sync on : sync rate 100

#constant scrx screen width()
#constant scry screen height()

#constant sm = 40
#constant sl = 10.0
#constant grav = -0.2
type T
    x# as float
    y# as float
    sx# as float
    sy# as float
endtype
dim S(sm) as T

`vectors
r = make vector2(1)

`Reposition all segments
for a = 1 to sm
    S(a).x# = 512 + a*5
    S(a).y# = 512
next a

do

    cls

    S(1).x# = mousex()
    S(1).y# = scrY - mousey()

    for a = 2 to sm
        HandleSegment(a)
    next a

    sync
loop

function HandleSegment(a)

    `Get the position of the parent segment
    px# = S(a - 1).x#
    py# = S(a - 1).y#
    dx# = S(a).x# - px#
    dy# = S(a).y# - py#
    
    `Gravity
    S(a).sy# = S(a).sy# + grav
    
    `Get the length
    set vector2 1, dx#, dy#
    l# = length vector2(1)
    
    `If the length is bigger than the max
    if l# > sl
    
        `Apply force
        fx# = dx# / l# * S(a).sy#
        fy# = dy# / l# * S(a).sy#
        
        inc S(a).sx#, fx# * 0.8
        if dy# < 0 then inc S(a).sy#, fy#
        
        `Reposition
        S(a).x# = px# + (dx# / l# * sl)
        S(a).y# = py# + (dy# / l# * sl) 
    
    endif

    `the acceleration depends on the mass, but i'll use a standard value
    S(a).sx# = S(a).sx# * 0.8
    S(a).sy# = S(a).sy# * 0.8

    `Update position
    inc S(a).x#, S(a).sx#
    inc S(a).y#, S(a).sy#

    ink rgb(rnd(255), rnd(255), rnd(255)), 0
    line S(a).x#, scry - S(a).y#, px#, scry - py#

endfunction