add_scale_bar.m

function add_scale_bar()
    global STL;
    hSI = evalin('base', 'hSI');
    hSICtl = evalin('base', 'hSICtl');
    
    relevant_images = draw_on_image_get_images();
    
    fov = hSI.hRoiManager.imagingFovUm;
    bounds = [fov(3,1) - fov(1,1)      fov(3,2) - fov(1,2)];
    
    for i = relevant_images
        fig_bounds = diff([get(hSICtl.hManagedGUIs(i).CurrentAxes, 'XLim')' get(hSICtl.hManagedGUIs(i).CurrentAxes, 'YLim')']);
        fov_transform = diag([1 1] .* fig_bounds ./ bounds);
        
        scale_bar_length = 10^floor(log10(bounds(1)*0.5));
        
        scale_bar_length = 50;
        scalelen = sprintf('%d {\\mu}m', scale_bar_length);
        scale_bar_xpos = fov(end,end) - 0.1 * bounds(1);
        scale_bar_ypos = fov(end,end) - 0.1 * bounds(2);
        
        z = draw_on_image_get_z(hSICtl.hManagedGUIs(i).CurrentAxes);
        
        scale_bar_pos = [-scale_bar_length/2 scale_bar_length/2; ...
            scale_bar_ypos * [1 1]];
        scale_bar_pos_x = [scale_bar_xpos * [1 1]; ...
            -scale_bar_length/2 scale_bar_length/2];
        scale_bar_pos_x = scale_bar_pos_x * fov_transform;
        scale_bar_pos = scale_bar_pos * fov_transform;
        line(scale_bar_pos(1,:), scale_bar_pos(2,:), [z z], 'Parent', hSICtl.hManagedGUIs(i).CurrentAxes, 'Color', [1 0 0], 'LineWidth', 11);
        text(0, scale_bar_pos(2,1), z, scalelen, 'HorizontalAlignment', 'center', 'VerticalAlignment', 'middle', 'Parent', hSICtl.hManagedGUIs(i).CurrentAxes, 'Color', [1 1 1]);
        line(scale_bar_pos_x(1,:), scale_bar_pos_x(2,:), [z z], 'Parent', hSICtl.hManagedGUIs(i).CurrentAxes, 'Color', [1 0 0], 'LineWidth', 11);
    end
end