+ dim_.add_point (pts[i] * rot + absolute_off);
+}
+
+/*
+ Rotate this stencil around the point RELATIVE_OFF.
+
+ RELATIVE_OFF is measured in terms of the extent of the stencil, so
+ -1 = LEFT/DOWN edge, 1 = RIGHT/UP edge.
+ */
+void
+Stencil::rotate_degrees (Real a, Offset relative_off)
+{
+ /*
+ * Calculate the center of rotation
+ */
+ const Real x = extent (X_AXIS).linear_combination (relative_off[X_AXIS]);
+ const Real y = extent (Y_AXIS).linear_combination (relative_off[Y_AXIS]);
+ rotate_degrees_absolute (a, Offset (x, y));