splitPointsBasedOnRing.m

%{
 * Copyright (C) 2020-2030, The Regents of The University of Michigan.
 * All rights reserved.
 * This software was developed in the Biped Lab (https://www.biped.solutions/) 
 * under the direction of Jessy Grizzle, grizzle@umich.edu. This software may 
 * be available under alternative licensing terms; contact the address above.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * AUTHOR: Bruce JK Huang (bjhuang[at]umich.edu)
 * WEBSITE: https://www.brucerobot.com/
%}

function data = splitPointsBasedOnRing(opts, point_cloud)
    data(opts.num_beams) = struct();
    data(opts.num_beams).points = [];
    data(opts.num_beams).point_with_I = [];
    for i = opts.pc_iter : opts.pc_iter+opts.num_scan
        total = 0;
        points = point_cloud(i, :, :);
        points = (reshape(points, size(points, 2),[]))';
        points = removeZeros(points);
        original_size = size(points,2);
        for n = 0:opts.num_beams-1
            if ~any(points(5,:)==n)
    %             disp("n")
    %             disp(n)
    %             disp("points")
    %             disp(points(:, points(5,:)==n))
    %             pause;
                continue
            end
            ring_point = points(:, points(5,:)==n);
            if size(ring_point,2) < opts.min_points
                original_size = original_size - size(ring_point,2);
                continue;
            end
            m = n+1;
            ring_point_homogeneous = [ring_point(1:3,:); ones(1,size(ring_point,2))];
            data(m).points = [data(m).points ring_point_homogeneous];
            data(m).point_with_I = [data(m).point_with_I ring_point];
            total= total+size(ring_point,2);
        end
        if total ~= original_size
            warning("inconsistent number of poins in splitPointsBasedOnRing.m");
            warning("split total: %i", total)
            warning("original total %i", size(points,2))
        end
    end
end