Add rotation support for wallmounted nodes in 'ceiling' or 'floor' mode (#11073)

builtin/common/item_s.lua

@@ -144,6 +144,8 @@ local wallmounted_to_dir = {
 	vector.new(-1,  0,  0),
 	vector.new( 0,  0,  1),
 	vector.new( 0,  0, -1),
+	vector.new( 0,  1,  0),
+	vector.new( 0, -1,  0),
 }
 function core.wallmounted_to_dir(wallmounted)
 	return wallmounted_to_dir[wallmounted % 8]

builtin/game/falling.lua

@@ -150,7 +150,12 @@ core.register_entity(":__builtin:falling_node", {
 
 		-- Rotate entity
 		if def.drawtype == "torchlike" then
-			self.object:set_yaw(math.pi*0.25)
+			if (def.paramtype2 == "wallmounted" or def.paramtype2 == "colorwallmounted")
+					and node.param2 % 8 == 7 then
+				self.object:set_yaw(-math.pi*0.25)
+			else
+				self.object:set_yaw(math.pi*0.25)
+			end
 		elseif ((node.param2 ~= 0 or def.drawtype == "nodebox" or def.drawtype == "mesh")
 				and (def.wield_image == "" or def.wield_image == nil))
 				or def.drawtype == "signlike"
@@ -190,6 +195,10 @@ core.register_entity(":__builtin:falling_node", {
 						pitch, yaw = 0, -math.pi/2
 					elseif rot == 4 then
 						pitch, yaw = 0, math.pi
+					elseif rot == 6 then
+						pitch, yaw = math.pi/2, 0
+					elseif rot == 7 then
+						pitch, yaw = -math.pi/2, math.pi
 					end
 				else
 					if rot == 1 then
@@ -202,6 +211,10 @@ core.register_entity(":__builtin:falling_node", {
 						pitch, yaw = math.pi/2, math.pi
 					elseif rot == 5 then
 						pitch, yaw = math.pi/2, 0
+					elseif rot == 6 then
+						pitch, yaw = math.pi, -math.pi/2
+					elseif rot == 7 then
+						pitch, yaw = 0, -math.pi/2
 					end
 				end
 				if def.drawtype == "signlike" then
@@ -210,10 +223,20 @@ core.register_entity(":__builtin:falling_node", {
 						yaw = yaw + math.pi/2
 					elseif rot == 1 then
 						yaw = yaw - math.pi/2
+					elseif rot == 6 then
+						yaw = yaw - math.pi/2
+						pitch = pitch + math.pi
+					elseif rot == 7 then
+						yaw = yaw + math.pi/2
+						pitch = pitch + math.pi
 					end
 				elseif def.drawtype == "mesh" or def.drawtype == "normal" or def.drawtype == "nodebox" then
-					if rot >= 0 and rot <= 1 then
+					if rot == 0 or rot == 1 then
 						roll = roll + math.pi
+					elseif rot == 6 or rot == 7 then
+						if def.drawtype ~= "normal" then
+							roll = roll - math.pi/2
+						end
 					else
 						yaw = yaw + math.pi
 					end

builtin/game/features.lua

@@ -32,6 +32,7 @@ core.features = {
 	hud_def_type_field = true,
 	random_state_restore = true,
 	after_order_expiry_registration = true,
+	wallmounted_rotate = true,
 }
 
 function core.has_feature(arg)

builtin/game/item.lua

@@ -202,7 +202,40 @@ function core.item_place_node(itemstack, placer, pointed_thing, param2,
 	elseif (def.paramtype2 == "wallmounted" or
 			def.paramtype2 == "colorwallmounted") and not param2 then
 		local dir = vector.subtract(under, above)
+		-- If you change this code, also change src/client/game.cpp
 		newnode.param2 = core.dir_to_wallmounted(dir)
+		if def.wallmounted_rotate_vertical and
+				(newnode.param2 == 0 or newnode.param2 == 1) then
+			local placer_pos = placer and placer:get_pos()
+			if placer_pos then
+				local pdir = {
+					x = above.x - placer_pos.x,
+					y = dir.y,
+					z = above.z - placer_pos.z
+				}
+				local rotate = false
+				if def.drawtype == "torchlike" then
+					if not ((pdir.x < 0 and pdir.z > 0) or
+							(pdir.x > 0 and pdir.z < 0)) then
+						rotate = true
+					end
+					if pdir.y > 0 then
+						rotate = not rotate
+					end
+				elseif def.drawtype == "signlike" then
+					if math.abs(pdir.x) < math.abs(pdir.z) then
+						rotate = true
+					end
+				else
+					if math.abs(pdir.x) > math.abs(pdir.z) then
+						rotate = true
+					end
+				end
+				if rotate then
+					newnode.param2 = newnode.param2 + 6
+				end
+			end
+		end
 	-- Calculate the direction for furnaces and chests and stuff
 	elseif (def.paramtype2 == "facedir" or
 			def.paramtype2 == "colorfacedir" or

doc/lua_api.md

@@ -1270,11 +1270,15 @@ The function of `param2` is determined by `paramtype2` in node definition.
