Rework functionality of leveled nodes (#9852)

Co-authored-by: sfan5 <sfan5@live.de>
Co-authored-by: SmallJoker <SmallJoker@users.noreply.github.com>

8 files changed, 79 insertions, 34 deletions

diff --git a/builtin/game/falling.lua b/builtin/game/falling.lua
index 7037ae885..cdbb13acc 100644
--- a/builtin/game/falling.lua
+++ b/builtin/game/falling.lua
@@ -109,6 +109,7 @@ core.register_entity(":__builtin:falling_node", {
 			if core.is_colored_paramtype(def.paramtype2) then
 				itemstring = core.itemstring_with_palette(itemstring, node.param2)
 			end
+			-- FIXME: solution needed for paramtype2 == "leveled"
 			local vsize
 			if def.visual_scale then
 				local s = def.visual_scale * SCALE
@@ -122,6 +123,24 @@ core.register_entity(":__builtin:falling_node", {
 			})
 		end
 
+		-- Set collision box (certain nodeboxes only for now)
+		local nb_types = {fixed=true, leveled=true, connected=true}
+		if def.drawtype == "nodebox" and def.node_box and
+			nb_types[def.node_box.type] then
+			local box = table.copy(def.node_box.fixed)
+			if type(box[1]) == "table" then
+				box = #box == 1 and box[1] or nil -- We can only use a single box
+			end
+			if box then
+				if def.paramtype2 == "leveled" and (self.node.level or 0) > 0 then
+					box[5] = -0.5 + self.node.level / 64
+				end
+				self.object:set_properties({
+					collisionbox = box
+				})
+			end
+		end
+
 		-- Rotate entity
 		if def.drawtype == "torchlike" then
 			self.object:set_yaw(math.pi*0.25)
@@ -196,13 +215,16 @@ core.register_entity(":__builtin:falling_node", {
 	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.leveled and
+		if bcd and bcd.paramtype2 == "leveled" and
 				bcn.name == self.node.name then
 			local addlevel = self.node.level
-			if not addlevel or addlevel <= 0 then
+			if (addlevel or 0) <= 0 then
 				addlevel = bcd.leveled
 			end
-			if core.add_node_level(bcp, addlevel) == 0 then
+			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
@@ -351,6 +373,7 @@ local function convert_to_falling_node(pos, node)
 	if not obj then
 		return false
 	end
+	-- remember node level, the entities' set_node() uses this
 	node.level = core.get_node_level(pos)
 	local meta = core.get_meta(pos)
 	local metatable = meta and meta:to_table() or {}
@@ -436,18 +459,23 @@ function core.check_single_for_falling(p)
 		-- 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 and
-
-				(core.get_item_group(n.name, "float") == 0 or
-				d_bottom.liquidtype == "none") and
-
-				(n.name ~= n_bottom.name or (d_bottom.leveled and
-				core.get_node_level(p_bottom) <
-				core.get_node_max_level(p_bottom))) and
-
-				(not d_bottom.walkable or d_bottom.buildable_to) then
-			convert_to_falling_node(p, n)
-			return true
+		if d_bottom then
+			local same = n.name == n_bottom.name
+			-- Let leveled nodes fall if it can merge with the bottom node
+			if same and d_bottom.paramtype2 == "leveled" and
+					core.get_node_level(p_bottom) <
+					core.get_node_max_level(p_bottom) then
+				convert_to_falling_node(p, n)
+				return true
+			end
+			-- Otherwise only if the bottom node is considered "fall through"
+			if not same and
+					(not d_bottom.walkable or d_bottom.buildable_to) and
+					(core.get_item_group(n.name, "float") == 0 or
+					d_bottom.liquidtype == "none") then
+				convert_to_falling_node(p, n)
+				return true
+			end
 		end
 	end
 
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 9c7c42436..8b7c412ab 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -4882,7 +4882,7 @@ Environment access
 * `minetest.add_node_level(pos, level)`
     * increase level of leveled node by level, default `level` equals `1`
     * if `totallevel > maxlevel`, returns rest (`total-max`)
-    * can be negative for decreasing
+    * `level` must be between -127 and 127
 * `minetest.fix_light(pos1, pos2)`: returns `true`/`false`
     * resets the light in a cuboid-shaped part of
       the map and removes lighting bugs.
@@ -7012,11 +7012,15 @@ Used by `minetest.register_node`.
         -- If true, a new liquid source can be created by placing two or more
         -- sources nearby
 
