wide stroke at sharp curve bends shows flattening artefacts

[Daniel Pope]

A curve's stroke is being computed from the view-tessellated curve, rather
than the source curve.

This means that the stroke itself appears incorrectly tessellated when
stroke width >> radius of curvature.

See attached for example of how this can go wrong; the shapes are small
circles (in fact, clones of one another), but they render as different
2^n-sided polygons because of the large stroke size. Furthermore the
rendering changes as you zoom in and out.

Expected behaviour is for the shapes to look circular at all zoom levels
and particularly so when exported as a PNG.

[Buliabyak-users (buliabyak-users)]

Originator: NO

Actually there's no renderer that would draw strokes without flattening.
That's the best practical algorithm these days. You can just vary its
precision; higher precision means less noticeable artefacts but slower
rendering.

[Mercury (mercury13)]

Confirmed. 0.45.1-1, Windows XP. Ways to reproduce.

1. Draw a VERY small circle or a Bezier with VERY sharp loop.
2. Make VERY wide stroke.
3. Zoom out a bit and enjoy.

[jazzynico (jazzynico)]

Reproduced on Ubuntu 10.10, Inkscape 0.48.0-1ubuntu1.2.
Not reproduced with trunk revision 10444 (new Cairo renderer).