Dancing with friends and enemies

main.lua

local G = love.graphics

math.randomseed(os.time())

parts = {}

function find_partner(p)
	while true do
		local q = parts[math.random(#parts)]
		if q ~= p and q ~= p.friend and q ~= p.enemy then
			return q
		end
	end
end


for i = 1, 5000 do
	local p = {
		x = math.random(-100, 100),
		y = math.random(-100, 100),
		c = 0
	}
	p.ox = p.x
	p.oy = p.y
	parts[i] = p
end

function love.update()

	for _, p in ipairs(parts) do


		local vx = p.x - p.ox
		local vy = p.y - p.oy

		p.ox = p.x
		p.oy = p.y

		if p.c == 0 then
			p.friend = find_partner(p)
			p.enemy = find_partner(p)
			p.c = math.random(5000)
		end
		p.c = p.c - 1

		local l = ((p.x^2+p.y^2) * 0.0001) ^ 0.5
		p.x = p.x * (1 - l * 0.001)
		p.y = p.y * (1 - l * 0.001)


		local dx = p.friend.x - p.x
		local dy = p.friend.y - p.y
		local l = 4.3 / (10 + (dx*dx + dy*dy) ^ 0.5)
		p.x = p.x + dx * l
		p.y = p.y + dy * l

		local dx = p.enemy.x - p.x
		local dy = p.enemy.y - p.y
		local l = -0.8 / (10 + (dx*dx + dy*dy) ^ 0.5)
		p.x = p.x + dx * l
		p.y = p.y + dy * l


		p.x = p.x + vx * 0.5
		p.y = p.y + vy * 0.5
	end
end

for _ = 1, 300 do love.update() end

function love.draw()
	G.translate(400, 300)
	G.setColor(255, 255, 255, 15)

--	love.graphics.setBlendMode("add")

	for _, p in ipairs(parts) do
		local rot = math.atan2(p.y - p.oy, p.x - p.ox)
		local l = math.max(1, ((p.x - p.ox) ^ 2 + (p.y - p.oy) ^ 2) ^ 0.4)
		G.push()
		G.translate(p.x, p.y)
		G.rotate(rot)
		G.scale(l, 1)
		G.circle("fill", 0, 0, 3, 4)
		G.pop()

--		G.circle("fill", p.x, p.y, 3, 3)
--		G.line(p.x, p.y, p.friend.x, p.friend.y)
	end
end