-        leveled = 16,
+        leveled = 0,
         -- Only valid for "nodebox" drawtype with 'type = "leveled"'.
         -- Allows defining the nodebox height without using param2.
         -- The nodebox height is 'leveled' / 64 nodes.
-        -- The maximum value of 'leveled' is 127.
+        -- The maximum value of 'leveled' is `leveled_max`.
+
+        leveled_max = 127,
+        -- Maximum value for `leveled` (0-127), enforced in
+        -- `minetest.set_node_level` and `minetest.add_node_level`.
 
         liquid_range = 8,  -- Number of flowing nodes around source (max. 8)
 
diff --git a/src/mapnode.cpp b/src/mapnode.cpp
index bf7e79a71..24d62b504 100644
--- a/src/mapnode.cpp
+++ b/src/mapnode.cpp
@@ -584,7 +584,7 @@ u8 MapNode::getMaxLevel(const NodeDefManager *nodemgr) const
 	if( f.liquid_type == LIQUID_FLOWING || f.param_type_2 == CPT2_FLOWINGLIQUID)
 		return LIQUID_LEVEL_MAX;
 	if(f.leveled || f.param_type_2 == CPT2_LEVELED)
-		return LEVELED_MAX;
+		return f.leveled_max;
 	return 0;
 }
 
@@ -603,14 +603,15 @@ u8 MapNode::getLevel(const NodeDefManager *nodemgr) const
 		if (level)
 			return level;
 	}
-	if (f.leveled > LEVELED_MAX)
-		return LEVELED_MAX;
+	// Return static value from nodedef if param2 isn't used for level
+	if (f.leveled > f.leveled_max)
+		return f.leveled_max;
 	return f.leveled;
 }
 
-u8 MapNode::setLevel(const NodeDefManager *nodemgr, s8 level)
+s8 MapNode::setLevel(const NodeDefManager *nodemgr, s16 level)
 {
-	u8 rest = 0;
+	s8 rest = 0;
 	const ContentFeatures &f = nodemgr->get(*this);
 	if (f.param_type_2 == CPT2_FLOWINGLIQUID
 			|| f.liquid_type == LIQUID_FLOWING
@@ -631,18 +632,18 @@ u8 MapNode::setLevel(const NodeDefManager *nodemgr, s8 level)
 		if (level < 0) { // zero means default for a leveled nodebox
 			rest = level;
 			level = 0;
-		} else if (level > LEVELED_MAX) {
-			rest = level - LEVELED_MAX;
-			level = LEVELED_MAX;
+		} else if (level > f.leveled_max) {
+			rest = level - f.leveled_max;
+			level = f.leveled_max;
 		}
 		setParam2((level & LEVELED_MASK) | (getParam2() & ~LEVELED_MASK));
 	}
 	return rest;
 }
 
-u8 MapNode::addLevel(const NodeDefManager *nodemgr, s8 add)
+s8 MapNode::addLevel(const NodeDefManager *nodemgr, s16 add)
 {
-	s8 level = getLevel(nodemgr);
+	s16 level = getLevel(nodemgr);
 	level += add;
 	return setLevel(nodemgr, level);
 }
diff --git a/src/mapnode.h b/src/mapnode.h
index 7a3d30ddc..32ac1b4f6 100644
--- a/src/mapnode.h
+++ b/src/mapnode.h
@@ -268,12 +268,12 @@ struct MapNode
 		std::vector<aabb3f> *boxes, u8 neighbors = 0) const;
 
 	/*
-		Liquid helpers
+		Liquid/leveled helpers
 	*/
 	u8 getMaxLevel(const NodeDefManager *nodemgr) const;
 	u8 getLevel(const NodeDefManager *nodemgr) const;
-	u8 setLevel(const NodeDefManager *nodemgr, s8 level = 1);
-	u8 addLevel(const NodeDefManager *nodemgr, s8 add = 1);
+	s8 setLevel(const NodeDefManager *nodemgr, s16 level = 1);
+	s8 addLevel(const NodeDefManager *nodemgr, s16 add = 1);
 
