Game Development Reference
In-Depth Information
87
@object
.
gun_angle
= [
actual
-
@retarget_speed
, desired
].
max
88
end
89
elsif
actual
<
desired
90
if
desired
-
actual
> 180
# 360 -> 0 fix
91
@object
.
gun_angle
=
(
360 +
actual
-
@retarget_speed
)
% 360
92
if
@object
.
gun_angle
>
desired
93
@object
.
gun_angle
=
desired
# damp
94
end
95
else
96
@object
.
gun_angle
= [
actual
+
@retarget_speed
, desired
].
min
97
end
98
end
99
end
100
end
There is some math involved, but it is pretty straightforward. We need to find out an angle
between two points, to know where our gun should point, and the other thing we need is
coordinates of point which is in some distance away from source at given angle. Here are
those functions:
module
Utils
# ...
def
self
.
angle_between
(x, y, target_x, target_y)
dx
=
target_x
-
x
dy
=
target_y
-
y
(
180 -
Math
.
atan2(dx, dy)
* 180 /
Math
::
PI
)
+ 360 % 360
end
def
self
.
point_at_distance
(source_x, source_y, angle, distance)
angle
=
(
90 -
angle)
*
Math
::
PI
/ 180
x
=
source_x
+
Math
.
cos(angle)
*
distance
y
=
source_y
-
Math
.
sin(angle)
*
distance
[
x, y
]
end
# ...
end
Implementing AI Input
At this point our tanks can already defend themselves, even through motion is not yet
implemented. Let's wire everything we have in
AiInput
class that we had prepared
earlier. We will need a blank
TankMotionFSM
class with 3 argument initializer and
