Game Development Reference
In-Depth Information
hx, hy
=
cx
+
max_distance, cy
+
max_distance
38
# Fast, rough results
39
results
=
@tree
.
query_range(
40
AxisAlignedBoundingBox
.
new(
[
cx, cy
]
,
[
hx, hy
]
))
41
# Sift through to select fine-grained results
42
results
.
select
do
|
o
|
43
o
!=
object
&&
44
Utils
.
distance_between(
45
o
.
x, o
.
y, object
.
x, object
.
y)
<=
max_distance
46
47
end
48
end
49
50
def
query_range
(box)
51
@tree
.
query_range(box)
52
end
53
end
An old fashioned array of all objects is still used, because we still need to loop through
everything and invoke
GameObject#update
.
ObjectPool#query_range
was
introduced to quickly grab objects that have to be rendered on screen, and
ObjectPool#nearby
now queries tree and measures distances only on rough result set.
This is how we will render things from now on:
class
PlayState
<
GameState
# ...
def
draw
cam_x
=
@camera
.
x
cam_y
=
@camera
.
y
off_x
=
$window
.
width
/ 2 -
cam_x
off_y
=
$window
.
height
/ 2 -
cam_y
viewport
=
@camera
.
viewport
x1, x2, y1, y2
=
viewport
box
=
AxisAlignedBoundingBox
.
new(
[
x1
+
(x2
-
x1)
/ 2
, y1
+
(y2
-
y1)
/ 2]
,
[
x1
-
Map
::
TILE_SIZE
, y1
-
Map
::
TILE_SIZE
]
)
$window
.
translate(off_x, off_y)
do
zoom
=
@camera
.
zoom
$window
.
scale(zoom, zoom, cam_x, cam_y)
do
@map
.
draw(viewport)
@object_pool
.
query_range(box)
.
map
do
|
o
|
o
.
draw(viewport)
end
end
