mars_game/mods/cratermg/mapgen.lua

505 lines
15 KiB
Lua

--[[
Crater MG - Crater Map Generator for Minetest
(c) Pierre-Yves Rollo
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
--]]
local debris = {}
local debristotalchance = 0
function cratermg.register_debris(def)
if not def.chance or def.chance < 0 then
return
end
local def = table.copy(def)
def.cid = minetest.get_content_id(def.name)
debristotalchance = debristotalchance + def.chance
debris[#debris + 1] = def
end
-- Simplification of math.fuctions call
local min = math.min
local max = math.max
local ceil = math.ceil
local floor = math.floor
local random = math.random
-- On map gen init, get map seed
cratermg.mapseed = 0
minetest.register_on_mapgen_init(function(mapgen_params)
-- Note on map seed: Lua does not seem to be able to correctly handle 64
-- bits integer so the 3 last digits are rounded. Same if we add small
-- numbers to the 64bits key, rounded result will not include small
-- number adition. So key is restricted to (inaccurate) 32 lower bits
cratermg.mapseed = mapgen_params.seed % (2^32)
end
)
-- Caclulate noise amplitude once for all
local small_noise_amplitude = cratermg.get_noise_amplitude(cratermg.noises.small)
-- Undersample scale for hills noise
local us_scale = 16
local function proba(radius)
if radius < 0 then return 0 end
local prev = { r = 0, p = 0 }
for _, next in ipairs(cratermg.probacurve) do
if radius < next.r then
return prev.p + (next.p - prev.p) * (radius - prev.r)
/ (next.r - prev.r)
end
prev = next
end
return 0
end
-- Scales
local scales = {
{ seed = 1234, rmin = 0, rmax = 80, mapsize = 80, maxproba = 1 },
{ seed = 5678, rmin = 80, rmax = 400, mapsize = 400, maxproba = proba(80) },
}
-- Scale calculated fields
local maxscalesize = 0
for _, scale in pairs(scales) do
-- sector seed y multiplier
scale.zseed = math.floor(32768 / scale.mapsize)
-- number of crater attemps multiplier (depends on the max proba and the map size)
scale.nummult = scale.maxproba * (scale.rmax - scale.rmin) * scale.mapsize * scale.mapsize
if maxscalesize < scale.mapsize then maxscalesize = scale.mapsize end
end
-- Reused mapgen vars
local mapdata = {}
local marenoise, hillnoise, smallnoise
local crack1noise, crack2noise, cracksizenoise
local maremap = {}
local hillmap = {}
local smallmap = {}
local crack1map = {}
local crack2map = {}
local cracksizemap = {}
local us_hillmap = {} -- Undersampled map for gross hill detection
-- Standard curves functions
local function get_peak_curve(d2, r2, dispertion)
-- d2 : distance^2 from center
-- r2 : ray^2 at which curve intersects 0
-- dispertion : shape of the peak (small value = thin peak)
return dispertion * (r2 - d2) / r2 / (d2 + dispertion)
end
local function get_parabolic_curve(d2, r2)
-- d2 : distance^2 from center
-- r2 : ray^2 at which curve intersects 0
return (r2 - d2) / r2
end
local function get_fill_height(crater, d2)
return get_parabolic_curve(d2, crater.holeR2) * crater.fill_mult
end
local function get_hole_height(crater, d2)
return get_parabolic_curve(d2, crater.holeR2) * crater.depth
end
-- Computes crater influence at a given distance
-- crater: crater array containing its caracteristics
-- smallmap: value of small noise at given point
-- ground_level: ground level before the crater happens
-- d2: Square of the distance to the crater center
local function compute_crater_deformation(crater, smallmap, ground_level, d2)
if d2 <= crater.totalR2 then
-- Min and max level of changes in map due to the crater
local min_level = ground_level
local max_level = ground_level
local fill_level, debris_level
-- Heights and levels
local debris_curve = get_peak_curve(d2, crater.holeR2, 20)
local edge_height = get_peak_curve(d2, crater.totalR2, 5)
* crater.edge_mult * (smallmap / small_noise_amplitude + 1)
local fill_height = get_fill_height(crater, d2)
local hole_level = crater.y - get_hole_height(crater, d2)
-- Ejected sediments
local edge_level = ground_level + edge_height --(+age noise?)
