[cairo] Cairo in Google Summer of Code

Bill Spitzak spitzak at thefoundry.co.uk
Tue Mar 18 12:19:01 PDT 2008

Carl Worth wrote:
>> On Tue, Mar 18, 2008 at 4:27 AM, Bill Spitzak <spitzak at thefoundry.co.uk> wrote:
>>> Well I can't edit the page but here are mine:
> Why not? It's supposed to be a world-editable wiki page, (just
> requiring registration first). Did you click the "edit" button at the
> lower left of the page?

Yea it would not let me log in. I think my account has disappeared from 
CairoGraphics.org? Anyway I did not try too hard because I figured it 
would be a bad idea to stick my ideas on this page.

> The stroke-width locking proposal does have the problem that a
> solution could introduce backwards-compatibility problems, so that's
> something potentially unpleasant to inflict on a student.

Figuring out if back-compatibility is necessary is probably the hardest 
problem. It seems likely to me that virtually all Cairo-using code is 
already compatible with this change, so it would be a waste of time to 
provide some kind of mode-switch. But I don't know and I suspect we 
can't find out unless this change is made and then find out how many 
users complain. Which is not a great way to research it...

In any case I would guess that this is not self-contained and that it 
would touch a lot of Cairo so it is not an appropriate project. For 
instance it will probably require some large changes to the PS and PDF 
backends (as some other email here indicates that they are passing the 
ctm to the backend currently).

> The "hinting mode" and "'fun' font API" are two things that might have
> some amount of controversy in them, which as you said, might make
> things un-fun for the student.

Actually the "hinting mode", since it would be a mode that is off by 
default, should not be controversial. I think it might make a very 
interesting project. Though it might be incredibly difficult. Correctly 
implementing this would make Cairo immensely more popular. (if it works 
really well, then perhaps Cairo should default to having the mode on and 
linewidth set to 1, but that controversy is later and not part of the 

I agree the fonts stuff is not self-contained and controversial.

> The fourth proposal is for addressing the seams issue. I don't think
> describing a problem and then saying "come up with a solution for
> this" is concrete enough for a student. If the proposal were instead
> something like "implement an FSAA approaching within cairo with
> such-and-such characteristics" then that would be more appropriate as
> a Summer of Code project idea.

Maybe the seams one is the best one to add to the list, if correctly 
worded. Oddly enough this is the only one on the list that is not 
bothering me, but I put it in there because I know this is a problem a 
lot of other Cairo users are encountering.

Therefore I now think that fixing the seams, and the hinting mode, are 
two things that maybe should be listed.

More information about the cairo mailing list