From 15068e5b4b578e6aac3966e5eca4cbad4c092ec7 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Fri, 14 Aug 2026 22:23:40 +0500
Subject: [PATCH 01/20] fix p.8

---
 res/content/base/modules/util.lua | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/res/content/base/modules/util.lua b/res/content/base/modules/util.lua
index 4d25ccb91..db5e4f2f3 100644
--- a/res/content/base/modules/util.lua
+++ b/res/content/base/modules/util.lua
@@ -2,6 +2,26 @@ local util = {}
 
 local DROP_FORCE = 8
 local DROP_INIT_VEL = {0, 3, 0}
+local DROP_MAX_ITEM_DIR_SHIFT_DEGREES = 65
+
+local function calculate_item_drop_dir(pid)
+    local yaw, pitch = player.get_rot(pid)
+    local vp = gui.get_viewport()
+    local mpos = table.map(input.get_mouse_pos(), function(i, v)
+        return v / vp[i] - 0.5
+    end)
+    if not hud.is_inventory_open() and not hud.is_player_inventory_open() then
+        mpos = {0, 0}
+    end
+    pitch = math.clamp(pitch - mpos[2]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2, -90, 90)
+    yaw = math.rad(yaw + 90 -mpos[1]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2)
+    pitch = math.rad(pitch)
+    return vec3.normalize({
+       math.cos(yaw) * math.cos(pitch),
+       math.sin(pitch),
+      -math.sin(yaw) * math.cos(pitch)
+     })
+end
 
 ---@param mode integer 0 - whole stack, 1 - single item, 2 - dupe whole stack
 function util.drop_from_slot(invid, slot, mode)
@@ -30,7 +50,8 @@ function util.drop_from_slot(invid, slot, mode)
     local data = inventory.get_all_data(invid, slot)
     local pvel = { player.get_vel(pid) }
     local ppos = vec3.add({ player.get_pos(pid) }, { 0, 0.7, 0 })
-    local throw_force = vec3.mul(player.get_dir(pid), DROP_FORCE)
+    local dir = calculate_item_drop_dir(pid)
+    local throw_force = vec3.mul(dir, DROP_FORCE)
     local drop = util.drop(ppos, itemid, drop_itemcount, data, 1.5)
     if not drop then
         return

From 3b3bf8e878d5a219f802f59dfdb0dfadb989b45d Mon Sep 17 00:00:00 2001
From: Neveix <87336789+Neveix@users.noreply.github.com>
Date: Fri, 14 Aug 2026 23:25:42 +0500
Subject: [PATCH 02/20] Inventory enhancements #897: 2, 5, 9, 11, 12 (#931)

* implement a bit

* change shift to ctrl

* add enhancement #2

* add ctrl-interaction with content access

* fix libinventory.move bug (none checking)

* fix p.5

* move shareinv logic into inventory_utils

* add inventory utils

* small refactor

* fix iframe.src = ""

---------

Co-authored-by: MihailRis <mexaruc@gmail.com>
---
 res/layouts/inventory.xml                     |  4 +-
 res/layouts/inventory.xml.lua                 | 13 +----
 res/modules/inventory_utils.lua               | 21 +++++++
 src/frontend/hud.cpp                          | 14 ++++-
 src/graphics/ui/elements/InventoryView.cpp    | 55 ++++++++++++-------
 src/graphics/ui/elements/InventoryView.hpp    |  2 +
 src/items/ItemStack.cpp                       |  8 +++
 src/items/ItemStack.hpp                       |  1 +
 src/logic/scripting/lua/libs/libinventory.cpp |  3 +-
 9 files changed, 84 insertions(+), 37 deletions(-)
 create mode 100644 res/modules/inventory_utils.lua

diff --git a/res/layouts/inventory.xml b/res/layouts/inventory.xml
index 4291ab4d3..7a33b054f 100644
--- a/res/layouts/inventory.xml
+++ b/res/layouts/inventory.xml
@@ -1,4 +1,4 @@
 <inventory>
-    <slots-grid pos="0, 164" rows="1" count="10" sharefunc="inventory_share_func"/>
-    <slots-grid rows="3" start-index="10" count="30" sharefunc="inventory_share_func"/>
+    <slots-grid pos="0, 164" rows="1" count="10" sharefunc="share_func"/>
+    <slots-grid rows="3" start-index="10" count="30" sharefunc="share_func"/>
 </inventory>
diff --git a/res/layouts/inventory.xml.lua b/res/layouts/inventory.xml.lua
index 9f836223d..5c79db6ff 100644
--- a/res/layouts/inventory.xml.lua
+++ b/res/layouts/inventory.xml.lua
@@ -1,12 +1 @@
-function inventory_share_func(invid, slotid)
-    local blockinv = hud.get_block_inventory()
-    if blockinv ~= 0 then
-        inventory.move(invid, slotid, blockinv)
-    elseif rules.get("allow-content-access") then
-        inventory.set(invid, slotid, 0, 0)
-    elseif slotid < 10 then
-        inventory.move_range(invid, slotid, invid, 10)
-    else
-        inventory.move_range(invid, slotid, invid, 0, 9)
-    end
-end
+share_func = require("core:inventory_utils").share_default_func
diff --git a/res/modules/inventory_utils.lua b/res/modules/inventory_utils.lua
new file mode 100644
index 000000000..17089cdab
--- /dev/null
+++ b/res/modules/inventory_utils.lua
@@ -0,0 +1,21 @@
+local M = {}
+
+function M.share_default_func(invid, slotid)
+    local blockinv = hud.get_block_inventory()
+    local playerinv = player.get_inventory(hud.get_player())
+    if blockinv ~= 0 then
+        if invid == blockinv then
+            inventory.move(blockinv, slotid, playerinv)
+        else
+            inventory.move(invid, slotid, blockinv)
+        end
+    elseif rules.get("allow-content-access") then
+        inventory.set(invid, slotid, 0, 0)
+    elseif slotid < 10 then
+        inventory.move_range(invid, slotid, invid, 10)
+    else
+        inventory.move_range(invid, slotid, invid, 0, 9)
+    end
+end
+
+return M
diff --git a/src/frontend/hud.cpp b/src/frontend/hud.cpp
index 08a4b8455..6751b885c 100644
--- a/src/frontend/hud.cpp
+++ b/src/frontend/hud.cpp
@@ -106,6 +106,7 @@ std::shared_ptr<UINode> HudElement::getNode() const {
 std::shared_ptr<InventoryView> Hud::createContentAccess() {
     auto& content = frontend.getLevel().content;
     auto& indices = *content.getIndices();
+    auto& input = this->input;
     auto inventory = player.getInventory();
     
     size_t itemsCount = indices.items.count();
@@ -115,12 +116,19 @@ std::shared_ptr<InventoryView> Hud::createContentAccess() {
     }
 
     SlotLayout slotLayout(-1, glm::vec2(), false, true, nullptr,
-    [inventory, &indices](uint, ItemStack& item) {
+    [inventory, &indices, &input](uint, ItemStack& item) {
         auto copy = ItemStack(item);
+        if (input.pressed(Keycode::LEFT_CONTROL)) {
+            copy.maximizeCount(indices);
+        }
         inventory->move(copy, indices);
     }, 
-    [this, inventory](uint, ItemStack& item) {
-        inventory->getSlot(player.getChosenSlot()).set(item);
+    [this, inventory, &indices, &input](uint, ItemStack& item) {
+        auto copy = ItemStack(item);
+        if (input.pressed(Keycode::LEFT_CONTROL)) {
+            copy.maximizeCount(indices);
+        }
+        inventory->getSlot(player.getChosenSlot()).set(copy);
     });
 
