mirror of
https://github.com/osmarks/random-stuff
synced 2024-10-31 19:06:15 +00:00
127 lines
4.2 KiB
Lua
127 lines
4.2 KiB
Lua
|
-- Perlin noise and more in pure Lua.
|
||
|
-- Found this on stackoverflow but can't find the URL anymore.
|
||
|
local noise = {}
|
||
|
|
||
|
local p = {}
|
||
|
local permutation = {151,160,137,91,90,15,
|
||
|
131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
|
||
|
190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
|
||
|
88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
|
||
|
77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
|
||
|
102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
|
||
|
135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
|
||
|
5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
|
||
|
223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
|
||
|
129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
|
||
|
251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
|
||
|
49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
|
||
|
138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
|
||
|
}
|
||
|
|
||
|
for i = 0, 255 do
|
||
|
p[i] = permutation[i + 1]
|
||
|
p[256 + i] = permutation[i + 1]
|
||
|
end
|
||
|
|
||
|
local function fade(t)
|
||
|
return t * t * t * (t * (t * 6 - 15) + 10)
|
||
|
end
|
||
|
|
||
|
local function lerp(t, a, b)
|
||
|
return a + t * (b - a)
|
||
|
end
|
||
|
|
||
|
local function grad(hash, x, y, z)
|
||
|
local h, u, v = hash % 16
|
||
|
if h < 8 then u = x else u = y end
|
||
|
if h < 4 then v = y elseif h == 12 or h == 14 then v = x else v = z end
|
||
|
local r
|
||
|
if h % 2 == 0 then r = u else r = -u end
|
||
|
if h % 4 == 0 then r = r + v else r = r - v end
|
||
|
return r
|
||
|
end
|
||
|
|
||
|
function noise.perlin(x, y, z)
|
||
|
y = y or 0
|
||
|
z = z or 0
|
||
|
local X = math.floor(x % 255)
|
||
|
local Y = math.floor(y % 255)
|
||
|
local Z = math.floor(z % 255)
|
||
|
x = x - math.floor(x)
|
||
|
y = y - math.floor(y)
|
||
|
z = z - math.floor(z)
|
||
|
local u = fade(x)
|
||
|
local v = fade(y)
|
||
|
local w = fade(z)
|
||
|
|
||
|
A = p[X ] + Y
|
||
|
AA = p[A ] + Z
|
||
|
AB = p[A + 1] + Z
|
||
|
B = p[X + 1] + Y
|
||
|
BA = p[B ] + Z
|
||
|
BB = p[B + 1] + Z
|
||
|
|
||
|
return lerp(w, lerp(v, lerp(u, grad(p[AA ], x , y , z ),
|
||
|
grad(p[BA ], x - 1, y , z )),
|
||
|
lerp(u, grad(p[AB ], x , y - 1, z ),
|
||
|
grad(p[BB ], x - 1, y - 1, z ))),
|
||
|
lerp(v, lerp(u, grad(p[AA + 1], x , y , z - 1),
|
||
|
grad(p[BA + 1], x - 1, y , z - 1)),
|
||
|
lerp(u, grad(p[AB + 1], x , y - 1, z - 1),
|
||
|
grad(p[BB + 1], x - 1, y - 1, z - 1))))
|
||
|
end
|
||
|
|
||
|
function noise.fbm(x, y, z, octaves, lacunarity, gain)
|
||
|
octaves = octaves or 8
|
||
|
lacunarity = lacunarity or 2
|
||
|
gain = gain or 0.5
|
||
|
local amplitude = 1.0
|
||
|
local frequency = 1.0
|
||
|
local sum = 0.0
|
||
|
for i = 0, octaves do
|
||
|
sum = sum + amplitude * noise.perlin(x * frequency, y * frequency, z * frequency)
|
||
|
amplitude = amplitude * gain
|
||
|
frequency = frequency * lacunarity
|
||
|
end
|
||
|
return sum
|
||
|
end
|
||
|
|
||
|
local holo = peripheral.find "hologram"
|
||
|
|
||
|
local W = 48
|
||
|
local H = 32
|
||
|
|
||
|
local perlin = noise.perlin
|
||
|
|
||
|
holo.setPaletteColor(1, 0x0000FF)
|
||
|
holo.setPaletteColor(2, 0x00FFFF)
|
||
|
holo.setPaletteColor(3, 0x00FF00)
|
||
|
|
||
|
holo.setScale(1/3)
|
||
|
while true do
|
||
|
local out = {}
|
||
|
for x = 1, W do
|
||
|
for z = 1, W do
|
||
|
local y = perlin(x / W * 4, z / W * 4, os.clock())
|
||
|
y = math.floor((y + 1) * (H / 2))
|
||
|
local apiaristics = perlin(x / W * 0.5, z / W * 0.5, os.clock() * 0.2 - 6) * 2.7
|
||
|
apiaristics = math.min(1.9, math.max(-1.9, apiaristics))
|
||
|
for Y = 1, y do
|
||
|
local color = 2
|
||
|
if apiaristics < -0.2 then
|
||
|
if math.random() < (math.abs(apiaristics) - 0.2) then
|
||
|
color = 1
|
||
|
end
|
||
|
elseif apiaristics > 0.2 then
|
||
|
if math.random() < (math.abs(apiaristics) - 0.2) then
|
||
|
color = 3
|
||
|
end
|
||
|
end
|
||
|
table.insert(out, string.char(color))
|
||
|
end --table.insert(out, (string.char(color)):rep(y) .. ("\x00"):rep(H - y))
|
||
|
table.insert(out, ("\x00"):rep(H - y))
|
||
|
end
|
||
|
end
|
||
|
holo.setRaw(table.concat(out))
|
||
|
sleep(0.1)
|
||
|
end
|