draftLinesForBackProjectionTest(scratchPad, numberOfLinesRequired, offset_x, offset_y, ...

function scratchPad = draftLinesForBackProjectionTest(scratchPad, numberOfLinesRequired, offset_x, offset_y, ...
                                x_range, y_range, imageSize)
%DRAFTLINESFORBACKPROJECTIONTEST 
% Caveat: only able to draw 180 degrees, for 360 degrees, a mirror feature
% may be implemented later

numberOfLinesRequired = numberOfLinesRequired*2; % as the range of 0 to -180 degrees is not covered

  % start the lines plotting
  %lengthOfLine = 100;
  % update the lines
  startPoints = [1 1];
  % numberOfLinesRequired = 10; % == numberOfEndPoints
  startPoints = repmat(startPoints, numberOfLinesRequired, 1); % replicate column-wise
  
  degreeStepSize = 360/numberOfLinesRequired;
  degreeRanges = 0:degreeStepSize:360; % determines the fanning out of the lines, ie. how widely spread they are apart
  radianRanges = degreeRanges*(pi/180);
  
  endPoints = [];
  
%   offset_x = 30;
%   offset_y = 30;
  startPoints = [offset_y*startPoints(:,1) offset_x*startPoints(:,2)];
  
  % compute the end-points
  for i = 1:numberOfLinesRequired
      gradient = tan(radianRanges(i));
      y = (gradient*x_range);
      endPoints = [endPoints; x_range y];
  end
  
  %endPoints = lengthOfLine.*[2 2];  
  [ind label] = drawline(startPoints, endPoints, imageSize); 
  
  scratchPad(ind) = label;

end