
7.4. POLYLINE DRAWINGS 243
(a) (b)
Figure 7.14 (a) A (darkened) vertex and its neighbors before a right shift of one unit.
(b) And after a right shift of one unit. The other vertices that are part of the shifting set
are hi ghli ghted, while those that are not are drawn dashed. Notice that the left port region
remains in place creating a location for one more port.
R
p
region of w
l
. Similarly, if d
l
(w
r
) = 0, we perform a right-shift of 2 units on w
r
, and
otherwise, we perform a right-shift of 1 unit.
Let l be the line of slope +1 passing through w
l
’s newly created maximal right port. Let
r be the line of slope −1 passing through w
r
’s newly created maximal ...