Game Development Reference

In-Depth Information

Remember that for this collision detection system to work, you need to find out two things:

The distance between the objects

The amount that they're overlapping

The previous line tells how far apart they are and copies that information into a variable called `t.

Technically, the
d
in `t stands for
delta
, but I'll let you off the hook and allow you to think it stands

for
distance
, which is a much more concrete concept to grasp. So `t is the distance between the two

objects on the x axis.

To find out the distance between the two objects, all you need to do is subtract the t position of k^fa_p=

from the t position of k^fa_p>. Sounds too easy to be true? Figure 7-38 explains how this works.

Figure 7-38.
Subtract objectA's position from objectB's position to find the

distance between them.