View.Set ("graphics:1000;600,offscreenonly")
for clr : 1 .. 100
RGB.SetColor (clr + 100, (clr + 50) * 2, (clr + 50) * 2, (clr + 50) * 2)
end for
var scale := 10
const mxm := 100
const renewal := 50
const SOL := 1.5
const freqlength := 30

type Emitter :
record
x, y, vx, vy : real
xx : array 1 .. mxm of real
yy : array 1 .. mxm of real
rr : array 1 .. mxm of real
i : int
end record



color (white)
colorback (black)
cls



proc initializeEmitter (var e : Emitter, x, y, vangle, vmag : real)
e.x := x
e.y := y
e.vx := cosd (vangle) * vmag
e.vy := sind (vangle) * vmag
for i : 1 .. mxm
e.xx (i) := e.x
e.yy (i) := e.y
e.rr (i) := 10
end for
e.i := 1
end initializeEmitter





proc drawEmitter (e : Emitter, c1, c2 : int)
for i : 1 .. mxm
drawoval (round (e.xx (i) / scale) + (maxx div 2), round (e.yy (i) / scale) + (maxy div 2), round (e.rr (i) / scale), round (e.rr (i) / scale), (((round (e.rr (i) / scale) div freqlength)
mod (c2 - c1))) + c1)
end for
drawfilloval (round (e.x / scale) + (maxx div 2), round (e.y / scale) + (maxy div 2), 5, 5, white)
end drawEmitter

proc moveEmitter (var e : Emitter)
e.x += e.vx
e.y += e.vy
e.i += 1
if e.i >= mxm * renewal then
e.i := 1
end if
e.xx (1 + (e.i div renewal)) := e.x
e.yy (1 + (e.i div renewal)) := e.y
e.rr (1 + (e.i div renewal)) := 10
for i : 1 .. mxm
e.rr (i) += SOL
end for

end moveEmitter



var e1, e2, e3 : Emitter
initializeEmitter (e1, 500, 0, 20, .8)
initializeEmitter (e2, -2000, 0, 200, 1)
initializeEmitter (e3, -500, 0, 160, 1.3)

loop
moveEmitter (e1)
moveEmitter (e2)
moveEmitter (e3)
drawEmitter (e1, 16, 31)
drawEmitter (e2, 16, 31)
drawEmitter (e3, 16, 31)

View.Update
%cls
end loop