How to Find Correct Vertice formation for polyxpoly function

I am trying to find intersection points of horizontal lines and drawn polygon with a hole. However, pgon.Vertices does not give proper formation for polyxpoly function and I get incorrect results for intersection points (For example y = 0 intersection point return 0.514 value). The code I am running as follows, how can I transform pgon.Vertices format format suitable for polyxpoly. Figure displays the lines and annulus I am trying to find intersection points.

Thanks

clear 
clc
clf
t = 0.05:0.005:2*pi;
x1 = cos(t);
y1 = sin(t);
x2 = 0.5*cos(t);
y2 = 0.5*sin(t);
pgon = polyshape({x1,x2},{y1,y2});

[corrected_x1,corrected_y1] = poly2ccw(pgon.Vertices(:,1), pgon.Vertices(:,2));
plot(pgon)
hold on
for j = -1.5:0.1:2
    x = [-2,4];
    y = [j, j];
    [xi,yi] = polyxpoly(x,y,corrected_x1,corrected_y1);
    plot(x,y)
end

[Torsten]

An annulus is not a polygon.

[Kayra Dernek]

Thanks I updated the question.

Answer 1

[Matt J]

Instead of polyxpoly, I would recommend downloading linexlines2D(),

https://www.mathworks.com/matlabcentral/fileexchange/93470-intersections-of-multiple-2d-lines-or-line-segments

t = 0.05:0.005:2*pi;
x1 = cos(t);
y1 = sin(t);
x2 = 0.5*cos(t);
y2 = 0.5*sin(t);
pgon = polyshape({x1,x2},{y1,y2});


lineEq=[0,1,-0.25];
xy=linexlines2D(pgon,lineEq); %intersection points


plot(pgon)
hold on
 fimplicit(@(x,y)lineEq*[x;y;x.^0],[-2,2]);  %plot line
 plot(xy(1,:), xy(2,:),'ro');   %plot intersection points
hold off
axis equal