how to draw a very short line with actionscript?

Answer 1

Did you try playing with the various caps and joints settings? Your values of null/null would direct Flash to use round caps and round joints. Your [last] parameter of "1" for the miter limit would also be ignored as you wouldn't be using miter joints.

I would suggest trying CapsStyle.NONE first. Then maybe miter joints. For reference: Graphics.lineStyle().

Edit: Try using pixel hinting, too.