diff --git a/src/event/Input.cpp b/src/event/Input.cpp
index 37e935a..abb984f 100644
--- a/src/event/Input.cpp
+++ b/src/event/Input.cpp
@@ -47,6 +47,7 @@ C2iVector Input::s_currentMouse;
 uint32_t Input::s_mouseHoldButton;
 MOUSEMODE Input::s_mouseMode;
 int32_t Input::s_numlockState;
+OS_MOUSE_MODE Input::s_osMouseMode;
 int32_t Input::s_simulatedRightButtonClick;
 uint32_t Input::s_metaKeyState;
 int32_t Input::s_queueHead;
@@ -142,6 +143,10 @@ void PostMouseDown(EvtContext* context, MOUSEBUTTON button, int32_t x, int32_t y
     IEvtQueueDispatch(context, EVENT_ID_MOUSEDOWN, &data);
 }
 
+void PostMouseModeChanged(EvtContext* context, MOUSEMODE mode) {
+    // TODO
+}
+
 void PostMouseMove(EvtContext* context, int32_t x, int32_t y, int32_t time) {
     EVENT_DATA_MOUSE data;
 
@@ -367,7 +372,7 @@ void EventSetMouseMode(MOUSEMODE mode, uint32_t holdButton) {
     );
 
     if (context) {
-        IEvtSetMouseMode(context, mode, holdButton);
+        IEvtInputSetMouseMode(context, mode, holdButton);
 
         if (findMask != -1) {
             TSingletonInstanceId<EvtContext, offsetof(EvtContext, m_id)>::s_idTable.Unlock(
@@ -477,8 +482,20 @@ int32_t IEvtInputProcess(EvtContext* context, int32_t* shutdown) {
     return v4;
 }
 
-void IEvtSetMouseMode(EvtContext* context, MOUSEMODE mode, uint32_t holdButton) {
-    // TODO
+void IEvtInputSetMouseMode(EvtContext* context, MOUSEMODE mode, uint32_t holdButton) {
+    STORM_ASSERT(context);
+    STORM_VALIDATE(context, ERROR_INVALID_PARAMETER);
+
+    if ((Input::s_buttonState & holdButton) == holdButton) {
+        Input::s_mouseHoldButton = holdButton;
+
+        if (Input::s_mouseMode != mode) {
+            OS_MOUSE_MODE osMouseMode = mode == MOUSE_MODE_NORMAL ? OS_MOUSE_MODE_NORMAL : OS_MOUSE_MODE_RELATIVE;
+            OsInputSetMouseMode(osMouseMode);
+
+            PostMouseModeChanged(context, mode);
+        }
+    }
 }
 
 const char* KeyCodeToString(KEY key) {
diff --git a/src/event/Input.hpp b/src/event/Input.hpp
index 4bc145b..e2b6569 100644
--- a/src/event/Input.hpp
+++ b/src/event/Input.hpp
@@ -49,7 +49,7 @@ void IEvtInputInitialize();
 
 int32_t IEvtInputProcess(EvtContext* context, int32_t* shutdown);
 
-void IEvtSetMouseMode(EvtContext* context, MOUSEMODE mode, uint32_t holdButton);
+void IEvtInputSetMouseMode(EvtContext* context, MOUSEMODE mode, uint32_t holdButton);
 
 const char* KeyCodeToString(KEY key);
 
@@ -61,6 +61,8 @@ bool OsInputIsUsingCocoaEventLoop();
 
 void OsInputPostEvent(OSINPUT id, int32_t param0, int32_t param1, int32_t param2, int32_t param3);
 
+void OsInputSetMouseMode(OS_MOUSE_MODE mode);
+
 int32_t OsQueueGet(OSINPUT* id, int32_t* param0, int32_t* param1, int32_t* param2, int32_t* param3);
 
 void OsQueuePut(OSINPUT id, int32_t param0, int32_t param1, int32_t param2, int32_t param3);
diff --git a/src/event/linux/Input.cpp b/src/event/linux/Input.cpp
index 38475df..72b06de 100644
--- a/src/event/linux/Input.cpp
+++ b/src/event/linux/Input.cpp
@@ -4,3 +4,7 @@ int32_t OsInputGet(OSINPUT* id, int32_t* param0, int32_t* param1, int32_t* param
     // TODO
     return 0;
 }
+
+void OsInputSetMouseMode(OS_MOUSE_MODE mode) {
+    // TODO
+}
diff --git a/src/event/mac/Input.cpp b/src/event/mac/Input.cpp
index 53b2592..65cf626 100644
--- a/src/event/mac/Input.cpp
+++ b/src/event/mac/Input.cpp
@@ -21,3 +21,7 @@ int32_t OsInputGet(OSINPUT* id, int32_t* param0, int32_t* param1, int32_t* param
 
     return OsQueueGet(id, param0, param1, param2, param3);
 }
+
+void OsInputSetMouseMode(OS_MOUSE_MODE mode) {
+    // TODO
+}
diff --git a/src/event/win/Input.cpp b/src/event/win/Input.cpp
index 7c12e1c..887e774 100644
--- a/src/event/win/Input.cpp
+++ b/src/event/win/Input.cpp
@@ -1,7 +1,16 @@
 #include "event/Input.hpp"
 #include "event/Window.hpp"
+#include <storm/Error.hpp>
 #include <windows.h>
 
+void CenterMouse() {
+    // TODO
+}
+
+void RestoreMouse() {
+    // TODO
+}
+
 int32_t OsInputGet(OSINPUT* id, int32_t* param0, int32_t* param1, int32_t* param2, int32_t* param3) {
     // TODO window rect comparisons
 
@@ -48,3 +57,20 @@ int32_t OsInputGet(OSINPUT* id, int32_t* param0, int32_t* param1, int32_t* param
     OsQueueGet(id, param0, param1, param2, param3);
     return 1;
 }
+
+void OsInputSetMouseMode(OS_MOUSE_MODE mode) {
+    STORM_ASSERT(mode < OS_MOUSE_MODES);
+    STORM_VALIDATE(mode < OS_MOUSE_MODES, ERROR_INVALID_PARAMETER);
+
+    if (Input::s_osMouseMode == mode) {
+        return;
+    }
+
+    if (mode == OS_MOUSE_MODE_NORMAL) {
+        Input::s_osMouseMode = mode;
+        RestoreMouse();
+    } else if (mode == OS_MOUSE_MODE_RELATIVE) {
+        Input::s_osMouseMode = mode;
+        CenterMouse();
+    }
+}