diff --git a/docs/progress.svg b/docs/progress.svg
index 47aa152..3b4ea37 100644
--- a/docs/progress.svg
+++ b/docs/progress.svg
@@ -69,10 +69,10 @@
 </g>
 <g transform="translate(0 116)">
 <text x="0" y="7.50">Tomb2.exe progress according to the physical function order:</text>
-<text class="todo" style="font-size: 12px; " x="747" y="9"><tspan text-anchor="end"><tspan class="decompiled">45.07% (549)</tspan> · <tspan class="known">52.46% (639)</tspan> · <tspan class="todo">0% (0)</tspan> · <tspan class="unused">2.46% (30)</tspan></tspan></text>
+<text class="todo" style="font-size: 12px; " x="747" y="9"><tspan text-anchor="end"><tspan class="decompiled">45.16% (550)</tspan> · <tspan class="known">52.38% (638)</tspan> · <tspan class="todo">0% (0)</tspan> · <tspan class="unused">2.46% (30)</tspan></tspan></text>
 <g transform="translate(0 20)">
-<rect width="336.70" height="6" x="0" y="0" class="decompiled"/>
-<rect width="391.90" height="6" x="336.70" y="0" class="known"/>
+<rect width="337.32" height="6" x="0" y="0" class="decompiled"/>
+<rect width="391.29" height="6" x="337.32" y="0" class="known"/>
 <rect width="18.40" height="6" x="728.60" y="0" class="unused"/>
 </g>
 <g transform="translate(0 31)">
@@ -223,7 +223,7 @@
 <rect width="12" height="12" x="660" y="30" class="decompiled"><title>void __cdecl CutscenePlayerGen_Initialise(int16_t item_num);</title></rect>
 <rect width="12" height="12" x="675" y="30" class="decompiled"><title>void __cdecl Camera_LoadCutsceneFrame(void);</title></rect>
 <rect width="12" height="12" x="690" y="30" class="decompiled"><title>void __cdecl Collide_GetCollisionInfo(COLL_INFO *coll, int32_t xpos, int32_t ypos, int32_t zpos, int16_t room_num, int32_t obj_height);</title></rect>
-<rect width="12" height="12" x="705" y="30" class="known"><title>int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);</title></rect>
+<rect width="12" height="12" x="705" y="30" class="decompiled"><title>int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);</title></rect>
 <rect width="12" height="12" x="720" y="30" class="known"><title>int32_t __cdecl Collide_CollideStaticObjects(COLL_INFO *coll, int32_t x, int32_t y, int32_t z, int16_t room_num, int32_t height);</title></rect>
 <rect width="12" height="12" x="735" y="30" class="known"><title>void __cdecl Room_GetNearbyRooms(int32_t x, int32_t y, int32_t z, int32_t r, int32_t h, int16_t room_num);</title></rect>
 <rect width="12" height="12" x="0" y="45" class="known"><title>void __cdecl Room_GetNewRoom(int32_t x, int32_t y, int32_t z, int16_t room_num);</title></rect>
@@ -1298,10 +1298,10 @@
 </g>
 <g transform="translate(0 546)">
 <text x="0" y="7.50">Tomb2.exe progress according to the function sizes:</text>
-<text class="todo" style="font-size: 12px; " x="747" y="9"><tspan text-anchor="end"><tspan class="decompiled">42.15%</tspan> · <tspan class="known">57.52%</tspan> · <tspan class="todo">0%</tspan> · <tspan class="unused">0.33%</tspan></tspan></text>
+<text class="todo" style="font-size: 12px; " x="747" y="9"><tspan text-anchor="end"><tspan class="decompiled">42.17%</tspan> · <tspan class="known">57.51%</tspan> · <tspan class="todo">0%</tspan> · <tspan class="unused">0.33%</tspan></tspan></text>
 <g transform="translate(0 20)">
-<rect width="314.88" height="6" x="0" y="0" class="decompiled"/>
-<rect width="429.68" height="6" x="314.88" y="0" class="known"/>
+<rect width="314.98" height="6" x="0" y="0" class="decompiled"/>
+<rect width="429.58" height="6" x="314.98" y="0" class="known"/>
 <rect width="2.44" height="6" x="744.56" y="0" class="unused"/>
 </g>
 <g transform="translate(0 31)">
@@ -2292,7 +2292,7 @@
 <rect width="3.18" height="3.45" x="737.65" y="303.07" class="known"><title>void __cdecl CleanupTextures(void);</title></rect>
 <rect width="3.18" height="3.45" x="743.82" y="303.07" class="known"><title>BOOL __cdecl OpenRegistryKey(LPCTSTR lpSubKey);</title></rect>
 <rect width="3.24" height="3.25" x="675.50" y="309.52" class="decompiled"><title>void __cdecl Creature_Initialise(int16_t item_num);</title></rect>
-<rect width="3.24" height="3.25" x="675.50" y="315.77" class="known"><title>int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);</title></rect>
+<rect width="3.24" height="3.25" x="675.50" y="315.77" class="decompiled"><title>int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);</title></rect>
 <rect width="3.24" height="3.25" x="675.50" y="322.02" class="known"><title>void __cdecl Inv_Ring_RotateLeft(RING_INFO *ring);</title></rect>
 <rect width="3.24" height="3.25" x="675.50" y="328.27" class="known"><title>void __cdecl Inv_Ring_RotateRight(RING_INFO *ring);</title></rect>
 <rect width="3.24" height="3.25" x="675.50" y="334.52" class="decompiled"><title>void __cdecl Lara_State_SwanDive(ITEM_INFO *item, COLL_INFO *coll);</title></rect>
diff --git a/docs/progress.txt b/docs/progress.txt
index cfb7fd4..e61e5af 100644
--- a/docs/progress.txt
+++ b/docs/progress.txt
@@ -2738,7 +2738,7 @@ typedef struct {
 