     * The rotation of the node is stored in `param2`
     * Node is 'mounted'/facing towards one of 6 directions
     * You can make this value by using `minetest.dir_to_wallmounted()`
-    * Values range 0 - 5
+    * Values range 0 - 7
     * The value denotes at which direction the node is "mounted":
       0 = y+,   1 = y-,   2 = x+,   3 = x-,   4 = z+,   5 = z-
+      6 = y+, but rotated by  90°
+      7 = y-, but rotated by -90°
     * By default, on placement the param2 is automatically set to the
-      appropriate rotation, depending on which side was pointed at
+      appropriate rotation (0 to 5), depending on which side was
+      pointed at. With the node field `wallmounted_rotate_vertical = true`,
+      the param2 values 6 and 7 might additionally be set
 * `paramtype2 = "facedir"`
     * Supported drawtypes: "normal", "nodebox", "mesh"
     * The rotation of the node is stored in `param2`.
@@ -5291,6 +5295,9 @@ Utilities
       -- minetest.after guarantees that coexisting jobs are executed primarily
       -- in order of expiry and secondarily in order of registration (5.9.0)
       after_order_expiry_registration = true,
+      -- wallmounted nodes mounted at floor or ceiling may additionally
+      -- be rotated by 90° with special param2 values (5.9.0)
+      wallmounted_rotate = true,
   }
   ```
 
@@ -8926,6 +8933,13 @@ Used by `minetest.register_node`.
     place_param2 = 0,
     -- Value for param2 that is set when player places node
 
+    wallmounted_rotate_vertical = false,
+    -- If true, place_param2 is nil, and this is a wallmounted node,
+    -- this node might use the special 90° rotation when placed
+    -- on the floor or ceiling, depending on the direction.
+    -- See the explanation about wallmounted for details.
+    -- Otherwise, the rotation is always the same on vertical placement.
+
     is_ground_content = true,
     -- If false, the cave generator and dungeon generator will not carve
     -- through this node.

games/devtest/mods/testnodes/drawtypes.lua

@@ -163,7 +163,7 @@ minetest.register_node("testnodes:torchlike", {
 
 minetest.register_node("testnodes:torchlike_wallmounted", {
 	description = S("Wallmounted \"torchlike\" Drawtype Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	drawtype = "torchlike",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
@@ -179,6 +179,24 @@ minetest.register_node("testnodes:torchlike_wallmounted", {
 	groups = { dig_immediate = 3 },
 })
 
+minetest.register_node("testnodes:torchlike_wallmounted_rot", {
+	description = S("Wallmounted Rotatable Torchlike Drawtype Test Node"),
+	drawtype = "torchlike",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	tiles = {
+		"testnodes_torchlike_floor.png^[colorize:#FFFF00:40",
+		"testnodes_torchlike_ceiling.png^[colorize:#FFFF00:40",
+		"testnodes_torchlike_wall.png^[colorize:#FFFF00:40",
+	},
+
+
+	walkable = false,
+	sunlight_propagates = true,
+	groups = { dig_immediate = 3 },
+})
+
 minetest.register_node("testnodes:signlike", {
 	description = S("Floor \"signlike\" Drawtype Test Node").."\n"..