     InventoryBuilder builder(gui);
diff --git a/src/graphics/ui/elements/InventoryView.cpp b/src/graphics/ui/elements/InventoryView.cpp
index 395c8d34e..614d4c913 100644
--- a/src/graphics/ui/elements/InventoryView.cpp
+++ b/src/graphics/ui/elements/InventoryView.cpp
@@ -366,28 +366,12 @@ void SlotView::performLeftClick(ItemStack& stack, ItemStack& grabbed) {
         );
         return;
     }
-
+    auto indices = *content->getIndices();
     if (!layout.itemSource && stack.accepts(grabbed) && layout.placing) {
         action = InteractionAction::PUT;
-        stack.move(grabbed, *content->getIndices());
+        stack.move(grabbed, indices);
     } else {
-        if (layout.itemSource) {
-            if (grabbed.isEmpty()) {
-                action = InteractionAction::TAKE;
-                grabbed.set(stack);
-            } else {
-                action = InteractionAction::PUT;
-                grabbed.clear();
-            }
-        } else if (grabbed.isEmpty()) {
-            if (layout.taking) {
-                action = InteractionAction::TAKE;
-                std::swap(grabbed, stack);
-            }
-        } else if (layout.taking && layout.placing) {
-            action = InteractionAction::PUT;
-            std::swap(grabbed, stack);
-        }
+        actIfCannotPut(stack, grabbed, action);
     }
     
     if (action != InteractionAction::UNDEFINED) {
@@ -400,6 +384,39 @@ void SlotView::performLeftClick(ItemStack& stack, ItemStack& grabbed) {
     }
 }
 
+void SlotView::actIfCannotPut(ItemStack& stack, ItemStack& grabbed, InteractionAction& action) {
+    const auto& input = gui.getInput();
+    auto indices = *content->getIndices();
+    if (layout.itemSource) {
+        if (grabbed.isEmpty()) {
+            action = InteractionAction::TAKE;
+            grabbed.set(stack);
+            if (input.pressed(Keycode::LEFT_CONTROL)) {
+                grabbed.maximizeCount(*content->getIndices());
+            }
+        } else {
+            if (grabbed.accepts(stack)) {
+                auto& def = indices.items.require(stack.getItemId());
+                if (grabbed.getCount() < def.stackSize) {
+                    action = InteractionAction::TAKE;
+                    grabbed.setCount(grabbed.getCount() + 1);
+                }
+            } else {
+                action = InteractionAction::PUT;
+                grabbed.clear();
+            }
+        }
+    } else if (grabbed.isEmpty()) {
+        if (layout.taking) {
+            action = InteractionAction::TAKE;
+            std::swap(grabbed, stack);
+        }
+    } else if (layout.taking && layout.placing) {
+        action = InteractionAction::PUT;
+        std::swap(grabbed, stack);
+    }
+}
+
 void SlotView::performRightClick(ItemStack& stack, ItemStack& grabbed) {
     if (layout.rightClick) {
         layout.rightClick(inventoryId, stack);
diff --git a/src/graphics/ui/elements/InventoryView.hpp b/src/graphics/ui/elements/InventoryView.hpp
index 243d8b6b5..fbfe3eee9 100644
--- a/src/graphics/ui/elements/InventoryView.hpp
+++ b/src/graphics/ui/elements/InventoryView.hpp
@@ -123,6 +123,8 @@ namespace gui {
             SHARE = 2,
             UNDEFINED,
         };
+    private:
+        void actIfCannotPut(ItemStack& stack, ItemStack& grabbed, InteractionAction& action);
     };
 
     class InventoryView final : public gui::Container {
diff --git a/src/items/ItemStack.cpp b/src/items/ItemStack.cpp
index f99d8700a..d0f39d5fe 100644
--- a/src/items/ItemStack.cpp
+++ b/src/items/ItemStack.cpp
@@ -48,6 +48,14 @@ void ItemStack::setCount(itemcount_t count) {
     }
 }
 
+void ItemStack::maximizeCount(const ContentIndices& indices) {
+    auto& def = indices.items.require(getItemId());
+    this->count = def.stackSize;
+    if (count == 0) {
+        clear();
+    }
+}
+
 void ItemStack::setField(std::string_view name, dv::value value) {
     if (fields == nullptr) {
         if (value == nullptr) {
diff --git a/src/items/ItemStack.hpp b/src/items/ItemStack.hpp
index 4896bc39e..1ec3fe41d 100644
--- a/src/items/ItemStack.hpp
+++ b/src/items/ItemStack.hpp
@@ -18,6 +18,7 @@ public:
     void set(const ItemStack& item);
     void set(ItemStack&& item);
     void setCount(itemcount_t count);
+    void maximizeCount(const ContentIndices& indices);
 
     /// @brief Set a field in the item stack data.
     void setField(std::string_view name, dv::value value);
diff --git a/src/logic/scripting/lua/libs/libinventory.cpp b/src/logic/scripting/lua/libs/libinventory.cpp
index 2aea52394..9d11d66c6 100644
--- a/src/logic/scripting/lua/libs/libinventory.cpp
+++ b/src/logic/scripting/lua/libs/libinventory.cpp
@@ -2,6 +2,7 @@
 #include "items/Inventories.hpp"
 #include "items/ItemStack.hpp"
 #include "logic/BlocksController.hpp"
+#include "logic/scripting/lua/lua_util.hpp"
 #include "world/Level.hpp"
 #include "api_lua.hpp"
 
@@ -180,7 +181,7 @@ static int l_move(lua::State* L) {
     validate_slotid(slotAid, invA);
 
     auto invBid = lua::tointeger(L, 3);
-    auto slotBid = lua::isnil(L, 4) ? -1 : lua::tointeger(L, 4);
+    auto slotBid = lua::isnoneornil(L, 4) ? -1 : lua::tointeger(L, 4);
     auto& invB = get_inventory(invBid, 3);
     auto& slot = invA.getSlot(slotAid);
     if (slotBid == -1) {

From efb4532536dd85c1edde19a6fc40e2ff19f807d6 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 00:55:04 +0500
Subject: [PATCH 03/20] add mul* functions to quats & fix to_string

---
 src/logic/scripting/lua/libs/libquat.cpp | 40 ++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/logic/scripting/lua/libs/libquat.cpp b/src/logic/scripting/lua/libs/libquat.cpp
index 53757cb36..5002e9bb3 100644
--- a/src/logic/scripting/lua/libs/libquat.cpp
+++ b/src/logic/scripting/lua/libs/libquat.cpp
@@ -1,3 +1,5 @@
+#include <iostream>
+#include <glm/gtx/string_cast.hpp> 
 #include "api_lua.hpp"
 
 #define GLM_ENABLE_EXPERIMENTAL
@@ -31,14 +33,14 @@ static int l_tostring(lua::State* L) {
     lua::check_argc(L, 1);
     auto quat = lua::toquat(L, 1);
 
+    float components[4] = {quat.w, quat.x, quat.y, quat.z};
     std::stringstream ss;
-    ss << "quat"
-       << "{";
+    ss << "quat" << "{";
     for (int i = 0; i < 4; i++) {
         if (i > 0) {
             ss << ", ";
         }
-        ss << quat[i];
+        ss << components[i];
     }
     ss << "}";
     return lua::pushstring(L, ss.str());
@@ -52,10 +54,42 @@ static int l_from_euler(lua::State *L) {
     return lua::pushquat(L, glm::quat(euler));
 }
 
