet->i = DEG_TO_RAD * (planet->iFirst + (planet->iSec * actTime));  // angle in radians
-    planet->e = planet->eFirst + (planet->eSec * actTime);
-    planet->a = planet->aFirst + (planet->aSec * actTime);
+   planet->M = DEG_TO_RAD * (planet->MFirst + (planet->MSec * actTime));
+   planet->w = DEG_TO_RAD * (planet->wFirst + (planet->wSec * actTime));
+   planet->N = DEG_TO_RAD * (planet->NFirst + (planet->NSec * actTime));
+   planet->i = DEG_TO_RAD * (planet->iFirst + (planet->iSec * actTime));
+   planet->e = planet->eFirst + (planet->eSec * actTime);
+   planet->a = planet->aFirst + (planet->aSec * actTime);
 }
 
 
 /* $Log$
-/* Revision 1.7  1998/02/12 21:59:33  curt
-/* Incorporated code changes contributed by Charlie Hotchkiss
-/* <chotchkiss@namg.us.anritsu.com>
+/* Revision 1.8  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 1.7  1998/02/12 21:59:33  curt
+ * Incorporated code changes contributed by Charlie Hotchkiss
+ * <chotchkiss@namg.us.anritsu.com>
+ *
  * Revision 1.6  1998/02/03 23:20:11  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