first stab at reorganizing fgUpdateSunPos() to make it use quats

src/Time/light.cxx

@@ -57,8 +57,6 @@ FGLight::FGLight ()
       _sun_lat(0),
       _moon_lon(0),
       _moon_gc_lat(0),
-      _sunpos(0, 0, 0),
-      _moonpos(0, 0, 0),
       _sun_vec(0, 0, 0, 0),
       _moon_vec(0, 0, 0, 0),
       _sun_vec_inv(0, 0, 0, 0),

src/Time/light.hxx

@@ -60,9 +60,6 @@ private:
     double _sun_lon, _sun_lat;
     double _moon_lon, _moon_gc_lat;
 
-    // in cartesian coordiantes
-    SGVec3d _sunpos, _moonpos;
-
     // (in view coordinates)
     SGVec4f _sun_vec, _moon_vec;
 
@@ -141,9 +138,6 @@ public:
     inline double get_sun_lat () const { return _sun_lat; }
     inline void set_sun_lat (double l) { _sun_lat = l; }
 
-    inline const SGVec3d& get_sunpos () const { return _sunpos; }
-    inline void set_sunpos (const SGVec3d& p) { _sunpos = p; }
-
     inline SGVec4f& sun_vec () { return _sun_vec; }
     inline SGVec4f& sun_vec_inv () { return _sun_vec_inv; }
 
@@ -162,9 +156,6 @@ public:
     inline double get_moon_gc_lat () const { return _moon_gc_lat; }
     inline void set_moon_gc_lat (double l) { _moon_gc_lat = l; }
 
-    inline const SGVec3d& get_moonpos () const { return _moonpos; }
-    inline void set_moonpos (const SGVec3d& p) { _moonpos = p; }
-
     inline const SGVec4f& moon_vec () const { return _moon_vec; }
     inline const SGVec4f& moon_vec_inv () const { return _moon_vec_inv; }
 };

src/Time/tmp.cxx

@@ -65,6 +65,43 @@ void fgUpdateLocalTime() {
 
 // update the cur_time_params structure with the current sun position
 void fgUpdateSunPos( void ) {
+#if 0
+    // This only works at lat,lon = 0,0
+    // need to find a way to get it working at other locations
+
+    FGLight *light = (FGLight *)(globals->get_subsystem("lighting"));
+    FGViewer *viewer = globals->get_current_view();
+    SGTime *time_now = globals->get_time_params();
+
+    SG_LOG( SG_EVENT, SG_DEBUG, "  Updating Sun position" );
+    SG_LOG( SG_EVENT, SG_DEBUG, "  Gst = " << time_now->getGst() );
+
+    double sun_lon;
+    double sun_gd_lat;
+    fgSunPositionGST(time_now->getGst(), &sun_lon, &sun_gd_lat);
+    light->set_sun_lon(sun_lon);
+    light->set_sun_lat(sun_gd_lat);
+
+    // update the sun light vector
+    // calculations are in the horizontal normal plane:
+    // x-north, y-east, z-down
+
+    SGGeod geodViewPos = SGGeod::fromCart(viewer->getViewPosition());
+    SGGeod geodSunPos = SGGeod::fromRad(sun_lon, sun_gd_lat);
+
+    //static SGQuatd q = SGQuatd::fromLonLat(SGGeod::fromRad(0,0));
+    SGQuatd hlOr = SGQuatd::fromLonLat(geodViewPos);
+    SGQuatd sunOr = SGQuatd::fromLonLat(geodSunPos);
+
+    SGVec3d sunDirection = (hlOr*sunOr).transform(SGVec3d::e3());
+    light->set_sun_rotation( acos(sunDirection[1]) - SGD_PI_2 );
+    light->set_sun_angle( acos(-sunDirection[2]) );
+
+    SGVec3d sunPos = SGVec3d::fromGeod(geodSunPos);
+    light->sun_vec() = SGVec4f(toVec3f(normalize(sunPos)), 0);
+    light->sun_vec_inv() = -light->sun_vec();
+
+#else
     FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
     SGTime *t = globals->get_time_params();
     FGViewer *v = globals->get_current_view();
@@ -77,15 +114,15 @@ void fgUpdateSunPos( void ) {
     fgSunPositionGST(t->getGst(), &sun_l, &sun_gd_lat);
     l->set_sun_lon(sun_l);
     l->set_sun_lat(sun_gd_lat);
-    l->set_sunpos(SGVec3d::fromGeod(SGGeod::fromRad(sun_l, sun_gd_lat)));
+    SGVec3d sunpos(SGVec3d::fromGeod(SGGeod::fromRad(sun_l, sun_gd_lat)));
 