ground_level = max(ground_level, edge_level)
max_level = max(max_level, ground_level)
-- Dig crater hole
edge_level = min(hole_level, edge_level)
ground_level = min(hole_level, ground_level)
min_level = min(min_level, ground_level)
-- Fill hole
if d2 < crater.holeR2 then
-- Add debris zone
debris_level = ground_level + min(fill_height,
floor(debris_curve*crater.depth/5 + random()))
-- Fill
fill_level = ground_level + fill_height
ground_level = max(debris_level, fill_level)
max_level = max(max_level, ground_level)
else
fill_level = ground_level
debris_level = ground_level
end
return ground_level, min_level, max_level,
edge_level, debris_level, fill_level
end
end
-- Crater inventory of all crater interserting a given map zone
local function get_craters_list(minp, maxp)
local craters = {}
-- Undersampled hills noise
local us_hillnoiseparam = table.copy(cratermg.noises.hill)
us_hillnoiseparam.spread = {
x = cratermg.noises.hill.spread.x / us_scale,
y = cratermg.noises.hill.spread.y / us_scale,
z = cratermg.noises.hill.spread.z / us_scale }
-- Undersampled noise, covers larger scale maximum surface
local us_noise_minp = {
x = maxscalesize*(floor(minp.x/maxscalesize)-1)/us_scale,
y = maxscalesize*(floor(minp.z/maxscalesize)-1)/us_scale,
}
local us_noise_maxp = {
x = maxscalesize*(ceil(maxp.x/maxscalesize)+1)/us_scale,
y = maxscalesize*(ceil(maxp.z/maxscalesize)+1)/us_scale,
}
minetest.get_perlin_map(us_hillnoiseparam, {
x = us_noise_maxp.x - us_noise_minp.x,
y = us_noise_maxp.y - us_noise_minp.y,
}):get_2d_map_flat(us_noise_minp, us_hillmap)
for _, scale in pairs(scales) do
-- Generate craters for sectors and neighboor sectors
for x = floor(minp.x / scale.mapsize) - 1,
ceil(maxp.x / scale.mapsize) do
for z = floor(minp.z / scale.mapsize) - 1,
ceil(maxp.z / scale.mapsize) do
math.randomseed( -- Sector seed
cratermg.mapseed + scale.zseed * z + x + scale.seed)
for _ = 1, cratermg.craternumber * scale.nummult do
local radius = scale.rmin + (scale.rmax - scale.rmin) * random()
if random() * scale.maxproba < proba(radius) then
local crater = {
x = x * scale.mapsize + random(scale.mapsize-1),
z = z * scale.mapsize + random(scale.mapsize-1),
totalR = radius,
totalR2 = radius * radius,
depth = radius * (random() + 1) * 0.2,
age = math.sqrt(radius) * (random()*0.7 + 0.3),
}
-- Chose a debris type for this crater
local chance = random(debristotalchance)
--TODO:Improve ugly code
for _, deb in ipairs(debris) do
if chance > 0 then
chance = chance - deb.chance
if chance <= 0 and deb.cid then
crater.debris = {
cid = deb.cid,
basechance = crater.depth * crater.depth / 500,
}
end
end
end
-- For consistance sake, no random stuff beyond here
-- Check crater intersects with map chunck
crater.minp = { x = crater.x - crater.totalR, z = crater.z - crater.totalR }
crater.maxp = { x = crater.x + crater.totalR, z = crater.z + crater.totalR }
crater.holeR = 0.8 * radius - 3
crater.holeR2 = crater.holeR * crater.holeR
crater.edge_mult = crater.totalR2 *
get_peak_curve(crater.age, cratermg.wipe_age, 1000)
crater.fill_mult = crater.depth / (1 + max(0,
get_peak_curve(crater.age, cratermg.fill_age, 10)))
if crater.maxp.x > minp.x and
