stability/init.lua
2014-01-23 04:32:14 +00:00

108 lines
3.0 KiB
Lua

-- stability 0.1.1 by paramat
-- For latest stable Minetest and back to 0.4.8
-- Depends default
-- License: code WTFPL
-- Parameters
local YMIN = 6000
local YMAX = 8000
local TCEN = 7000
local WATY = 7000 -- approximate water y, is rounded down to near base of chunk
local GRAD = 128
local STOT = 0.04
-- 3D noise for terrain
local np_terrain = {
offset = 0,
scale = 1,
spread = {x=256, y=192, z=256},
seed = 5900033,
octaves = 5,
persist = 0.67
}
-- Stuff
stability = {}
waty = (80 * math.floor((WATY + 32) / 80)) - 32 + 12
-- On generated function
minetest.register_on_generated(function(minp, maxp, seed)
if minp.y < YMIN or maxp.y > YMAX then
return
end
local t1 = os.clock()
local x1 = maxp.x
local y1 = maxp.y
local z1 = maxp.z
local x0 = minp.x
local y0 = minp.y
local z0 = minp.z
print ("[stability] chunk minp ("..x0.." "..y0.." "..z0..")")
local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
local data = vm:get_data()
local c_air = minetest.get_content_id("air")
local c_stone = minetest.get_content_id("default:stone")
local c_sand = minetest.get_content_id("default:sand")
local c_water = minetest.get_content_id("default:water_source")
local sidelen = x1 - x0 + 1
local chulens = {x=sidelen, y=sidelen, z=sidelen}
local minpos = {x=x0, y=y0, z=z0}
local nvals_terrain = minetest.get_perlin_map(np_terrain, chulens):get3dMap_flat(minpos)
local ni = 1
local stable = {} -- stability table, a true/false entry for the top node in each vertical column of xy plane
for z = z0, z1 do -- for each xy plane progressing northwards
for x = x0, x1 do -- set initial values of stability table by scanning top x row of chunk below
local si = x - x0 + 1 -- stability table index starts from 1 not 0
local nodename = minetest.get_node({x=x,y=y0-1,z=z}).name
if nodename == "air"
or nodename == "default:water_source" then
stable[si] = false
else -- solid nodes
stable[si] = true -- assume "ignore" in ungenerated chunks is solid
end
end
for y = y0, y1 do -- for each x row progressing upwards
local vi = area:index(x0, y, z) -- get voxel index for first node in x row
for x = x0, x1 do -- for each node do
local si = x - x0 + 1
local grad = (TCEN - y) / GRAD
local density = nvals_terrain[ni] + grad
if density >= STOT then
data[vi] = c_stone
stable[si] = true -- only stone can reset an unstable column to stable
elseif density >= 0 and density < STOT and stable[si] then -- only add if node is stable
data[vi] = c_sand
elseif y <= waty then
data[vi] = c_water
stable[si] = false -- set to unstable
else
data[vi] = c_air
stable[si] = false -- set to unstable
end
ni = ni + 1 -- increment perlinmap noise index
vi = vi + 1 -- increment voxel index along x row
end
end
end
vm:set_data(data)
vm:set_lighting({day=0, night=0})
vm:calc_lighting()
vm:write_to_map(data)
local chugent = math.ceil((os.clock() - t1) * 1000)
print ("[stability] "..chugent.." ms")
end)