HTML and CSS Reference
In-Depth Information
In
drawScreen()
, we simply add
xunits
and
yunits
to
ball.x
and
ball.y
. We don't check
to see whether
moves
has been exhausted because we are not moving to a particular
point—we are simply moving along the vector, seemingly forever. In the next section,
we will explore what we can do if we want the moving object to change direction when
it hits something such as a wall:
ball.x += xunits;
ball.y += yunits;
Figure 5-3
shows what
Example 5-3
looks like when it is executed in a web browser.
Recall that the points are drawn for illustration only.
Figure 5-3. Moving an object on a vector
Example 5-3
gives the full code listing.