+static int l_mul(lua::State* L) {
+    uint argc = lua::check_argc(L, 2, 3);
+    glm::quat a = lua::toquat(L, 1);
+    glm::quat b = lua::toquat(L, 2);
+    
+    glm::quat result = a * b;
+    
+    if (argc == 3) {
+        lua::setquat(L, 3, result);
+        return 0;
+    }
+    
+    return lua::pushquat(L, result);
+}
+
+static int l_mul_vec3(lua::State* L) {
+    uint argc = lua::check_argc(L, 2, 3);
+    glm::quat q = lua::toquat(L, 1);
+    glm::vec3 v = lua::tovec3(L, 2);
+
+    glm::vec3 result = q * v;
+    
+    if (argc == 3) {
+        lua::setvec(L, 3, result);
+        return 0;
+    }
+    
+    return lua::pushvec3(L, result);
+}
+
 const luaL_Reg quatlib[] = {
     {"from_mat4", lua::wrap<l_from_mat4>},
     {"from_euler", lua::wrap<l_from_euler>},
     {"slerp", lua::wrap<l_slerp>},
     {"tostring", lua::wrap<l_tostring>},
+    {"mul", lua::wrap<l_mul>},
+    {"mul_vec3", lua::wrap<l_mul_vec3>},
     {nullptr, nullptr}
 };

From ae5c1a4533ae10b026761d6609617b25719c7003 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 01:08:32 +0500
Subject: [PATCH 04/20] move GLM_EXPERIMENTAL to the top

---
 src/logic/scripting/lua/libs/libquat.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/logic/scripting/lua/libs/libquat.cpp b/src/logic/scripting/lua/libs/libquat.cpp
index 5002e9bb3..d062f40a4 100644
--- a/src/logic/scripting/lua/libs/libquat.cpp
+++ b/src/logic/scripting/lua/libs/libquat.cpp
@@ -1,8 +1,8 @@
+#define GLM_ENABLE_EXPERIMENTAL
 #include <iostream>
 #include <glm/gtx/string_cast.hpp> 
 #include "api_lua.hpp"
 
-#define GLM_ENABLE_EXPERIMENTAL
 #include <glm/ext/matrix_transform.hpp>
 #include <glm/gtx/quaternion.hpp>
 #include <sstream>

From 516b4064768db430eb3e91665367ed9f096fce45 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 01:18:39 +0500
Subject: [PATCH 05/20] fix stringstream usage

---
 src/logic/scripting/lua/libs/libquat.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/logic/scripting/lua/libs/libquat.cpp b/src/logic/scripting/lua/libs/libquat.cpp
index d062f40a4..a3fe62149 100644
--- a/src/logic/scripting/lua/libs/libquat.cpp
+++ b/src/logic/scripting/lua/libs/libquat.cpp
@@ -35,7 +35,7 @@ static int l_tostring(lua::State* L) {
 
     float components[4] = {quat.w, quat.x, quat.y, quat.z};
     std::stringstream ss;
-    ss << "quat" << "{";
+    ss << "quat {";
     for (int i = 0; i < 4; i++) {
         if (i > 0) {
             ss << ", ";

From dbe1dfd380192702d9398c6f926a1d6552ee684e Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 13:11:56 +0500
Subject: [PATCH 06/20] fix gimbal lock

---
 res/content/base/modules/util.lua | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/res/content/base/modules/util.lua b/res/content/base/modules/util.lua
index db5e4f2f3..4991331d0 100644
--- a/res/content/base/modules/util.lua
+++ b/res/content/base/modules/util.lua
@@ -13,14 +13,18 @@ local function calculate_item_drop_dir(pid)
     if not hud.is_inventory_open() and not hud.is_player_inventory_open() then
         mpos = {0, 0}
     end
-    pitch = math.clamp(pitch - mpos[2]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2, -90, 90)
-    yaw = math.rad(yaw + 90 -mpos[1]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2)
-    pitch = math.rad(pitch)
-    return vec3.normalize({
-       math.cos(yaw) * math.cos(pitch),
-       math.sin(pitch),
-      -math.sin(yaw) * math.cos(pitch)
-     })
+
+    local q_yaw = quat.from_euler({0, yaw, 0})
+    local q_pitch = quat.from_euler({pitch, 0, 0})
+    local q_rotation = quat.mul(q_yaw, q_pitch)
+
+    local q_shift = quat.from_euler({
+        -mpos[2]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2,
+        -mpos[1]*DROP_MAX_ITEM_DIR_SHIFT_DEGREES*2,
+        0,
+    })
+    quat.mul(q_rotation, q_shift, q_rotation)
+    return quat.mul_vec3(q_rotation, {0, 0, -1})
 end
 
 ---@param mode integer 0 - whole stack, 1 - single item, 2 - dupe whole stack

From 22b70b701e192472ab859345fbc611cf69b7ce63 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 14:01:46 +0500
Subject: [PATCH 07/20] add quaternion mul* docs

---
 doc/en/scripting/builtins/libquat.md | 37 +++++++++++++++++++++++++++-
 doc/ru/scripting/builtins/libquat.md | 23 +++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/doc/en/scripting/builtins/libquat.md b/doc/en/scripting/builtins/libquat.md
index f7cc7a0f6..4ad15bad7 100644
--- a/doc/en/scripting/builtins/libquat.md
+++ b/doc/en/scripting/builtins/libquat.md
@@ -2,7 +2,10 @@
 
 Quaternions manipulation library.
 
-## Quaternion from matrix - *mat4.from_quat(...)*
+Quaternions can be created as a table of 4 numbers:
+`{w, x, y, z}`
+
+## Quaternion from matrix - *quat.from_mat4(...)*
 
 ```lua
 -- creates a quaternion based on the rotation matrix
@@ -12,6 +15,38 @@ quat.from_mat4(m: matrix)
 quat.from_mat4(m: matrix, dst: quat)
 ```
 
+## Quaternion of Euler angles - *quat.from_euler(...)*
+
+```lua
+-- creates quaternion from euler angles passed as XYZ (pitch, yaw, roll)
+-- angles in degrees
+quat.from_euler(euler: vec3) -> quat
+
+-- writes quaternion from euler angles passed as XYZ (pitch, yaw, roll) to dst
+-- angles in degrees
+quat.from_euler(euler: vec3, dst: quat)
+```
+
+## Quaternion composition - quat.mul(...)
+
+```lua
+-- multiplies quaternions
+quat.mul(a: quat, b: quat) -> quat
+
+-- writes a quaternions multiplication result to dst
+quat.mul(a: quat, b: quat, dst: quat)
+```
+
+## 3D vector rotation - quat.mul_vec3(...)
+
+```lua
+-- rotates vector by quaternion
+quat.mul_vec3(a: quat, b: vec3) -> vec3
+
+-- writes rotated vector by quaternion to dst
+quat.mul_vec3(a: quat, b: vec3, dst: vec3)
+```
+
 ## Spherical linear interpolation - *quat.slerp(...)*
 
 The interpolation always take the short path and the rotation is performed at constant speed.
diff --git a/doc/ru/scripting/builtins/libquat.md b/doc/ru/scripting/builtins/libquat.md
index e991de252..745ac6822 100644
--- a/doc/ru/scripting/builtins/libquat.md
+++ b/doc/ru/scripting/builtins/libquat.md
@@ -2,6 +2,9 @@
 
 Библиотека для работы с кватернионами.
 
+Кватернионы задаюся таблицей, состоящей из 4 компонентов:
+`{w, x, y, z}`
+
 ## Кватернион из матрицы - *quat.from_mat4(...)*
 
 ```lua
@@ -24,6 +27,26 @@ quat.from_euler(euler: vec3) -> quat
 quat.from_euler(euler: vec3, dst: quat)
 ```
 
+## Композиция кватернионов - quat.mul(...)
+
+```lua
+-- Умножает два кватерниона (композиция поворотов)
+quat.mul(a: quat, b: quat) -> quat
+
+-- Записывает кватернион как произведение двух кватернионов (композиция поворотов)
+quat.mul(a: quat, b: quat, dst: quat)
+```
+
+## Поворот 3д вектора на кватернион - quat.mul_vec3(...)
+
+```lua
+-- Поворачивает вектор на заданный кватернион
+quat.mul_vec3(a: quat, b: vec3) -> vec3
+
+-- Записывает результат поворота вектора на заданный кватернион
+quat.mul_vec3(a: quat, b: vec3, dst: vec3)
+```
+
 ## Сферическая линейная интерполяция - *quat.slerp(...)*
 
 Интерполяция всегда выполняется по короткому пути, а вращение выполняется с постоянной скоростью.

