%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-07-02 16:21:35
 % @LastEditTime: 2021-07-02 16:45:10
%--------------------------
function plot_control_points(U_bezier, nelx, nely, num_b)
    [ref_nodes, ~, ~] = multi_generate_mesh(1, nelx, nely, num_b);    

    offset = [0.9, 0.5];
    regulated = [1, -1];
    cp = colormap(jet);    
    
    u0 = reshape(U_bezier, 2, [])';

    for kk = 1:2
        mc = regulated(kk);
            
        figure;        
        scatter3(ref_nodes(:,1),ref_nodes(:,2), mc*u0(:,kk) + offset(kk), 8, 'k','filled'); hold on;

        maxk = max(mc*u0(:, kk));
        mink = min(mc*u0(:, kk));
        cci = round((mc * u0(:,kk) - mink) / (maxk-mink) * 255)+1;
        colors1 = cp(cci, :);
        
        x = [ref_nodes(:,1), ref_nodes(:,1)]';
        y = [ref_nodes(:,2), ref_nodes(:,2)]';
        z = [mc * u0(:,kk)+offset(kk), 0 * u0(:,kk)]';
        for i2 = 1 : size(u0, 1)
            plot3(x(:,i2), y(:,i2), z(:,i2), '-', 'LineWidth',1,'Color',colors1(i2,:)); hold on;
        end     
        
        axis equal; axis off; colormap(jet);
    end
end