Game Development Reference
In-Depth Information
Respawning Tanks And Removing Dead Ones
To implement respawning we could use
Map#find_spawn_point
every time we
wanted to respawn, but it may get slow, because it brute forces the map for random spots
that are not water. We don't want our game to start freezing when tanks are respawning, so
we will change how tank spawning works. Instead of looking for a new respawn point all
the time, we will pre-generate several of them for reuse.
class
Map
# ...
def
spawn_points
(max)
@spawn_points
=
(
0.
.max)
.
map
do
find_spawn_point
end
@spawn_points_pointer
= 0
end
def
spawn_point
@spawn_points
[
(
@spawn_points_pointer
+= 1
)
%
@spawn_points
.
size
]
end
# ...
end
Here we have
spawn_points
method that prepares a number of spawn points and stores
them in
@spawn_points
instance variable, and
spawn_point
method that cycles
through all
@spawn_points
and returns them one by one.
find_spawn_point
can
now become
private
.
We will use
Map#spawn_points
when initializing
PlayState
and pass
ObjectPool
to
PlayerInput
(
AiInput
already has it), so that we will be able to
call
@object_pool.map.spawn_point
when needed.
class
PlayState
<
GameState
# ...
def
initialize
# ...
@map
=
Map
.
new(
@object_pool
)
@map
.
spawn_points(
15
)
@tank
=
Tank
.
new(
@object_pool
,
PlayerInput
.
new(
'Player'
,
@camera
,
@object_pool
))
# ...
10.
times
do
|
i
|
Tank
.
new(
@object_pool
,
AiInput
.
new(
