Game Development Reference
In-Depth Information
Figure 6.4
When you use a negative value for the slope, the line slopes from quadrant II to IV.
the corresponding value on the
y
axis is
3. The same applies to the y-intercept
values. A value of 2 for the y-intercept causes the line to cross the
y
axis at 2.
As the lines in quadrant II of Figure 6.4 reveal, when a domain (
x
) value is
negative, multiplying by a negative slope generates a positive range value. As a
result, the value of
y
continues to grow as
x
becomes more negative. On the other
hand, since the values of
x
are positive, multiplying by a negative slope generates
a negative number, so the range values become more negative in quadrant IV as
the positive value of
x
increases.