 		S("Always on floor"),
@@ -186,16 +204,14 @@ minetest.register_node("testnodes:signlike", {
 	paramtype = "light",
 	tiles = { "testnodes_signlike.png^[colorize:#FF0000:64" },
 
-
 	walkable = false,
-	groups = { dig_immediate = 3 },
 	sunlight_propagates = true,
+	groups = { dig_immediate = 3 },
 })
 
-
 minetest.register_node("testnodes:signlike_wallmounted", {
 	description = S("Wallmounted \"signlike\" Drawtype Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	drawtype = "signlike",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
@@ -207,6 +223,22 @@ minetest.register_node("testnodes:signlike_wallmounted", {
 	sunlight_propagates = true,
 })
 
+minetest.register_node("testnodes:signlike_rot", {
+	description = S("Wallmounted Rotatable Signlike Drawtype Test Node"),
+	drawtype = "signlike",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	tiles = { "testnodes_signlike.png^[colorize:#FFFF00:40" },
+
+
+	walkable = false,
+	groups = { dig_immediate = 3 },
+	sunlight_propagates = true,
+})
+
+
+
 minetest.register_node("testnodes:plantlike", {
 	description = S("\"plantlike\" Drawtype Test Node"),
 	drawtype = "plantlike",
@@ -235,7 +267,7 @@ minetest.register_node("testnodes:plantlike_waving", {
 
 minetest.register_node("testnodes:plantlike_wallmounted", {
 	description = S("Wallmounted \"plantlike\" Drawtype Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	drawtype = "plantlike",
 	paramtype = "light",
 	paramtype2 = "wallmounted",
@@ -366,7 +398,7 @@ minetest.register_node("testnodes:plantlike_rooted", {
 
 minetest.register_node("testnodes:plantlike_rooted_wallmounted", {
 	description = S("Wallmounted \"rooted_plantlike\" Drawtype Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	drawtype = "plantlike_rooted",
 	paramtype = "light",
 	paramtype2 = "wallmounted",

games/devtest/mods/testnodes/meshes.lua

@@ -92,7 +92,7 @@ minetest.register_node("testnodes:mesh_color4dir", {
 -- Wallmounted mesh: pyramid
 minetest.register_node("testnodes:mesh_wallmounted", {
 	description = S("Wallmounted Mesh Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	drawtype = "mesh",
 	mesh = "testnodes_pyramid.obj",
 	tiles = {"testnodes_mesh_stripes9.png"},
@@ -105,7 +105,7 @@ minetest.register_node("testnodes:mesh_wallmounted", {
 
 minetest.register_node("testnodes:mesh_colorwallmounted", {
 	description = S("Color Wallmounted Mesh Test Node").."\n"..
