mirror of
https://gitlab.com/gaelysam/mapgen_rivers.git
synced 2024-11-14 06:40:21 +01:00
257 lines
8.0 KiB
Lua
257 lines
8.0 KiB
Lua
local modpath = mapgen_rivers.modpath
|
|
local mod_data_path = modpath .. 'river_data/'
|
|
if not io.open(mod_data_path .. 'size', 'r') then
|
|
mod_data_path = modpath .. 'demo_data/'
|
|
end
|
|
|
|
local world_data_path = mapgen_rivers.world_data_path
|
|
minetest.mkdir(world_data_path)
|
|
|
|
dofile(modpath .. 'load.lua')
|
|
|
|
mapgen_rivers.grid = {}
|
|
|
|
local X = mapgen_rivers.settings.grid_x_size
|
|
local Z = mapgen_rivers.settings.grid_z_size
|
|
|
|
local function offset_converter(o)
|
|
return (o + 0.5) * (1/256)
|
|
end
|
|
|
|
local load_all = mapgen_rivers.settings.load_all
|
|
|
|
-- Try to read file 'size'
|
|
local sfile = io.open(world_data_path..'size', 'r')
|
|
local first_mapgen = true
|
|
if sfile then
|
|
X, Z = tonumber(sfile:read('*l')), tonumber(sfile:read('*l'))
|
|
sfile:close()
|
|
first_mapgen = false
|
|
end
|
|
|
|
if first_mapgen then
|
|
-- Generate a map!!
|
|
local pregenerate = dofile(mapgen_rivers.modpath .. '/pregenerate.lua')
|
|
minetest.register_on_mods_loaded(function()
|
|
minetest.log("action", '[mapgen_rivers] Generating grid, this may take a while...')
|
|
pregenerate(load_all)
|
|
|
|
if load_all then
|
|
local offset_x = mapgen_rivers.grid.offset_x
|
|
local offset_y = mapgen_rivers.grid.offset_y
|
|
for i=1, X*Z do
|
|
offset_x[i] = offset_converter(offset_x[i])
|
|
offset_y[i] = offset_converter(offset_y[i])
|
|
end
|
|
end
|
|
end)
|
|
end
|
|
|
|
-- if data not already loaded
|
|
if not (first_mapgen and load_all) then
|
|
local load_map
|
|
if load_all then
|
|
load_map = mapgen_rivers.load_map
|
|
else
|
|
load_map = mapgen_rivers.interactive_loader
|
|
end
|
|
|
|
minetest.register_on_mods_loaded(function()
|
|
if load_all then
|
|
minetest.log("action", '[mapgen_rivers] Loading full grid')
|
|
else
|
|
minetest.log("action", '[mapgen_rivers] Loading grid as interactive loaders')
|
|
end
|
|
local grid = mapgen_rivers.grid
|
|
|
|
grid.dem = load_map('dem', 2, true, X*Z)
|
|
grid.lakes = load_map('lakes', 2, true, X*Z)
|
|
grid.dirs = load_map('dirs', 1, false, X*Z)
|
|
grid.rivers = load_map('rivers', 4, false, X*Z)
|
|
|
|
grid.offset_x = load_map('offset_x', 1, true, X*Z, offset_converter)
|
|
grid.offset_y = load_map('offset_y', 1, true, X*Z, offset_converter)
|
|
end)
|
|
end
|
|
|
|
mapgen_rivers.grid.size = {x=X, y=Z}
|
|
|
|
local function index(x, z)
|
|
return z*X+x+1
|
|
end
|
|
|
|
local blocksize = mapgen_rivers.settings.blocksize
|
|
local min_catchment = mapgen_rivers.settings.min_catchment
|
|
local max_catchment = mapgen_rivers.settings.max_catchment
|
|
|
|
local map_offset = {x=0, z=0}
|
|
if mapgen_rivers.settings.center then
|
|
map_offset.x = blocksize*X/2
|
|
map_offset.z = blocksize*Z/2
|
|
end
|
|
|
|
-- Localize for performance
|
|
local floor, ceil, min, max, abs = math.floor, math.ceil, math.min, math.max, math.abs
|
|
|
|
local min_catchment = mapgen_rivers.settings.min_catchment / (blocksize*blocksize)
|
|
local wpower = mapgen_rivers.settings.river_widening_power
|
|
local wfactor = 1/(2*blocksize * min_catchment^wpower)
|
|
local function river_width(flow)
|
|
flow = abs(flow)
|
|
if flow < min_catchment then
|
|
return 0
|
|
end
|
|
|
|
return min(wfactor * flow ^ wpower, 1)
|
|
end
|
|
|
|
local noise_heat -- Need a large-scale noise here so no heat blend
|
|
local elevation_chill = mapgen_rivers.settings.elevation_chill
|
|
local function get_temperature(x, y, z)
|
|
local pos = {x=x, y=z}
|
|
return noise_heat:get2d(pos) - y*elevation_chill
|
|
end
|
|
|
|
local glaciers = mapgen_rivers.settings.glaciers
|
|
local glacier_factor = mapgen_rivers.settings.glacier_factor
|
|
|
|
local init = false
|
|
|
|
-- On map generation, determine into which polygon every point (in 2D) will fall.
