splitPointsBasedOnSegment.m

%{
 * Copyright (C) 2013-2025, The Regents of The University of Michigan.
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 * under the direction of Jessy Grizzle, grizzle@umich.edu. This software may 
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 * AUTHOR: Bruce JK Huang (bjhuang[at]umich.edu)
 * WEBSITE: https://www.brucerobot.com/
%}

function data = splitPointsBasedOnSegment(points, num_beams, datatype)
    data(num_beams) = struct();
    total = 0;
    if isempty(points)
        warning("No point is on this target")
        data(num_beams).points = [];
        data(num_beams).point_with_I = [];
        return
    end
    % Note: Here we assume the lidar ring in experiment is 0 indexing, so we shift it to
    % fit the matlab routine. However, I fyou use the simulator, the lidar
    % ring will be 1 indexing. Be very careful with this.
    if(datatype == "Experiment")
        for n = 0:num_beams-1
            if ~any(points(5,:)==n)
                continue
            end
            ring_point = points(:, points(5,:)==n);
            m = n+1;
            data(m).points = [ring_point(1:3,:); ones(1,size(ring_point,2))];
            data(m).point_with_I = ring_point;
            total= total+size(ring_point,2);
        end
    elseif datatype == "Simulation"
        for n = 1:num_beams
            current_points = points(n).points_mat;
            if isempty(current_points)
                continue;
            end
            if ~any(current_points(5,:)==n)
                continue
            end
            ring_point = current_points(:, current_points(5,:)==n);
            data(n).points = [ring_point(1:3,:); ones(1,size(ring_point,2))];
            data(n).point_with_I = ring_point;
            total= total+size(ring_point,2);
        end     
    end
    if total ~= size(current_points,2)
        warning("inconsistent number of poins in splitPointsBasedOnRing.m");
        warning("split total: %i", total)
        warning("original total %i", size(current_points,2))
    end
end