FractalNoise

-- x, y, z are the positions to sample
-- iter is how many iterations (octaves) of the noise (default: 1)
-- amp is the amplitude factor (default: 0.5)
-- freq is the frequency factor (default: 2)

-- returns a fractal noise value in the range [-1.0, 1.0]
function genFractalNoise2(x, y, iter, amp, freq)
    val = love.math.noise(x, y)*2-1
    freq = freq or 2
    iter = iter or 1
    amp = amp or 0.5
    local n = 0
    while n < iter-1 do
        val = val + (love.math.noise(x*freq, y*freq)*2-1)*amp
        freq = freq * freq
        amp = amp * amp
        n = n + 1
    end
    return math.max(math.min(val, 1.0), -1.0)
end

-- returns a fractal noise value in the range [-1.0, 1.0]
function genFractalNoise3(x, y, z, iter, amp, freq)
    local val = love.math.noise(x, y, z)*2-1
    freq = freq or 2
    iter = iter or 1
    amp = amp or 0.5
    local n = 0
    while n < iter-1 do
        val = val + (love.math.noise(x*freq, y*freq, z*freq)*2-1)*amp
        freq = freq * freq
        amp = amp * amp
        n = n + 1
    end
    return math.max(math.min(val, 1.0), -1.0)
end