-
- // copy values from the AIManager
- double user_latitude = manager->get_user_latitude();
- double user_longitude = manager->get_user_longitude();
- double user_altitude = manager->get_user_altitude();
- double user_heading = manager->get_user_heading();
- double user_pitch = manager->get_user_pitch();
- double user_yaw = manager->get_user_yaw();
- double user_speed = manager->get_user_speed();
-
- // calculate range to target in feet and nautical miles
- double lat_range = fabs(pos.lat() - user_latitude) * ft_per_deg_lat;
- double lon_range = fabs(pos.lon() - user_longitude) * ft_per_deg_lon;
- double range_ft = sqrt( lat_range*lat_range + lon_range*lon_range );
- range = range_ft / 6076.11549;
-
- // calculate bearing to target
- if (pos.lat() >= user_latitude) {
- bearing = atan2(lat_range, lon_range) * SG_RADIANS_TO_DEGREES;
- if (pos.lon() >= user_longitude) {
- bearing = 90.0 - bearing;
- } else {
- bearing = 270.0 + bearing;
- }
- } else {
- bearing = atan2(lon_range, lat_range) * SG_RADIANS_TO_DEGREES;
- if (pos.lon() >= user_longitude) {
- bearing = 180.0 - bearing;
- } else {
- bearing = 180.0 + bearing;
- }
- }
-
- // calculate look left/right to target, without yaw correction
- horiz_offset = bearing - user_heading;
- if (horiz_offset > 180.0) horiz_offset -= 360.0;
- if (horiz_offset < -180.0) horiz_offset += 360.0;
-
- // calculate elevation to target
- elevation = atan2( altitude_ft - user_altitude, range_ft )
- * SG_RADIANS_TO_DEGREES;
-
- // calculate look up/down to target
- vert_offset = elevation + user_pitch;
-
-/* this calculation needs to be fixed, but it isn't important anyway
- // calculate range rate
- double recip_bearing = bearing + 180.0;
- if (recip_bearing > 360.0) recip_bearing -= 360.0;
- double my_horiz_offset = recip_bearing - hdg;
- if (my_horiz_offset > 180.0) my_horiz_offset -= 360.0;
- if (my_horiz_offset < -180.0) my_horiz_offset += 360.0;
- rdot = (-user_speed * cos( horiz_offset * SG_DEGREES_TO_RADIANS ))
- + (-speed * 1.686 * cos( my_horiz_offset * SG_DEGREES_TO_RADIANS ));
-*/
-
- // now correct look left/right for yaw
- horiz_offset += user_yaw;
-
- // calculate values for radar display
- y_shift = range * cos( horiz_offset * SG_DEGREES_TO_RADIANS);
- x_shift = range * sin( horiz_offset * SG_DEGREES_TO_RADIANS);
- rotation = hdg - user_heading;
- if (rotation < 0.0) rotation += 360.0;