From 305dab7ead4b2a5b52bb91d83e8b689a7edd286f Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Sat, 15 Aug 2026 14:58:09 +0500
Subject: [PATCH 08/20] remove duplicated

---
 doc/en/scripting/builtins/libquat.md | 29 ++++++----------------------
 doc/ru/scripting/builtins/libquat.md | 27 +++++---------------------
 2 files changed, 11 insertions(+), 45 deletions(-)

diff --git a/doc/en/scripting/builtins/libquat.md b/doc/en/scripting/builtins/libquat.md
index 4ad15bad7..5d72413e2 100644
--- a/doc/en/scripting/builtins/libquat.md
+++ b/doc/en/scripting/builtins/libquat.md
@@ -9,10 +9,7 @@ Quaternions can be created as a table of 4 numbers:
 
 ```lua
 -- creates a quaternion based on the rotation matrix
-quat.from_mat4(m: matrix)
-
--- writes a quaternion from the rotation matrix to dst
-quat.from_mat4(m: matrix, dst: quat)
+quat.from_mat4(m: matrix, [optional] dst: quat) -> quat
 ```
 
 ## Quaternion of Euler angles - *quat.from_euler(...)*
@@ -20,31 +17,21 @@ quat.from_mat4(m: matrix, dst: quat)
 ```lua
 -- creates quaternion from euler angles passed as XYZ (pitch, yaw, roll)
 -- angles in degrees
-quat.from_euler(euler: vec3) -> quat
-
--- writes quaternion from euler angles passed as XYZ (pitch, yaw, roll) to dst
--- angles in degrees
-quat.from_euler(euler: vec3, dst: quat)
+quat.from_euler(euler: vec3, [optional] dst: quat) -> quat
 ```
 
 ## Quaternion composition - quat.mul(...)
 
 ```lua
 -- multiplies quaternions
-quat.mul(a: quat, b: quat) -> quat
-
--- writes a quaternions multiplication result to dst
-quat.mul(a: quat, b: quat, dst: quat)
+quat.mul(a: quat, b: quat, [optional] dst: quat) -> quat
 ```
 
 ## 3D vector rotation - quat.mul_vec3(...)
 
 ```lua
 -- rotates vector by quaternion
-quat.mul_vec3(a: quat, b: vec3) -> vec3
-
--- writes rotated vector by quaternion to dst
-quat.mul_vec3(a: quat, b: vec3, dst: vec3)
+quat.mul_vec3(a: quat, b: vec3, [optional] dst: vec3) -> vec3
 ```
 
 ## Spherical linear interpolation - *quat.slerp(...)*
@@ -54,16 +41,12 @@ The interpolation always take the short path and the rotation is performed at co
 ```lua
 -- creates a quaternion as an interpolation between a and b,
 -- where t is interpolation factor
-quat.slerp(a: quat, b: quat, t: number)
-
--- writes a quaternion as an interpolation between a and b to dst,
--- where t is interpolation factor
-quat.slerp(a: quat, b: quat, t: number, dst: quat)
+quat.slerp(a: quat, b: quat, t: number, [optional] dst: quat) -> quat
 ```
 
 ## Casting to string - *quat.tostring(...)*
 
 ```lua
 -- returns a string representing the contents of the quaternion
-quat.tostring(q: quat)
+quat.tostring(q: quat) -> string
 ```
diff --git a/doc/ru/scripting/builtins/libquat.md b/doc/ru/scripting/builtins/libquat.md
index 745ac6822..a32a24e6d 100644
--- a/doc/ru/scripting/builtins/libquat.md
+++ b/doc/ru/scripting/builtins/libquat.md
@@ -9,10 +9,7 @@
 
 ```lua
 -- создаёт кватернион на основе матрицы вращения
-quat.from_mat4(m: matrix) -> quat
-
--- записывает кватернион по матрице вращения в dst
-quat.from_mat4(m: matrix, dst: quat)
+quat.from_mat4(m: matrix, [опционально] dst: quat) -> quat
 ```
 
 ## Кватернион из углов Эйлера - *quat.from_euler(...)*
@@ -20,31 +17,21 @@ quat.from_mat4(m: matrix, dst: quat)
 ```lua
 -- создаёт кватернион на основе вектора, содержащего углы Эйлера в порядке XYZ (pitch, yaw, roll)
 -- (значения углов строго в градусах)
-quat.from_euler(euler: vec3) -> quat
-
--- записывает кватернион в dst на основе вектора, содержащего углы Эйлера в порядке XYZ (pitch, yaw, roll)
--- (значения углов строго в градусах)
-quat.from_euler(euler: vec3, dst: quat)
+quat.from_euler(euler: vec3, [опционально] dst: quat) -> quat
 ```
 
 ## Композиция кватернионов - quat.mul(...)
 
 ```lua
 -- Умножает два кватерниона (композиция поворотов)
-quat.mul(a: quat, b: quat) -> quat
-
--- Записывает кватернион как произведение двух кватернионов (композиция поворотов)
-quat.mul(a: quat, b: quat, dst: quat)
+quat.mul(a: quat, b: quat, [опционально] dst: quat) -> quat
 ```
 
 ## Поворот 3д вектора на кватернион - quat.mul_vec3(...)
 
 ```lua
 -- Поворачивает вектор на заданный кватернион
-quat.mul_vec3(a: quat, b: vec3) -> vec3
-
--- Записывает результат поворота вектора на заданный кватернион
-quat.mul_vec3(a: quat, b: vec3, dst: vec3)
+quat.mul_vec3(a: quat, b: vec3, [опционально] dst: vec3) -> vec3
 ```
 
 ## Сферическая линейная интерполяция - *quat.slerp(...)*
@@ -54,11 +41,7 @@ quat.mul_vec3(a: quat, b: vec3, dst: vec3)
 ```lua
 -- создаёт кватернион как интерполяцию между a и b, 
 -- где t - фактор интерполяции
-quat.slerp(a: quat, b: quat, t: number) -> quat
-
--- записывает кватернион как интерполяцию между a и b в dst, 
--- где t - фактор интерполяции
-quat.slerp(a: quat, b: quat, t: number, dst: quat)
+quat.slerp(a: quat, b: quat, t: number, [опционально] dst: quat) -> quat
 ```
 
 ## Перевод в строку - *quat.tostring(...)*

From fa0f87349b5c61ee0ca43d7d6b5b64237c39a6a4 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 17:19:54 +0300
Subject: [PATCH 09/20] fix blank texture overwritten by screen frame output

---
 src/graphics/ui/elements/Frame.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/graphics/ui/elements/Frame.cpp b/src/graphics/ui/elements/Frame.cpp
index f99673f22..0387f5c1e 100644
--- a/src/graphics/ui/elements/Frame.cpp
+++ b/src/graphics/ui/elements/Frame.cpp
@@ -48,10 +48,14 @@ void gui::Frame::draw(const DrawContext& pctx, const Assets& assets) {
 void gui::Frame::updateOutput(Assets& assets) {
     if (fbo && (fbo->getWidth() != size.x || fbo->getHeight() != size.y)) {
         fbo->resize(size.x, size.y);
-        assets.store(fbo->getSharedTexture(), outputTexture);
+        if (!outputTexture.empty()) {
+            assets.store(fbo->getSharedTexture(), outputTexture);
+        }
     } else if (fbo == nullptr) {
         fbo = std::make_unique<Framebuffer>(size.x, size.y, true);
-        assets.store(fbo->getSharedTexture(), outputTexture);
+        if (!outputTexture.empty()) {
+            assets.store(fbo->getSharedTexture(), outputTexture);
+        }
     }
 }
 

