gen_smooth_noise

gen.lua

local lerp = function(a, b, amount)
	return a + (b - a) * (amount < 0 and 0 or (amount > 1 and 1 or amount))
end

function gen_smooth_noise(width, height, baseNoise, octave)
	local bit = require("bit")
	local idata = love.image.newImageData( width, height )
	
	-- Sample period = 2 ^ octave;
	local samplePeriod = bit.lshift(1, octave)
	local sampleFrequency = 1 / samplePeriod;

	local y, sample_y0, sample_y1, vert_blend
	local x, sample_x0, sample_x1, horz_blend
	local top, bot, val
	for y = 0, height-1 do
		-- Calculate vertical sample index
		sample_y0 = (y / samplePeriod)*samplePeriod
		sample_y1 = math.fmod((sample_y0 + samplePeriod), height)
		vert_blend = (y - sample_y0) * sampleFrequency

		for x = 0, width-1 do
			-- Calculate horizontal sample index
			sample_x0 = (x / samplePeriod)*samplePeriod	-- Automaticaly floors
			sample_x1 = math.fmod((sample_x0 + samplePeriod), width)	-- Wraps
			horz_blend = (x - sample_x0) * sampleFrequency

			top = lerp(baseNoise[sample_x0 + (width*sample_y0)], baseNoise[sample_x1 + (width*sample_y0)], horz_blend)
			bot = lerp(baseNoise[sample_x0 + (width*sample_y1)], baseNoise[sample_x1 + (width*sample_y1)], horz_blend)
			
			-- Round the value to a flat integer between 0 and 255
			val = lerp(top, bot, vert_blend)*255
			val = val >= 0 and math.floor(val + .5) or math.ceil(val - .5)
			
			idata:setPixel(x, y, val, val, val, 255)
		end
	end

	return idata
end

main.lua

local gen = require("gen")
local coolpic

function love.load(args)
	local width, height = 64, 64
	local noise = {}
	local x, y
	for y = 0, height-1 do
		for x = 0, width-1 do
			noise[x + width * y] = love.math.random()
		end
	end
	
	coolpic = love.graphics.newImage(gen_smooth_noise(width, height, noise, 3))
end

function love.draw()
	love.graphics.draw(coolpic)
end