Color up the enable/disable buttons for sorttube

common.lua

@@ -126,9 +126,18 @@ end
 function fs_helpers.cycling_button(meta, base, meta_name, values)
 	local current_value = meta:get_int(meta_name)
 	local new_value = (current_value + 1) % (#values)
-	local text = values[current_value + 1]
+	local val = values[current_value + 1]
+	local text
+	local texture_name = nil
+	--when we get a table, we know the caller wants an image_button
+	if type(val) == "table" then
+		text = val["text"]
+		texture_name = val["texture"]
+	else
+		text = val
+	end
 	local field = "fs_helpers_cycling:"..new_value..":"..meta_name
-	return base..";"..field..";"..minetest.formspec_escape(text).."]"
+	return base..";"..(texture_name and texture_name..";" or "")..field..";"..minetest.formspec_escape(text).."]"
 end
 
 ---------

tubes.lua

@@ -249,6 +249,12 @@ if pipeworks.enable_mese_tube then
 				end
 			end
 		end
+		local buttons_formspec = ""
+		for i = 0, 5 do
+			buttons_formspec = buttons_formspec .. fs_helpers.cycling_button(meta,
+				"image_button[7,"..(i)..";1,1", "l"..(i+1).."s",
+				{{text="",texture="pipeworks_button_off.png"}, {text="",texture="pipeworks_button_on.png"}})
+		end
 		meta:set_string("formspec",
 			"size[8,11]"..
 			"list[current_name;line1;1,0;6,1;]"..
@@ -263,12 +269,7 @@ if pipeworks.enable_mese_tube then
 			"image[0,3;1,1;pipeworks_yellow.png]"..
 			"image[0,4;1,1;pipeworks_blue.png]"..
 			"image[0,5;1,1;pipeworks_red.png]"..
-			fs_helpers.cycling_button(meta, "button[7,0;1,1", "l1s", {"Off", "On"})..
-			fs_helpers.cycling_button(meta, "button[7,1;1,1", "l2s", {"Off", "On"})..
-			fs_helpers.cycling_button(meta, "button[7,2;1,1", "l3s", {"Off", "On"})..
-			fs_helpers.cycling_button(meta, "button[7,3;1,1", "l4s", {"Off", "On"})..
-			fs_helpers.cycling_button(meta, "button[7,4;1,1", "l5s", {"Off", "On"})..
-			fs_helpers.cycling_button(meta, "button[7,5;1,1", "l6s", {"Off", "On"})..
+			buttons_formspec..
 			"list[current_player;main;0,7;8,4;]")
 	end
 	pipeworks.register_tube("pipeworks:mese_tube", "Sorting Pneumatic Tube Segment", mese_plain_textures, mese_noctr_textures,