# Circles question

I am trying to write a piece of code which will place a number of circles that do not overlap, just touch at the edges on the screen. However i don’t think my code is doing what I think it is doing. If someone could help that would be great, thanks for any replies.

``````
--# Main

function setup()
num=100
circs={}
for i=1,num do
local x,y=math.random(0,WIDTH),math.random(0,HEIGHT)
local r=math.random(50,100)
for n,c in ipairs(circs) do
local dist=c.pos:dist(vec2(x,y))
dist=dist-c.rad
while dist<=0 do
x,y=math.random(0,WIDTH),math.random(0,HEIGHT)
dist=c.pos:dist(vec2(x,y))
dist=dist-c.rad

end
r=math.min(dist,r)
end
table.insert(circs,Circ(x,y,r))
end
end

function draw()
background(0)
for i=1,#circs do
circs[i]:draw()
end
end

--# Circ
Circ = class()

function Circ:init(x,y,r)
self.pos=vec2(x,y)
self.rad=r
end

function Circ:draw()
pushStyle()
ellipseMode(RADIUS)
fill(255,50)
ellipse(self.pos.x,self.pos.y,self.rad)
popStyle()
end
``````

@Coder You need to create a table that has the x,y,radius values. Then each time you want to create another circle, you need to check each circle in the table to make sure you’re not creating a new circle inside an existing one.

@Coder, the most obvious thing I see is your line `while dist <= 0` this would be ignored unless the circles are exactly on top of each other, or the first one is on the left (i believe). try changing it to `while math.abs(dist) < c.rad + r` this will be true only if the distance between the center of the two circles is less than their radii added together - i.e. they are overlapping

@Coder Here’s an easy way.

``````
displayMode(FULLSCREEN)

function setup()
physics.continuous=true
circ={}
count=0
e1=physics.body(EDGE,vec2(0,0),vec2(0,HEIGHT))
e2=physics.body(EDGE,vec2(0,0),vec2(WIDTH,0))
e3=physics.body(EDGE,vec2(WIDTH,0),vec2(WIDTH,HEIGHT))
end

function draw()
background(40,40,50)
noFill()
stroke(255)
strokeWidth(2)
if count<300 then
count=count+1
c=physics.body(CIRCLE,math.random(5,50))
c.x=math.random(WIDTH)
c.y=1.5*HEIGHT
table.insert(circ,c)
end
for a,b in pairs(circ) do
ellipse(b.x,b.y,b.radius*2+2)
end
end

``````

@Coder Here’s another version.

``````
displayMode(FULLSCREEN)

function setup()
circ={}
loop=0
min=20
max=80
circles=800
while loop<circles do
x=math.random(WIDTH)
y=math.random(HEIGHT)
d=max
ok=true
for a,b in pairs(circ) do
v1=vec2(x,y)
dis=v1:dist(vec2(b.x,b.y))
if dis<b.z/2 then
ok=false
loop=loop+1
elseif dis-b.z/2<d then
d=dis-b.z/2
end
end
if ok then
if d<max then
d=d*2
end
if d>min then
table.insert(circ,vec3(x,y,d))
end
end
end
end

function draw()
background(40, 40, 50)
noFill()
stroke(255)
strokeWidth(2)
for a,b in pairs(circ) do
ellipse(b.x,b.y,b.z+2)
end
end

``````

Here’s another version of non overlapping circles.

``````
displayMode(FULLSCREEN)

function setup()
circ={}
col={}
min=5
max=50
end

function draw()
background(0)
for a,b in pairs(circ) do
fill(col[a])
ellipse(b.x,b.y,b.z+2)
end
x=math.random(WIDTH)
y=math.random(HEIGHT)
d=max
ok=true
for a,b in pairs(circ) do
v1=vec2(x,y)
dis=v1:dist(vec2(b.x,b.y))
if dis<b.z/2 then
ok=false
elseif dis-b.z/2<d then
d=dis-b.z/2
end
end
if ok then
if d<max then
d=d*2
end
if d>min then
table.insert(circ,vec3(x,y,d))
table.insert(col,color(math.random(255),
math.random(255),math.random(255)))
end
end
end

``````

Thanks for the replies everyone, I will have to disect you code to see how it works