Renderer: Dashed Stroke not drawn correctly

[Bug Importer]

When drawing a Star and using a Dashed Stroke (7th one
from the bottom), sometimes the screen does not draw
the stroke properly. It's very sensitive to
scale/size, star configuration and stroke type. If I
scale it, adjust the star properties or change the
stroke type, everything looks perfect. In my case, the
star is a 10 point star with actually 20 pointy parts
(sorry, dunno how to describe it) because I pulled the
inner node to be 180 degrees from the outer node.

I'm using Windows XP, Inkscape 0.40.

Attached is a file with a star that shows the behavior.

[Bug Importer (bug-importer)]

I cannot duplicate this with 0.40 win32 2000.
vellum

[Bug Importer (bug-importer)]

I found another discovery. If I change the zoom factor in
the lower left corner to 100%, everything looks correct. If
I change it to 93% a part of the stroke disappears. If I
change it to 87%, a different part of the stroke disappears.
 Also, if I change the stroke to a different style, it
always appears correct.

[ScislaC (scislac)]

confirmed winxp pro, 0.40 using his/her attached file

It happens starting at 80% and runs through 94%. A couple
numbers being fine, and rest have slightly different
rendering flaws (mostly the odd #s).

[Novalis-dt (novalis-dt)]

Fixed in CVS.

[Buliabyak-users (buliabyak-users)]

novalis_dt: I tested your fix and it seems incomplete. On
initial load of the attached file (zoom 85%) the stroke is
now OK. However if you zoom out to 30%, part of the stroke
on the right side of the star still disappears.

[Buliabyak-users (buliabyak-users)]

I reattached the file with 30% initial zoom so you can see
the problem upon load.

[Peter Moulder (pjrm)]

"Fix" introduced a bug.

Create a shape (say rectangle or text). Set its stroke
style to paint if necessary, and choose a dasharray of long
dash followed by short gap. Set line cap to butt to make it
clearer where the dashes end.

In the build of 2004-12-07 00:10 +0000, it is rendered
correctly.
In the build of 2004-12-07 00:30 +0000, it is rendered with
equally long gaps as the dashes.

[Buliabyak-users (buliabyak-users)]

Novalis, I reverted your change because of the problems
reported below, of which the last one (dasharray "1 4" looks
like "2 2") is very serious. Please rethink your fix.

[Buliabyak-users (buliabyak-users)]

Now the attached file has some dashes lost at exactly 100%
and 50% zooms.

[Felix Rabe (public-felixrabe)]

Using Inkscape 0.41 on WinXP (at work), I have a similar
problem with a path with a dashed stroke style, where I
found a dot missing at 300dpi PNG export.

[Jon A. Cruz (jon-joncruz)]

Attaching the png xitnalta wanted to include.

[Felix Rabe (public-felixrabe)]

This attachement is a snippet of the 300dpi export I did.
Hope it helps.
The dot is also missing at zoom levels between (ca.) 400% -
450%, among
others.

[Aaron C Spike (acspike)]

Comments from duplicate bug #1208884
https://sourceforge.net/tracker/?func=detail&atid=604306&aid=1208884&group_id=93438

 Dependent on zoom level, size and position of objects
sometimes the stroke disappears.

attachments:
in line.svg select object with node tool and observe
that the stroke is hidden where two segments are
completely overlapped.

in disappear2.svg select the top right object and nudge
up and down to see the paths alternate disappearing.

[Lucychili-users (lucychili-users)]

These ones all look related to zoom and stroke render.

1077213 Renderer: Dashed Stroke not drawn correctly
1215245 Render: stroke invisible at certain zoom, also in
export (no example provided of export impact.)
1244737 Render: path disappears when viewed at 56% zoom
1254932 Some subpaths not rendered at all zooms

[Buliabyak-users (buliabyak-users)]

Originator: NO

in svn, star is almost ok, only a small gap at 60%.

in line.svg, bottom right subpath still disappears.
File Added: line.svg

[su_v (suv-lp)]

confirmed with Inkscape 0.46+devel r22457 on OS X 10.5.8. This is the oldest report I could find in a series of related bugs.

Bug #166112 “Renderer: Dashed Stroke not drawn correctly”
Bug #166588 “Render: stroke invisible at certain zoom, also in export”
Bug #166735 “Render: path disappears when viewed at 56% zoom”
Bug #168437 “wide stroke misrendered”
Bug #166839 “Some subpaths not rendered at all zooms”
Bug #166867 “Renderer: at 229% zoom a path gets black fill”
Bug #180495 “RENDERING: Errors with missing vertices and fill areas”
Bug #192305 “svg file doesn't render correctly at a specific zoom level”
Bug #401744 “path not displayed depending on zoom level”
Bug #448754 “object shows different color at different zoom levels”

[su_v (suv-lp)]

more bugs related to zoom and stroke render:
Bug #168595 in Inkscape: “Renderer: adds horizontal lines”
Bug #183375 in Inkscape: “artifacts on exported png”

[ScislaC (scislac)]

Cannot reproduce with Inkscape trunk (still reproduced with 0.48.x). Closing this report, if you feel this was closed in error, please re-open the report and explain why.