[REBOL] Re: Slow map generator
From: nitsch-lists:netcologne at: 9-Nov-2001 10:30
RE: [REBOL] Slow map generator
[oliva--david--seznam--cz] wrote:
> Slow map generator
> > I know, that Rebol is not the best tool for things like that, but I cannot help myself...
> ....Does anybody know how to speed up the script below somehow?
>
> What's so slow? I'm going thru a matrix (image in this example) to create random heights
of the map and then several times to make somethink like erosion of the land. I need
to find adjacent cells in the matrix and that's the slow thing I think:-)
>
> Holger, do you think it would be posible to make some native support for that kind
of operations (matrix neighbours) I would find it useful in more of my scripts (in the
RBox2 as well) - it's always the slowest part?
>
> thank you, Oldes
> ;----------------------------------
Hi Oldes!
speeded it up 3*, from 45 sec down to 15 sec now (350Mhz).
not really fast, but could give 2-sec framerates.
well, gives that rate now.. run script :-)
note it keeps the wall-fields constant now,
that way i drop border-checking.
-Volker
rebol [title: "stars coming out"]
;map_size_x: 10 map_size_y: 10
map_size_x: 200 map_size_y: 200
random/seed 1000
height_map: make block! (map_size_x * map_size_y)
set-pixel: func [
im [image!]
x [integer!]
y [integer!]
color [tuple!]
/local x-siz y-siz siz
] [
x-siz: im/size/x
y-siz: im/size/y
poke im (y-siz - y * x-siz + x) color
]
t: now/precise/time
for y 1 map_size_y 1 [
for x 1 map_size_x 1 [
insert tail height_map (random 40 + ((500 - abs (map_size_y / 2 - y)) / 10))
]
]
;probe t: now/time/precise - t
map_adjust_y: func [y] [either y < 1 [map_size_y] [either y > map_size_y [1] [y]]]
map_adjust_x: func [x] [either x < 1 [map_size_x] [either x > map_size_x [1] [x]]]
get_hmap: func [x y] [pick height_map ((y - 1) * map_size_y + x)]
set_hmap: func [x y val] [poke height_map ((y - 1) * map_size_y + x) val]
;we use skip as implicit + 1
map2: copy/deep height_map
smooth_map: func [] [
repeat y-1 map_size_y - 2 [
c.y-1: at height_map y-1 - 1 * map_size_y
c.y: skip c.y-1 map_size_y
c.y+1: skip c.y map_size_y
repeat x-1 map_size_x - 2 [
x: x-1 + 1 x+1: x-1 + 2
a: 2 * c.y/:x
+ c.y-1/:x-1 + c.y-1/:x + c.y-1/:x+1
+ c.y/:x-1 + c.y/:x+1
+ c.y+1/:x-1 + c.y+1/:x + c.y+1/:x+1
;d: at map2 index? c.y
;poke d x 0.1 * max (a - 30 + random 60) 0
poke c.y x 0.1 * max (a - 30 + random 60) 0
]
]
;set [height_map map2] reduce [map2 height_map]
]
peeks: make block! 40
do [
loop 20 [
x: random map_size_x
y: random map_size_y
insert tail peeks reduce [x y]
set_hmap x y 255
x: x - 1
set_hmap x y min (60 + get_hmap x y) 255
y: y - 1
set_hmap x y min (60 + get_hmap x y) 255
]
]
/do [
t: now/precise/time
loop 8 [smooth_map] ;really slow loop (map erosion)
;loop 1 [smooth_map] ;really slow loop (map erosion)
probe t: now/time/precise - t
]
do [
map-img: make image! to-pair reduce [map_size_x map_size_y]
do make-map-image: does [
forall height_map [
poke map-img index? height_map 1.1.1 * first height_map
]
foreach [x y] peeks [set-pixel map-img x y 255.100.0]
height_map: head height_map
]
view center-face layout lay: [
size 400x400
backdrop
map-img effect [fit luma 10 contrast] 400x400
[quit]
rate :00:02 feel [engage: func [face act e] [
if act = 'time [
t: now/precise/time
smooth_map
t: now/precise/time - t
make-map-image face/image: map-img show face
timer/text: mold t show timer
]]
]
across label "smoth-secs:" font-color gray
timer: info 100x24 center font-color gray + 30.30.30
". o O o ."
at 240x10 title "Stars comming out.." gray
do []
]
]