From 98326627f55791d8d2308be3547901c53141d6aa Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 17:27:03 +0300
Subject: [PATCH 10/20] revert "fix vcm texture sides"

This reverts commit 38bebac37ee2a290315c3148576e98c825efa46d.
---
 src/coders/vcm.cpp                       | 12 ++++++------
 src/graphics/commons/Model.cpp           | 24 ++++++++++++------------
 src/graphics/ui/elements/ModelViewer.cpp | 10 +++++-----
 3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/src/coders/vcm.cpp b/src/coders/vcm.cpp
index 3083e1d36..308fb8462 100644
--- a/src/coders/vcm.cpp
+++ b/src/coders/vcm.cpp
@@ -55,12 +55,12 @@ model::Model VcmModel::squashed() const {
 }
 
 static const std::unordered_map<std::string, int> side_indices {
-    {"east", 0},
-    {"west", 1},
-    {"bottom", 2},
-    {"top", 3},
-    {"south", 4},
-    {"north", 5},
+    {"north", 0},
+    {"south", 1},
+    {"top", 2},
+    {"bottom", 3},
+    {"west", 4},
+    {"east", 5},
 };
 
 static bool to_boolean(const xml::Attribute& attr) {
diff --git a/src/graphics/commons/Model.cpp b/src/graphics/commons/Model.cpp
index 8c2194775..2de10ad30 100644
--- a/src/graphics/commons/Model.cpp
+++ b/src/graphics/commons/Model.cpp
@@ -136,18 +136,18 @@ void Mesh::addBox(
     const bool enabledSides[6],
     const glm::mat4& transform
 ) {
-    if (enabledSides[0]) // east
-        addPlane(pos-X*size, Z*size, Y*size, -X, uvs[0], transform);
-    if (enabledSides[1]) // west
-        addPlane(pos+X*size, -Z*size, Y*size, X, uvs[1] * glm::vec2(-1, 1), transform);
-    if (enabledSides[2]) // bottom
-        addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[2], transform);
-    if (enabledSides[3]) // top
-        addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[3] * glm::vec2(-1, 1), transform);
-    if (enabledSides[4]) // south
-        addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[4], transform);
-    if (enabledSides[5]) // north
-        addPlane(pos+Z*size, X*size, Y*size, Z, uvs[5] * glm::vec2(-1, 1), transform);
+    if (enabledSides[0]) // north
+        addPlane(pos+Z*size, X*size, Y*size, Z, uvs[0], transform);
+    if (enabledSides[1]) // south
+        addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[1], transform);
+    if (enabledSides[2]) // top
+        addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[2] * glm::vec2(-1), transform);
+    if (enabledSides[3]) // bottom
+        addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[3] * glm::vec2(-1, 1), transform);
+    if (enabledSides[4]) // west
+        addPlane(pos+X*size, -Z*size, Y*size, X, uvs[4], transform);
+    if (enabledSides[5]) // east
+        addPlane(pos-X*size, Z*size, Y*size, -X, uvs[5] * glm::vec2(-1, 1), transform);
 }
 
 void Mesh::scale(const glm::vec3& size) {
diff --git a/src/graphics/ui/elements/ModelViewer.cpp b/src/graphics/ui/elements/ModelViewer.cpp
index 748eabae5..bfeed086d 100644
--- a/src/graphics/ui/elements/ModelViewer.cpp
+++ b/src/graphics/ui/elements/ModelViewer.cpp
@@ -83,12 +83,12 @@ static util::TextureRegion determine_texture_region(
     const Assets& assets, const std::string& texture
 ) {
     static std::array<std::string, 6> faces {
-        "blocks:dbg_east",
-        "blocks:dbg_west",
-        "blocks:dbg_bottom",
-        "blocks:dbg_top",
-        "blocks:dbg_south",
         "blocks:dbg_north",
+        "blocks:dbg_south",
+        "blocks:dbg_top",
+        "blocks:dbg_bottom",
+        "blocks:dbg_west",
+        "blocks:dbg_east",
     };
 
     if (texture.length() < 2 || texture.at(0) != '$') {

From 22a9ab4b7a322e4ee4000454cca02c73c96496f0 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 19:50:38 +0300
Subject: [PATCH 11/20] fix region again

---
 src/coders/vcm.cpp                       | 18 +++++++++++-------
 src/graphics/commons/Model.cpp           | 24 ++++++++++++------------
 src/graphics/ui/elements/ModelViewer.cpp | 10 +++++-----
 3 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/src/coders/vcm.cpp b/src/coders/vcm.cpp
index 308fb8462..fb405cfac 100644
--- a/src/coders/vcm.cpp
+++ b/src/coders/vcm.cpp
@@ -55,12 +55,12 @@ model::Model VcmModel::squashed() const {
 }
 
 static const std::unordered_map<std::string, int> side_indices {
-    {"north", 0},
-    {"south", 1},
-    {"top", 2},
-    {"bottom", 3},
-    {"west", 4},
-    {"east", 5},
+    {"east", 0},
+    {"west", 1},
+    {"bottom", 2},
+    {"top", 3},
+    {"south", 4},
+    {"north", 5},
 };
 
 static bool to_boolean(const xml::Attribute& attr) {
@@ -306,7 +306,11 @@ static void perform_box(const xmlelement& root, ModelBuilder& builder) {
                     texfaces[idx] = elem->attr("texture").getText();
                 }
                 if (elem->has("region")) {
-                    regions[idx].set(elem->attr("region").asVec4());
+                    auto region = elem->attr("region").asVec4();
+                    if (idx % 2 == 1) {
+                        std::swap(region[0], region[2]);
+                    }
+                    regions[idx].set(region);
                 }
                 if (elem->has("region-scale")) {
                     regions[idx].scale(elem->attr("region-scale").asVec2());
diff --git a/src/graphics/commons/Model.cpp b/src/graphics/commons/Model.cpp
index 2de10ad30..8c2194775 100644
--- a/src/graphics/commons/Model.cpp
+++ b/src/graphics/commons/Model.cpp
@@ -136,18 +136,18 @@ void Mesh::addBox(
     const bool enabledSides[6],
     const glm::mat4& transform
 ) {
-    if (enabledSides[0]) // north
-        addPlane(pos+Z*size, X*size, Y*size, Z, uvs[0], transform);
-    if (enabledSides[1]) // south
-        addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[1], transform);
-    if (enabledSides[2]) // top
-        addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[2] * glm::vec2(-1), transform);
-    if (enabledSides[3]) // bottom
-        addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[3] * glm::vec2(-1, 1), transform);
-    if (enabledSides[4]) // west
-        addPlane(pos+X*size, -Z*size, Y*size, X, uvs[4], transform);
-    if (enabledSides[5]) // east
-        addPlane(pos-X*size, Z*size, Y*size, -X, uvs[5] * glm::vec2(-1, 1), transform);
+    if (enabledSides[0]) // east
+        addPlane(pos-X*size, Z*size, Y*size, -X, uvs[0], transform);
+    if (enabledSides[1]) // west
+        addPlane(pos+X*size, -Z*size, Y*size, X, uvs[1] * glm::vec2(-1, 1), transform);
+    if (enabledSides[2]) // bottom
+        addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[2], transform);
+    if (enabledSides[3]) // top
+        addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[3] * glm::vec2(-1, 1), transform);
+    if (enabledSides[4]) // south
+        addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[4], transform);
+    if (enabledSides[5]) // north
+        addPlane(pos+Z*size, X*size, Y*size, Z, uvs[5] * glm::vec2(-1, 1), transform);
 }
 
 void Mesh::scale(const glm::vec3& size) {
diff --git a/src/graphics/ui/elements/ModelViewer.cpp b/src/graphics/ui/elements/ModelViewer.cpp
index bfeed086d..748eabae5 100644
--- a/src/graphics/ui/elements/ModelViewer.cpp
+++ b/src/graphics/ui/elements/ModelViewer.cpp
@@ -83,12 +83,12 @@ static util::TextureRegion determine_texture_region(
     const Assets& assets, const std::string& texture
 ) {
     static std::array<std::string, 6> faces {
-        "blocks:dbg_north",
-        "blocks:dbg_south",
-        "blocks:dbg_top",
-        "blocks:dbg_bottom",
-        "blocks:dbg_west",
         "blocks:dbg_east",
+        "blocks:dbg_west",
+        "blocks:dbg_bottom",
+        "blocks:dbg_top",
+        "blocks:dbg_south",
+        "blocks:dbg_north",
     };
 
     if (texture.length() < 2 || texture.at(0) != '$') {

From c481997b8243a2ecf617fe2f1c7135f1bfe00f55 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 20:41:41 +0300
Subject: [PATCH 12/20] fix editor toolbar

