shithub: graphical-algorithms

ref: 747c2898908601d3c6c41ea72d70c57be36fd0f7
dir: /sierpinski-chaos/

#!/bin/slug

-- Sierpinski triangle generation using the chaos game algorithm
-- see https://en.wikipedia.org/wiki/Sierpi%C5%84ski_triangle#Chaos_game

x0 = 0
y0 = 0
x1 = 0
y1 = 0
x2 = 0
y2 = 0
x  = 0
y  = 0

function setup()
	size(800, 800)
	x0 = width/2
	y0 = 0
	x1 = 0
	y1 = height
	x2 = width
	y2 = height
	x  = math.floor(math.random(width))
	y  = math.floor(math.random(height))
	background(0)
	strokeWeight(2)
	strokeCap(ROUND)
end

function draw()
	for i = 1, 10 do
		r = math.floor(math.random(3)) - 1
		if r == 0 then
			stroke(255, 0, 0)
			x = math.floor(0.5 + math.lerp(x, x0, 0.5))
			y = math.floor(0.5 + math.lerp(y, y0, 0.5))
			circle(x, y, 1)
		elseif r == 1 then
			stroke(0, 255, 0)
			x = math.floor(0.5 + math.lerp(x, x1, 0.5))
			y = math.floor(0.5 + math.lerp(y, y1, 0.5))
			circle(x, y, 1)
		elseif r == 2 then
			stroke(0, 0, 255)
			x = math.floor(0.5 + math.lerp(x, x2, 0.5))
			y = math.floor(0.5 + math.lerp(y, y2, 0.5))
			circle(x, y, 1)
		end
	end
end