other_worlds/asteroid_layer_helpers.lua
2020-05-22 16:30:26 +01:00

339 lines
8.4 KiB
Lua

-- submodule
otherworlds.asteroids = {}
-- Approximate realm limits
local XMIN = -33000
local XMAX = 33000
local ZMIN = -33000
local ZMAX = 33000
local ASCOT = 1.0 -- Large asteroid / comet nucleus noise threshold
local SASCOT = 1.0 -- Small asteroid / comet nucleus noise threshold
local STOT = 0.125 -- Asteroid stone threshold
local COBT = 0.05 -- Asteroid cobble threshold
local GRAT = 0.02 -- Asteroid gravel threshold
local ICET = 0.05 -- Comet ice threshold
local ATMOT = -0.2 -- Comet atmosphere threshold
local FISTS = 0.01 -- Fissure noise threshold at surface. Controls size of fissures and amount / size of fissure entrances
local FISEXP = 0.3 -- Fissure expansion rate under surface
local ORECHA = 3*3*3 -- Ore 1/x chance per stone node
local CPCHU = 0 -- Maximum craters per chunk
local CRMIN = 5 -- Crater radius minimum, radius includes dust and obsidian layers
local CRRAN = 8 -- Crater radius range
local random = math.random
local floor = math.floor
-- Note: for fewer large objects: increase the 'spread' numbers in 'np_large' noise parameters. For fewer small objects do the same in 'np_small'. Then tune size with 'ASCOT'
-- 3D Perlin noise 1 for large structures
local np_large = {
offset = 0,
scale = 1,
spread = {x = 256, y = 128, z = 256},
seed = -83928935,
octaves = 5,
persist = 0.6
}
-- 3D Perlin noise 3 for fissures
local np_fissure = {
offset = 0,
scale = 1,
spread = {x = 64, y = 64, z = 64},
seed = -188881,
octaves = 4,
persist = 0.5
}
-- 3D Perlin noise 4 for small structures
local np_small = {
offset = 0,
scale = 1,
spread = {x = 128, y = 64, z = 128},
seed = 1000760700090,
octaves = 4,
persist = 0.6
}
-- 3D Perlin noise 5 for ore selection
local np_ores = {
offset = 0,
scale = 1,
spread = {x = 128, y = 128, z = 128},
seed = -70242,
octaves = 1,
persist = 0.5
}
-- 3D Perlin noise 6 for comet atmosphere
local np_latmos = {
offset = 0,
scale = 1,
spread = {x = 256, y = 128, z = 256},
seed = -83928935,
octaves = 3,
persist = 0.6
}
-- 3D Perlin noise 7 for small comet atmosphere
local np_satmos = {
offset = 0,
scale = 1,
spread = {x = 128, y = 64, z = 128},
seed = 1000760700090,
octaves = 2,
persist = 0.6
}
-- On dignode function. Atmosphere flows into a dug hole.
minetest.register_on_dignode(function(pos, oldnode, digger)
if minetest.find_node_near(pos, 1, {"asteroid:atmos"}) then
minetest.set_node(pos, {name = "asteroid:atmos"})
end
end)
-- Generate on_generated function based on parameters
function otherworlds.asteroids.create_on_generated(ymin, ymax, content_ids)
local YMIN = ymin
local YMAX = ymax
local c_air = content_ids.c_air
local c_stone = content_ids.c_stone
local c_cobble = content_ids.c_cobble
local c_gravel = content_ids.c_gravel
local c_dust = content_ids.c_dust
local c_ironore = content_ids.c_ironore
local c_copperore = content_ids.c_copperore
local c_goldore = content_ids.c_goldore
local c_diamondore = content_ids.c_diamondore
local c_meseore = content_ids.c_meseore
local c_waterice = content_ids.c_waterice
local c_atmos = content_ids.c_atmos
local c_snowblock = content_ids.c_snowblock
local c_obsidian = content_ids.c_obsidian
-- return the function closed over the upvalues we want
return function(minp, maxp, seed)
if minp.x < XMIN or maxp.x > XMAX
or minp.y < YMIN or maxp.y > YMAX
or minp.z < ZMIN or maxp.z > ZMAX then
return
end
local x1 = maxp.x
local y1 = maxp.y
local z1 = maxp.z
local x0 = minp.x
local y0 = minp.y
local z0 = minp.z
-- local t1 = os.clock()
--print ("[asteroid] chunk ("..x0.." "..y0.." "..z0..")")
