ns_cavegen/lua/engine.lua

294 lines
8.5 KiB
Lua
Raw Normal View History

2024-04-18 08:49:45 +00:00
-- Convert 3d relative coordinates to an index on a flat array
local function from_3d_to_flat(dx, dy, dz, nx, ny)
return (nx * ny * dz) + (nx * dy) + dx + 1
end
-- Convert an index on a flat array to 3d relative coordinates
local function from_flat_to_3d(i, nx, ny)
return {
dx = (i - 1) % nx,
2024-04-18 12:17:38 +00:00
dy = math.floor((i - 1) / nx) % ny,
dz = math.floor((i - 1) / (nx * ny))
2024-04-18 08:49:45 +00:00
}
end
-- Iterate over a 3d area, both indexing by the index and the ansolute position
local function iter_3d_area(minp, maxp, callback)
local nx = maxp.x - minp.x + 1
local ny = maxp.y - minp.y + 1
local nz = maxp.z - minp.z + 1
for i = 1, nx * ny * nz do
local dpos = from_flat_to_3d(i, nx, ny)
local pos = {
2024-04-18 12:17:38 +00:00
x = minp.x + dpos.dx,
y = minp.y + dpos.dy,
z = minp.z + dpos.dz,
2024-04-18 08:49:45 +00:00
}
callback(i, pos)
end
end
-- Get an enhanced function from the def function that warns us when the
-- function does not behave properly
local function enhanced_func(def)
if type(def.name) ~= "string" then
error("Invalid nameless shape definition")
elseif type(def.func) ~= "function" then
error(
"Invalid shape definition misses an adjustment function"
)
else
return function(pos, n)
local out = def.func(pos, n)
if type(out) == "number" then
return out
elseif n == nil then
error(
"Shape " .. def.name .. " function must return a number. The input `n` was nil. Perhaps your `noise_params` field is invalid?"
)
else
error("Shape " .. def.name .. " function must return a number.")
end
end
end
end
-- Get a flat array of cave shape noise values from a given cave shape def
local function get_flat_from_shape_def(def, minp, maxp)
local f = enhanced_func(def)
local nx = maxp.x - minp.x + 1
local ny = maxp.y - minp.y + 1
local nz = maxp.z - minp.z + 1
local noise_flat_map = {}
-- If noise parameters have been defined, fill the table with noise
-- If not, all values remain nil
if def.noise_params ~= nil then
local p = PerlinNoiseMap(def.noise_params, { x = nx, y = ny, z = nz })
if nz == 1 then
p:get_2d_map_flat(minp, noise_flat_map)
else
p:get_3d_map_flat(minp, noise_flat_map)
end
end
iter_3d_area(minp, maxp, function(i, pos)
noise_flat_map[i] = f(pos, noise_flat_map[i])
end)
return noise_flat_map
end
local function get_flat_from_noise_params(minp, maxp, noise_params)
local nx = maxp.x - minp.x + 1
local ny = maxp.y - minp.y + 1
local nz = maxp.z - minp.z + 1
local buffer = {}
local p = PerlinNoiseMap(noise_params, { x = nx, y = ny, z = nz })
if nz == 1 then
p:get_2d_map_flat(minp, buffer)
else
p:get_3d_map_flat(minp, buffer)
end
return buffer
end
-- Based on the number of cave shapes, calculate how quickly connectivity is
-- meant to change
local function get_connectivity_noise_params(shape_size)
local factor = math.max(math.abs(shape_size) ^ 0.5, 1)
return {
offset = 50,
scale = 50,
spread = { x = factor * 250, y = factor * 100, z = factor * 250 },
seed = 297948,
octaves = 2,
persistence = 0.2,
lacunarity = 2.0,
flags = "eased"
}
end
-- Based on the number of cave shapes, calculate how quickly verticality is
-- meant to change
local function get_verticality_noise_params(shape_size)
local factor = math.max(math.abs(shape_size) ^ 0.5, 1)
return {
offset = 50,
scale = 50,
spread = { x = factor * 100, y = factor * 250, z = factor * 100 },
seed = 35644,
octaves = 2,
persistence = 0.2,
lacunarity = 2.0,
flags = "eased"
}
end
-- Get the distance of each cave shape to calculate their weight.
