From 2db0e176b315968363998f6c655920a174840a76 Mon Sep 17 00:00:00 2001 From: iliekprogrammar Date: Thu, 8 Apr 2021 12:04:29 +0800 Subject: [PATCH] Prevent param2 overflow when adding stems. Fix #1490 --- mods/ITEMS/mcl_ocean/kelp.lua | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/mods/ITEMS/mcl_ocean/kelp.lua b/mods/ITEMS/mcl_ocean/kelp.lua index 3aefe85f8..bbdae64ee 100644 --- a/mods/ITEMS/mcl_ocean/kelp.lua +++ b/mods/ITEMS/mcl_ocean/kelp.lua @@ -1,6 +1,9 @@ -- TODO: whenever it becomes possible to fully implement kelp without the -- plantlike_rooted limitation, please update accordingly. -- +-- TODO: whenever it becomes possible to make kelp grow infinitely without +-- resorting to making intermediate kelp stem node, please update accordingly. +-- -- TODO: In MC, you can't actually destroy kelp by bucket'ing water in the middle. -- However, because of the plantlike_rooted hack, we'll just allow it for now. @@ -191,17 +194,18 @@ end -- Converts param2 to kelp height. +-- For the special case where the max param2 is reached, interpret that as the +-- 16th kelp stem. function kelp.get_height(param2) - return math_floor(param2 / 16) + return param2 ~= 255 and math_floor(param2 / 16) or 16 -- 256/16 end -- Obtain pos and node of the tip of kelp. -function kelp.get_tip(pos, param2) - -- Optional params: param2 - local height = kelp.get_height(param2 or mt_get_node(pos).param2) - local pos_tip = {x=pos.x, y=pos.y, z=pos.z} - pos_tip.y = pos_tip.y + height + 1 +function kelp.get_tip(pos, height) + -- Optional params: height + local height = height or kelp.get_height(mt_get_node(pos).param2) + local pos_tip = {x=pos.x, y=pos.y+height+1, z=pos.z} return pos_tip, mt_get_node(pos_tip), height end @@ -227,7 +231,8 @@ end -- Obtain next param2. function kelp.next_param2(param2) - return param2+16 - param2 % 16 + -- param2 max value is 255, so adding to 256 causes overflow. + return math_min(param2+16 - param2 % 16, 255); end @@ -526,7 +531,7 @@ function kelp.kelp_on_place(itemstack, placer, pointed_thing) -- When placed on kelp. if mt_get_item_group(nu_name, "kelp") == 1 then - pos_tip,node_tip = kelp.get_tip(pos_under, node_under.param2) + pos_tip,node_tip = kelp.get_tip(pos_under, kelp.get_height(node_under.param2)) def_tip = mt_registered_nodes[node_tip.name] -- When placed on surface.