Move around some group code and make the craftguide render well without a recipe

This also keeps recipes aligned to the right, close to the arrow.
It also calculates the craft's height.

1 files changed, 66 insertions, 0 deletions

diff --git a/group.lua b/group.lua
new file mode 100644
index 0000000..d888ef0
--- /dev/null
+++ b/group.lua
@@ -0,0 +1,66 @@
+
+unified_inventory.registered_group_items = {
+	mesecon_conductor_craftable = "mesecons:wire_00000000_off",
+	wool = "wool:white",
+}
+
+function unified_inventory.register_group_item(groupname, itemname)
+	unified_inventory.registered_group_items[groupname] = itemname
+end
+
+
+-- This is used when displaying craft recipes, where an ingredient is
+-- specified by group rather than as a specific item.  A single-item group
+-- is represented by that item, with the single-item status signalled
+-- in the "sole" field.  If the group contains no items at all, the item
+-- field will be nil.
+--
+-- Within a multiple-item group, we prefer to use an item that has the
+-- same specific name as the group, and if there are more than one of
+-- those items we prefer the one registered for the group by a mod.
+-- Among equally-preferred items, we just pick the one with the
+-- lexicographically earliest name.
+
+function compute_group_item(group_name)
+	local candidate_items = {}
+	for itemname, itemdef in pairs(minetest.registered_items) do
+		if (itemdef.groups.not_in_creative_inventory or 0) == 0 and
+				(itemdef.groups[group_name] or 0) ~= 0 then
+			table.insert(candidate_items, itemname)
+		end
+	end
+	local num_candidates = #candidate_items
+	if num_candidates == 0 then
+		return {sole = true}
+	elseif num_candidates == 1 then
+		return {item = candidate_items[1], sole = true}
+	end
+	local bestitem = ""
+	local bestpref = 0
+	for _, item in ipairs(candidate_items) do
+		local pref
+		if item == unified_inventory.registered_group_items[group_name] then
+			pref = 3
+		elseif item:gsub("^[^:]+:", "") == group_name then
+			pref = 2
+		else
+			pref = 1
+		end
+		if pref > bestpref or (pref == bestpref and item < bestitem) then
+			bestitem = item
+			bestpref = pref
+		end
+	end
+	return {item = bestitem, sole = false}
+end
+
+
+local group_item_cache = {}
+
+function unified_inventory.get_group_item(group_name)
+	if not group_item_cache[group_name] then
+		group_item_cache[group_name] = compute_group_item(group_name)
+	end
+	return group_item_cache[group_name]
+end
+