I have a problem that may be specific to Flash, or it may be a general issue with the way computer graphics work. I need to understand better what's going on, in order to find a solution.

I'm drawing a line chart in Flash. There's a way of selecting parts of the chart where I put an overlay on top of it and redraw all lines twice as thick. The resulting overlay is not quite aligned with the original beneath it, and the misalignment seems to accumulate towards the right end:

Round joints

I've randomly tried stuff to fix this. For example, adding half the line width to pixel coordinates helped a little, which makes no sense to me, and the picture was still not as nice as I'd like to have it. One way of getting quite a crisp picture is by changing the way line ends are joined together to what they call "miter joints":

Miter joints

Now, all would be well, if Flash Player didn't slow down badly (it goes from no noticeable delay to a 2-second pause on my fast quadcore machine) when rendering with miter joints.

It seems I have to find some clever workaround, but I just don't understand this well enough. Is the effect of the joint styles specific to Flash, or is this a natural consequence of the two methods? For example, do SVG graphics behave similarly?

  • There aren't a lot of Flash fans on HTML/CSS boards. Nathan Duran about 9 years ago
  • @Nathan - This question is (very likely, at least) not about Flash in particular. Hanno Fietz about 9 years ago

1 answer


Try http://www.stackoverflow.com/

Answered about 9 years ago by Marko Ivanovski