% mesh_refine.m — Changing a mesh's resolution.
%
% A mesh can be modified by changing the polynomial degree per patch
% ("p-refinement", via resample) or by splitting patches ("h-refinement",
% via refine).

mip load --install flatironinstitute/flatironinstitute/surfacefun

p = 16;
dom = surfacemesh.sphere(p + 1, 1);

figure(1);
plot(dom, surface='off')
title(sprintf('Original: %d patches, order %d', length(dom), order(dom)));

% p-refinement: resample each patch down to 4 nodes per dimension.
dom2 = resample(dom, 4);

figure(2);
plot(dom2, surface='off')
title(sprintf('Resampled to order %d', order(dom2)));

% h-refinement: split each patch into four.
dom3 = refine(dom2);

figure(3);
plot(dom3, surface='off')
title(sprintf('Refined: %d patches', length(dom3)));