collision particles

[Homer_simpson]

i was messing around with the numbers on one of my old physics program and accidentally got a neat effect. particles stick together until they are broken again when they collide with eachother

Quote:

View.Set ("offscreenonly,graphics:700;350")

function distance (x1, y1, x2, y2 : real) : real
result sqrt (((x2 - x1) ** 2) + ((y2 - y1) ** 2)) %y

end distance
function findangle (x1, y1, x2, y2 : real) : real
var ang, slope : real
if not (x2 = x1) then
slope := (y2 - y1) / (x2 - x1)
else
slope := 999999999
end if
ang := arctand (slope)
if slope > 0 then
if y2 < y1 then
ang := 180 + ang
end if
end if
if slope < 0 then
if x2 < x1 then
ang := 180 + ang
end if
if x2 > x1 then
ang := 360 + ang
end if
end if
if slope = 0 then
if x2 > x1 then
ang := 0
end if
if x2 < x1 then
ang := 180
end if
end if
result ang
end findangle
type Particle_Type :
record
x, y, vx, vy, w : real
end record

const MaxParticles := 50

var Particles : array 1 .. MaxParticles of Particle_Type


procedure RenewParticle (var p : Particle_Type, x, y : int, a, r, w : real)
p.x := x
p.y := y
p.vx := a
p.vy := r
p.w := w
end RenewParticle

for i : 1 .. MaxParticles
RenewParticle (Particles (i), Rand.Int (1, 700), Rand.Int (0, 350), 0, 0, Rand.Int (10, 100))
end for
colorback (black)
cls

RenewParticle (Particles (1), 20, 150, 4, 2, Rand.Int (10, 100))
RenewParticle (Particles (2), 500, 150, -4, 2, Rand.Int (10, 100))
var chars : array char of boolean

color (white)
var col := false
var temp1, temp2, temp3, magnitude : real
loop
Input.KeyDown (chars)
if chars ('+') then
end if

for i : 1 .. MaxParticles
if not col then

Particles (i).x += Particles (i).vx
Particles (i).y += Particles (i).vy
end if
drawfilloval (round (Particles (i).x), round (Particles (i).y), 10, 10, gray)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%ball collision%%%%%%%%%%%%%%%%%%%%%%%%
for ii : 1 .. MaxParticles
if distance (Particles (i).x, Particles (i).y, Particles (ii).x, Particles (ii).y) <= 20 and i not= ii then

%put ii
temp1 := findangle (Particles (i).x, Particles (i).y, Particles (ii).x, Particles (ii).y)
temp2 := findangle (0, 0, Particles (ii).vx, Particles (ii).vy)
%put "collision angle = ", temp1
%put "Vellocity angle = ", temp2
%put "relative angle = ", temp2 - temp1
%put "------------"
temp3 := arccosd (-cosd (temp2 - temp1)) + temp1
magnitude :=-2% sqrt ((Particles (ii).vx ** 2) + (Particles (ii).vy ** 2))
/*drawline (round (Particles (i).x), round (Particles (i).y), round (Particles (ii).x), round (Particles (ii).y), red)

drawline (round (Particles (ii).x), round (Particles (ii).y), round (Particles (ii).x) + round (Particles (ii).vx * 4), round (Particles (ii).y) + round (Particles (ii).vy * 4),
yellow)
drawline (round (Particles (ii).x), round (Particles (ii).y), round (Particles (ii).x) + round (cosd (temp3) * magnitude * 4), round (Particles (ii).y) + round (sind (temp3) *
magnitude * 4),
11)

drawline (0, round (Particles (ii).y), 700, round (Particles (ii).y), green)%*/
%col := true
Particles (i).vx := cosd (temp3) * magnitude
Particles (i).vy := sind (temp3) * magnitude
end if
end for
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%ball collision%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%wall collision%%%%%%%%%%%%%%%
if Particles (i).x >= 690 and Particles (i).vx > 0 then
Particles (i).vx := -Particles (i).vx
end if
if Particles (i).x <= 10 and Particles (i).vx < 0 then
Particles (i).vx := -Particles (i).vx
end if
if Particles (i).y >= 340 and Particles (i).vy > 0 then
Particles (i).vy := -Particles (i).vy
end if
if Particles (i).y <= 10 and Particles (i).vy < 0 then
Particles (i).vy := -Particles (i).vy
end if
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%wall collision%%%%%%%%%%%%%%%



end for
View.Update
cls

end loop

[Homer_simpson]

here's a slightly different effect:

