Graphics Reference
In-Depth Information
The line segments are parallel if the denominator in Eq. (3.69) or Eq. (3.70) is zero. Table 3.2
illustrates the relative positions of the line segments for different values of and .
Table 3.2
a
b
b
b
0
0
0 <<1
1
a
a
a
b
b
0 <<1
0
0 <<1
1
b
a
a
b
a
b
b
1
0
0 <<1
1
a
a
