[cairo] simple surface size question

[Dan McMahill]

Hello,

I'm new to cairo and am finishing up a cairo driver for pstoedit and had 
a question.  To test out the generated code, I'm doing something like this:



main()
{
cairo_surface_t *cs;
cairo_t *cr;

cs = cairo_pdf_surface_create("myfile.pdf", SIZEX, SIZEY);
cr = render_page_1(cs);
cairo_show_page(cr);
cairo_destroy(cr);
}

and the render_page_1() function is the generated code coming out of 
pstoedit

cairo_t *render_page1(cairo_surface_t *cs)
{
   cairo_t *cr;

   cr = cairo_create(cs);

   // now there are lots of calls like
   // cairo_moveto(), cairo_line_to(), cairo_stroke(), etc

   return cr;
}


It seems I have a chicken and egg problem.  In main() I set the size of 
my surface.  But I don't *know* what my size really is yet.  That 
depends on all the drawing that was done in render_page_1() and that 
came out of my pstoedit driver.

How do I handle not knowing the x/y limits of my drawing up front?  In 
fact, unless I do something drastic to the pstoedit driver, I might even 
have negative x and y coordinates in my cairo calls.  Is that even 
allowed (negative coordinates)?

Thanks
-Dan