In a real graphic LCD, it is the user who draws the lines / circles using Bresenhams algorithm or a variant. PBP, C or ASM is just a matter of choice.
I am curious to know why you want to use a character lcd this way other than for the thrill of doing it. You only get 8 programmable characters which is about a 4th of the 16x2 display. Your demos too show repeated patterns. It is much more challenging and fun to get a graphic lcd come upto video speed (20fps and more).
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