---
 res/layouts/code_editor.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/res/layouts/code_editor.xml b/res/layouts/code_editor.xml
index b3cd2ed9c..3d3e584d5 100644
--- a/res/layouts/code_editor.xml
+++ b/res/layouts/code_editor.xml
@@ -17,7 +17,7 @@
                             color="#FFFFFF80" size="16" pos="4,6"
                             hover-color="#1080FF"></image>
                     <panel orientation="horizontal" gravity="top-right" 
-                            size="76,24" padding="8" interval="8" color="0">
+                            size="76,24" padding="8,6,8,2" interval="8" color="0">
                         <image id="saveIcon" src="gui/save" tooltip="@Save" 
                             enabled="false" interactive="true" 
                             hover-color="#1080FF"

From ebcbc017ac1fa4e3766cf50faf1f2056be56d41b Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Mon, 17 Aug 2026 22:55:17 +0500
Subject: [PATCH 13/20] move hud.get_player() out from util.lua & add error
 returning

---
 res/content/base/modules/util.lua | 41 ++++++++++++++++++-------------
 res/content/base/scripts/hud.lua  |  7 +++---
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/res/content/base/modules/util.lua b/res/content/base/modules/util.lua
index 4d25ccb91..57bc6ccb6 100644
--- a/res/content/base/modules/util.lua
+++ b/res/content/base/modules/util.lua
@@ -1,20 +1,21 @@
 local util = {}
 
 local DROP_FORCE = 8
-local DROP_INIT_VEL = {0, 3, 0}
+local DROP_INIT_VEL = { 0, 3, 0 }
 
+--- Create a drop from slot, set it velocity, and return it
 ---@param mode integer 0 - whole stack, 1 - single item, 2 - dupe whole stack
-function util.drop_from_slot(invid, slot, mode)
+---@return table? entity, string? error
+function util.drop_from_slot(pid, invid, slot, mode)
     if invid == 0 then
-        return
+        return nil, "invid cannot be 0"
     end
-    local pid = hud.get_player()
     if mode == 2 and not player.is_infinite_items(pid) then
-        return
+        return nil, "no permission to dupe items"
     end
     local itemid, itemcount = inventory.get(invid, slot)
     if itemid == 0 then
-        return
+        return nil, "no item in slot"
     end
 
     local drop_itemcount = 1
@@ -31,24 +32,28 @@ function util.drop_from_slot(invid, slot, mode)
     local pvel = { player.get_vel(pid) }
     local ppos = vec3.add({ player.get_pos(pid) }, { 0, 0.7, 0 })
     local throw_force = vec3.mul(player.get_dir(pid), DROP_FORCE)
-    local drop = util.drop(ppos, itemid, drop_itemcount, data, 1.5)
+    local drop, err = util.drop(ppos, itemid, drop_itemcount, data, 1.5)
     if not drop then
-        return
+        return nil, err
     end
     local velocity = vec3.add(throw_force, vec3.add(pvel, DROP_INIT_VEL))
     drop.rigidbody:set_vel(velocity)
+    return drop
 end
 
+---@return table? entity, string? error
 function util.drop(ppos, itemid, count, data, pickup_delay)
     if itemid == 0 or not itemid then
-        return nil
+        return nil, "item is empty"
     end
-    return entities.spawn("base:drop", ppos, {base__drop={
-        id=itemid,
-        count=count,
-        data=data,
-        pickup_delay=pickup_delay
-    }})
+    return entities.spawn("base:drop", ppos, {
+        base__drop = {
+            id = itemid,
+            count = count,
+            data = data,
+            pickup_delay = pickup_delay
+        }
+    })
 end
 
 function util.calc_loot(loot_table)
@@ -66,7 +71,9 @@ function util.calc_loot(loot_table)
             if count == 0 then
                 goto continue
             end
-            table.insert(results, {item=item.index(loot.item), count=count})
+            table.insert(results, {
+                item = item.index(loot.item), count = count
+            })
         end
         ::continue::
     end
@@ -78,7 +85,7 @@ function util.block_loot(blockid)
     if lootscheme then
         return util.calc_loot(lootscheme)
     end
-    return {{item=block.get_picking_item(blockid), count=1}}
+    return { { item = block.get_picking_item(blockid), count = 1 } }
 end
 
 return util
diff --git a/res/content/base/scripts/hud.lua b/res/content/base/scripts/hud.lua
index d0e3d1532..313e7b5b4 100644
--- a/res/content/base/scripts/hud.lua
+++ b/res/content/base/scripts/hud.lua
@@ -2,8 +2,9 @@ local base_util = require "util"
 
 function on_hud_open()
     events.on("core:drop_outside_inventory", function(mode)
+        local pid = hud.get_player()
         local invid = hud.get_exchange_inventory()
-        base_util.drop_from_slot(invid, 0, mode)
+        base_util.drop_from_slot(pid, invid, 0, mode)
     end)
     input.add_callback("player.drop", function()
         if hud.is_paused() or hud.is_inventory_open() then
@@ -13,9 +14,9 @@ function on_hud_open()
         local invid, slot = player.get_inventory(pid)
         local mode = 1
         if input.is_pressed("key:left-ctrl") or input.is_pressed("key:right-ctrl") then
-          mode = 0
+            mode = 0
         end
-        base_util.drop_from_slot(invid, slot, mode)
+        base_util.drop_from_slot(pid, invid, slot, mode)
     end)
     rules.create("do-loot-non-player", true)
 end

From c0b73998ed7325b0d537592ce0fceab23af436b8 Mon Sep 17 00:00:00 2001
From: neveix <i@neveix.ru>
Date: Mon, 17 Aug 2026 23:47:51 +0500
Subject: [PATCH 14/20] move hud away from utils 2 & add new argument

---
 res/content/base/modules/util.lua | 33 ++++++++++++++-----------------
 res/content/base/scripts/hud.lua  |  6 +++++-
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/res/content/base/modules/util.lua b/res/content/base/modules/util.lua
index 6d5a77705..843f818c7 100644
--- a/res/content/base/modules/util.lua
+++ b/res/content/base/modules/util.lua
@@ -1,26 +1,22 @@
 local util = {}
 
-local DROP_FORCE = 8
-local DROP_INIT_VEL = { 0, 3, 0 }
-local DROP_MAX_ITEM_DIR_SHIFT_DEGREES = 65
+util.DROP_FORCE = 8
+util.DROP_INIT_VEL = { 0, 3, 0 }
+util.DROP_MAX_ITEM_DIR_SHIFT_DEGREES = 65
 