 	/*
 		Serialization functions
diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 65199830f..b8211fceb 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -368,6 +368,7 @@ void ContentFeatures::reset()
 	floodable = false;
 	rightclickable = true;
 	leveled = 0;
+	leveled_max = LEVELED_MAX;
 	liquid_type = LIQUID_NONE;
 	liquid_alternative_flowing = "";
 	liquid_alternative_source = "";
@@ -478,6 +479,7 @@ void ContentFeatures::serialize(std::ostream &os, u16 protocol_version) const
 	writeU8(os, legacy_wallmounted);
 
 	os << serializeString(node_dig_prediction);
+	writeU8(os, leveled_max);
 }
 
 void ContentFeatures::correctAlpha(TileDef *tiles, int length)
@@ -586,6 +588,10 @@ void ContentFeatures::deSerialize(std::istream &is)
 
 	try {
 		node_dig_prediction = deSerializeString(is);
+		u8 tmp_leveled_max = readU8(is);
+		if (is.eof()) /* readU8 doesn't throw exceptions so we have to do this */
+			throw SerializationError("");
+		leveled_max = tmp_leveled_max;
 	} catch(SerializationError &e) {};
 }
 
diff --git a/src/nodedef.h b/src/nodedef.h
index 0fce6eab1..497e7ee0e 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -326,8 +326,10 @@ struct ContentFeatures
 	std::vector<content_t> connects_to_ids;
 	// Post effect color, drawn when the camera is inside the node.
 	video::SColor post_effect_color;
-	// Flowing liquid or snow, value = default level
+	// Flowing liquid or leveled nodebox, value = default level
 	u8 leveled;
+	// Maximum value for leveled nodes
+	u8 leveled_max;
 
 	// --- LIGHTING-RELATED ---
 
diff --git a/src/script/common/c_content.cpp b/src/script/common/c_content.cpp
index de9634c42..116a59c09 100644
--- a/src/script/common/c_content.cpp
+++ b/src/script/common/c_content.cpp
@@ -694,6 +694,8 @@ ContentFeatures read_content_features(lua_State *L, int index)
 	f.liquid_range = getintfield_default(L, index,
 			"liquid_range", f.liquid_range);
 	f.leveled = getintfield_default(L, index, "leveled", f.leveled);
+	f.leveled_max = getintfield_default(L, index,
+			"leveled_max", f.leveled_max);
 
 	getboolfield(L, index, "liquid_renewable", f.liquid_renewable);
 	f.drowning = getintfield_default(L, index,
@@ -860,6 +862,8 @@ void push_content_features(lua_State *L, const ContentFeatures &c)
 	lua_setfield(L, -2, "post_effect_color");
 	lua_pushnumber(L, c.leveled);
 	lua_setfield(L, -2, "leveled");
+	lua_pushnumber(L, c.leveled_max);
+	lua_setfield(L, -2, "leveled_max");
 	lua_pushboolean(L, c.sunlight_propagates);
 	lua_setfield(L, -2, "sunlight_propagates");
 	lua_pushnumber(L, c.light_source);
diff --git a/src/script/lua_api/l_env.cpp b/src/script/lua_api/l_env.cpp
index b8a8a5ce1..89ec9dc7e 100644
--- a/src/script/lua_api/l_env.cpp
+++ b/src/script/lua_api/l_env.cpp
@@ -529,13 +529,13 @@ int ModApiEnvMod::l_set_node_level(lua_State *L)
 
 // add_node_level(pos, level)
 // pos = {x=num, y=num, z=num}
-// level: 0..63
+// level: -127..127
 int ModApiEnvMod::l_add_node_level(lua_State *L)
 {
 	GET_ENV_PTR;
 
 	v3s16 pos = read_v3s16(L, 1);
-	u8 level = 1;
+	s16 level = 1;
 	if(lua_isnumber(L, 2))
 		level = lua_tonumber(L, 2);
 	MapNode n = env->getMap().getNode(pos);