gistfile1.c

void draw(cairo_t* cr)
{
    // ... do some vector drawing
    cairo_surface_t* surface = cairo_get_target(cr);
    cairo_surface_flush(surface);
    CGContextRef cgctx = cairo_quartz_surface_get_cg_context(surface);

    // use Apple's CoreText API

    cairo_surface_mark_dirty(surface);

    // do more vector drawing
}