Game Development Reference
In-Depth Information
56
x1
=
$window
.
width
-
WIDTH
-
PADDING
57
x2
=
$window
.
width
-
PADDING
58
y1
=
$window
.
height
-
HEIGHT
-
PADDING
59
y2
=
$window
.
height
-
PADDING
60
[
x1, x2, y1, y2
]
61
end
62
end
Radar
, like
Camera
, also has a target. It uses
ObjectPool
to query nearby objects and
filters out instances of alive
Tank
. Then it draws a transparent black background and small
dots for each tank, green for target, red for the rest.
To avoid querying
ObjectPool
too often,
Radar
updates itself only once every second.
It is initialized, updated and drawn in
PlayState
, right after
Camera
:
class
PlayState
<
GameState
# ...
def
initialize
# ...
@camera
.
target
=
@tank
@radar
=
Radar
.
new(
@object_pool
,
@tank
)
# ...
end
# ...
def
update
# ...
@camera
.
update
@radar
.
update
# ...
end
# ...
def
draw
# ...
@camera
.
draw_crosshair
@radar
.
draw
end
# ...
end
Time to enjoy the results.
