-- genuary #13 2023
-- something you've always wanted to learn
-- by carson kompon
-- resource: https://datagenetics.com/blog/july22018
points={}
col=1.1
drag=0.999
grav=0
objs={}
function create_obj(pts,c)
obj={
pts=pts,c=c,
sticka={},stickb={},sticklen={}
}
ptlen=#pts
if ptlen>1 then
for i=1,ptlen do
nxt=1+(i)%ptlen
obj.sticka[i]=i
obj.stickb[i]=nxt
dx=pts[i].x-pts[nxt].x
dy=pts[i].y-pts[nxt].y
obj.sticklen[i]=sqrt((dx*dx)+(dy*dy))
end
end
add(objs,obj)
end
function objs_update_points()
for i=1,#objs do
a=objs[i]
for j=1,#a.pts do
o=a.pts[j]
vx=(o.x-o.xprev)*drag
vy=(o.y-o.yprev)*drag
mdx=mx-o.x
mdy=my-o.y
if ((mdx*mdx)+(mdy*mdy))<64 then
vx+=(mx-lmx)/3
vy+=(my-lmy)/3
end
o.xprev=o.x
o.yprev=o.y
o.x+=vx
o.y+=vy
o.y+=grav
end
end
end
function objs_constrain_points()
for i=1,#objs do
a=objs[i]
for j=1,#a.pts do
o=a.pts[j]
if o.x>(128-o.r) then
o.x=128-o.r
o.xprev=o.x+(vx*col)
elseif o.x<o.r then
o.x=o.r
o.xprev=o.x+(vx*col)
end
if o.y>(128-o.r) then
o.y=128-o.r
o.yprev=o.y+(vy*col)
elseif o.y<o.r then
o.y=o.r
o.yprev=o.y+(vy*col)
end
end
end
end
function objs_update_sticks()
for i=1,#objs do
a=objs[i]
for j=1,#a.sticka do
o=a.pts[a.sticka[j]]
par=a.pts[a.stickb[j]]
dx=o.x-par.x
dy=o.y-par.y
dist=sqrt((dx*dx)+(dy*dy))
am=((dist-a.sticklen[j])/dist)/2
o.x-=dx*am
o.y-=dy*am
par.x+=dx*am
par.y+=dy*am
end
end
end
function objs_draw()
for i=1,#objs do
a=objs[i]
if #a.pts > 1 then
for j=1,#a.sticka do
lx1=a.pts[a.sticka[j]].x
ly1=a.pts[a.sticka[j]].y
lx2=a.pts[a.stickb[j]].x
ly2=a.pts[a.stickb[j]].y
line(lx1,ly1,lx2,ly2,a.c)
end
end
for j=1,#a.pts do
o=a.pts[j]
circfill(o.x,o.y,o.r,a.c)
end
end
end
function create_point(x,y,xprev,yprev)
xprev=xprev or x+rnd(2)-1
yprev=yprev or y+rnd(2)-1
return {
x=x,y=y,r=1.5,
xprev=xprev,yprev=yprev,
}
end
--[[
for i=1,20 do
px=rnd(128)
py=rnd(128)
ppx=px+(rnd(2)-1)*5
ppy=py+(rnd(2)-1)*5
p=create_point(px,py,ppx,ppy)
ang=rnd()
dst=6+rnd()*16
create_point(
px+cos(ang)*dst,
py+sin(ang)*dst,
px,py,p
)
end
]]--
poke(0x5f2d, 1)
lmx=stat(32)
lmy=stat(33)
for i=1,6 do
pts={}
basept=create_point(rnd(128),rnd(128))
add(pts,basept)
siz=2+rnd(2)\1
for j=1,siz do
add(pts,create_point(basept.x+rnd(64)-32,basept.y+rnd(64)-32))
end
create_obj(pts,i)
end
::_::
cls()
mx=stat(32)
my=stat(33)
mc=stat(34)
objs_update_points()
objs_constrain_points()
objs_update_sticks()
objs_draw()
circfill(mx,my,1,7)
lmx=mx
lmy=my
flip()
goto _
