EB mesh

[lalmanohar]

Was mesh pruning implemented in the AMRex code? I have gone through AMReX documentation but could not find anything. There is some discussion in the MFIX-EXA paper but I am unsure on how to change the BoxArray structure.

[WeiqunZhang]

Maybe something like this? (May not compile due to typos.)

// Existing Geometry geom                                                                                                                                                    
// Existing BoxArray ba_old                                                                                                                                                  
// Existing DistributionMapping dm_old                                                                                                                                       
amrex::BoxArray ba_new;
amrex::DistributionMapping dm_new;
{
    auto fact = amrex::makeEBFabFactory(geom, ba_old, dm_old, {1,1,1},
                                        amrex::EBSupport::basic);
    auto const& flags = fact->getMultiEBCellFlagFab();
    amrex::Vector<Box> boxes;
    for (amrex::MFIter mfi(flags); mfi.isValid(); ++mfi) {
        if (flags[mfi].getType() != amrex::FabType::covered) {
            boxes.push_back(mfi.validbox());
        }
    }
    amrex::AllGatherBoxes(boxes);
    ba_new = amrex::BoxArray(amrex::BoxList(std::move(boxes)));
    dm_new = DistributionMapping(ba_new);
}