-- refractor
-- modified for Pixopedia 24 by Sinisa Petric, 2008  

image_OUT = 0
image_INP = 1

patternsize = 20;

function val(n,minv,maxv)
  return minv + (n/255)*(maxv-minv);
end;

function hypot(xx,yy)
  return math.sqrt((xx*xx)+(yy*yy))
end

M = hypot(vp24_width, vp24_height) / 2

for y = 0, vp24_height-1 do
  for x = 0, vp24_width-1 do
    d1 = x + math.mod(x,val(patternsize,0,M/2))
    d2 = y + math.mod(y,val(patternsize,0,M/2))
    if d1 >= vp24_width-1 then
      d1 = vp24_width-1
    end
    if d2 >= vp24_height-1 then
      d2 = vp24_height-1
    end
    r,g,b = fp24_getImageRGB(image_INP, d1,d2)
    fp24_setImageRGB(image_OUT, x,y,r,g,b)
  end
  fp24_showProgress(y, vp24_height)
end