function [] = plot_wall(x,y, scale_factor, theta);
% x=0;
% y=0;
% 
% theta = 0;
% scale_factor = 1;

x_vals = [-0.25 0     0   -0.25];
y_vals = [0.25 0.25 -0.25 -0.25];

R = [ cos(theta) -sin(theta); sin(theta) cos(theta)];

vals = [x_vals; y_vals];
vals = [vals fliplr((vals)*.9 - repmat([0.025;0],1,4)) vals(:,1)];

vals = repmat([x;y],1,length(vals)) + scale_factor * R * vals;



fill(vals(1,:), vals(2,:),'k')