[cairo] Cairo developers conference call 2004-10-19 18:00 UTC

Ravindra rkumar at novell.com
Mon Oct 18 02:09:32 PDT 2004


On Sat, 2004-10-16 at 00:25, Carl Worth wrote:
> Thanks for the list. I don't mind you repeating some feature requests if
> you don't mind me repeating some replies.

Thanks !

> I've already responded to the antialiasing request in another
> reply. Please follow up in that thread.

Ok!

> > 2. Lines with single end cap
> > 3. Lines with different end caps for both the ends
> 
> My plan here is to enable the user to provide full-custom caps, (eg. for
> arrow-heads etc.). Basically, the approach will be for the user to call
> cairo_stroke_path, (a function which is still in progress), then add the
> custom caps, and then fill the path.
> 
> In order for this work seamlessly, you'll probably also need to be able
> to query the coordinates of the butt caps used during the
> cairo_stroke_path. This is especially important if the path is to be
> filled with alpha < 1.0.

This is a good news for us, as we need customized caps as well. Do you
think it would be ready by Cairo 1.0 ?

> I've added a note to the cairo/TODO file for this item.

Thanks !

> > 4. End caps for dashes in a line
> 
> I think the dashes are already capped. If not, there's a bug there. Or
> do you need custom caps on the dashes too? That might be trickier.

GDI+ allows to have three types of DashCaps. Following link will explain
what do we want, [please note that URL might have been wrapped]
http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemDrawingPenClassDashCapTopic.asp?frame=true

Also, GDI+ allows to have different end caps for line and dashes at a
time. I mean I can have, for example, 'a round cap at line starting end,
triangle cap for dashes in the line and flat cap at the ending end of
the line'.

> Oh, and there is currently a bug in that only the final sub-path of a
> complex path is getting caps. I'll be sure to check the capped-dash
> situation at the same time I fix that one.

Thanks !

> > 5. PathGradient pattern
> 
> I'll still need to learn what this is. I know there are some old threads
> on this which I will dig up. I know that I do want to add some sort of
> full-custom gradient to cairo, but I'm not yet sure what form that
> should take.

Following link has some images that explain what pattern is it.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdicpp/GDIPlus/usingGDIPlus/fillingshapeswithagradientbrush/creatingapathgradient.asp

> > 6. Support for Bitwise operations for drawing stuff like self erasing
> > line
> 
> Bitwise manipulation of pixels won't happen in cairo. It just can't be
> supported in all backends.

It's ok. We'll see, if the suggested workaround is useful for us.

> If we're talking past each other on any of these points, then lets try
> to get together on the conference call and help each other understand
> the positions.

I think you got pretty much what I wanted to say. I got your points as
well. Thanks for the offer to join the conference call. I'll join the
conference call, if I get something more to talk about. Otherwise, I'm
almost done with my needs.

IIRC, once you guys were talking about adding printing support to Cairo.
Is anybody working on it ? Is it in your TODO list ? OR you never had
any such thoughts/plans ?

Thanks for your efforts you put in Cairo and also for your response to
the mails.

Regards,
 - Ravi




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