double dashes[2] = {1, 1};

snippet_normalize(cr, width, height);

cairo_scale(cr, .0000001, .0000001);
cairo_set_line_width(cr, 100000);
cairo_set_dash(cr, dashes, 2, 0);
cairo_move_to(cr, 0, 0);
cairo_line_to(cr, 5000000.0, 5000000.0);
cairo_stroke(cr);