mi.base.changeFrac();
cell(0).metrics(mi, dim0);
cell(1).metrics(mi, dim1);
dim.asc = dim0.height() + 1 + dy/2 + dy;
dim.des = max(0, dim1.height() + 1 + dy/2 - dy);
dim.wid = max(dim0.wid, dim1.wid) + 2 * dw(dim.height()) + 4;
mi.base.changeFrac();
cell(0).metrics(mi, dim0);
cell(1).metrics(mi, dim1);
dim.asc = dim0.height() + 1 + dy/2 + dy;
dim.des = max(0, dim1.height() + 1 + dy/2 - dy);
dim.wid = max(dim0.wid, dim1.wid) + 2 * dw(dim.height()) + 4;