+void xrchart_draw_scatterplot (const struct chart_item *, cairo_t *,
+ struct xrchart_geometry *);
+
+void xr_draw_chart (const struct chart_item *, cairo_t *,
+ double width, double height);
+
+char *xr_draw_png_chart (const struct chart_item *,
+ const char *file_name_template, int number,
+ const struct cell_color *fg,
+ const struct cell_color *bg);