crater.minp.x < maxp.x and
crater.maxp.z > minp.z and
crater.minp.z < maxp.z then
table.insert(craters, crater)
end
end
end
end
end
end
-- Sort by age
table.sort(craters, function(a,b) return a.age>b.age end)
-- Compute impact heights and remove impacts on hills
-- (this is a gross calculation)
local index = 1
while index <= #craters do
local crater = craters[index]
local incrater = false
crater.y = cratermg.surface -- Near mare height
-- Apply older craters transformations
for olderindex = 1, index-1 do
local oldercrater = craters[olderindex]
if crater.x>=oldercrater.minp.x and crater.x<=oldercrater.maxp.x and
crater.z>=oldercrater.minp.z and crater.z<=oldercrater.maxp.z
then
local d2 =
(oldercrater.x-crater.x) * (oldercrater.x-crater.x) +
(oldercrater.z-crater.z) * (oldercrater.z-crater.z)
if d2 < oldercrater.holeR2 then
crater.y = compute_crater_deformation(oldercrater, 0,
crater.y, d2)
incrater = true
end
end
end
-- Check crater center is not on hills (only if not yet in a crater)
if not incrater and
us_hillmap[1 + floor(crater.x/us_scale) - us_noise_minp.x
+ (floor(crater.z/us_scale) - us_noise_minp.y)
* (us_noise_maxp.x - us_noise_minp.x)] > cratermg.surface-10
then
table.remove(craters, index)
else
index = index + 1
end
end
return craters
end
-- Map generation
minetest.register_on_generated(function (minp, maxp, blockseed)
local tstart = os.clock()
local p = cratermg.profile
p.init()
p.start('total')
-- Crater inventory
-------------------
local craters
if minp.y < cratermg.surfacemax and maxp.y > cratermg.surfacemin then
p.start('crater inventory')
craters = get_craters_list(minp, maxp)
p.stop('crater inventory')
else
craters = {}
end
-- Map generation
-----------------
local c = cratermg.materials
local chulens3d = {
x=maxp.x - minp.x + 1,
y=maxp.y - minp.y + 1,
z=maxp.z - minp.z + 1}
marenoise = marenoise or minetest.get_perlin_map(cratermg.noises.mare, chulens3d)
hillnoise = hillnoise or minetest.get_perlin_map(cratermg.noises.hill, chulens3d)
smallnoise = smallnoise or minetest.get_perlin_map(cratermg.noises.small, chulens3d)
crack1noise = crack1noise or minetest.get_perlin_map(cratermg.noises.crack1, chulens3d)
crack2noise = crack2noise or minetest.get_perlin_map(cratermg.noises.crack2, chulens3d)
cracksizenoise = cracksizenoise or minetest.get_perlin_map(cratermg.noises.cracksize, chulens3d)
marenoise:get_2d_map_flat({x=minp.x,y=minp.z}, maremap)
hillnoise:get_2d_map_flat({x=minp.x,y=minp.z}, hillmap)
smallnoise:get_2d_map_flat({x=minp.x,y=minp.z}, smallmap)
crack1noise:get_3d_map_flat(minp, crack1map)
crack2noise:get_3d_map_flat(minp, crack2map)
cracksizenoise:get_3d_map_flat(minp, cracksizemap)
-- Get the vmanip mapgen object and the nodes and VoxelArea
p.start('get voxelarea')
local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
vm:get_data(mapdata)
local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
p.stop('get voxelarea')
p.start('main loop')
-- Voxel manip indexes
local vmix, vmiy, vmiz
vmiz = area:index(minp.x, minp.y, minp.z)
-- Increments of voxel manip index
local xinc = area:index(minp.x + 1, minp.y, minp.z) - vmiz
local yinc = area:index(minp.x, minp.y + 1, minp.z) - vmiz