-		S("param2 = color + wallmounted rotation (0..5, 8..13, ...)"),
+		S("param2 = color + wallmounted rotation (0..7, 8..15, ...)"),
 	drawtype = "mesh",
 	mesh = "testnodes_pyramid.obj",
 	tiles = {"testnodes_mesh_stripes10.png"},

games/devtest/mods/testnodes/nodeboxes.lua

@@ -180,3 +180,63 @@ minetest.register_node("testnodes:facedir_to_connect_to", {
 	paramtype2 = "facedir",
 	connect_sides = {"left", "top"},
 })
+
+-- 3D sign and button:
+-- These are example nodes for more realistic example uses
+-- of wallmounted_rotate_vertical
+minetest.register_node("testnodes:sign3d", {
+	description = S("Nodebox Sign, Nodebox Type \"fixed\""),
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	sunlight_propagates = true,
+	walkable = false,
+	tiles = {
+		"testnodes_sign3d.png",
+	},
+	groups = { dig_immediate = 3 },
+	node_box = {
+		type = "fixed",
+		fixed = {-0.4375, -0.5, -0.3125, 0.4375, -0.4375, 0.3125},
+	},
+})
+
+minetest.register_node("testnodes:sign3d_wallmounted", {
+	description = S("Nodebox Sign, Nodebox Type \"wallmounted\""),
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	sunlight_propagates = true,
+	walkable = false,
+	tiles = {
+		"testnodes_sign3d.png^[colorize:#ff0000:127",
+	},
+	groups = { dig_immediate = 3 },
+	node_box = {
+		type = "wallmounted",
+		wall_top    = {-0.4375, 0.4375, -0.3125, 0.4375, 0.5, 0.3125},
+		wall_bottom = {-0.4375, -0.5, -0.3125, 0.4375, -0.4375, 0.3125},
+		wall_side   = {-0.5, -0.3125, -0.4375, -0.4375, 0.3125, 0.4375},
+	},
+})
+
+minetest.register_node("testnodes:button", {
+	description = S("Button Nodebox Test Node"),
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	sunlight_propagates = true,
+	walkable = false,
+	tiles = {
+		"testnodes_nodebox.png",
+	},
+	groups = { dig_immediate = 3 },
+	node_box = {
+		type = "fixed",
+		fixed = { -4/16, -8/16, -2/16, 4/16, -6/16, 2/16 },
+	},
+})
+

games/devtest/mods/testnodes/param2.lua

@@ -80,7 +80,7 @@ minetest.register_node("testnodes:4dir_nodebox", {
 
 minetest.register_node("testnodes:wallmounted", {
 	description = S("Wallmounted Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	paramtype2 = "wallmounted",
 	tiles = {
 		"testnodes_1w.png",
@@ -94,9 +94,25 @@ minetest.register_node("testnodes:wallmounted", {
 	groups = { dig_immediate = 3 },
 })
 
+minetest.register_node("testnodes:wallmounted_rot", {
+	description = S("Wallmounted Rotatable Test Node"),
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	tiles = {
+		"testnodes_1w.png^[colorize:#FFFF00:40",
+		"testnodes_2w.png^[colorize:#FFFF00:40",
+		"testnodes_3w.png^[colorize:#FFFF00:40",
+		"testnodes_4w.png^[colorize:#FFFF00:40",
+		"testnodes_5w.png^[colorize:#FFFF00:40",
+		"testnodes_6w.png^[colorize:#FFFF00:40",
+	},
+
+	groups = { dig_immediate = 3 },
+})
+
 minetest.register_node("testnodes:wallmounted_nodebox", {
 	description = S("Wallmounted Nodebox Test Node").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	paramtype2 = "wallmounted",
 	paramtype = "light",
 	tiles = {
@@ -118,6 +134,30 @@ minetest.register_node("testnodes:wallmounted_nodebox", {
 	groups = { dig_immediate = 3 },
 })
 
+minetest.register_node("testnodes:wallmounted_nodebox_rot", {
+	description = S("Wallmounted Rotatable Nodebox Test Node"),
+	paramtype2 = "wallmounted",
+	wallmounted_rotate_vertical = true,
+	paramtype = "light",
+	tiles = {
+		"testnodes_1w.png^[colorize:#FFFF00:40",
+		"testnodes_2w.png^[colorize:#FFFF00:40",
+		"testnodes_3w.png^[colorize:#FFFF00:40",
+		"testnodes_4w.png^[colorize:#FFFF00:40",
+		"testnodes_5w.png^[colorize:#FFFF00:40",
+		"testnodes_6w.png^[colorize:#FFFF00:40",
+	},
+	drawtype = "nodebox",
+	node_box = {
+		type = "wallmounted",
+		wall_top = { -0.5, 0, -0.5, 0.5, 0.5, 0.5 },
+		wall_bottom = { -0.5, -0.5, -0.5, 0.5, 0, 0.5 },
+		wall_side = { -0.5, -0.5, -0.5, 0, 0.5, 0.5 },
+	},
+
+	groups = { dig_immediate = 3 },
+})
+
 minetest.register_node("testnodes:color", {
 	description = S("Color Test Node").."\n"..