-local function calculate_item_drop_dir(pid)
-    local yaw, pitch = player.get_rot(pid)
-    local vp = gui.get_viewport()
-    local mpos = table.map(input.get_mouse_pos(), function(i, v)
-        return v / vp[i] - 0.5
-    end)
-    if not hud.is_inventory_open() and not hud.is_player_inventory_open() then
-        mpos = { 0, 0 }
+---@param dir_shift? vec2 direction shift for drop; x and y must be clamped to [-0.5, 0.5]
+local function calculate_item_drop_dir(pid, dir_shift)
+    if not dir_shift then
+        dir_shift = { 0, 0 }
     end
-
+    local yaw, pitch = player.get_rot(pid)
     local q_yaw = quat.from_euler({ 0, yaw, 0 })
     local q_pitch = quat.from_euler({ pitch, 0, 0 })
     local q_rotation = quat.mul(q_yaw, q_pitch)
 
     local q_shift = quat.from_euler({
-        -mpos[2] * DROP_MAX_ITEM_DIR_SHIFT_DEGREES * 2,
-        -mpos[1] * DROP_MAX_ITEM_DIR_SHIFT_DEGREES * 2,
+        -dir_shift[2] * util.DROP_MAX_ITEM_DIR_SHIFT_DEGREES * 2,
+        -dir_shift[1] * util.DROP_MAX_ITEM_DIR_SHIFT_DEGREES * 2,
         0,
     })
     quat.mul(q_rotation, q_shift, q_rotation)
@@ -29,8 +25,9 @@ end
 
 --- Create a drop from slot, set it velocity, and return it
 ---@param mode integer 0 - whole stack, 1 - single item, 2 - dupe whole stack
+---@param dir_shift? vec2 direction shift for drop; x and y must be clamped to [-0.5, 0.5]
 ---@return table? entity, string? error
-function util.drop_from_slot(pid, invid, slot, mode)
+function util.drop_from_slot(pid, invid, slot, mode, dir_shift)
     if invid == 0 then
         return nil, "invid cannot be 0"
     end
@@ -55,13 +52,13 @@ function util.drop_from_slot(pid, invid, slot, mode)
     local data = inventory.get_all_data(invid, slot)
     local pvel = { player.get_vel(pid) }
     local ppos = vec3.add({ player.get_pos(pid) }, { 0, 0.7, 0 })
-    local dir = calculate_item_drop_dir(pid)
-    local throw_force = vec3.mul(dir, DROP_FORCE)
+    local dir = calculate_item_drop_dir(pid, dir_shift)
+    local throw_force = vec3.mul(dir, util.DROP_FORCE)
     local drop, err = util.drop(ppos, itemid, drop_itemcount, data, 1.5)
     if not drop then
         return nil, err
     end
-    local velocity = vec3.add(throw_force, vec3.add(pvel, DROP_INIT_VEL))
+    local velocity = vec3.add(throw_force, vec3.add(pvel, util.DROP_INIT_VEL))
     drop.rigidbody:set_vel(velocity)
     return drop
 end
diff --git a/res/content/base/scripts/hud.lua b/res/content/base/scripts/hud.lua
index 313e7b5b4..5d3bfeb46 100644
--- a/res/content/base/scripts/hud.lua
+++ b/res/content/base/scripts/hud.lua
@@ -4,7 +4,11 @@ function on_hud_open()
     events.on("core:drop_outside_inventory", function(mode)
         local pid = hud.get_player()
         local invid = hud.get_exchange_inventory()
-        base_util.drop_from_slot(pid, invid, 0, mode)
+        local vp = gui.get_viewport()
+        local dir_shift = table.map(input.get_mouse_pos(), function(i, v)
+            return v / vp[i] - 0.5
+        end)
+        base_util.drop_from_slot(pid, invid, 0, mode, dir_shift)
     end)
     input.add_callback("player.drop", function()
         if hud.is_paused() or hud.is_inventory_open() then

From d54bb5bf54d536fe602c15378433cf95de21a159 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 22:20:25 +0300
Subject: [PATCH 15/20] change: flip the planet

---
 src/coders/vcm.cpp                       | 12 ++++++------
 src/graphics/ui/elements/ModelViewer.cpp |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/coders/vcm.cpp b/src/coders/vcm.cpp
index fb405cfac..8c4965ca4 100644
--- a/src/coders/vcm.cpp
+++ b/src/coders/vcm.cpp
@@ -55,12 +55,12 @@ model::Model VcmModel::squashed() const {
 }
 
 static const std::unordered_map<std::string, int> side_indices {
-    {"east", 0},
-    {"west", 1},
-    {"bottom", 2},
-    {"top", 3},
-    {"south", 4},
-    {"north", 5},
+    {"west", 0},   // -X
+    {"east", 1},   // +X
+    {"bottom", 2}, // -Y
+    {"top", 3},    // +Y
+    {"north", 4},  // -Z
+    {"south", 5},  // +Z
 };
 
 static bool to_boolean(const xml::Attribute& attr) {
diff --git a/src/graphics/ui/elements/ModelViewer.cpp b/src/graphics/ui/elements/ModelViewer.cpp
index 748eabae5..435f3340d 100644
--- a/src/graphics/ui/elements/ModelViewer.cpp
+++ b/src/graphics/ui/elements/ModelViewer.cpp
@@ -83,12 +83,12 @@ static util::TextureRegion determine_texture_region(
     const Assets& assets, const std::string& texture
 ) {
     static std::array<std::string, 6> faces {
-        "blocks:dbg_east",
         "blocks:dbg_west",
+        "blocks:dbg_east",
         "blocks:dbg_bottom",
         "blocks:dbg_top",
-        "blocks:dbg_south",
         "blocks:dbg_north",
+        "blocks:dbg_south",
     };
 
     if (texture.length() < 2 || texture.at(0) != '$') {

From c713015134a4baaeb3922b56654a38ac481a0be2 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 22:23:20 +0300
Subject: [PATCH 16/20] add vcm old models converter button to the editor
 temporary

---
 res/layouts/code_editor.xml     |  6 +++
 res/layouts/code_editor.xml.lua | 72 +++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/res/layouts/code_editor.xml b/res/layouts/code_editor.xml
index 3d3e584d5..fb4833da1 100644
--- a/res/layouts/code_editor.xml
+++ b/res/layouts/code_editor.xml
@@ -31,6 +31,12 @@
                             hover-color="#1080FF"
                             onclick="run_current_file()"
                             color="#FFFFFF80" size="16"></image>
+                        <!-- TODO: remove after 0.32-->
+                        <image src="gui/item" size="16"
+                            enabled="true" interactive="true"
+                            hover-color="#1080FF"
+                            tooltip="Fix old VCM regions (0.31 bug)"
+                            onclick="fix_vcm_regions()"></image>
                     </panel>
                     <label id="title" pos="26,8"></label>
                 </container>
diff --git a/res/layouts/code_editor.xml.lua b/res/layouts/code_editor.xml.lua
index 733fa9036..61e90842f 100644
--- a/res/layouts/code_editor.xml.lua
+++ b/res/layouts/code_editor.xml.lua
@@ -113,6 +113,78 @@ local function reload_model(filename, name)
     assets.parse_model(file.ext(filename), document.editor.text, name)
 end
 