local function shape_distance_weight(shape_size, dx, dy)
local factor = math.max(math.abs(shape_size) ^ 0.5, 1)
local max_distance = 100 / factor
if dx^2 + dy^2 > max_distance^2 then
return 0
else
return 1 / (dx^5 + dy^5)
end
end
-- Get a flat map containing all flat threshold values
local function get_threshold_flat(minp, maxp)
local connectivity = get_flat_from_noise_params(
minp, maxp,
get_connectivity_noise_params(#noordstar_caves.registered_shapes)
)
local verticality = get_flat_from_noise_params(
minp, maxp,
get_verticality_noise_params(#noordstar_caves.registered_shapes)
)
local noise = {}
-- Get noise for all cave shapes
for key, def in pairs(noordstar_caves.registered_shapes) do
noise[key] = {
key = key,
noise = get_flat_from_shape_def(def, minp, maxp),
def = def
}
end
local thresholds = {}
-- Fill the table
iter_3d_area(minp, maxp, function(i, pos)
local total = 0
local count = 0
local x = connectivity[i]
local y = verticality[i]
for _, n in pairs(noise) do
local v = n.noise[i]
2024-04-18 12:17:38 +00:00
local dx = math.abs(x - n.def.connectivity_point)
local dy = math.abs(y - n.def.verticality_point)
2024-04-18 08:49:45 +00:00
local w = math.abs(shape_distance_weight(
#noordstar_caves.registered_shapes, dx, dy
))
total = total + v * w
count = count + w
end
if count <= 0 then
thresholds[i] = -1000
else
thresholds[i] = total / count
end
end)
return thresholds
end
-- Old minimum height for the overworld
local old_overworld_min = mcl_vars.mg_overworld_min
-- If another mod doesn't override the maximum world depth, we will assume that
-- the world depth is the following value.
local world_depth = -800
-- Otherwise, this variable can be changed using the following function,
-- which will also update all the other necessary variables
function noordstar_caves.set_world_depth(h)
-- Set world depth variable
world_depth = h
end
noordstar_caves.set_world_depth(world_depth)
-- The `cave_vastness` is a variable that determines the size of caves.
-- The function takes in an x, y and z variable, and returns a number between
-- 0 and 1.
-- Low numbers mean very rare and tiny caves, while high numbers mean massive
-- caves, with massive open spaces.
-- If you wish to overwrite this function, it is good to keep in mind to:
-- - Make sure that the output changes VERY SLOWLY over time
-- - This function will be run a LOT so it is very performance sensitive
noordstar_caves.cave_vastness = function(pos)
2024-04-18 12:17:38 +00:00
return pos.y / world_depth
2024-04-18 08:49:45 +00:00
end
-- Secretly, we're using an internal function that also adds a safe layer for
-- when we're approaching bedrock levels
local function cave_vastness(pos)
if world_depth + 20 < pos.y then
return noordstar_caves.cave_vastness(pos)
elseif world_depth + 5 < pos.y then
2024-04-18 12:17:38 +00:00
return noordstar_caves.cave_vastness(pos) * math.abs(pos.y - world_depth - 5) / 15
2024-04-18 08:49:45 +00:00
else
2024-04-18 12:17:38 +00:00
return 0
2024-04-18 08:49:45 +00:00
end
end
2024-04-18 12:17:38 +00:00
local tpd_yet = false
2024-04-18 08:49:45 +00:00
minetest.register_on_generated(function(minp, maxp, blockseed)
2024-04-18 12:17:38 +00:00
if maxp.y < world_depth then
return
end
2024-04-18 08:49:45 +00:00
-- Get voxelmanip
local vm = minetest.get_mapgen_object("voxelmanip")
local data = vm:get_data()
-- Get threshold values
local thresholds = get_threshold_flat(minp, maxp)
2024-04-18 12:17:38 +00:00
local air = minetest.get_content_id("mcl_core:glass")
local count = 0
2024-04-18 08:49:45 +00:00
iter_3d_area(minp, maxp, function(i, pos)
2024-04-18 12:17:38 +00:00
local nx = maxp.x - minp.x + 1 + 32
local ny = maxp.y - minp.y + 1 + 32
local dx = pos.x - minp.x
local dy = pos.y - minp.y
local dz = pos.z - minp.z
local vi = from_3d_to_flat(dx + 16, dy + 16, dz + 16, nx, ny)
if not data[vi] then
error("Vi is not in data (len " .. #data .. "): " .. vi .. " for (dx, dy, dz) = (" .. dx .. ", " .. dy .. ", " .. dz .. ") with minp = (" .. minp.x .. ", " .. minp.y .. ", " .. minp.z .. ") and maxp = (" .. maxp.x .. ", " .. maxp.y .. ", " .. maxp.z .. ") and pos = (" .. pos.x .. ", " .. pos.y .. ", " .. pos.z .. ")")
end
if thresholds[i] >= (1 - cave_vastness(pos)) then
data[vi] = air
count = count + 1
2024-04-18 08:49:45 +00:00
end
end)
-- Write all changes to the Minetest world
vm:set_data(data)
vm:write_to_map()
2024-04-18 12:17:38 +00:00
minetest.chat_send_all("Updated " .. count .. " squares")
2024-04-18 08:49:45 +00:00
end)