Mods in den Spieleordner reingeschoben. So richtig tief.

mods/leads/internal.lua

@@ -0,0 +1,104 @@
+--[[
+    Leads — Adds leads for transporting animals to Minetest.
+    Copyright © 2023, Silver Sandstone <@SilverSandstone@craftodon.social>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+]]
+
+
+--- Internal functions and overrides.
+-- @module internal
+
+
+leads.interaction_blockers = {};
+
+
+function leads._after_register_item(name, def)
+    local old_on_place = def.on_place;
+    local old_on_secondary_use = def.on_secondary_use;
+
+    local overrides = {};
+
+    function overrides.on_place(itemstack, placer, pointed_thing, ...)
+        -- Try knotting the placer's held lead:
+        if placer and not placer:get_player_control().sneak then
+            local node = pointed_thing.under and minetest.get_node_or_nil(pointed_thing.under);
+            if node and leads.is_knottable(node.name) then
+                if leads.knot(placer, pointed_thing.under) then
+                    return nil;
+                end;
+            end;
+        end;
+
+        -- Fallback to the item's old on_place function:
+        return (old_on_place or minetest.item_place)(itemstack, placer, pointed_thing, ...);
+    end;
+
+    function overrides.on_secondary_use(itemstack, user, pointed_thing, ...)
+        local object = pointed_thing and pointed_thing.ref;
+        local keys = user:get_player_control();
+
+        -- If the player is holding a knotted lead, tie it to the object instead:
+        if user and object and leads.is_leashable(object) and not leads.is_immobile(object) and not keys.sneak then
+            for lead in leads.find_connected_leads(user, true, false) do
+                local lead_entity = lead:get_luaentity();
+                local follower = lead_entity:get_follower();
+                if follower and leads.is_immobile(follower) then
+                    lead_entity:reverse(); -- Reverse the lead so the knot becomes the leader.
+                    if lead_entity:set_follower(object) then
+                        return nil;
+                    end;
+                end;
+            end;
+        end;
+
+        -- Hold Aux1 to leash an animal to another animal:
+        if object and keys.aux1 and leads.is_leashable(object) then
+            for lead in leads.find_connected_leads(user, true, false) do
+                if lead:get_luaentity():set_leader(object) then
+                    return nil;
+                end;
+            end;
+        end;
+
+        return (old_on_secondary_use or minetest.item_secondary_use)(itemstack, user, pointed_thing, ...);
+    end;
+
+    minetest.override_item(name, overrides);
+end;
+
+
+local old_is_protected = minetest.is_protected;
+function minetest.is_protected(pos, name)
+    if leads.interaction_blockers[name] then
+        return true;
+    end;
+    return old_is_protected(pos, name);
+end;
+
+
+for name, def in pairs(minetest.registered_items) do
+    leads._after_register_item(name, def);
+end;
+
+local old_register_item = minetest.register_item;
+function minetest.register_item(name, def)
+    old_register_item(name, def);
+    leads._after_register_item(string.gsub(name, '^:+', ''), def);
+end;