local zinc = area:index(minp.x, minp.y, minp.z + 1) - vmiz
-- Noises indexes
local n2d = 1
local n3dx, n3dy, n3dz
n3dz = 1
local n3dxinc = 1
local n3dyinc = chulens3d.x
local n3dzinc = chulens3d.x * chulens3d.y
for z = minp.z, maxp.z do
vmix = vmiz
n3dx = n3dz
for x = minp.x, maxp.x do
-- Base rock + mare generation (must be before crater generation)
p.start('base generation')
local hill_level = hillmap[n2d] + smallmap[n2d] * 10
local mare_level = maremap[n2d]
local ground_level = max(hill_level, mare_level)
vmiy = vmix
for y = minp.y, maxp.y do
if y < floor(hill_level) then
mapdata[vmiy] = c.hills
elseif y < floor(mare_level) then
mapdata[vmiy] = c.mare
else
mapdata[vmiy] = c.vacuum
end
vmiy = vmiy + yinc
end
p.stop('base generation')
-- Crater generation
p.start('crater generation')
local min_level, max_level, edge_level, debris_level, fill_level
for _, crater in pairs(craters) do
if crater.maxp.x >= x and crater.minp.x <= x and
crater.maxp.z >= z and crater.minp.z <= z
then
local d2 = (x-crater.x)*(x-crater.x) +
(z-crater.z)*(z-crater.z)
if d2 <= crater.totalR2 then
ground_level, min_level, max_level,
edge_level, debris_level, fill_level
= compute_crater_deformation(
crater, smallmap[n2d], ground_level, d2)
-- Y loop (mare height added to all to introduce some noise)
if min_level < maxp.y+1 and max_level >= minp.y then
min_level = min(max(floor(min_level), minp.y), maxp.y)
max_level = min(max(ceil(max_level), minp.y), maxp.y)
vmiy = vmix + (min_level - minp.y) * yinc
for y = min_level, max_level do
if y < floor(edge_level) then
mapdata[vmiy] = c.crater_edge
elseif y < floor(debris_level) then
mapdata[vmiy] = crater.debris and
crater.debris.cid or c.crater_fill
elseif y < floor(fill_level) then
mapdata[vmiy] = c.crater_fill
else
mapdata[vmiy] = c.vacuum
end
vmiy = vmiy + yinc
end
end
end
end
end -- Crater loop
p.stop('crater generation')
--Dust generation
if floor(ground_level) >= minp.y
and floor(ground_level) <= maxp.y then
vmiy = vmix + (floor(ground_level) - minp.y) * yinc
mapdata[vmiy] = c.dust
end
--stone generation
if floor(ground_level) >= minp.y
and floor(ground_level) <= maxp.y then
vmiy = vmix + (floor(ground_level+1) - minp.y) * yinc
if random(30) == 1 then
mapdata[vmiy] = cratermg.stones[random(3)]
end
end
p.start('cave generation')
-- Caves
vmiy = vmix
n3dy = n3dx
for y = minp.y, maxp.y do
local proba = cracksizemap[n3dy] * (1000 - y + cratermg.surface) / 1000
if math.abs(crack1map[n3dy]) < proba or
math.abs(crack2map[n3dy]) < proba
then
mapdata[vmiy] = c.vacuum
end
n3dy = n3dy + n3dyinc
vmiy = vmiy + yinc
end
p.stop('cave generation')
n2d = n2d + 1
n3dx = n3dx + n3dxinc
vmix = vmix + xinc
end -- Z loop
n3dz = n3dz + n3dzinc
vmiz = vmiz + zinc
end -- X loop
p.stop('main loop')
p.start('oregen')
cratermg.ore_generate(minp, maxp, mapdata, area, p)
p.stop('oregen')
-- Save to map
p.start('save')
vm:set_data(mapdata)
vm:set_lighting( {day=0, night=0})
vm:calc_lighting()
vm:write_to_map()
p.stop('save')
p.stop('total')
-- p.show()
-- print("generation "..(minetest.pos_to_string(minp)).." - "..(minetest.pos_to_string(maxp))..
-- " took ".. string.format("%.2fms", (os.clock() - tstart) * 1000))
end)