[cairo] Observations from a newb

[Dirk Schönberger]

> > cairo_t *cr;
> > cairo_matrix_t *ctx;
> > cairo_image_t *img;
> > cairo_render_image (cr, img, ctx);

> It's the combination of cairo_set_source_surface() and cairo_paint()
> that does that.

Hmm. Seems the API documenttation is too high for me. I had not extracted
this from the documentation.

> > Creating the cairo_image_t (or more generically a device independent
> > image, aka a RGBA buffer) would be left to other parties.

> Did you read the tutorial:

I had not before. Now I did read it, even if only cursory. I have not found
mentioned cairo_set_source_surface.
OTOH I had found it under samples, after looking for it.

Seems I miss a couple of convenience / high level functions in cair. Things
like

cairo_draw_image
cairo_render_path
cairo_add_rectangle

and such. Implementing this would rather be straight forward, but I think it
would work wonders uin understandability of the API. Not everybody
understands the abstractions which are used for cairo.

Regards
Dirk