|
|
-- Also store polygon-specific data
|
|
local function make_polygons(minp, maxp)
|
|
|
|
local grid = mapgen_rivers.grid
|
|
local dem = grid.dem
|
|
local lakes = grid.lakes
|
|
local dirs = grid.dirs
|
|
local rivers = grid.rivers
|
|
|
|
local offset_x = grid.offset_x
|
|
local offset_z = grid.offset_y
|
|
|
|
if not init then
|
|
if glaciers then
|
|
noise_heat = minetest.get_perlin(mapgen_rivers.noise_params.heat)
|
|
end
|
|
init = true
|
|
end
|
|
|
|
local chulens = maxp.x - minp.x + 1
|
|
|
|
local polygons = {}
|
|
-- Determine the minimum and maximum coordinates of the polygons that could be on the chunk, knowing that they have an average size of 'blocksize' and a maximal offset of 0.5 blocksize.
|
|
local xpmin, xpmax = max(floor((minp.x+map_offset.x)/blocksize - 0.5), 0), min(ceil((maxp.x+map_offset.x)/blocksize + 0.5), X-2)
|
|
local zpmin, zpmax = max(floor((minp.z+map_offset.z)/blocksize - 0.5), 0), min(ceil((maxp.z+map_offset.z)/blocksize + 0.5), Z-2)
|
|
|
|
-- Iterate over the polygons
|
|
for xp = xpmin, xpmax do
|
|
for zp=zpmin, zpmax do
|
|
local iA = index(xp, zp)
|
|
local iB = index(xp+1, zp)
|
|
local iC = index(xp+1, zp+1)
|
|
local iD = index(xp, zp+1)
|
|
-- Extract the vertices of the polygon
|
|
local poly_x = {
|
|
(offset_x[iA]+xp) * blocksize - map_offset.x,
|
|
(offset_x[iB]+xp+1) * blocksize - map_offset.x,
|
|
(offset_x[iC]+xp+1) * blocksize - map_offset.x,
|
|
(offset_x[iD]+xp) * blocksize - map_offset.x,
|
|
}
|
|
local poly_z = {
|
|
(offset_z[iA]+zp) * blocksize - map_offset.z,
|
|
(offset_z[iB]+zp) * blocksize - map_offset.z,
|
|
(offset_z[iC]+zp+1) * blocksize - map_offset.z,
|
|
(offset_z[iD]+zp+1) * blocksize - map_offset.z,
|
|
}
|
|
local polygon = {x=poly_x, z=poly_z, i={iA, iB, iC, iD}}
|
|
|
|
local bounds = {} -- Will be a list of the intercepts of polygon edges for every Z position (scanline algorithm)
|
|
-- Calculate the min and max Z positions
|
|
local zmin = max(floor(min(unpack(poly_z)))+1, minp.z)
|
|
local zmax = min(floor(max(unpack(poly_z))), maxp.z)
|
|
-- And initialize the arrays
|
|
for z=zmin, zmax do
|
|
bounds[z] = {}
|
|
end
|
|
|
|
local i1 = 4
|
|
for i2=1, 4 do -- Loop on 4 edges
|
|
local z1, z2 = poly_z[i1], poly_z[i2]
|
|
-- Calculate the integer Z positions over which this edge spans
|
|
local lzmin = floor(min(z1, z2))+1
|
|
local lzmax = floor(max(z1, z2))
|
|
if lzmin <= lzmax then -- If there is at least one position in it
|
|
local x1, x2 = poly_x[i1], poly_x[i2]
