Re: transforming stroked paths (was libart transforming svp's)

[Lauris Kaplinski <lauris ariman ee>]

On Fri, 7 Apr 2000 chrismail@gnwy100.wuh.wustl.edu wrote:

> I've got an isolated example of the problem I'm having transforming stroked
> paths.  I'm following the previous advice of stroking a vpath to an svp, then
> using vpath_from_svp to return it to vpath land and transforming it there.
> 
> When I do this and invert the y-axis in my transform, the output looks very
> ugly: no antialiasing, the line is much thicker.  My guess is that it has
> something to do with the orientations of the paths getting inverted and
> therefore the wrong regions are getting filled.  I would hypothesize that
> orientatio preserving affine transformations would be fine.
> 
> Has anyone worked around this problem before?  Am I doing something wrong?  Or,
> shoudl I go ahead and invest the effort into writing an
> svp_transform_stroke_vpath(..) or something which does the transform together
> with the stroke operation so that creating the SVP can be the last step before
> rendering.
> 
> Thanks for all the help I've gotten so far.

As much, as I can remember vpaths have to be CCW, if you want to fill
these. Mirroring stroked vpath inverses its orientation.

Lauris.