Quote:

View.Set ("offscreenonly,graphics:700;350")

function distance (x1, y1, x2, y2 : real) : real
result sqrt (((x2 - x1) ** 2) + ((y2 - y1) ** 2)) %y

end distance
function findangle (x1, y1, x2, y2 : real) : real
var ang, slope : real
if not (x2 = x1) then
slope := (y2 - y1) / (x2 - x1)
else
slope := 999999999
end if
ang := arctand (slope)
if slope > 0 then
if y2 < y1 then
ang := 180 + ang
end if
end if
if slope < 0 then
if x2 < x1 then
ang := 180 + ang
end if
if x2 > x1 then
ang := 360 + ang
end if
end if
if slope = 0 then
if x2 > x1 then
ang := 0
end if
if x2 < x1 then
ang := 180
end if
end if
result ang
end findangle
type Particle_Type :
record
x, y, vx, vy, w : real
end record

const MaxParticles := 50

var Particles : array 1 .. MaxParticles of Particle_Type


procedure RenewParticle (var p : Particle_Type, x, y : int, a, r, w : real)
p.x := x
p.y := y
p.vx := a
p.vy := r
p.w := w
end RenewParticle

for i : 1 .. MaxParticles
RenewParticle (Particles (i), Rand.Int (1, 700), Rand.Int (0, 350), 1, 1, Rand.Int (10, 100))
end for
colorback (black)
cls

RenewParticle (Particles (1), 20, 150, 4, 2, Rand.Int (10, 100))
RenewParticle (Particles (2), 500, 150, -4, 2, Rand.Int (10, 100))
var chars : array char of boolean

color (white)
var col := false
var temp1, temp2, temp3, magnitude : real
loop
Input.KeyDown (chars)
if chars ('+') then
end if

for i : 1 .. MaxParticles
if not col then

Particles (i).x += Particles (i).vx
Particles (i).y += Particles (i).vy
end if
drawfilloval (round (Particles (i).x), round (Particles (i).y), 10, 10, gray)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%ball collision%%%%%%%%%%%%%%%%%%%%%%%%
for ii : 1 .. MaxParticles
if distance (Particles (i).x, Particles (i).y, Particles (ii).x, Particles (ii).y) <= 20 and i not= ii then

%put ii
temp1 := findangle (Particles (i).x, Particles (i).y, Particles (ii).x, Particles (ii).y)
temp2 := findangle (0, 0, Particles (ii).vx, Particles (ii).vy)
%put "collision angle = ", temp1
%put "Vellocity angle = ", temp2
%put "relative angle = ", temp2 - temp1
%put "------------"
temp3 := arcsind (-sind (temp2 - temp1)) + temp1
magnitude := sqrt ((Particles (i).vx ** 2) + (Particles (i).vy ** 2)) * 1.05
if magnitude > 11 then
magnitude := 1
end if
/*drawline (round (Particles (i).x), round (Particles (i).y), round (Particles (ii).x), round (Particles (ii).y), red)

drawline (round (Particles (ii).x), round (Particles (ii).y), round (Particles (ii).x) + round (Particles (ii).vx * 4), round (Particles (ii).y) + round (Particles (ii).vy * 4),
yellow)
drawline (round (Particles (ii).x), round (Particles (ii).y), round (Particles (ii).x) + round (cosd (temp3) * magnitude * 4), round (Particles (ii).y) + round (sind (temp3) *
magnitude * 4),
11)

drawline (0, round (Particles (ii).y), 700, round (Particles (ii).y), green)%*/
%col := true
Particles (i).vx := cosd (temp3) * magnitude
Particles (i).vy := sind (temp3) * magnitude
end if
end for
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%ball collision%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%wall collision%%%%%%%%%%%%%%%
if Particles (i).x >= 690 and Particles (i).vx > 0 then
Particles (i).vx := -Particles (i).vx
end if
if Particles (i).x <= 10 and Particles (i).vx < 0 then
Particles (i).vx := -Particles (i).vx
end if
if Particles (i).y >= 340 and Particles (i).vy > 0 then
Particles (i).vy := -Particles (i).vy
end if
if Particles (i).y <= 10 and Particles (i).vy < 0 then
Particles (i).vy := -Particles (i).vy
end if
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%wall collision%%%%%%%%%%%%%%%



end for
View.Update
cls

end loop