 		S("param2 = color (0..255)"),
@@ -212,7 +252,7 @@ minetest.register_node("testnodes:color4dir_nodebox", {
 
 minetest.register_node("testnodes:colorwallmounted", {
 	description = S("Color Wallmounted Test Node").."\n"..
-		S("param2 = color + wallmounted rotation (0..5, 8..13, ...)"),
+		S("param2 = color + wallmounted rotation (0..7, 8..15, ...)"),
 	paramtype2 = "colorwallmounted",
 	paramtype = "light",
 	palette = "testnodes_palette_wallmounted.png",
@@ -230,7 +270,7 @@ minetest.register_node("testnodes:colorwallmounted", {
 
 minetest.register_node("testnodes:colorwallmounted_nodebox", {
 	description = S("Color Wallmounted Nodebox Test Node").."\n"..
-		S("param2 = color + wallmounted rotation (0..5, 8..13, ...)"),
+		S("param2 = color + wallmounted rotation (0..7, 8..15, ...)"),
 	paramtype2 = "colorwallmounted",
 	paramtype = "light",
 	palette = "testnodes_palette_wallmounted.png",

games/devtest/mods/testnodes/properties.lua

@@ -61,8 +61,8 @@ minetest.register_node("testnodes:attached", {
 -- when the node it attaches to is gone.
 minetest.register_node("testnodes:attached_wallmounted", {
 	description = S("Wallmounted Attached Node").."\n"..
-		S("Attaches to wall; drops as item if neighbor node is gone").."\n"..
+		S("Attaches to solid node it was placed on; drops as item if neighbor node is gone").."\n"..
-		S("param2 = wallmounted rotation (0..5)"),
+		S("param2 = wallmounted rotation (0..7)"),
 	paramtype2 = "wallmounted",
 	tiles = {
 		"testnodes_attachedw_top.png",
@@ -72,9 +72,29 @@ minetest.register_node("testnodes:attached_wallmounted", {
 	groups = { attached_node = 1, dig_immediate = 3 },
 })
 
+-- This node attaches to the side of a node and drops as item
+-- when the node it attaches to is gone.
+-- Also adds vertical 90° rotation variants.
+minetest.register_node("testnodes:attached_wallmounted_rot", {
+	description = S("Rotatable Wallmounted Attached Node").."\n"..
+		S("Attaches to solid node it was placed on; drops as item if neighbor node is gone").."\n"..
+		S("param2 = wallmounted rotation (0..7)").."\n"..
+		S("May be rotated by 90° if placed at floor or ceiling"),
+	paramtype2 = "wallmounted",
+	tiles = {
+		"testnodes_attachedwr_top.png",
+		"testnodes_attachedwr_bottom.png",
+		"testnodes_attachedwr_side.png",
+	},
+	wallmounted_rotate_vertical = true,
+	groups = { attached_node = 1, dig_immediate = 3 },
+})
+
 -- Wallmounted node that always attaches to the floor
 minetest.register_node("testnodes:attached_wallmounted_floor", {
-	description = S("Floor-Attached Wallmounted Node"),
+	description = S("Floor-Attached Wallmounted Node").."\n"..
+		S("Drops as item if no solid node below (regardless of rotation)").."\n"..
+		S("param2 = wallmounted rotation (visual only) (0..7)"),
 	paramtype2 = "wallmounted",
 	tiles = {
 		"testnodes_attached_top.png",
@@ -85,10 +105,28 @@ minetest.register_node("testnodes:attached_wallmounted_floor", {
 	color = "#FF8080",
 })
 
+-- Wallmounted node that always attaches to the floor.
+-- Also adds 90° rotation variants.
+minetest.register_node("testnodes:attached_wallmounted_floor_rot", {
+	description = S("Rotatable Floor-Attached Wallmounted Node").."\n"..
+		S("Drops as item if no solid node below (regardless of rotation)").."\n"..
+		S("param2 = wallmounted rotation (visual only) (0..7)").."\n"..
