mapgen_rivers/init.lua
2021-06-26 11:26:45 +02:00

246 lines
7.0 KiB
Lua

mapgen_rivers = {}
local modpath = minetest.get_modpath(minetest.get_current_modname()) .. '/'
mapgen_rivers.modpath = modpath
mapgen_rivers.world_data_path = minetest.get_worldpath() .. '/river_data/'
dofile(modpath .. 'settings.lua')
local sea_level = mapgen_rivers.settings.sea_level
local elevation_chill = mapgen_rivers.settings.elevation_chill
local use_distort = mapgen_rivers.settings.distort
local use_biomes = mapgen_rivers.settings.biomes
local use_biomegen_mod = use_biomes and minetest.global_exists('biomegen')
use_biomes = use_biomes and not use_biomegen_mod
if use_biomegen_mod then
biomegen.set_elevation_chill(elevation_chill)
end
dofile(modpath .. 'noises.lua')
local heightmaps = dofile(modpath .. 'heightmap.lua')
-- Linear interpolation
local function interp(v00, v01, v11, v10, xf, zf)
local v0 = v01*xf + v00*(1-xf)
local v1 = v11*xf + v10*(1-xf)
return v1*zf + v0*(1-zf)
end
local data = {}
local noise_x_obj, noise_z_obj, noise_distort_obj, noise_heat_obj, noise_heat_blend_obj
local noise_x_map = {}
local noise_z_map = {}
local noise_distort_map = {}
local noise_heat_map = {}
local noise_heat_blend_map = {}
local mapsize
local init = false
local sumtime = 0
local sumtime2 = 0
local ngen = 0
local function generate(minp, maxp, seed)
print(("[mapgen_rivers] Generating from %s to %s"):format(minetest.pos_to_string(minp), minetest.pos_to_string(maxp)))
local chulens = {
x = maxp.x-minp.x+1,
y = maxp.y-minp.y+1,
z = maxp.z-minp.z+1,
}
if not init then
mapsize = {
x = chulens.x,
y = chulens.y+1,
z = chulens.z,
}
if use_distort then
noise_x_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_x, mapsize)
noise_z_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_z, mapsize)
noise_distort_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_amplitude, chulens)
end
if use_biomes then
noise_heat_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.heat, chulens)
noise_heat_blend_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.heat_blend, chulens)
end
init = true
end
local t0 = os.clock()
local minp2d = {x=minp.x, y=minp.z}
if use_distort then
noise_x_obj:get_3d_map_flat(minp, noise_x_map)
noise_z_obj:get_3d_map_flat(minp, noise_z_map)
noise_distort_obj:get_2d_map_flat(minp2d, noise_distort_map)
end
if use_biomes then
noise_heat_obj:get_2d_map_flat(minp2d, noise_heat_map)
noise_heat_blend_obj:get_2d_map_flat(minp2d, noise_heat_blend_map)
end
local terrain_map, lake_map, incr, i_origin
if use_distort then
local xmin, xmax, zmin, zmax = minp.x, maxp.x, minp.z, maxp.z
local i = 0
local i2d = 0
for z=minp.z, maxp.z do
for y=minp.y, maxp.y+1 do
for x=minp.x, maxp.x do
i = i+1
i2d = i2d+1
local distort = noise_distort_map[i2d]
local xv = noise_x_map[i]*distort + x
if xv < xmin then xmin = xv end
if xv > xmax then xmax = xv end
noise_x_map[i] = xv
local zv = noise_z_map[i]*distort + z
if zv < zmin then zmin = zv end
if zv > zmax then zmax = zv end
noise_z_map[i] = zv
end
i2d = i2d-chulens.x
end
end
local pminp = {x=math.floor(xmin), z=math.floor(zmin)}
local pmaxp = {x=math.floor(xmax)+1, z=math.floor(zmax)+1}
incr = pmaxp.x-pminp.x+1
i_origin = 1 - pminp.z*incr - pminp.x
terrain_map, lake_map = heightmaps(pminp, pmaxp)
else
terrain_map, lake_map = heightmaps(minp, maxp)
end
local c_stone = minetest.get_content_id("default:stone")
local c_dirt = minetest.get_content_id("default:dirt")
local c_lawn = minetest.get_content_id("default:dirt_with_grass")
local c_dirtsnow = minetest.get_content_id("default:dirt_with_snow")
local c_snow = minetest.get_content_id("default:snowblock")
local c_sand = minetest.get_content_id("default:sand")
local c_water = minetest.get_content_id("default:water_source")
local c_rwater = minetest.get_content_id("default:river_water_source")
local c_ice = minetest.get_content_id("default:ice")
local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
vm:get_data(data)
local a = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
local ystride = a.ystride -- Tip : the ystride of a VoxelArea is the number to add to the array index to get the index of the position above. It's faster because it avoids to completely recalculate the index.
