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