[cairo] Drawing/painting multiple images

[Sakari Aaltonen]

I would like to include several images (PNG's) on a Cairo surface.
I have seen examples of how to do this with one image, say at
   http://zetcode.com/tutorials/cairographicstutorial/cairoimages/
or
   http://cairographics.org/samples/
But I cannot figure out the correct way to handle multiple ones.
My current code looks like this:
-------------------------------------------------------------
    cairo_surface_t *surface;
    double scale = 300;
    cairo_t *cr;
    int imagw, imagh;
    cairo_surface_t *image;

    surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
                                         scale, scale);
    cr = cairo_create(surface);
    cairo_scale(cr, scale, scale);
    cairo_set_line_width(cr, 0.10);

    cairo_set_source_rgb (cr, 0.4, 0.0, 0.6);
    cairo_rectangle (cr, 0.1, 0.1, 0.5, 0.8);      // rectangle outline
    cairo_stroke(cr);

    image = cairo_image_surface_create_from_png ("button.png");
    imagw = cairo_image_surface_get_width (image);
    imagh = cairo_image_surface_get_height (image);
    cairo_scale (cr, 0.15/imagw, 0.15/imagh);
    cairo_set_source_surface (cr, image, 0, 0);

    cairo_paint (cr);
    cairo_surface_destroy (image);

    cairo_destroy(cr);
    cairo_surface_destroy (surface);
------------------------------------------------------------------

This seems to work in that <button.png> is drawn. But I don't understand
how one is supposed to paint another image on the same surface. Or even,
how to put the single image somewhere else, that is, not at the upper
left corner.


Thank you in advance,
Sakari Aaltonen