// ---------------------------------------------------------------------------------------
// Select previous segment.
// If there is a connection on the side opposite to the current side, then choose that segment.
// If there is no connecting segment on the opposite face, try any segment.
__attribute_warn_unused_result
static std::pair<vsegptridx_t, uint_fast32_t> get_previous_segment_side(const vsegptridx_t curseg_num, const uint_fast32_t curside)
{
const auto &newseg_num = get_previous_segment(curseg_num, curside);
// Now make Curside point at the segment we just left (unless we couldn't leave it).
return {newseg_num, newseg_num == curseg_num ? curside : find_connect_side(curseg_num, newseg_num)};
}
// -------------------------------------------------------------------------------------
int SelectCurrentSegBackward()
{
int newseg_num,newside;
get_previous_segment(Cursegp-Segments,Curside,&newseg_num,&newside);
Cursegp = &Segments[newseg_num];
Curside = newside;
if (Lock_view_to_cursegp)
set_view_target_from_segment(Cursegp);
Update_flags |= UF_ED_STATE_CHANGED;
mine_changed = 1;
med_create_new_segment_from_cursegp();
return 1;
}