// 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, sun_lat;
+ fgSunPositionGST(time_now->getGst(), &sun_lon, &sun_lat);
+ light->set_sun_lon(sun_lon);
+ light->set_sun_lat(sun_lat);
+
+ // update the sun light vector
+ // calculations are in the horizontal normal plane: x-north, y-east, z-down
+ static SGQuatd q = SGQuatd::fromLonLat(SGGeod::fromRad(0,0));
+
+ // sun orientation
+ SGGeod geodSunPos = SGGeod::fromRad(sun_lon, sun_lat);
+ SGQuatd sunOr = SGQuatd::fromLonLat(geodSunPos);
+
+ // scenery orientation
+ SGGeod geodViewPos = SGGeod::fromCart(viewer->getViewPosition());
+ SGQuatd hlOr = SGQuatd::fromLonLat(geodViewPos);
+ SGVec3d localAt = hlOr.backTransform(SGVec3d::e3());
+
+ // transpose the sun direction from (lat,lon) to (0,0)
+ SGVec3d transSunDir = (q*sunOr).transform(-localAt);
+ SGQuatd sunDirOr = SGQuatd::fromRealImag(0, transSunDir);
+
+ // transpose the calculated sun vector back to (lat,lon)
+ SGVec3d sunDirection = sunDirOr.transform(localAt);
+ 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();
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
- << " Geodetic lat = " << sun_gd_lat );
+ " Sun 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
- SGVec3f nup(normalize(v->get_world_up()));
- SGVec3f nsun(toVec3f(normalize(l->get_sunpos())));
- // cout << "nup = " << nup[0] << "," << nup[1] << ","
+ SGVec3d viewPos = v->get_view_pos();
+ SGQuatd hlOr = SGQuatd::fromLonLat(SGGeod::fromCart(viewPos));
+ SGVec3f world_up = toVec3f(hlOr.backTransform(-SGVec3d::e3()));
+ SGVec3f nsun = toVec3f(normalize(sunpos));
+ // 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 ) ) );
+ l->set_sun_angle( acos( dot ( world_up, 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 = globals->get_scenery()->get_center();
- rel_sunpos += l->get_sunpos() - toVec3d(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);
// earth's surface the sun is directly over, map into onto the
// local plane representing "horizontal".
- SGVec3f world_up = v->get_world_up();
- SGVec3f view_pos = v->get_view_pos();
// surface direction to go to head towards sun
SGVec3f surface_to_sun;
+ SGVec3f view_pos = toVec3f(v->get_view_pos());
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
// 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. :-(
- float east_dot = dot( surface_to_sun, v->get_surface_east() );
+ SGVec3f surface_east(toVec3f(hlOr.backTransform(SGVec3d::e2())));
+ float east_dot = dot( surface_to_sun, 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
- float dot_ = dot( surface_to_sun, v->get_surface_south() );
+ SGVec3f surface_south(toVec3f(hlOr.backTransform(-SGVec3d::e1())));
+ float dot_ = dot( surface_to_sun, surface_south );
// cout << " Dot product = " << dot << endl;
if (dot_ > 1.0) {
}
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
}