Call for testing: cairo backend for win32
T Rowley
considering changing the backend graphics library for Mozilla SVG on
win32 from GDI+ to cairo. The primary reason for switching is support
- using cairo we can have SVG just work out of the box for everyone,
rather than requiring people on pre-XP systems to download and install
GDI+ (which realistically speaking, a typical user won't do). For
content authors, the switch means that all platforms will be using the
same graphics library and will behave similarly (rather than having
unfixable discrepancies, like GDI+'s radial gradient repeat modes).
For these reasons we are planning on switching backends to cairo prior
to Firefox 1.5. We do not take this step lightly, but think it's in
the best interest for the future of SVG in Mozilla.
We have created a build of Firefox 1.5 beta 1 that uses the cairo
library as the backend instead of GDI+. Our own testing hasn't found
any serious problems, but we would like more widespread testing. If
you could download and use it for testing SVG content to help us find
any issues we may have missed it would be greatly appreciated.
The cairo build may be obtained from the following URL.
It will unzip with a "bin" directory containing the firefox executable.
Please test and respond with your findings. Please be specific about
problems encountered and URLs to the content in question if possible.
In addition to testing just SVG content, try complicated DHTML sites
as well to check the new backend isn't overwriting memory.
Some general notes about testing new builds: by default Firefox checks
to see if there's another running Firefox, and if so just sends it a
message to open a new window. The easiest way to make sure you're
really running the cairo version of Firefox is to make sure all
Firefox windows are closed before starting a new build. The cairo
build can easily be distinguished from the official 1.5b1 release by
the unofficial build artwork (blue globe icon and "deer park"
labeling).
Note that as this cairo build is based on Firefox 1.5 beta 1, it is
vulnerable to the recently publicized IDN buffer overflow problem.
You can protect yourself by going to this document and following the
"Manually Configuring the Browser" steps:
https://addons.mozilla.org/messages/307259.html
Two bugs are known:
* Dashed curved lines show solid. This is a limitation of
cairo-1.0.0, fixed in 1.0.2 which we hope will be released in time
to be considered for Firefox 1.5
* Curved paths sometimes have a wedge missing. This appears to be
bug specific to cairo on win32, as the same SVG renders fine with
cairo on linux. Under investigation.
skeeter
However do notice a size difference and in:
<g font-family="Comic Sans MS" font-weight="bold" font-size="15"
fill="#c02222">
<text y="300px" x="20px">Give it a go and let me know.</text>
<text y="315px" x="20px">If the ball gets in the way:</text>
<text y="330px" x="20px">Just grab it with the mouse and move it.</text>
</g>
Plus the font is not being picked up.
Bad styling on my part or is the broken?
Might add that with GDI is shows as expected.
skeeter
Anyway, on looking closer it is picking up the font-family, just not
getting the font-size or font-weight correct.
simon
the background, and the crashdown game has some parts disappear. All
were ok in the gdi version on the same machine and all work on the
cairo version on non-win32.