Init

init.lua

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+-- alpha_workaround/init.lua
+-- Fix rendering issues on client 5.9 caused by boolean values of use_texture_alpha
+--[[
+  Copyright (C) 2024  1F616EMO
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU Affero General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+]]
+
+if not minetest.features.use_texture_alpha_string_modes then
+    error("[alpha_workaround] This version of Minetest Engine does not support string mode alpha.")
+end
+
+-- According to https://github.com/minetest/minetest/pull/10819
+local value_map   = {}
+
+value_map.normal  = { "clip", "opaque" }
+value_map.other   = { "blend", "clip" }
+value_map.nodebox = { "blend", "opaque" }
+value_map.mesh    = value_map.nodebox
+
+local defaults    = {
+    normal        = "opaque",
+    other         = "clip",
+    nodebox       = "clip", -- Adopting old client value
+    mesh          = "clip",
+    liquid        = "opaque",
+    flowingliquid = "opaque"
+}
+
+minetest.register_on_mods_loaded(function()
+    for name, def in pairs(minetest.registered_nodes) do
+        local alpha_type = type(def.use_texture_alpha)
+        if alpha_type ~= "string" then
+            local drawtype = def.drawtype or "normal"
+            local alpha
+
+            if alpha_type == "boolean" then
+                alpha = (value_map[drawtype] or value_map.other)[def.use_texture_alpha and 1 or 2]
+                minetest.log("warning", "[alpha_workaround] Node " .. name .. " is using boolean use_texture_alpha, " ..
+                    "assuming use_texture_alpha = " .. alpha)
+            elseif (drawtype == "liquid" or drawtype == "flowingliquid") and def.alpha then
+                alpha = def.alpha == 255 and "opaque" or "blend"
+                minetest.log("warning", "[alpha_workaround] Node " .. name .. " is using the alpha field, " ..
+                    "assuming use_texture_alpha = " .. alpha)
+            else
+                -- DAMN, we cannot detect texture transparency
+                -- So we apply defaults no matter what
+                alpha = defaults[drawtype] or defaults.other
+            end
+
+            minetest.override_item(name, {
+                use_texture_alpha = alpha
+            })
+        end
+    end
+end)

mod.conf

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+name = alpha_workaround
+title = use_texture_alpha workaround
+description = Fix rendering issues on client 5.9 caused by boolean values of use_texture_alpha
+min_minetest_version = 5.4