[cairo] [RFC] Add device_extents api

[Behdad Esfahbod]

On 03/26/2009 04:30 PM, Robert O'Callahan wrote:
> On Fri, Mar 27, 2009 at 8:12 AM, Behdad Esfahbod <behdad at behdad.org
> <mailto:behdad at behdad.org>> wrote:
>
>     What I like to see is Mozilla come up with a proposed patch that
>     makes you happy and is in line with cairo's API guidelines.  Carl
>     and I have said numerous times that making stroke width locking is
>     how we'd like to see this solved, and there have been patches for it
>     before.  So all needed is for someone to sit down and finish them.
>       Makes sense?
>
> That makes sense. It wasn't clear to me that there was a decision that
> stroke width locking is the right way to go.
>
> Is this the latest word on desired API?
> http://lists.cairographics.org/archives/cairo/2006-May/006985.html
> That proposal changes cairo_set_line_width to lock to the current CTM.
> Is that behaviour change still acceptable to you and Carl at this point?

Yes, that is my impression.  Last time someone gave this a shot, the remaining 
problem was how to handle dash offsets in a backward compatible way.  One way 
to deal with that is to lock a separate dash matrix at the time of 
cairo_set_dash().  In that case, cairo_[sg]et_dash_matrix() may also be 
desirable.  cairo_get_pen_width() also needs adjustment to return an 
approximation of the pen matrix in the current CTM.

behdad


> Rob