the template 34 the spot exits template 34 and enters template 36 at 34 s 7 34 corresponding to section lb in the template 36 it exits template 36 at 34 t 7 34 and enters template 38 at 34 u 7 34 which is at section 5c in the template 38 it exits at 34 u03b4 7 34 and enters template 40 at 34 u03b5 7 34 which is at the same point i e section it in the template 40 as for template 30 and the sequence of it 3b 3t 1b and 5c repeats looking at the relative points of entry and exit in each case one need only use one set of values to determine if the write spot 20 should be turned on or off the values corresponding to one dot template provided that we obtain both a status determining value selected from the look up table and a pointer to the next address to look up in the table the pointer typically comprises a precalculated address for the next value selection the calculation being based on the desired dot centerline angle and dot spacing distribution the selected value may be a value which is predetermined to generate a particular dot shape the status on or off of the spot is established by comparing the selected.