function h3d_scan_whats_your_view_test(scan)
	% function h3d_scan_whats_your_view_test(scan)
	%
	% Tests the function h3d_scan_whats_your_view()

	nrays = numel(scan.thetas_deg);
	nscans = numel(scan.tilt_deg);


	thetas = deg2rad(scan.thetas_deg);
	tilts = deg2rad(scan.tilt_deg);
	
	if thetas(1) > thetas(end)
		fprintf('I assume that thetas increase \n');
	end
	if tilts(1) > tilts(end)
		fprintf('I assume that tilts increase \n');
	end

 	[visible, rho, singular] = h3d_scan_whats_your_view(scan, h3d_scan_tt2dir(thetas(1)-0.1, tilts(10)));
	assert(not(visible));
	[visible, rho, singular] = h3d_scan_whats_your_view(scan, h3d_scan_tt2dir(thetas(end)+0.1, tilts(10)));
	assert(not(visible));
	[visible, rho, singular] = h3d_scan_whats_your_view(scan, h3d_scan_tt2dir(thetas(10), tilts(1)-0.1));
	assert(not(visible));
	[visible, rho, singular] = h3d_scan_whats_your_view(scan, h3d_scan_tt2dir(thetas(10), tilts(end)+0.1));
	assert(not(visible));
	
	
	[visible, rho, singular] = h3d_scan_whats_your_view(scan, [-1;0;0]);
	assert(not(visible));
	

	for k=1:nscans
	for i=1:nrays
	
		if not(scan.valid(k,i))
            fprintf('X');
			continue
		end

		theta = deg2rad(scan.thetas_deg(i));
		tilt = deg2rad(scan.tilt_deg(k));

		direction = h3d_scan_tt2dir(tilt, theta);
	
	 	[visible, rho, singular] = h3d_scan_whats_your_view(scan, direction);

		assert(visible == 1);
        
        if not(singular)
    		assert(rho == scan.readings(k,i));
            fprintf('.');
        else
           fprintf('S'); 
        end

    end
        fprintf('\n');
	end