The above!
Alright!
Thanks
Hi,
Sorry i could not add more but much has already been said. The main idea i guess is that a single line can not be drawn with no jagged edges on a regular computer screen because the only thing we have to work with is a digital pixel. This is a spatial concept which is similar to how an ADC converts signals to digital signals which never have infinite resolution like our eyes usually appear to have. The only way is to make the line thicker and taper the edges by varying the brightness of some of the pixels.
In your case you have an entire block that has to be tapered, so you get off easy
New screens are out now that have much better resolution. Not in very widespread use yet though as most people i think have monitors that are anywhere from 1024x768 up to maybe 1920x1080.