+void
+Diamond::move_to (double x, double y)
+{
+ _x = x;
+ _y = y;
+
+ points->coords[0] = _x;
+ points->coords[1] = _y + (_h * 2.0);
+
+ points->coords[2] = _x + _h;
+ points->coords[3] = _y + _h;
+
+ points->coords[4] = _x;
+ points->coords[5] = _y;
+
+ points->coords[6] = _x - _h;
+ points->coords[7] = _y + _h;
+
+ g_object_set (gobj(), "points", points, NULL);
+}
+
+void
+Diamond::move_by (double dx, double dy)
+{
+ points->coords[0] += dx;
+ points->coords[1] += dy;
+
+ points->coords[2] += dx;
+ points->coords[3] += dy;
+
+ points->coords[4] += dx;
+ points->coords[5] += dy;
+
+ points->coords[6] += dx;
+ points->coords[7] += dy;
+
+ g_object_set (gobj(), "points", points, NULL);
+}