protected static boolean isNameVisible(
DrawContext dc, PlaceNameService service, Position namePosition) {
double elevation = dc.getVerticalExaggeration() * namePosition.getElevation();
Vec4 namePoint =
dc.getGlobe()
.computePointFromPosition(
namePosition.getLatitude(), namePosition.getLongitude(), elevation);
Vec4 eyeVec = dc.getView().getEyePoint();
double dist = eyeVec.distanceTo3(namePoint);
return dist >= service.getMinDisplayDistance() && dist <= service.getMaxDisplayDistance();
}
/**
* Compute the lat/lon position of the view center
*
* @param dc the current DrawContext
* @param view the current View
* @return the ground position of the view center or null
*/
protected Position computeGroundPosition(DrawContext dc, View view) {
if (view == null) return null;
Position groundPos =
view.computePositionFromScreenPoint(
view.getViewport().getWidth() / 2, view.getViewport().getHeight() / 2);
if (groundPos == null) return null;
double elevation =
dc.getGlobe().getElevation(groundPos.getLatitude(), groundPos.getLongitude());
return new Position(
groundPos.getLatitude(),
groundPos.getLongitude(),
elevation * dc.getVerticalExaggeration());
}