From 7c766d959779d377a6d24f1b5d25f6bcd77c6697 Mon Sep 17 00:00:00 2001
From: Sokomine <wegwerf@anarres.dyndns.org>
Date: Fri, 19 Jan 2024 19:43:47 +0100
Subject: [PATCH] added soft_falling.lua - which is a slight modification of
 builtin/game/falling.lua but more suitable for snow

---
 init.lua         |   1 +
 soft_falling.lua | 106 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 soft_falling.lua

diff --git a/init.lua b/init.lua
index 55953d0..b3ab7fd 100644
--- a/init.lua
+++ b/init.lua
@@ -89,6 +89,7 @@ dofile(modpath..'crafts.lua')
 -- make sure default:snow does not crush plants
 minetest.registered_nodes["default:snow"].groups.soft_falling = 1
 
+dofile(modpath..'soft_falling.lua')
 
 --[[
 -- remove the "attached_node" value from farming plants;
diff --git a/soft_falling.lua b/soft_falling.lua
new file mode 100644
index 0000000..a5c61a2
--- /dev/null
+++ b/soft_falling.lua
@@ -0,0 +1,106 @@
+
+-- moresnow shall not crush plants (buildable_to is set) when falling
+-- on them - snow is not like sand or gravel (at least when falling slowly)
+local old_try_place = minetest.registered_entities["__builtin:falling_node"].try_place
+minetest.registered_entities["__builtin:falling_node"].try_place = function(self, bcp, bcn)
+	if core.get_item_group(self.node.name, "soft_falling") == 0 then
+		return old_try_place(self, bcp, bcn)
+	end
+	return moresnow.new_try_place(self, bcp, bcn)
+end
+
+
+-- avoid cascades of dropping moresnow nodes that are actually sitting
+-- perfectly well on buildable_to plants
+local old_check_single_for_falling = core.check_single_for_falling
+core.check_single_for_falling = function(p)
+	return moresnow.check_single_for_falling(p)
+end
+
+
+-- this is a only minimally modified copy of the function in builtin/game/falling.lua:
+moresnow.new_try_place = function(self, bcp, bcn)
+		local bcd = core.registered_nodes[bcn.name]
+		-- Add levels if dropped on same leveled node
+		if bcd and bcd.paramtype2 == "leveled" and
+				bcn.name == self.node.name then
+			local addlevel = self.node.level
+			if (addlevel or 0) <= 0 then
+				addlevel = bcd.leveled
+			end
+			if core.add_node_level(bcp, addlevel) < addlevel then
+				return true
+			elseif bcd.buildable_to then
+				-- Node level has already reached max, don't place anything
+				return true
+			end
+		end
+
+		-- Decide if we're replacing the node or placing on top
+		local np = vector.copy(bcp)
+		if bcd and bcd.buildable_to and
+				(not self.floats or bcd.liquidtype == "none") then
+			core.remove_node(bcp)
+		else
+			np.y = np.y + 1
+		end
+
+		-- Check what's here
+		local n2 = core.get_node(np)
+		local nd = core.registered_nodes[n2.name]
+		-- If it's not air or liquid, remove node and replace it with
+		-- it's drops
+		if n2.name ~= "air" and (not nd or nd.liquidtype == "none") then
+			if nd and nd.buildable_to == false then
+				nd.on_dig(np, n2, nil)
+				-- If it's still there, it might be protected
+				if core.get_node(np).name == n2.name then
+					return false
+				end
+			else
+				if core.get_item_group(self.node.name, "soft_falling") == 0 then
+					core.remove_node(np)
+				else
+					-- do not crush the plant below!
+					np.y = np.y + 1
+				end
+			end
+		end
+
+		-- Create node
+		local def = core.registered_nodes[self.node.name]
+		if def then
+			core.add_node(np, self.node)
+			if self.meta then
+				core.get_meta(np):from_table(self.meta)
+			end
+			if def.sounds and def.sounds.place then
+				core.sound_play(def.sounds.place, {pos = np}, true)
+			end
+		end
+		core.check_for_falling(np)
+		return true
+end
+
+
+-- this is a only minimally modified copy of the function in builtin/game/falling.lua:
+moresnow.check_single_for_falling = function(p)
+	local n = core.get_node(p)
+	if core.get_item_group(n.name, "falling_node") ~= 0 then
+		local p_bottom = vector.offset(p, 0, -1, 0)
+		-- Only spawn falling node if node below is loaded
+		local n_bottom = core.get_node_or_nil(p_bottom)
+		local d_bottom = n_bottom and core.registered_nodes[n_bottom.name]
+		if d_bottom then
+			-- do not trigger a cascade of falling nodes when it's just
+			-- moresnow nodes that rest perfectly well on top of plants (buildable_to)
+			if(d_bottom.name and d_bottom.name ~= "air"
+			  and core.get_item_group(n.name, "soft_falling") > 0) then
+				return false
+			end
+		end
+	end
+	-- makes use of local builtin_shared variable which we don't have available here - so
+	-- we need to call the original
+	return old_check_single_for_falling(p)
+end