sparkle along a ray

[tsh73]

If you run this program
justbasiccom.proboards.com/thread/950/light-lenses-table-simulation-more
and pressed L, you saw how rays grow, one by one.
But after drawing they stay static.

I wonder about way to "liven it up", make it somehow sparkle.
I dunno, make a sparkle (or short burst of sparkles) run along the ray during idle loop?

I got something but it does not look any good.
:(
But it might be a start.

(and by capturing and enlarging I found that dot with "size 3".."size 6" somehow take EVEN pixels height, so it impossible to align it properly over a line)

nomainwin

NN=1000
dim x(NN), y(NN)

open "test" for graphics_nsb_fs as #gr
#gr "home; down; posxy cx cy"
#gr "fill black; flush"
#gr "trapclose [quit]"

N=100
#gr "color white"
#gr "line 0 ";cy-1;" ";2*cx;" ";cy-1
#gr "size 4"
'#gr "size 5"
#gr "rule XOR"  'works for black over white
#gr "rule ";_R2_XORPEN  'for white over black?

'initial placement
x=0
y=cy
   for i = 1 to N
       x=x+int(rnd(0)*100)
       if x > 2*cx then N=i: exit for  'initial N is too big
       x = x mod(2*cx)
       y=cy
       x(i)=x: y(i)=y
       #gr "set ";x(i);" ";y(i)
   next

'wait

dt=10

timer dt, [tick]
wait

[tick]
   for i = 1 to N
   SCAN
       'clear
       #gr "set ";x(i);" ";y(i)
       'move
       x(i)=(x(i)+5) mod(2*cx)
       y(i)=cy
       'redraw
       #gr "set ";x(i);" ";y(i)
   next

wait

wait

[quit]
   timer 0
   close #gr
   end



[plus]

eh! everything I can think that sparkles needs at least 2D graphics and jb not so fast with screen clear graphics, maybe a sparkle sprite or several!

Actually I am seeing something like a burning fuse. Have I ever translated my Basic, Le Bomb, probably not, need lots of fast graphics for explosions.