diff --git a/src/v_video.h b/src/v_video.h
index 69741c7f8..5250cdaa9 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -398,8 +398,8 @@ public:
 	virtual void WipeEndScreen();
 	virtual bool WipeDo(int ticks);
 	virtual void WipeCleanup();
-	virtual int GetPixelDoubling() const { return 0; }
-	virtual int GetTrueHeight() { return GetHeight(); }
+
+	virtual void ScaleCoordsFromWindow(SWORD &x, SWORD &y) {}
 
 	uint32 GetLastFPS() const { return LastCount; }
 
diff --git a/src/win32/fb_d3d9.cpp b/src/win32/fb_d3d9.cpp
index e23275734..9fd185431 100644
--- a/src/win32/fb_d3d9.cpp
+++ b/src/win32/fb_d3d9.cpp
@@ -1028,6 +1028,28 @@ bool D3DFB::IsFullscreen ()
 	return !Windowed;
 }
 
+//==========================================================================
+//
+// D3DFB :: ScaleCoordsFromWindow
+//
+// Given coordinates in window space, return coordinates in what the game
+// thinks screen space is.
+//
+//==========================================================================
+
+void D3DFB::ScaleCoordsFromWindow(SWORD &x, SWORD &y)
+{
+	RECT rect;
+
+	if (GetClientRect(Window, &rect))
+	{
+		x = SWORD(x * Width / (rect.right - rect.left));
+		y = SWORD(y * TrueHeight / (rect.bottom - rect.top));
+	}
+	// Subtract letterboxing borders
+	y -= (TrueHeight - Height) / 2;
+}
+
 //==========================================================================
 //
 // D3DFB :: Lock
diff --git a/src/win32/fb_ddraw.cpp b/src/win32/fb_ddraw.cpp
index 2aa694f3b..ecf570ff8 100644
--- a/src/win32/fb_ddraw.cpp
+++ b/src/win32/fb_ddraw.cpp
@@ -806,6 +806,19 @@ bool DDrawFB::Is8BitMode()
 	return vid_displaybits == 8;
 }
 
+void DDrawFB::ScaleCoordsFromWindow(SWORD &x, SWORD &y)
+{
+	RECT rect;
+
+	if (GetClientRect(Window, &rect))
+	{
+		x = SWORD(x * Width / (rect.right - rect.left));
+		y = SWORD(y * TrueHeight / (rect.bottom - rect.top));
+	}
+	// Subtract letterboxing borders
+	y -= (TrueHeight - Height) / 2;
+}
+
 bool DDrawFB::IsValid ()
 {
 	return PrimarySurf != NULL;
diff --git a/src/win32/i_input.cpp b/src/win32/i_input.cpp
index ed7c81cf1..a26ff320e 100644
--- a/src/win32/i_input.cpp
+++ b/src/win32/i_input.cpp
@@ -323,11 +323,11 @@ bool GUIWndProcHook(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam, LRESU
 			if (BlockMouseMove > 0) return true;
 		}
 
+		ev.data1 = LOWORD(lParam);
+		ev.data2 = HIWORD(lParam);
+		if (screen != NULL)
 		{
-			int shift = screen? screen->GetPixelDoubling() : 0;
-			ev.data1 = LOWORD(lParam) >> shift; 
-			ev.data2 = HIWORD(lParam) >> shift; 
-			if (screen) ev.data2 -= (screen->GetTrueHeight() - screen->GetHeight())/2;
+			screen->ScaleCoordsFromWindow(ev.data1, ev.data2);
 		}
 
 		if (wParam & MK_SHIFT)				ev.data3 |= GKM_SHIFT;
diff --git a/src/win32/win32iface.h b/src/win32/win32iface.h
index 2704de0fa..9699157cd 100644
--- a/src/win32/win32iface.h
+++ b/src/win32/win32iface.h
@@ -164,8 +164,8 @@ public:
 	void SetVSync (bool vsync);
 	void NewRefreshRate();
 	HRESULT GetHR ();
-	virtual int GetTrueHeight() { return TrueHeight; }
 	bool Is8BitMode();
+	void ScaleCoordsFromWindow(SWORD &x, SWORD &y);
 
 	void Blank ();
 	bool PaintToWindow ();
@@ -269,8 +269,8 @@ public:
 	bool WipeDo(int ticks);
 	void WipeCleanup();
 	HRESULT GetHR ();
-	virtual int GetTrueHeight() { return TrueHeight; }
 	bool Is8BitMode() { return false; }
+	void ScaleCoordsFromWindow(SWORD &x, SWORD &y);
 
 private:
 	friend class D3DTex;
@@ -380,7 +380,6 @@ private:
 	void EndLineBatch();
 	void EndBatch();
 	void CopyNextFrontBuffer();
-	int GetPixelDoubling() const { return PixelDoubling; }
 
 	D3DCAPS9 DeviceCaps;