line corners with terminals for vector graphics

[Mojca M. <moj...@gm...>]

Hello,

I experienced some problems with MetaPost driver recently when drawing
a function similar to sin(1000*x), ie. with sharp turns up and down.
MetaPost draws a continuous line instead of isolated line segments,
which is OK and even much better in most cases. But it uses "sharp"
corners (instead of the rounded ones) which then stick out way above
and below the line where the function passes through. (I have to check
how this is solved in PostScript.)

I don't say that MetaPost should use round corners. For example, it's
much better to use sharp (square) corners instead of the rounded ones
for drawing rectangular frames, but I intend to write a new terminal
(ConTeXt) based on metapost, so I would like to solve this problem.

Is there a way to distinguish rectangular frames (perhaps polygons as
well) from "random" functions which have to use rounded corners (at
least in my opinion), so that they don't stick out in extremely sharp
corners? Or does anyone have a better suggestion how to deal with this
problem? In the worst case I'll just use rounded corners everywhere.


One thing can be (has to be) fixed in the terminal itself however:
when MetaPost draws a rectangular frame, it uses continuous line from
4 line segments, but the beginning of the first line and the end of
the last line are "not properly connected" (the curve is not closed).

Thanks a lot,
    Mojca Miklavec