%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-05-28 17:13:42
 % @LastEditTime: 2021-05-29 15:12:12
%--------------------------
% extract macro-dofs from full-dofs
function lambda_ma = extract_macro_dofs(full_lambda, nelx, nely, microx)

    globalx = nelx * microx;
    globaly = nely * microx;
    [iK_full, jK_full, edofMat_full] = forAssemble(globalx, globaly);
    [iK_ma, jK_ma, edofMat_ma] = forAssemble(nelx, nely);
    [~, ~, edofMat_mi] = forAssemble(microx, microx);

    lambda_ma = zeros(2*(nelx+1)*(nely+1), 1);

    % TODO: PLOT macro-lambda curves
    for i = 1:nelx
        for j = 1:nely            
            jj = microx; ii = 1;
            global_edof = full_scale_edof(ii, jj, microx, globaly, edofMat_full);
            fe1 = full_lambda(global_edof([1,2]));

            jj = microx; ii = microx;
            global_edof = full_scale_edof(ii, jj, microx, globaly, edofMat_full);
            fe2 = full_lambda(global_edof([3,4]));

            jj = 1; ii = microx;
            global_edof = full_scale_edof(ii, jj, microx, globaly, edofMat_full);
            fe3 = full_lambda(global_edof([5,6]));

            jj = 1; ii = 1;
            global_edof = full_scale_edof(ii, jj, microx, globaly, edofMat_full);
            fe4 = full_lambda(global_edof([7,8]));

            fe = [fe1(:); fe2(:); fe3(:); fe4(:)];
            
            edof_ma = edofMat_ma(j + (i-1)*nely, :);
            lambda_ma(edof_ma) = fe;
        end
    end
end

function global_edof = full_scale_edof(ii, jj, microx, globaly, edofMat_full, i)
    % which micro element in full domain
    last_col_full = (i - 1) * microx + ii - 1;
    this_col_full = (j - 1) * microx + jj;
    global_ele = last_col_full * globaly + this_col_full;
    global_edof = edofMat_full(global_ele, :);
end