Added more metal sign colors

Red w/white border (e.g. "Stop" or similar),
white w/red border (e.g. "Yield", "Do not enter", and similar),
white w/black border (speed limit, other info signs)

renamed and simplified their edge/top/bottom textures since they always have
metal edges anyways (made them all use the same files).  Simplified the code
that creates them.  Minor changes to the code that places them to facilitate
this expansion (also allows for future expansion if necessary).

signs_lib/init.lua

@@ -512,9 +512,7 @@ signs_lib.update_sign = function(pos, fields)
 		sign_info = signs_lib.yard_sign_model.textpos[minetest.get_node(pos).param2 + 1]
 	elseif signnode.name == "signs:sign_hanging" then
 		sign_info = signs_lib.hanging_sign_model.textpos[minetest.get_node(pos).param2 + 1]
-	elseif signnode.name == "default:sign_wall" 
-		or signnode.name == "signs:sign_wall_green"
-		or signnode.name == "signs:sign_wall_yellow" then
+	elseif string.find(signnode.name, "sign_wall") then
 		sign_info = signs_lib.wall_sign_model.textpos[minetest.get_node(pos).param2 + 1]
 	else -- ...it must be a sign on a fence post.
 		sign_info = signs_lib.sign_post_model.textpos[minetest.get_node(pos).param2 + 1]
@@ -593,7 +591,7 @@ function signs_lib.determine_sign_type(itemstack, placer, pointed_thing)
 			minetest.add_node(above, {name = "signs:sign_yard", param2 = fdir})
 			sign_info = signs_lib.yard_sign_model.textpos[fdir + 1]
 
-		else
+		else -- it must be a wooden or metal wall sign.
 			minetest.add_node(above, {name = signname, param2 = fdir})
 			sign_info = signs_lib.wall_sign_model.textpos[fdir + 1]
 		end
@@ -743,46 +741,15 @@ minetest.register_node(":signs:sign_post", {
     },
 })
 
-minetest.register_node(":signs:sign_wall_green", {
-	description = S("Sign (green, metal)"),
-	inventory_image = "signs_green_inv.png",
-	wield_image = "signs_green_inv.png",
-	node_placement_prediction = "",
-	paramtype = "light",
-	sunlight_propagates = true,
-	paramtype2 = "facedir",
-	drawtype = "nodebox",
-	node_box = signs_lib.wall_sign_model.nodebox,
-	tiles = {
-		"signs_green_top.png",
-		"signs_green_bottom.png",
-		"signs_green_sides.png",
-		"signs_green_sides.png",
-		"signs_back_metal.png",
-		"signs_green_front.png"
-	},
-	groups = sign_groups,
-	on_place = function(itemstack, placer, pointed_thing)
-		return signs_lib.determine_sign_type(itemstack, placer, pointed_thing)
-	end,
-	on_construct = function(pos)
-		signs_lib.construct_sign(pos)
-	end,
-	on_destruct = function(pos)
-		signs_lib.destruct_sign(pos)
-	end,
-	on_receive_fields = function(pos, formname, fields, sender)
-		signs_lib.receive_fields(pos, formname, fields, sender)
-	end,
-	on_punch = function(pos, node, puncher)
-		signs_lib.update_sign(pos)
-	end,
-})
+-- metal, colored signs
 
-minetest.register_node(":signs:sign_wall_yellow", {
-	description = S("Sign (yellow, metal)"),
-	inventory_image = "signs_yellow_inv.png",
-	wield_image = "signs_yellow_inv.png",
+local sign_colors = { "green", "yellow", "red", "white_red", "white_black" }
+
+for _, color in ipairs(sign_colors) do
+	minetest.register_node(":signs:sign_wall_"..color, {
+		description = S("Sign ("..color..", metal)"),
+		inventory_image = "signs_"..color.."_inv.png",
+		wield_image = "signs_"..color.."_inv.png",
 		node_placement_prediction = "",
 		paramtype = "light",
 		sunlight_propagates = true,
@@ -790,12 +757,12 @@ minetest.register_node(":signs:sign_wall_yellow", {
 		drawtype = "nodebox",
 		node_box = signs_lib.wall_sign_model.nodebox,
 		tiles = {
-		"signs_yellow_top.png",
-		"signs_yellow_bottom.png",
-		"signs_yellow_sides.png",
-		"signs_yellow_sides.png",
-		"signs_back_metal.png",
-		"signs_yellow_front.png"
+			"signs_metal_tb.png",
+			"signs_metal_tb.png",
+			"signs_metal_sides.png",
+			"signs_metal_sides.png",
+			"signs_metal_back.png",
+			"signs_"..color.."_front.png"
 		},
 		groups = sign_groups,
 		on_place = function(itemstack, placer, pointed_thing)
@@ -813,7 +780,8 @@ minetest.register_node(":signs:sign_wall_yellow", {
 		on_punch = function(pos, node, puncher)
 			signs_lib.update_sign(pos)
 		end,
-})
+	})
+end
 
 local signs_text_on_activate
 
@@ -925,7 +893,7 @@ minetest.register_abm({
 	end
 })
 
--- craft recipes for the green and yellow signs
+-- craft recipes for the metal signs
 
 minetest.register_craft( {
         output = "signs:sign_wall_green 4",
@@ -959,6 +927,54 @@ minetest.register_craft( {
         },
 })
 
+minetest.register_craft( {
+        output = "signs:sign_wall_red 4",
+        recipe = {
+			{ "dye:red", "dye:white", "dye:red" },
+			{ "default:steel_ingot", "default:steel_ingot", "default:steel_ingot" }
+        },
+})
+
+minetest.register_craft( {
+        output = "signs:sign_wall_red 2",
+        recipe = {
+			{ "dye:red", "dye:white", "dye:red" },
+			{ "steel:sheet_metal", "steel:sheet_metal", "steel:sheet_metal" }
+        },
+})
+
+minetest.register_craft( {
+        output = "signs:sign_wall_white_red 4",
+        recipe = {
+			{ "dye:white", "dye:red", "dye:white" },
+			{ "default:steel_ingot", "default:steel_ingot", "default:steel_ingot" }
+        },
+})
+
+minetest.register_craft( {
+        output = "signs:sign_wall_white_red 2",
+        recipe = {
+			{ "dye:white", "dye:red", "dye:white" },
+			{ "steel:sheet_metal", "steel:sheet_metal", "steel:sheet_metal" }
+        },
+})
+
+minetest.register_craft( {
+        output = "signs:sign_wall_white_black 4",
+        recipe = {
+			{ "dye:white", "dye:black", "dye:white" },
+			{ "default:steel_ingot", "default:steel_ingot", "default:steel_ingot" }
+        },
+})
+
+minetest.register_craft( {
+        output = "signs:sign_wall_white_black 2",
+        recipe = {
+			{ "dye:white", "dye:black", "dye:white" },
+			{ "steel:sheet_metal", "steel:sheet_metal", "steel:sheet_metal" }
+        },
+})
+
 if minetest.setting_get("log_mods") then
 	minetest.log("action", S("signs loaded"))
 end