     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
+            "    Sun Geodetic lat = " << sun_gd_lat
-	    << " Geodetic lat = " << sun_gd_lat );
+            << " Geodetic lat = " << sun_gd_lat );
 
     // update the sun light vector
-    l->sun_vec() = SGVec4f(toVec3f(normalize(l->get_sunpos())), 0);
+    l->sun_vec() = SGVec4f(toVec3f(normalize(sunpos)), 0);
     l->sun_vec_inv() = - l->sun_vec();
 
     // calculate the sun's relative angle to local up
@@ -93,18 +130,18 @@ void fgUpdateSunPos( void ) {
     SGQuatd hlOr = SGQuatd::fromLonLat(SGGeod::fromCart(viewPos));
     SGVec3f nup(toVec3f(hlOr.backTransform(-SGVec3d::e3())));
 
-    SGVec3f nsun(toVec3f(normalize(l->get_sunpos())));
+    SGVec3f nsun(toVec3f(normalize(sunpos)));
-    // cout << "nup = " << nup[0] << "," << nup[1] << "," 
+    // cout << "nup = " << nup[0] << "," << nup[1] << ","
     //      << nup[2] << endl;
-    // cout << "nsun = " << nsun[0] << "," << nsun[1] << "," 
+    // cout << "nsun = " << nsun[0] << "," << nsun[1] << ","
     //      << nsun[2] << endl;
 
     l->set_sun_angle( acos( dot ( nup, nsun ) ) );
     SG_LOG( SG_EVENT, SG_DEBUG, "sun angle relative to current location = "
-	    << l->get_sun_angle() );
+            << l->get_sun_angle() );
-    
+
     // calculate vector to sun's position on the earth's surface
-    SGVec3d rel_sunpos = l->get_sunpos() - v->get_view_pos();
+    SGVec3d rel_sunpos = sunpos - v->get_view_pos();
     // vector in cartesian coordinates from current position to the
     // postion on the earth's surface the sun is directly over
     SGVec3f to_sun = toVec3f(rel_sunpos);
@@ -120,13 +157,13 @@ void fgUpdateSunPos( void ) {
     // surface direction to go to head towards sun
     SGVec3f surface_to_sun;
     sgmap_vec_onto_cur_surface_plane( world_up.data(), view_pos.data(),
-				      to_sun.data(), surface_to_sun.data() );
+                                      to_sun.data(), surface_to_sun.data() );
     surface_to_sun = normalize(surface_to_sun);
     // cout << "(sg) Surface direction to sun is "
-    //   << surface_to_sun[0] << "," 
+    //   << surface_to_sun[0] << ","
     //   << surface_to_sun[1] << ","
     //   << surface_to_sun[2] << endl;
-    // cout << "Should be close to zero = " 
+    // cout << "Should be close to zero = "
     //   << sgScalarProductVec3(nup, surface_to_sun) << endl;
 
     // calculate the angle between surface_to_sun and
@@ -156,11 +193,13 @@ void fgUpdateSunPos( void ) {
      }
 
     if ( east_dot >= 0 ) {
-	l->set_sun_rotation( acos(dot_) );
+        l->set_sun_rotation( acos(dot_) );
     } else {
-	l->set_sun_rotation( -acos(dot_) );
+        l->set_sun_rotation( -acos(dot_) );
     }
     // cout << "  Sky needs to rotate = " << angle << " rads = "
     //      << angle * SGD_RADIANS_TO_DEGREES << " degrees." << endl;
+
+#endif
 }