|
|
-- Calculate coefficient of the equation defining the edge: X=aZ+b
|
|
local a = (x1-x2) / (z1-z2)
|
|
local b = (x1 - a*z1)
|
|
for z=max(lzmin, minp.z), min(lzmax, maxp.z) do
|
|
-- For every Z position involved, add the intercepted X position in the table
|
|
table.insert(bounds[z], a*z+b)
|
|
end
|
|
end
|
|
i1 = i2
|
|
end
|
|
for z=zmin, zmax do
|
|
-- Now sort the bounds list
|
|
local zlist = bounds[z]
|
|
table.sort(zlist)
|
|
local c = floor(#zlist/2)
|
|
for l=1, c do
|
|
-- Take pairs of X coordinates: all positions between them belong to the polygon.
|
|
local xmin = max(floor(zlist[l*2-1])+1, minp.x)
|
|
local xmax = min(floor(zlist[l*2]), maxp.x)
|
|
local i = (z-minp.z) * chulens + (xmin-minp.x) + 1
|
|
for x=xmin, xmax do
|
|
-- Fill the map at these places
|
|
polygons[i] = polygon
|
|
i = i + 1
|
|
end
|
|
end
|
|
end
|
|
|
|
local poly_dem = {dem[iA], dem[iB], dem[iC], dem[iD]}
|
|
polygon.dem = poly_dem
|
|
polygon.lake = {lakes[iA], lakes[iB], lakes[iC], lakes[iD]}
|
|
|
|
-- Now, rivers.
|
|
-- Load river flux values for the 4 corners
|
|
local riverA = river_width(rivers[iA])
|
|
local riverB = river_width(rivers[iB])
|
|
local riverC = river_width(rivers[iC])
|
|
local riverD = river_width(rivers[iD])
|
|
if glaciers then -- Widen the river
|
|
if get_temperature(poly_x[1], poly_dem[1], poly_z[1]) < 0 then
|
|
riverA = min(riverA*glacier_factor, 1)
|
|
end
|
|
if get_temperature(poly_x[2], poly_dem[2], poly_z[2]) < 0 then
|
|
riverB = min(riverB*glacier_factor, 1)
|
|
end
|
|
if get_temperature(poly_x[3], poly_dem[3], poly_z[3]) < 0 then
|
|
riverC = min(riverC*glacier_factor, 1)
|
|
end
|
|
if get_temperature(poly_x[4], poly_dem[4], poly_z[4]) < 0 then
|
|
riverD = min(riverD*glacier_factor, 1)
|
|
end
|
|
end
|
|
|
|
polygon.river_corners = {riverA, 1-riverB, 2-riverC, 1-riverD}
|
|
|
|
-- Flow directions
|
|
local dirA, dirB, dirC, dirD = dirs[iA], dirs[iB], dirs[iC], dirs[iD]
|
|
-- Determine the river flux on the edges, by testing dirs values
|
|
local river_west = (dirA==1 and riverA or 0) + (dirD==3 and riverD or 0)
|
|
local river_north = (dirA==2 and riverA or 0) + (dirB==4 and riverB or 0)
|
|
local river_east = 1 - (dirB==1 and riverB or 0) - (dirC==3 and riverC or 0)
|
|
local river_south = 1 - (dirD==2 and riverD or 0) - (dirC==4 and riverC or 0)
|
|
|
|
polygon.rivers = {river_west, river_north, river_east, river_south}
|
|
end
|
|
end
|
|
|
|
return polygons
|
|
end
|
|
|
|
return make_polygons
|