+		S("May be rotated by 90° if placed at floor or ceiling"),
+	paramtype2 = "wallmounted",
+	tiles = {
+		"testnodes_attachedfr_top.png",
+		"testnodes_attachedfr_bottom.png",
+		"testnodes_attachedfr_side.png",
+	},
+	wallmounted_rotate_vertical = true,
+	groups = { attached_node = 3, dig_immediate = 3 },
+})
+
 -- This node attaches to the ceiling and drops as item
 -- when the ceiling is gone.
 minetest.register_node("testnodes:attached_top", {
-	description = S("Ceiling-Attached Node"),
+	description = S("Ceiling-Attached Node").."\n"..
+		S("Drops as item if no solid node above"),
 	tiles = {
 		"testnodes_attached_bottom.png",
 		"testnodes_attached_top.png",
@@ -99,7 +137,9 @@ minetest.register_node("testnodes:attached_top", {
 
 -- Same as wallmounted attached, but for facedir
 minetest.register_node("testnodes:attached_facedir", {
-	description = S("Facedir Attached Node"),
+	description = S("Facedir Attached Node").."\n"..
+		S("Attaches to a neighboring solid node; drops as item if that node is gone").."\n"..
+		S("param2 = facedir rotation (0..23)"),
 	paramtype2 = "facedir",
 	tiles = {
 		"testnodes_attachedf_side.png^[transformR180",
@@ -114,7 +154,9 @@ minetest.register_node("testnodes:attached_facedir", {
 
 -- Same as facedir attached, but for 4dir
 minetest.register_node("testnodes:attached_4dir", {
-	description = S("4dir Attached Node"),
+	description = S("4dir Attached Node").."\n"..
+		S("Attaches to the side of a solid node; drops as item if that node is gone").."\n"..
+		S("param2 = 4dir rotation (0..3)"),
 	paramtype2 = "4dir",
 	tiles = {
 		"testnodes_attached4_side.png^[transformR180",

src/client/content_mapblock.cpp

@@ -1008,7 +1008,9 @@ void MapblockMeshGenerator::drawTorchlikeNode()
 	switch (wall) {
 		case DWM_YP: tileindex = 1; break; // ceiling
 		case DWM_YN: tileindex = 0; break; // floor
-		default:     tileindex = 2; // side (or invalid—should we care?)
+		case DWM_S1: tileindex = 1; break; // ceiling, but rotated
+		case DWM_S2: tileindex = 0; break; // floor, but rotated
+		default: tileindex = 2; // side (or invalid, shouldn't happen)
 	}
 	useTile(tileindex, MATERIAL_FLAG_CRACK_OVERLAY, MATERIAL_FLAG_BACKFACE_CULLING);
 
@@ -1044,6 +1046,17 @@ void MapblockMeshGenerator::drawTorchlikeNode()
 			case DWM_ZN:
 				vertex.X += -size + BS/2;
 				vertex.rotateXZBy(-90);
+				break;
+			case DWM_S1:
+				// same as DWM_YP, but rotated 90°
+				vertex.Y += -size + BS/2;
+				vertex.rotateXZBy(45);
+				break;
+			case DWM_S2:
+				// same as DWM_YN, but rotated -90°
+				vertex.Y += size - BS/2;
+				vertex.rotateXZBy(-45);
+				break;
 		}
 	}
 	drawQuad(vertices);
@@ -1077,6 +1090,10 @@ void MapblockMeshGenerator::drawSignlikeNode()
 				vertex.rotateXZBy( 90); break;
 			case DWM_ZN:
 				vertex.rotateXZBy(-90); break;
+			case DWM_S1:
+				vertex.rotateXYBy( 90); vertex.rotateXZBy(90); break;
+			case DWM_S2:
+				vertex.rotateXYBy(-90); vertex.rotateXZBy(-90); break;
 		}
 	}
 	drawQuad(vertices);

src/client/game.cpp

@@ -3704,7 +3704,36 @@ bool Game::nodePlacement(const ItemDefinition &selected_def,
