[cairo] Always keep text in foreground?

[Daniel Goldman]

> 2010/8/16 Daniel Goldman <dagoldman at yahoo.com>:
> > Thanks  for the replies. I ended up reading the data file twice, stroking 
and
> >  filling the polygons first pass, and applying the labels the second pass,  
>as
> > shown in a simplified form by Arjen. It was somewhat inconvenient,  but not 
a
> > big deal. I already knew that was a possible  solution.
> >
> > It's a big data file, which I would rather not read  twice. But it's still
> > fast enough. It would even be possible to split  the data file into two data
> > files: one with the points, the other with  the labels. But I'll only do 
that
> > if ever a speed problem.
> 
> You  can always do the drawing of the text to a second surface and
> combine them  afterwards, like Benjamin suggested. The second surface
> for the text can be  created with:
> text_surface =  cairo_surface_create_similar(poly_surface,
> CAIRO_CONTENT_COLOR_ALPHA, width,  height);
> 
> This way you only have to go over your dataset once.
> 
> >  The reason I posted was to understand cairo better, to clarify if cairo  
has
> > the luxury of automatically keeping the text in the foreground. I  
appreciate
> > Benjamin explaining why this is not the case. I can live  without the 
luxury.
> >
> > Daniel
> 
> Maarten
>

Thanks. I'll try that.