+-- === TODO: remove after 0.32 ===
+local pattern =
+    "region %(%s*"
+    .. "([+-]?%d+%.?%d*[eE]?[+-]?%d*)%s*,%s*"
+    .. "([+-]?%d+%.?%d*[eE]?[+-]?%d*)%s*,%s*"
+    .. "([+-]?%d+%.?%d*[eE]?[+-]?%d*)%s*,%s*"
+    .. "([+-]?%d+%.?%d*[eE]?[+-]?%d*)"
+    .. "%s*%)"
+
+local function replace1(x1, y1, x2, y2)
+    return string.format("region (%s, %s, %s, %s)", x2, y2, x1, y1)
+end
+
+local function replace2(x1, y1, x2, y2)
+    return string.format("region (%s, %s, %s, %s)", x2, y1, x1, y2)
+end
+
+function convert_vcm(text)
+    local lines = {}
+    local zpairs = {
+        {"%(north%)", "%(south%)", "(TMPS)", "(TMPN)"},
+        {"%,north", "%,south", ",TMPS", ",TMPN"},
+        {"north%,", "south%,", "TMPS,", "TMPN,"},
+    }
+    local xpairs = {
+        {"%(west%)", "%(east%)", "(TMPE)", "(TMPW)"},
+        {"%,west", "%,east", ",TMPE", ",TMPW"},
+        {"west%,", "east%,", "TMPE,", "TMPW,"},
+    }
+
+    for i, pair in ipairs(zpairs) do
+        text = text:gsub(pair[1], pair[3])
+        text = text:gsub(pair[2], pair[4])
+    end
+    text = text:gsub("TMPS", "south")
+    text = text:gsub("TMPN", "north")
+
+    for i, pair in ipairs(xpairs) do
+        text = text:gsub(pair[1], pair[3])
+        text = text:gsub(pair[2], pair[4])
+    end
+    text = text:gsub("TMPW", "west")
+    text = text:gsub("TMPE", "east")
+
+    for line in text:gmatch("[^\n]*\n?") do
+        if line == "" then
+            break
+        end
+
+        if line:find("(top)", 1, true) then
+            line = line:gsub(pattern, replace1)
+        end
+
+        if line:find("(bottom)", 1, true)
+            or line:find("(east)", 1, true) then
+            line = line:gsub(pattern, replace2)
+        end
+
+        table.insert(lines, line)
+    end
+
+    return table.concat(lines)
+end
+
+function fix_vcm_regions()
+    if not current_file.filename then
+        return
+    end
+    document.editor.text = convert_vcm(document.editor.text)
+end
+-- ===============================
+
 function run_current_file()
     if not current_file.filename then
         return

From 423685139fe83bb2e571fbdfa41327ce61a64dd0 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 23:24:54 +0300
Subject: [PATCH 17/20] fix stairs model

---
 res/models/stairs.vcm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/res/models/stairs.vcm b/res/models/stairs.vcm
index 2027c09e3..b13cd2d80 100644
--- a/res/models/stairs.vcm
+++ b/res/models/stairs.vcm
@@ -1,4 +1,4 @@
-@box from (0,0,0) to (1,0.5,1) delete (top,south)
-@box from (0,0.5,0) to (1,1,0.5) delete (bottom,south)
+@box from (0,0,0) to (1,0.5,1) delete (top,north)
+@box from (0,0.5,0) to (1,1,0.5) delete (bottom,north)
 @rect from (0,0.5,0.5) right (1,0,0) up (0,0,0.5) texture "$2"
 @rect from (0,0,0) right (1,0,0) up (0,1,0) texture "$1"

From fdd8d865d21c8ff1708e0448401f51a05d9ff710 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 23:25:18 +0300
Subject: [PATCH 18/20] update doc/*/block-properties.md

---
 doc/en/block-properties.md | 8 ++++----
 doc/ru/block-properties.md | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/doc/en/block-properties.md b/doc/en/block-properties.md
index 61f44e844..82ba10484 100644
--- a/doc/en/block-properties.md
+++ b/doc/en/block-properties.md
@@ -192,12 +192,12 @@ An array of 6 numbers describing an offset an size of a block hitbox.
 The numbers are specified in the range [0.0, 1.0] - i.e. within the block (in the case of an extended block, the hitbox can be larger than one, but must not go beyond the "size" property).
 
 Array *\[0.25, 0.0, 0.5,  0.75, 0.4, 0.3\]* describes hitbox width:
-- offset 0.25m east
+- offset 0.25m west
 - offset 0.0m up
-- offset 0.5m north
-- 0.75m width (from east to west)
+- offset 0.5m south
+- 0.75m width (from west to east)
 - 0.4m height
-- 0.3m length (from south to north)
+- 0.3m length (from north to south)
 
 For composite hitboxes, the *hitboxes* property is used - an array of hitboxes, for example:
 
diff --git a/doc/ru/block-properties.md b/doc/ru/block-properties.md
index 6d613d888..09db5c8ef 100644
--- a/doc/ru/block-properties.md
+++ b/doc/ru/block-properties.md
@@ -194,12 +194,12 @@
 Числа указываются в диапазоне [0.0, 1.0] - т.е в пределах блока (в случае расширенного блока хитбокс может быть больше единицы, но не должен выходить за пределы size).
 
 Массив `[0.25, 0.0, 0.5,  0.75, 0.4, 0.3]` описывает хитбокс:
-- смещен на 0.25 м на запад
+- смещен на 0.25 м на восток
 - смещен на 0.0 м вверх
-- смещен на 0.5 м на север
-- шириной (с востока на запад) 0.75 м
+- смещен на 0.5 м на юг
+- шириной (с запада на восток) 0.75 м
 - высотой 0.4 м
-- длиной (с юга на север) 0.3 м
+- длиной (с севера на юг) 0.3 м
 
 Для составных хитбоксов используется свойство *hitboxes* - массив хитбоксов, например:
 

From 02dbd01e73f2c69168a1ba4c1929c9d5be263718 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 23:34:38 +0300
Subject: [PATCH 19/20] fix custom models solidity detection

---
 src/content/ContentBuilder.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/content/ContentBuilder.cpp b/src/content/ContentBuilder.cpp
index 97498b497..83836dfe3 100644
--- a/src/content/ContentBuilder.cpp
+++ b/src/content/ContentBuilder.cpp
@@ -39,16 +39,18 @@ std::unique_ptr<Content> ContentBuilder::build() {
         } else {
             def.defaults.rt.solid = isSolid(def.defaults) || def.explictlySolid;
         }
-        if (def.material.empty()) {
-            defaults.at("block-material").get(def.material);
-        }
+        def.rt.solid = def.defaults.rt.solid;
 
         const float EPSILON = 0.01f;
-        def.rt.solid =
+        def.rt.solid = def.rt.solid &&
             def.obstacle &&
             (glm::i8vec3(def.hitboxes[0].size() + EPSILON) == def.size);
         def.rt.extended = def.size.x > 1 || def.size.y > 1 || def.size.z > 1;
 
+        if (def.material.empty()) {
+            defaults.at("block-material").get(def.material);
+        }
+
         if (def.rotatable) {
             for (uint i = 0; i < BlockRotProfile::MAX_COUNT; i++) {
                 def.rt.hitboxes[i].reserve(def.hitboxes.size());

From 693befcde8d6a4dddfc9049d74d303b027953b25 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Aug 2026 23:41:24 +0300
Subject: [PATCH 20/20] fix default vcm aabb uv generation

---
 src/coders/vcm.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/coders/vcm.cpp b/src/coders/vcm.cpp
index 8c4965ca4..260657338 100644
--- a/src/coders/vcm.cpp
+++ b/src/coders/vcm.cpp
@@ -267,12 +267,12 @@ static void perform_box(const xmlelement& root, ModelBuilder& builder) {
     }
 
     UVRegion regions[6] {};
-    regions[0].scale(to.x - from.x, to.y - from.y);
-    regions[1].scale(from.x - to.x, to.y - from.y);
+    regions[0].scale(to.z - from.z, to.y - from.y);
+    regions[1].scale(from.z - to.z, to.y - from.y);
     regions[2].scale(to.x - from.x, to.z - from.z);
     regions[3].scale(from.x - to.x, to.z - from.z);
-    regions[4].scale(to.z - from.z, to.y - from.y);
-    regions[5].scale(from.z - to.z, to.y - from.y);
+    regions[4].scale(to.x - from.x, to.y - from.y);
+    regions[5].scale(from.x - to.x, to.y - from.y);
 
     auto center = (from + to) * 0.5f;
     auto halfsize = (to - from) * 0.5f;