cairo_surface_t *pdf;
		cairo_t *cr;
		cairo_pattern_t *pat;

		double x0      = 100,   /* parameters like cairo_rectangle */
					 y0      = 100,
					 rect_width  = 50,
					 rect_height = 50,
					 radius = 20;

		double x1,y1;

		double w = 100, h=100;
		double dx0=20, dx1=20, dx2=dx0+w, dy0=20+h, dy1=20, dy2=20;


		x1=x0+rect_width;
		y1=y0+rect_height;

		pdf = cairo_pdf_surface_create("test.pdf", 500, 800);
		cr = cairo_create(pdf);

		cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);


		cairo_set_line_width (cr, 10);


		pat = cairo_pattern_create_linear (dx2, dy2,dx0, dy0);

		cairo_pattern_add_color_stop_rgba (pat, 0.5, 1, 1, 1, 1);
		cairo_pattern_add_color_stop_rgba (pat, 0.5, 0, 0, 0, 1);
		cairo_set_source (cr, pat);


		cairo_move_to  (cr, dx0, dy0);
		cairo_curve_to (cr, dx0, dy0, dx1, dy1, dx2, dy2);

		cairo_stroke(cr);

		cairo_move_to(cr, dx0, dy0-1);
		cairo_line_to(cr, dx0, dy0+200);
		cairo_stroke(cr);

		cairo_set_line_width (cr, 1);
		cairo_set_source_rgba(cr, 1,0,0,1);

		cairo_move_to(cr, dx0, dy0);
		cairo_arc(cr, dx0, dy0,3,0,2*M_PI);
		cairo_stroke(cr);

		cairo_move_to(cr, dx1, dy1);
		cairo_arc(cr, dx1, dy1,3,0,2*M_PI);
		cairo_stroke(cr);

		cairo_move_to(cr, dx2, dy2);
		cairo_arc(cr, dx2, dy2,3,0,2*M_PI);
		cairo_stroke(cr);


		cairo_show_page(cr);

		cairo_surface_destroy(pdf);
		cairo_destroy(cr);