320280 - Marker-end implementation broken - negative content trashed

Status: RESOLVED INVALID

(Core :: SVG, defect)

Description

[Patrik Carlsson]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; sv-SE; rv:1.8) Gecko/20051111 Firefox/1.5
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; sv-SE; rv:1.8) Gecko/20051111 Firefox/1.5

Marker-end arrows does not show if drawn with negative
coordinates or rotated into negative coordinates.

Further the markerHeight and markerWidth seems to be
defined as "0" by default and can only be enlarged into
positive coordinates. This may or may not be the cause of 
the bug.

See attached examples.

Reproducible: Always

Actual Results:  
Nothing is shown

Expected Results:  
The marker should be drawn

Guess who's generating these images,
however except from not defining a
base fontsize it should be drawn 
without errors in Firefox.

When a base fontsize is defined in
image 2 the following code does not
work: <tspan x="28.98" dy="1.2em">test</tspan>
'test' should have moved down 1.2 ems!
However I will not file a bug on this
until basic text works.

Comment 1

[Patrik Carlsson]

Attachment: Testcase not working

Comment 2

[Patrik Carlsson]

Attachment: Image showing that it works with some positive coordinates in markers.

I have filed another bug report about the "scale with negative values" bugs shown in these attachements

Comment 3

[Patrik Carlsson]

Another testcase with simpler svg:
http://www.zvon.org/HowTo/Output/howto_jj_svg_27_output_0.svg

Comment 4

[Jonathan Watt [:jwatt]]

This behaviour is expected and required for conformance to the spec. If you want paint outside the viewport established by the 'marker' element to be visible you have to specify style="overflow:visible" on your <marker> tag. If Visio paint outside the viewport without that then it's broken and you should report it to Microsoft.

The properties markerHeight and markerWidth default to 3 if not specified.

The problem with <tspan x="28.98" dy="1.2em">test</tspan> is known: see bug 305859.

Comment 5

[Patrik Carlsson]

Thank you,
I put this line into userContent.css as a workaround for the Visio bug:
marker { overflow: visible !important; }

  / Patrik

Comment 6

[Patrik Carlsson]

Attachment: Zvon example with refX="4" refY="4"

Comment 7

[Patrik Carlsson]

Attachment: Zvon example with correct viewBox and refX refY that will still not render in Firefox

Comment 8

[Patrik Carlsson]

Please reconsider this bug,
I cannot get the zvon example in comment #3 to work even after editing
my latest attachment should be OK but will still not render.

To get it to work I had to change refX, refY since Firefox
behaved differently than other viewers and applied a 
translate tranform to the viewport before determining origin,
- but this seems correct according to how viewBox is defined.

Then I made the viewbox to fit the lines drawn from x=6 to 0 and y=-2 to 2 and rotated to negative x coordinates, e.g -6 -2 6 4. markerWidth and markerHeight
were changed accordingly.

Firefox does still not draw anything except for half a pixel that
happens to be in the positive quadrant (look at the end of the line),
if I make the overflow visible I can see everyting in negative coordinates.
The header for this bug seems correct unless there is some other bug
that prevents lines from being drawn if they are defined out of the
viewport and then rotated into place.

Comment 9

[Robert Longson [:longsonr]]

As Jonathan said in comment 4, this bug is invalid. FWIW Opera displays the testcases the same as Mozilla.

Comment 11

[石庭豐 (Seak, Teng-Fong)]

(In reply to Jonathan Watt [:jwatt] from comment #4)
> This behaviour is expected and required for conformance to the spec. If you
> want paint outside the viewport established by the 'marker' element to be
> visible you have to specify style="overflow:visible" on your <marker> tag.
> If Visio paint outside the viewport without that then it's broken and you
> should report it to Microsoft.

My bug 520133 was marked as a duplicate of this one.

I'm no expert in SVG, however, I have tried attachment 205853 [details] ("Testcase not working" - visio2003.svg) uploaded by Patrik in both Adobe SVG viewer 3.03 AND Inkscape 0.48.1 and all I see is that they both display the mark arrows.

Or maybe you would also tell me that they both do not conform to SVG spec?

PS: I'm not sure what's supposed to be displayed by the attached "howto_jj_svg_27_output_1.svg". What seems right, what seems wrong?

Comment 12

[Jeremie Patonnier :Jeremie]

(In reply to 石庭豐 (Seak, Teng-Fong) from comment #11)
> Or maybe you would also tell me that they both do not conform to SVG spec?

Yes, there are not conform.

As per the spec : http://www.w3.org/TR/SVG/painting.html#Markers

"SVG's user agent style sheet sets the ‘overflow’ property for ‘marker’ elements to hidden, which causes a rectangular clipping path to be created at the bounds of the marker tile. Unless the ‘overflow’ property is overridden, any graphics within the marker which goes outside of the marker rectangle will be clipped."