local sidelen = x1 - x0 + 1 -- chunk side length
--local vplanarea = sidelen ^ 2 -- vertical plane area, used if calculating noise index from x y z
local chulens = {x = sidelen, y = sidelen, z = sidelen}
local minpos = {x = x0, y = y0, z = z0}
local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
local area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}
local data = vm:get_data()
local nvals1 = minetest.get_perlin_map(np_large,
chulens):get3dMap_flat(minpos)
local nvals3 = minetest.get_perlin_map(np_fissure,
chulens):get3dMap_flat(minpos)
local nvals4 = minetest.get_perlin_map(np_small,
chulens):get3dMap_flat(minpos)
local nvals5 = minetest.get_perlin_map(np_ores,
chulens):get3dMap_flat(minpos)
local nvals6 = minetest.get_perlin_map(np_latmos,
chulens):get3dMap_flat(minpos)
local nvals7 = minetest.get_perlin_map(np_satmos,
chulens):get3dMap_flat(minpos)
local ni = 1
for z = z0, z1 do -- for each vertical plane do
for y = y0, y1 do -- for each horizontal row do
local vi = area:index(x0, y, z) -- LVM index for first node in x row
for x = x0, x1 do -- for each node do
local noise1abs = math.abs(nvals1[ni])
local noise4abs = math.abs(nvals4[ni])
local comet = false
-- comet biome
if nvals6[ni] < -(ASCOT + ATMOT)
or (nvals7[ni] < -(SASCOT + ATMOT) and nvals1[ni] < ASCOT) then
comet = true
end
-- if below surface
if noise1abs > ASCOT or noise4abs > SASCOT then
-- noise1dep zero at surface, positive beneath
local noise1dep = noise1abs - ASCOT
-- if no fissure
if math.abs(nvals3[ni]) > FISTS + noise1dep * FISEXP then
-- noise4dep zero at surface, positive beneath
local noise4dep = noise4abs - SASCOT
if not comet
or (comet and (noise1dep > random() + ICET
or noise4dep > random() + ICET)) then
-- asteroid or asteroid materials in comet
if noise1dep >= STOT or noise4dep >= STOT then
-- stone/ores
if random(ORECHA) == 2 then
if nvals5[ni] > 0.6 then
data[vi] = c_goldore
elseif nvals5[ni] < -0.6 then
data[vi] = c_diamondore
elseif nvals5[ni] > 0.2 then
data[vi] = c_meseore
elseif nvals5[ni] < -0.2 then
data[vi] = c_copperore
else
data[vi] = c_ironore
end
else
data[vi] = c_stone
end
elseif noise1dep >= COBT or noise4dep >= COBT then
data[vi] = c_cobble
elseif noise1dep >= GRAT or noise4dep >= GRAT then
data[vi] = c_gravel
else
data[vi] = c_dust
end
else -- comet materials
if noise1dep >= ICET or noise4dep >= ICET then
data[vi] = c_waterice
else
data[vi] = c_snowblock
end
end
elseif comet then -- fissures, if comet then add atmosphere
data[vi] = c_atmos
end
elseif comet then -- if comet atmosphere then
data[vi] = c_atmos
end
ni = ni + 1
vi = vi + 1
end
end
end
-- craters
for ci = 1, CPCHU do -- iterate
-- exponential radius
local cr = CRMIN + floor(random() ^ 2 * CRRAN)
local cx = random(minp.x + cr, maxp.x - cr) -- centre x
local cz = random(minp.z + cr, maxp.z - cr) -- centre z
local comet = false
local surfy = false
for y = y1, y0 + cr, -1 do
local vi = area:index(cx, y, cz) -- LVM index for node
local nodeid = data[vi]
if nodeid == c_dust
or nodeid == c_gravel
or nodeid == c_cobble then
surfy = y
break
elseif nodename == c_snowblock
or nodename == c_waterice then
comet = true
surfy = y
break
end
end
-- if surface found and 8 node space above impact node then
if surfy and y1 - surfy > 8 then
for x = cx - cr, cx + cr do -- for each plane do
for z = cz - cr, cz + cr do -- for each column do
for y = surfy - cr, surfy + cr do -- for each node do
-- LVM index for node
local vi = area:index(x, y, z)
local nr = ((x - cx) ^ 2 + (y - surfy) ^ 2
+ (z - cz) ^ 2) ^ 0.5
if nr <= cr - 2 then
if comet then
data[vi] = c_atmos
else
data[vi] = c_air
end
elseif nr <= cr - 1 then
local nodeid = data[vi]
if nodeid == c_gravel
or nodeid == c_cobble
or nodeid == c_stone
or nodeid == c_diamondore
or nodeid == c_goldore
or nodeid == c_meseore
or nodeid == c_copperore
or nodeid == c_ironore then
data[vi] = c_dust
end
elseif nr <= cr then
local nodeid = data[vi]
if nodeid == c_cobble
or nodeid == c_stone then
data[vi] = c_obsidian -- obsidian buried under dust
end
end
end
end
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 ("[asteroid] time "..chugent.." ms")
data = nil
end
end