A quick spiral visualization. Written in Lua for PICO-8.

pico-spiral.p8

pico-8 cartridge // http://www.pico-8.com
version 33
__lua__
function _init()
	frme=0
	pi=3.141592653589793
	
	cx=64
	cy=64
	
	size=4
 prtcles={}
 clrs={0,5,6,15,14,8,2,4,9,10,11,3,12,13,1}
	clr_pos=1
end

function _update()
	local fps=stat(8)
	
	frme+=flr(100/fps)
	
	if frme>=32767 then
		frme=0
	end
	
	if frme%16==0 then
		clr_pos+=1
		
		if clr_pos==15 then
			clr_pos=1
		end
	
	end
end

function _draw()
	cls(7)

	local rd=frme*(pi*270)

 add(prtcles,{
  pos={x=cx,y=cy},
  vel={x=cos(rd),y=sin(rd)},
  col=clrs[clr_pos],
  odd=frme%2==0
 })
 
 for i=1,count(prtcles),1 do
		local p=prtcles[i]
  p.pos.x+=p.vel.x
 	p.pos.y+=p.vel.y

		if p.odd then
	 	circfill(p.pos.x,p.pos.y,size-2,p.col)
		else
			circfill(p.pos.x,p.pos.y,size,p.col)
		end
 end
 
 if count(prtcles)>5000 then
 	local st={}

  for i=1,#prtcles,1 do
    st[#st+1]=prtcles[i]
  end
  
  prtcles=st
 end
 
end
__gfx__
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