use classic bresenham line draw algorithm

[tenox7]

[tenox7]

https://www.geeksforgeeks.org/bresenhams-circle-drawing-algorithm/

[larsbrinkhoff]

I made this simple implementation.

https://github.com/simh/simh/blob/master/display/display.c#L812-L876

[larsbrinkhoff]

I see the geeksforgeeks article is for drawing a circle. To go really classic, I'd suggest Minsky's algorithm. It draws an approximation of a circle, but I understand it's good enough to do trigonometry on a satellite.

[tenox7]

Ha! Interesting. Thank you! I will take a look at your implementation.