add a horizontal banister, rename the diagonals (+alias)

includes just enough code to try to auto-route them as they're placed.

the "root" node is now the horizontal one - if you have diagonals and
they don't place right, they should after you dig them and place again.

homedecor/handlers/expansion.lua

@@ -222,20 +222,74 @@ function homedecor.place_banister(itemstack, placer, pointed_thing)
 		return
 	end
 
+	local lxd = homedecor.fdir_to_left[fdir+1][1]
+	local lzd = homedecor.fdir_to_left[fdir+1][2]
+
 	local rxd = homedecor.fdir_to_right[fdir+1][1]
 	local rzd = homedecor.fdir_to_right[fdir+1][2]
 
 	local fxd = homedecor.fdir_to_fwd[fdir+1][1]
 	local fzd = homedecor.fdir_to_fwd[fdir+1][2]
 
+	local fwd_pos =             { x=pos.x+fxd, y=pos.y, z=pos.z+fzd }
+	local left_pos =            { x=pos.x+lxd, y=pos.y, z=pos.z+lzd }
+	local right_pos =           { x=pos.x+rxd, y=pos.y, z=pos.z+rzd }
+
 	local right_fwd_above_pos = { x=pos.x+rxd+fxd, y=pos.y+1, z=pos.z+rzd+fzd }
+	local left_fwd_above_pos =  { x=pos.x+lxd+fxd, y=pos.y+1, z=pos.z+lzd+fzd }
+
+	local fwd_node =             minetest.get_node(fwd_pos)
+	local left_node =            minetest.get_node(left_pos)
+	local right_node =           minetest.get_node(right_pos)
+
+	local left_below_node =      minetest.get_node({x=left_pos.x, y=left_pos.y-1, z=left_pos.z})
+	local right_below_node =     minetest.get_node({x=right_pos.x, y=right_pos.y-1, z=right_pos.z})
+
 	local right_fwd_above_node = minetest.get_node(right_fwd_above_pos)
+	local left_fwd_above_node =  minetest.get_node(left_fwd_above_pos)
 
 	local new_place_name = itemstack:get_name()
+	local n = 0
 
-	if placer:get_player_control()["sneak"]
-	  or not is_buildable_to(placer_name, right_fwd_above_pos, nil, right_fwd_above_pos) then
+	-- try to place a diagonal one on the side of blocks stacked like stairs
+	if not is_buildable_to(placer_name, right_fwd_above_pos, nil, right_fwd_above_pos) then
+		new_place_name = string.gsub(new_place_name, "_horizontal", "_diagonal_right")
+	elseif not is_buildable_to(placer_name, left_fwd_above_pos, nil, left_fwd_above_pos) then
+		new_place_name = string.gsub(new_place_name, "_horizontal", "_diagonal_left")
+
+	-- try to follow a diagonal with the corresponding horizontal
+	-- from the top of a diagonal...
+	elseif left_below_node and string.find(left_below_node.name, "homedecor:banister_.*_diagonal") then
+		fdir = left_below_node.param2
+		new_place_name = string.gsub(left_below_node.name, "_diagonal_.-$", "_horizontal")
+	elseif right_below_node and string.find(right_below_node.name, "homedecor:banister_.*_diagonal") then
+		fdir = right_below_node.param2
+		new_place_name = string.gsub(right_below_node.name, "_diagonal_.-$", "_horizontal")
+
+	-- from the bottom of it
+	elseif left_node and string.find(left_node.name, "homedecor:banister_.*_diagonal") then
+		fdir = left_node.param2
+		new_place_name = string.gsub(left_node.name, "_diagonal_.-$", "_horizontal")
+	elseif right_node and string.find(right_node.name, "homedecor:banister_.*_diagonal") then
+		fdir = right_node.param2
+		new_place_name = string.gsub(right_node.name, "_diagonal_.-$", "_horizontal")
+
+	-- try to follow a horizontal with another of the same
+	elseif left_node and string.find(left_node.name, "homedecor:banister_.*_horizontal") then
+		fdir = left_node.param2
+		new_place_name = left_node.name
+	elseif right_node and string.find(right_node.name, "homedecor:banister_.*_horizontal") then
+		fdir = right_node.param2
+		new_place_name = right_node.name
+	end
+
+	-- manually invert left-right orientation
+	if placer:get_player_control()["sneak"] then
+		if string.find(new_place_name, "banister_.*_diagonal") then
 			new_place_name = string.gsub(new_place_name, "_left", "_right")
+		else
+			new_place_name = string.gsub(new_place_name, "_right", "_left")
+		end
 	end
 
 	minetest.set_node(pos, {name = new_place_name, param2 = fdir})

homedecor/misc-nodes.lua

@@ -727,26 +727,31 @@ homedecor.banister_materials = {
 	}
 }
 
-for _, side in ipairs({"left", "right"}) do
+for _, side in ipairs({"diagonal_left", "diagonal_right", "horizontal"}) do
 
 	for i in ipairs(homedecor.banister_materials) do
 
 		local name = homedecor.banister_materials[i][1]
+		local nodename = "banister_"..name.."_"..side
+
+		local groups = { snappy = 3, not_in_creative_inventory = 1 }
 		local cbox = {
 			type = "fixed",
-			fixed = { -9/16, -3/16, 5/16, 9/16, 24/16, 8/16}
+			fixed = { -9/16, -3/16, 5/16, 9/16, 24/16, 8/16 }
 		}
 