local nid = mapsize.x*(mapsize.y-1) + 1
local incrY = -mapsize.x
local incrX = 1 - mapsize.y*incrY
local incrZ = mapsize.x*mapsize.y - mapsize.x*incrX - mapsize.x*mapsize.y*incrY
local i2d = 1
for z = minp.z, maxp.z do
for x = minp.x, maxp.x do
local ivm = a:index(x, minp.y, z)
local ground_above = false
local temperature
if use_biomes then
temperature = noise_heat_map[i2d]+noise_heat_blend_map[i2d]
end
local terrain, lake
if not use_distort then
terrain = terrain_map[i2d]
lake = lake_map[i2d]
end
for y = maxp.y+1, minp.y, -1 do
if use_distort then
local xn = noise_x_map[nid]
local zn = noise_z_map[nid]
local x0 = math.floor(xn)
local z0 = math.floor(zn)
local i0 = i_origin + z0*incr + x0
local i1 = i0+1
local i2 = i1+incr
local i3 = i2-1
terrain = interp(terrain_map[i0], terrain_map[i1], terrain_map[i2], terrain_map[i3], xn-x0, zn-z0)
lake = math.min(lake_map[i0], lake_map[i1], lake_map[i2], lake_map[i3])
end
if y <= maxp.y then
local is_lake = lake > terrain
local ivm = a:index(x, y, z)
if y <= terrain then
if not use_biomes or y <= terrain-1 or ground_above then
data[ivm] = c_stone
elseif is_lake or y < sea_level then
data[ivm] = c_sand
else
local temperature_y = temperature - y*elevation_chill
if temperature_y >= 15 then
data[ivm] = c_lawn
elseif temperature_y >= 0 then
data[ivm] = c_dirtsnow
else
data[ivm] = c_snow
end
end
elseif y <= lake and lake > sea_level then
if not use_biomes or temperature - y*elevation_chill >= 0 then
data[ivm] = c_rwater
else
data[ivm] = c_ice
end
elseif y <= sea_level then
data[ivm] = c_water
end
end
ground_above = y <= terrain
ivm = ivm + ystride
if use_distort then
nid = nid + incrY
end
end
if use_distort then
nid = nid + incrX
end
i2d = i2d + 1
end
if use_distort then
nid = nid + incrZ
end
end
if use_biomegen_mod then
biomegen.generate_all(data, a, vm, minp, maxp, seed)
else
vm:set_data(data)
minetest.generate_ores(vm, minp, maxp)
end
vm:set_lighting({day = 0, night = 0})
vm:calc_lighting()
vm:update_liquids()
vm:write_to_map()
local t1 = os.clock()
local t = t1-t0
ngen = ngen + 1
sumtime = sumtime + t
sumtime2 = sumtime2 + t*t
print(("[mapgen_rivers] Done in %5.3f s"):format(t))
end
minetest.register_on_generated(generate)
minetest.register_on_shutdown(function()
local avg = sumtime / ngen
local std = math.sqrt(sumtime2/ngen - avg*avg)
print(("[mapgen_rivers] Mapgen statistics:\n- Mapgen calls: %4d\n- Mean time: %5.3f s\n- Standard deviation: %5.3f s"):format(ngen, avg, std))
end)