create_mask.m

% Creates a mask from given inputs
% Author Darren Brogan
% Heavily derived from createMask2 by Dan Malone
% Diff @ https://gist.github.com/BroganD1993/51217ec380e9bc383291/revisions

function image_mask = create_mask(image_mask, fft, num_shapes)
    image_mask = generate_user_shapes(image_mask, fft, num_shapes);
    image_mask = flip_mask_and_combine(image_mask);
    image(256*image_mask);               
end

function image_mask = generate_user_shapes(image_mask, fft, num_shapes)
    [size_y, size_x] = size(fft);
    for current_shape = 0:(num_shapes - 1),
        image_mask = flip_mask_and_combine(image_mask); 
        image(256 * (image_mask + log(abs(fft)) / max(max(log(abs(fft))))));
        colormap(gray(256));
        [x, y] = read_points_and_repair(size_x, size_y);
        image_mask = plot_user_mask(image_mask, x, y);
    end
end

function [x, y] = read_points_and_repair(size_x, size_y)
    [x, y] = ginput(2);
    [x, y] = reorient_coordinates(x, y);
    [x, y] = handle_bounds_errors_on_coordinates(x, y, size_x, size_y);

    disp('The input co-ordinates are: ');
    disp([x, y]); 
end

function [x, y] = reorient_coordinates(x, y)
    x = reorient_coordinate(x);
    y = reorient_coordinate(y);
end

function coordinate = reorient_coordinate(coordinate)
    if(coordinate(2) < coordinate(1))
        coordinate = switch_coordinates(coordinate);
    end
end

function coordinates = switch_coordinates(coordinates)
    temp_coordinate = coordinates(1);
    coordinates(1)  = coordinates(2);
    coordinates(2)  = temp_coordinate;
end

function [x, y] = handle_bounds_errors_on_coordinates(x, y, size_x, size_y)
    x = max(x, 1);
    y = max(y, 1);
    x = min(x, size_x);
    y = min(y, size_y);
    x = round(x);
    y = round(y);
end

function image_mask = plot_user_mask(image_mask, x, y)
    image_mask((y(1)):(y(2)), (x(1)):(x(2))) = 1;
end

function image_mask = flip_mask_and_combine(image_mask)
    flipped_mask = flip_mask(image_mask); 
    image_mask = combine_masks(image_mask, flipped_mask); 
end

function mirrored_mask = flip_mask(image_mask)
    mirrored_mask = rot90(image_mask, 2);
end

function combined_masks = combine_masks(image_mask, mirrored_mask)
    combined_masks = bitor(image_mask, mirrored_mask);
end