From eaa06289a112a8eed3cd479f7a82429dde81d4fe Mon Sep 17 00:00:00 2001
From: cora <coradelamouche@gmx.ch>
Date: Tue, 7 Jun 2022 04:22:50 +0200
Subject: [PATCH] use gennotify for lakegen

---
 mods/MAPGEN/mcl_biomes/init.lua     | 20 ++++++++++++++++++--
 mods/MAPGEN/mcl_lush_caves/init.lua | 17 +++--------------
 2 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/mods/MAPGEN/mcl_biomes/init.lua b/mods/MAPGEN/mcl_biomes/init.lua
index 194ca8907a..48002b8343 100644
--- a/mods/MAPGEN/mcl_biomes/init.lua
+++ b/mods/MAPGEN/mcl_biomes/init.lua
@@ -2451,7 +2451,7 @@ local function register_dimension_ores()
 
 end
 
-
+local deco_id_makelake
 -- All mapgens except mgv6
 
 -- Template to register a grass or fern decoration
@@ -4389,13 +4389,14 @@ local function register_decorations()
 	})
 
 	minetest.register_decoration({
+		name = "mcl_biomes:lake_structblock",
 		decoration = "mcl_lush_caves:lake_structblock",
 		deco_type = "simple",
 		place_on = {"group:material_stone","mcl_core:gravel","mcl_lush_caves:moss","mcl_core:clay"},
 		spawn_by = {"air"},
 		num_spawn_by = 4,
 		sidelen = 16,
-		fill_ratio = 10,
+		fill_ratio = 4,
 		flags = "place_center_x, place_center_z, force_placement, all_floors",
 		biomes = lushcaves,
 	})
@@ -4825,6 +4826,9 @@ local function register_dimension_decorations()
 	deco_id_chorus_plant = minetest.get_decoration_id("mcl_biomes:chorus_plant")
 	minetest.set_gen_notify({decoration=true}, { deco_id_chorus_plant })
 
+	deco_id_makelake = minetest.get_decoration_id("mcl_biomes:lake_structblock")
+	minetest.set_gen_notify({decoration=true}, { deco_id_makelake })
+
 	-- TODO: End cities
 
 end
@@ -4895,4 +4899,16 @@ if mg_name ~= "singlenode" then
 		end)
 	end
 
+	mcl_mapgen_core.register_generator("mcl_lush_caves:lakegen", nil, function(minp, maxp, blockseed)
+		local gennotify = minetest.get_mapgen_object("gennotify")
+		local pr = PseudoRandom(blockseed + 15)
+		for _, pos in ipairs(gennotify["decoration#"..deco_id_makelake] or {}) do
+			local realpos = vector.offset(pos,0,1,0)
+			local node = minetest.get_node(realpos)
+			if node and node.name == "mcl_lush_caves:lake_structblock" then
+				minetest.remove_node(realpos)
+				mcl_lush_caves.makelake(realpos, pr)
+			end
+		end
+	end)
 end
diff --git a/mods/MAPGEN/mcl_lush_caves/init.lua b/mods/MAPGEN/mcl_lush_caves/init.lua
index 2732e4f702..bdc1a157a3 100644
--- a/mods/MAPGEN/mcl_lush_caves/init.lua
+++ b/mods/MAPGEN/mcl_lush_caves/init.lua
@@ -1,6 +1,5 @@
 local S = minetest.get_translator(minetest.get_current_modname())
 
-local pr = PseudoRandom(minetest.get_mapgen_setting("seed"))
 local adjacents = {
 	vector.new(1,0,0),
 	vector.new(-1,0,0),
@@ -14,8 +13,8 @@ local vector_distance_xz = function(a, b)
 		{ x=b.x, y=0, z=b.z }
 	)
 end
-
-local function makelake(pos)
+mcl_lush_caves = {}
+function mcl_lush_caves.makelake(pos,pr)
 	local p1 = vector.offset(pos,-5,-2,-5)
 	local p2 = vector.offset(pos,5,1,5)
 	local nn = minetest.find_nodes_in_area_under_air(p1,p2,{"group:material_stone","mcl_core:clay"})
@@ -23,7 +22,7 @@ local function makelake(pos)
 		   return vector_distance_xz(pos, a) < vector_distance_xz(pos, b)
 	end)
 	if not nn[1] then return end
-	for i=1,math.random(#nn) do
+	for i=1,pr:next(1,#nn) do
 		minetest.set_node(nn[i],{name="mcl_core:water_source"})
 	end
 	local nnn = minetest.find_nodes_in_area_under_air(p1,p2,{"mcl_core:water_source","group:water"})
@@ -348,13 +347,3 @@ minetest.register_abm({
 		end
 	end
 })
-
-minetest.register_lbm({
-	name = "mcl_lush_caves:make_lakes",
-	run_at_every_load = true,
-	nodenames = {"mcl_lush_caves:lake_structblock"},
-	action = function(pos, node)
-		minetest.set_node(pos,{name="air"})
-		makelake(pos)
-	end
-})