Fix Gnomonic projection criterion for points on the lower hemisphere.
Fix Gnomonic projection criterion for points on the lower hemisphere.

probonopd/marble,tzapzoor/marble,quannt24/marble,tzapzoor/marble,tzapzoor/marble,tucnak/marble,quannt24/marble,tzapzoor/marble,quannt24/marble,tucnak/marble,quannt24/marble,probonopd/marble,tucnak/marble,tucnak/marble,quannt24/marble,tzapzoor/marble,probonopd/marble,probonopd/marble,probonopd/marble,probonopd/marble,tucnak/marble,tucnak/marble,quannt24/marble,probonopd/marble,tzapzoor/marble,tzapzoor/marble,tzapzoor/marble,quannt24/marble,tucnak/marble