-		local onplace = nil
-		groups = { snappy = 3, not_in_creative_inventory = 1}
-
-		if side == "left" then
-			onplace = homedecor.place_banister
+		if side == "horizontal" then
 			groups = { snappy = 3 }
+			cbox = {
+				type = "fixed",
+				fixed = { -8/16, -8/16, 5/16, 8/16, 8/16, 8/16 }
+			}
+		else
+			minetest.register_alias(string.gsub("homedecor:"..nodename, "diagonal_", ""), "homedecor:"..nodename)
 		end
 
-		homedecor.register("banister_"..name.."_"..side, {
-			description = S("Banister for Stairs ("..homedecor.banister_materials[i][2]..", "..side.." side)"),
+		homedecor.register(nodename, {
+			description = S("Banister for Stairs ("..homedecor.banister_materials[i][2]..", "..side..")"),
 			mesh = "homedecor_banister_"..side..".obj",
 			tiles = {
 				homedecor.banister_materials[i][3],
@@ -756,8 +761,8 @@ for _, side in ipairs({"left", "right"}) do
 			groups = groups,
 			selection_box = cbox,
 			collision_box = cbox,
-			on_place = onplace,
-			drop = "homedecor:banister_"..name.."_left",
+			on_place = homedecor.place_banister,
+			drop = "homedecor:banister_"..name.."_horizontal",
 		})
 	end
 end

homedecor/models/homedecor_banister_horizontal.obj

@@ -0,0 +1,87 @@
+# Blender v2.73 (sub 0) OBJ File: 'banister-horizontal_left.blend'
+# www.blender.org
+o Cylinder_Cylinder_verticals
+v -0.312500 0.437500 0.437500
+v -0.312500 0.437500 0.500000
+v -0.250000 0.437500 0.500000
+v -0.250000 0.437500 0.437500
+v -0.312500 -0.500000 0.437500
+v -0.312500 -0.500000 0.500000
+v -0.250000 -0.500000 0.500000
+v -0.250000 -0.500000 0.437500
+v 0.500000 0.437500 0.312500
+v 0.500000 0.437500 0.500000
+v -0.500000 0.437500 0.500000
+v -0.500000 0.437500 0.312500
+v 0.500000 0.500000 0.312500
+v 0.500000 0.500000 0.500000
+v -0.500000 0.500000 0.500000
+v -0.500000 0.500000 0.312500
+v 0.312500 -0.500000 0.437500
+v 0.312500 -0.500000 0.500000
+v 0.250000 -0.500000 0.500000
+v 0.250000 -0.500000 0.437500
+v 0.312500 0.437500 0.437500
+v 0.312500 0.437500 0.500000
+v 0.250000 0.437500 0.500000
+v 0.250000 0.437500 0.437500
+vt 0.750000 0.062500
+vt 0.750000 0.000000
+vt 0.812500 0.000000
+vt 0.812500 0.062500
+vt 0.937500 0.000000
+vt 0.937500 0.062500
+vt 0.000000 0.062500
+vt 0.000000 -0.000000
+vt 0.937500 0.562500
+vt 0.937500 0.625000
+vt -0.000000 0.625000
+vt -0.000000 0.562500
+vt 0.937500 0.875000
+vt 0.937500 0.812500
+vt 0.000000 0.812500
+vt 0.000000 0.875000
+vt 0.937500 0.750000
+vt 0.937500 0.687500
+vt -0.000000 0.687500
+vt -0.000000 0.750000
+vt 0.187500 0.062500
+vt 0.187500 0.000000
+vt 0.250000 0.000000
+vt 0.250000 0.062500
+vt -0.062500 1.000000
+vt 0.125000 1.000000
+vt 0.125000 0.937500
+vt -0.062500 0.937500
+vt 0.000000 1.000000
+vt 1.000000 1.000000
+vt 1.000000 0.937500
+vt -0.000000 0.937500
+vt 0.000000 0.187500
+vt 1.000000 0.187500
+vt 1.000000 0.000000
+vn 0.000000 -1.000000 0.000000
+vn 0.000000 0.000000 -1.000000
+vn -1.000000 0.000000 0.000000
+vn 0.000000 0.000000 1.000000
+vn 1.000000 0.000000 0.000000
+vn 0.000000 1.000000 0.000000
+g Cylinder_Cylinder_verticals_Cylinder_Cylinder_verticals_verticals
+s off
+f 8/1/1 7/2/1 6/3/1 5/4/1
+f 1/5/2 4/6/2 8/7/2 5/8/2
+f 2/9/3 1/10/3 5/11/3 6/12/3
+f 3/6/4 2/5/4 6/8/4 7/7/4
+f 21/13/5 22/14/5 18/15/5 17/16/5
+f 22/17/4 23/18/4 19/19/4 18/20/4
+f 23/9/3 24/10/3 20/11/3 19/12/3
+f 24/18/2 21/17/2 17/20/2 20/19/2
+f 17/21/1 18/22/1 19/23/1 20/24/1
+f 4/13/5 3/14/5 7/15/5 8/16/5
+g Cylinder_Cylinder_verticals_Cylinder_Cylinder_verticals_railing
+f 13/25/5 14/26/5 10/27/5 9/28/5
+f 14/29/4 15/30/4 11/31/4 10/32/4
+f 15/26/3 16/25/3 12/28/3 11/27/3
+f 16/30/2 13/29/2 9/32/2 12/31/2
+f 9/8/1 10/33/1 11/34/1 12/35/1
+f 16/35/6 15/34/6 14/33/6 13/8/6