From 3aefa5d3ceaaa9299f42cc10921dec65fa53c5e0 Mon Sep 17 00:00:00 2001 From: paramat Date: Thu, 15 Sep 2016 22:40:19 +0100 Subject: [PATCH] Register.lua: Throw error if node 'light_source' > core.LIGHT_MAX Add 'core.LIGHT_MAX = 14' to builtin/game/constants.lua with the intention to replace misplaced 'default.LIGHT_MAX = 14' in Minetest Game. Add comment in light.h requiring the constant be changed in both places. Add lighting bug warning to note in lua_api.txt. There are hundreds of mod uses of 15 which causes a lighting bug. --- builtin/game/constants.lua | 5 +++++ builtin/game/register.lua | 3 +++ doc/lua_api.txt | 5 ++++- src/light.h | 6 ++++-- 4 files changed, 16 insertions(+), 3 deletions(-) diff --git a/builtin/game/constants.lua b/builtin/game/constants.lua index 56fca928..50c515b2 100644 --- a/builtin/game/constants.lua +++ b/builtin/game/constants.lua @@ -19,4 +19,9 @@ core.EMERGE_FROM_DISK = 3 core.EMERGE_GENERATED = 4 -- constants.h +-- Size of mapblocks in nodes core.MAP_BLOCKSIZE = 16 + +-- light.h +-- Maximum value for node 'light_source' parameter +core.LIGHT_MAX = 14 diff --git a/builtin/game/register.lua b/builtin/game/register.lua index 05dc5fef..d3f6b3df 100644 --- a/builtin/game/register.lua +++ b/builtin/game/register.lua @@ -127,6 +127,9 @@ function core.register_item(name, itemdef) fixed = {-1/8, -1/2, -1/8, 1/8, 1/2, 1/8}, } end + if itemdef.light_source and itemdef.light_source > core.LIGHT_MAX then + error("Unable to register node: 'light_source' exceeds maximum: " .. name) + end setmetatable(itemdef, {__index = core.nodedef_default}) core.registered_nodes[itemdef.name] = itemdef elseif itemdef.type == "craft" then diff --git a/doc/lua_api.txt b/doc/lua_api.txt index b6e6520b..6f69360c 100644 --- a/doc/lua_api.txt +++ b/doc/lua_api.txt @@ -3664,7 +3664,10 @@ Definition tables ^ Don't forget to use "leveled" type nodebox. ]] liquid_range = 8, -- number of flowing nodes around source (max. 8) drowning = 0, -- Player will take this amount of damage if no bubbles are left - light_source = 0, -- Amount of light emitted by node (max. 14) + light_source = 0, --[[ + ^ Amount of light emitted by node. + ^ To set the maximum (currently 14), use the value 'minetest.LIGHT_MAX'. + ^ A value outside the range 0 to minetest.LIGHT_MAX causes undefined behavior.]] damage_per_second = 0, -- If player is inside node, this damage is caused node_box = {type="regular"}, -- See "Node boxes" connects_to = nodenames, --[[ diff --git a/src/light.h b/src/light.h index f49be451..984e6d7c 100644 --- a/src/light.h +++ b/src/light.h @@ -27,8 +27,10 @@ with this program; if not, write to the Free Software Foundation, Inc., */ // This directly sets the range of light. -// Actually this is not the real maximum, and this is not the -// brightest. The brightest is LIGHT_SUN. +// Actually this is not the real maximum, and this is not the brightest, the +// brightest is LIGHT_SUN. +// If changed, this constant as defined in builtin/game/constants.lua must +// also be changed. #define LIGHT_MAX 14 // Light is stored as 4 bits, thus 15 is the maximum. // This brightness is reserved for sunlight