 		v3s16 dir = nodepos - neighborpos;
 
 		if (abs(dir.Y) > MYMAX(abs(dir.X), abs(dir.Z))) {
-			predicted_node.setParam2(dir.Y < 0 ? 1 : 0);
+			// If you change this code, also change builtin/game/item.lua
+			u8 predicted_param2 = dir.Y < 0 ? 1 : 0;
+			if (selected_def.wallmounted_rotate_vertical) {
+				bool rotate90 = false;
+				v3f fnodepos = v3f(neighborpos.X, neighborpos.Y, neighborpos.Z);
+				v3f ppos = client->getEnv().getLocalPlayer()->getPosition() / BS;
+				v3f pdir = fnodepos - ppos;
+				switch (predicted_f.drawtype) {
+					case NDT_TORCHLIKE: {
+						rotate90 = !((pdir.X < 0 && pdir.Z > 0) ||
+								(pdir.X > 0 && pdir.Z < 0));
+						if (dir.Y > 0) {
+							rotate90 = !rotate90;
+						}
+						break;
+					};
+					case NDT_SIGNLIKE: {
+						rotate90 = abs(pdir.X) < abs(pdir.Z);
+						break;
+					}
+					default: {
+						rotate90 = abs(pdir.X) > abs(pdir.Z);
+						break;
+					}
+				}
+				if (rotate90) {
+					predicted_param2 += 6;
+				}
+			}
+			predicted_node.setParam2(predicted_param2);
 		} else if (abs(dir.X) > abs(dir.Z)) {
 			predicted_node.setParam2(dir.X < 0 ? 3 : 2);
 		} else {

src/itemdef.cpp

@@ -76,6 +76,7 @@ ItemDefinition& ItemDefinition::operator=(const ItemDefinition &def)
 	groups = def.groups;
 	node_placement_prediction = def.node_placement_prediction;
 	place_param2 = def.place_param2;
+	wallmounted_rotate_vertical = def.wallmounted_rotate_vertical;
 	sound_place = def.sound_place;
 	sound_place_failed = def.sound_place_failed;
 	sound_use = def.sound_use;
@@ -124,6 +125,7 @@ void ItemDefinition::reset()
 	range = -1;
 	node_placement_prediction.clear();
 	place_param2.reset();
+	wallmounted_rotate_vertical = false;
 }
 
 void ItemDefinition::serialize(std::ostream &os, u16 protocol_version) const
@@ -183,6 +185,7 @@ void ItemDefinition::serialize(std::ostream &os, u16 protocol_version) const
 	os << (u8)place_param2.has_value(); // protocol_version >= 43
 	if (place_param2)
 		os << *place_param2;
+	writeU8(os, wallmounted_rotate_vertical);
 }
 
 void ItemDefinition::deSerialize(std::istream &is, u16 protocol_version)
@@ -251,6 +254,8 @@ void ItemDefinition::deSerialize(std::istream &is, u16 protocol_version)
 
 		if (readU8(is)) // protocol_version >= 43
 			place_param2 = readU8(is);
+
+		wallmounted_rotate_vertical = readU8(is); // 0 if missing
 	} catch(SerializationError &e) {};
 }
 

src/itemdef.h

@@ -89,6 +89,7 @@ struct ItemDefinition
 	// "" = no prediction
 	std::string node_placement_prediction;
 	std::optional<u8> place_param2;
+	bool wallmounted_rotate_vertical;
 
 	/*
 		Some helpful methods

src/mapnode.cpp

@@ -95,6 +95,8 @@ v3s16 MapNode::getWallMountedDir(const NodeDefManager *nodemgr) const
 	case 3: return v3s16(-1,0,0);
 	case 4: return v3s16(0,0,1);
 	case 5: return v3s16(0,0,-1);
+	case 6: return v3s16(0,1,0);
+	case 7: return v3s16(0,-1,0);
 	}
 }
 
@@ -323,16 +325,45 @@ void transformNodeBox(const MapNode &n, const NodeBox &nodebox,
 	else if(nodebox.type == NODEBOX_WALLMOUNTED)
 	{
 		v3s16 dir = n.getWallMountedDir(nodemgr);