 # game/collide.c
 0x004128F0  0x067C  +       void __cdecl Collide_GetCollisionInfo(COLL_INFO *coll, int32_t xpos, int32_t ypos, int32_t zpos, int16_t room_num, int32_t obj_height);
-0x00412FB0  0x002F  -       int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);
+0x00412FB0  0x002F  +       int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);
 0x00412FE0  0x03D2  -       int32_t __cdecl Collide_CollideStaticObjects(COLL_INFO *coll, int32_t x, int32_t y, int32_t z, int16_t room_num, int32_t height);
 0x004133D0  0x00C8  -       void __cdecl Room_GetNearbyRooms(int32_t x, int32_t y, int32_t z, int32_t r, int32_t h, int16_t room_num);
 0x004134A0  0x0055  -       void __cdecl Room_GetNewRoom(int32_t x, int32_t y, int32_t z, int16_t room_num);
diff --git a/src/game/room.c b/src/game/room.c
index 566e21a..62d71f9 100644
--- a/src/game/room.c
+++ b/src/game/room.c
@@ -19,3 +19,19 @@ int16_t Room_GetIndexFromPos(const int32_t x, const int32_t y, const int32_t z)
     }
     return NO_ROOM;
 }
+
+int32_t __cdecl Room_FindGridShift(int32_t src, const int32_t dst)
+{
+    const int32_t src_w = src >> WALL_SHIFT;
+    const int32_t dst_w = dst >> WALL_SHIFT;
+    if (src_w == dst_w) {
+        return 0;
+    }
+
+    src &= WALL_L - 1;
+    if (dst_w > src_w) {
+        return WALL_L - (src - 1);
+    } else {
+        return -(src + 1);
+    }
+}
diff --git a/src/game/room.h b/src/game/room.h
index 35d163b..22b458c 100644
--- a/src/game/room.h
+++ b/src/game/room.h
@@ -3,3 +3,4 @@
 #include <stdint.h>
 
 int16_t Room_GetIndexFromPos(int32_t x, int32_t y, int32_t z);
+int32_t __cdecl Room_FindGridShift(int32_t src, int32_t dst);
diff --git a/src/global/funcs.h b/src/global/funcs.h
index 1fe1f0a..2c8c772 100644
--- a/src/global/funcs.h
+++ b/src/global/funcs.h
@@ -6,7 +6,6 @@
 
 // clang-format off
 #define Output_InsertInventoryBackground ((void __cdecl (*)(const int16_t *obj_ptr))0x00401D50)
-#define Room_FindGridShift ((int32_t __cdecl (*)(int32_t src, int32_t dst))0x00412FB0)
 #define Collide_CollideStaticObjects ((int32_t __cdecl (*)(COLL_INFO *coll, int32_t x, int32_t y, int32_t z, int16_t room_num, int32_t height))0x00412FE0)
 #define Room_GetNearbyRooms ((void __cdecl (*)(int32_t x, int32_t y, int32_t z, int32_t r, int32_t h, int16_t room_num))0x004133D0)
 #define Room_GetNewRoom ((void __cdecl (*)(int32_t x, int32_t y, int32_t z, int16_t room_num))0x004134A0)
diff --git a/src/inject_exec.c b/src/inject_exec.c
index 2ed3b5c..be3a617 100644
--- a/src/inject_exec.c
+++ b/src/inject_exec.c
@@ -26,6 +26,7 @@
 #include "game/output.h"
 #include "game/overlay.h"
 #include "game/random.h"
+#include "game/room.h"
 #include "game/shell.h"
 #include "game/sound.h"
 #include "game/text.h"
@@ -39,6 +40,7 @@ static void Inject_HWR(bool enable);
 
 static void Inject_Camera(bool enable);
 static void Inject_Collide(bool enable);
+static void Inject_Room(bool enable);
 static void Inject_Math(bool enable);
 static void Inject_Matrix(bool enable);
 static void Inject_Shell(bool enable);
@@ -228,6 +230,11 @@ static void Inject_Collide(const bool enable)
     INJECT(enable, 0x004128F0, Collide_GetCollisionInfo);
 }
 
+static void Inject_Room(const bool enable)
+{
+    INJECT(enable, 0x00412FB0, Room_FindGridShift);
+}
+
 static void Inject_Matrix(const bool enable)
 {
     INJECT(enable, 0x00401000, Matrix_GenerateW2V);
@@ -732,6 +739,7 @@ void Inject_Exec(void)
 
     Inject_Camera(true);
     Inject_Collide(true);
+    Inject_Room(true);
     Inject_Math(true);
     Inject_Matrix(true);
     Inject_Shell(true);