[cairo] SVG & PS/EPS surfaces

[Andreas Lobinger]

Hello, (i might write something stupid here, because the thread isn't
somehow fully available to me)

to combine drawings i use drawing functions that operate on a context
with some input parameters/data and just call them sequentially.

function draw_frame(cr)
  save(cr)
  pathconstruction -> fill/stroke
  restore(cr)
end

function draw_xg(cr, right_shift)
  save(cr)
  translate(cr,right_shift,0)
  pathconstruction -> fill/stroke
  restore(cr)
end

# main
i = Cairo.image_surface(400,300,RGBA)
cr = CarioContext(i)

draw_frame(cr)
for l in 10:10:120
     draw_xg(cr,l)
     end

save_to_png(i)

or similar. Also in the cases where i is a vector surface i get vector
output with it (obviously not on .png)
Using surfaces as sources can lead to rasterization - i had some
problems (but this was pre-1.14, and i never checked again) with
recording surfaces and scaling before painting. I rather see surfaces
as output devices.
Some intermediate drawing -if needed- can be done by push/pop groups.

But i think i agree, it should be clearer in documentation, in which
steps rasterization is enforced.

Wishing a happy day,
          Andreas