bulk island generation, better island distribution algorhythm

nc_sky_isgen/init.lua

@@ -121,10 +121,13 @@ local function island(pos,r)
   end)
 end
 local f,abs = math.floor, math.abs
-local function spawn_island(name,pos)
-  local ref = minetest.get_player_by_name(name)
+local function raw_spawn_island(pos)
   pos = {x=f(pos.x),y=f(pos.y),z=f(pos.z)}
   island(pos,48,name)
+end
+local function spawn_island(name,pos)
+  local ref = minetest.get_player_by_name(name)
+  raw_spawn_island(pos)
   ref:set_pos({x=pos.x,y=pos.y+256,z=pos.z})
 end
 local store = minetest.get_mod_storage()
@@ -284,37 +287,56 @@ local function get_standing_island(name)
   return closesti
 end
 
-local function gen_island_pos(name)
+local function gen_island_pos(name,fgen)
+  for n=1,fgen or 1 do
+    minetest.after((n-1)*30,function()
       local x,y,z = 0,0,0
-  x,z = x+math.random(-64,64),z+math.random(-64,64)
+      x,z = x+math.random(-96,96),z+math.random(-96,96)
       y=256+math.random(-32,32)
-  for k,isl in ipairs(cells) do
+      if not fgen then
+        for k,isl in pairs(cells) do
           if isl and isl.valid then
             table.remove(cells,k)
             local ip = isl.pos
             local ref = minetest.get_player_by_name(name)
             local pos = ip
-      players[name] = {pos = pos, valid = false}
+            players[name] = {pos = pos, valid = true}
             save()
             pos = {x=f(pos.x),y=f(pos.y),z=f(pos.z)}
             ref:set_pos({x=pos.x,y=pos.y+256,z=pos.z})
             return
           end
         end
+      end
       local ok = checkpos(x,y,z)
       while not ok do
-    x,z = x+math.random(-64,64),z+math.random(-64,64)
+        local sx,sz = math.random(-96,96),math.random(-96,96)
+        if ((x+sx)^2+(z+sz)^2)^0.5 < (x^2+z^2)^0.5 then
+          sx=-sx
+          sz=-sz
+        end
+        x,z = x+sx,z+sz
         y=256+math.random(-32,32)
         ok = checkpos(x,y,z)
       end
       local ip = {x=x,y=y,z=z}
+      if not fgen then
         spawn_island(name,ip)
+      else
+        raw_spawn_island(ip)
+      end
       local pl = {
         pos = ip,
-    valid = false
+        valid = true
       }
+      if not fgen then
         players[name] = pl
+      else
+        table.insert(cells,pl)
+      end
       save()
+    end)
+  end
 end
 local updrate = 0.5
 local to_upd = updrate
@@ -515,6 +537,14 @@ minetest.register_chatcommand("reset",{
   end
 })
 
+minetest.register_chatcommand("islandgen",{
+  description = S"Bulk island generation",
+  privs = {interact = true, server = true},
+  func = function(name,param)
+    gen_island_pos(name,tonumber(param) or 1)
+  end
+})
+
 minetest.register_on_joinplayer(function(ref)
   local meta = ref:get_meta()
   local name = ref:get_player_name()