+		u8 wall = n.getWallMounted(nodemgr);
 
 		// top
 		if(dir == v3s16(0,1,0))
 		{
-			boxes.push_back(nodebox.wall_top);
+			if (wall == DWM_S1) {
+				v3f vertices[2] =
+				{
+					nodebox.wall_top.MinEdge,
+					nodebox.wall_top.MaxEdge
+				};
+				for (v3f &vertex : vertices) {
+					vertex.rotateXZBy(90);
+				}
+				aabb3f box = aabb3f(vertices[0]);
+				box.addInternalPoint(vertices[1]);
+				boxes.push_back(box);
+			} else {
+				boxes.push_back(nodebox.wall_top);
+			}
 		}
 		// bottom
 		else if(dir == v3s16(0,-1,0))
 		{
-			boxes.push_back(nodebox.wall_bottom);
+			if (wall == DWM_S2) {
+				v3f vertices[2] =
+				{
+					nodebox.wall_bottom.MinEdge,
+					nodebox.wall_bottom.MaxEdge
+				};
+				for (v3f &vertex : vertices) {
+					vertex.rotateXZBy(-90);
+				}
+				aabb3f box = aabb3f(vertices[0]);
+				box.addInternalPoint(vertices[1]);
+				boxes.push_back(box);
+			} else {
+				boxes.push_back(nodebox.wall_bottom);
+			}
 		}
 		// side
 		else

src/script/common/c_content.cpp

@@ -136,6 +136,8 @@ void read_item_definition(lua_State* L, int index,
 	int place_param2;
 	if (getintfield(L, index, "place_param2", place_param2))
 		def.place_param2 = rangelim(place_param2, 0, U8_MAX);
+
+	getboolfield(L, index, "wallmounted_rotate_vertical", def.wallmounted_rotate_vertical);
 }
 
 /******************************************************************************/
@@ -195,6 +197,8 @@ void push_item_definition_full(lua_State *L, const ItemDefinition &i)
 	lua_setfield(L, -2, "sound_place_failed");
 	lua_pushstring(L, i.node_placement_prediction.c_str());
 	lua_setfield(L, -2, "node_placement_prediction");
+	lua_pushboolean(L, i.wallmounted_rotate_vertical);
+	lua_setfield(L, -2, "wallmounted_rotate_vertical");
 }
 
 /******************************************************************************/

src/util/directiontables.cpp

@@ -110,13 +110,15 @@ const v3s16 g_27dirs[27] =
 	v3s16(0,0,0),
 };
 
-const u8 wallmounted_to_facedir[6] = {
+const u8 wallmounted_to_facedir[8] = {
 	20,
 	0,
 	16 + 1,
 	12 + 3,
 	8,
-	4 + 2
+	4 + 2,
+	20 + 1, // special 1
+	0 + 1 // special 2
 };
 
 const v3s16 wallmounted_dirs[8] = {

src/util/directiontables.h

@@ -69,16 +69,22 @@ enum Direction6D {
 /// Direction in the wallmounted format.
 /// P is Positive, N is Negative.
 enum DirectionWallmounted {
+	// The 6 wallmounted directions
 	DWM_YP,
 	DWM_YN,
 	DWM_XP,
 	DWM_XN,
 	DWM_ZP,
 	DWM_ZN,
-	DWM_COUNT,
+	// There are 6 wallmounted directions, but 8 possible states (3 bits).
+	// So we have 2 additional states, which drawtypes might use for
+	// special ("S") behavior.
+	DWM_S1,
+	DWM_S2,
+	DWM_COUNT
 };
 
-extern const v3s16 g_6dirs[DWM_COUNT];
+extern const v3s16 g_6dirs[6];
 
 extern const v3s16 g_7dirs[7];
 
@@ -87,9 +93,9 @@ extern const v3s16 g_26dirs[26];
 // 26th is (0,0,0)
 extern const v3s16 g_27dirs[27];
 
-extern const u8 wallmounted_to_facedir[6];
+extern const u8 wallmounted_to_facedir[DWM_COUNT];
 
-extern const v3s16 wallmounted_dirs[8];
+extern const v3s16 wallmounted_dirs[DWM_COUNT];
 
 extern const v3s16 facedir_dirs[32];