mirror of
https://github.com/sbrl/Minetest-WorldEditAdditions.git
synced 2024-11-23 23:53:44 +01:00
131 lines
3.9 KiB
Lua
131 lines
3.9 KiB
Lua
local wea = worldeditadditions
|
|
local wea_c = worldeditadditions_core
|
|
local Vector3 = wea_c.Vector3
|
|
|
|
--- Perlin noise generation engine.
|
|
-- Original code by Ken Perlin: http://mrl.nyu.edu/~perlin/noise/
|
|
-- Port from this StackOverflow answer: https://stackoverflow.com/a/33425812/1460422
|
|
-- @class
|
|
local Perlin = {}
|
|
Perlin.__index = Perlin
|
|
|
|
Perlin.p = {}
|
|
Perlin.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
|
|
}
|
|
Perlin.size = 256
|
|
Perlin.gx = {}
|
|
Perlin.gy = {}
|
|
Perlin.randMax = 256
|
|
|
|
--- Creates a new Perlin instance.
|
|
-- @return Perlin A new perlin instance.
|
|
function Perlin.new()
|
|
local instance = {}
|
|
setmetatable(instance, Perlin)
|
|
instance:load()
|
|
return instance
|
|
end
|
|
|
|
--- Initialises this Perlin instance.
|
|
-- Called automatically by the constructor - you do NOT need to call this
|
|
-- yourself.
|
|
function Perlin:load()
|
|
for i = 1, self.size do
|
|
self.p[i - 1] = self.permutation[i]
|
|
self.p[i + 255] = self.permutation[i]
|
|
end
|
|
end
|
|
|
|
--- Returns a noise value for a given point in 3D space.
|
|
-- @param x number The x co-ordinate.
|
|
-- @param y number The y co-ordinate.
|
|
-- @param z number The z co-ordinate.
|
|
-- @returns number The calculated noise value.
|
|
function Perlin:noise( x, y, z )
|
|
y = y or 0
|
|
z = z or 0
|
|
local xi = wea_c.bit.band(math.floor(x), 255)
|
|
local yi = wea_c.bit.band(math.floor(y), 255)
|
|
local zi = wea_c.bit.band(math.floor(z), 255)
|
|
|
|
-- print("x", x, "y", y, "z", z, "xi", xi, "yi", yi, "zi", zi)
|
|
-- print("p[xi]", self.p[xi])
|
|
x = x - math.floor(x)
|
|
y = y - math.floor(y)
|
|
z = z - math.floor(z)
|
|
local u = self:fade(x)
|
|
local v = self:fade(y)
|
|
local w = self:fade(z)
|
|
local A = self.p[xi] + yi
|
|
local AA = self.p[A] + zi
|
|
local AB = self.p[A + 1] + zi
|
|
local AAA = self.p[AA]
|
|
local ABA = self.p[AB]
|
|
local AAB = self.p[AA + 1]
|
|
local ABB = self.p[AB + 1]
|
|
|
|
local B = self.p[xi + 1] + yi
|
|
local BA = self.p[B] + zi
|
|
local BB = self.p[B + 1] + zi
|
|
local BAA = self.p[BA]
|
|
local BBA = self.p[BB]
|
|
local BAB = self.p[BA + 1]
|
|
local BBB = self.p[BB + 1]
|
|
|
|
-- Add 0.5 to rescale to 0 - 1 instead of -0.5 - +0.5
|
|
return 0.5 + self:lerp(w,
|
|
self:lerp(v,
|
|
self:lerp(u,
|
|
self:grad(AAA,x,y,z),
|
|
self:grad(BAA,x-1,y,z)
|
|
),
|
|
self:lerp(u,
|
|
self:grad(ABA,x,y-1,z),
|
|
self:grad(BBA,x-1,y-1,z)
|
|
)
|
|
),
|
|
self:lerp(v,
|
|
self:lerp(u,
|
|
self:grad(AAB,x,y,z-1), self:grad(BAB,x-1,y,z-1)
|
|
),
|
|
self:lerp(u,
|
|
self:grad(ABB,x,y-1,z-1), self:grad(BBB,x-1,y-1,z-1)
|
|
)
|
|
)
|
|
)
|
|
end
|
|
|
|
function Perlin:fade(t)
|
|
return t * t * t * (t * (t * 6 - 15) + 10)
|
|
end
|
|
|
|
function Perlin:lerp(t, a, b)
|
|
return a + t * (b - a)
|
|
end
|
|
|
|
function Perlin:grad(hash, x, y, z)
|
|
local h = wea_c.bit.band(hash, 15)
|
|
local u = h < 8 and x or y
|
|
local v = h < 4 and y or ((h == 12 or h == 14) and x or z)
|
|
return ((h and 1) == 0 and u or - u) + ((h and 2) == 0 and v or - v)
|
|
end
|
|
|
|
|
|
return Perlin
|