Separate game responses from native window events

code/gamewindow.cpp

@@ -0,0 +1,69 @@
+/*******************************************************************************
+ *                                O P E N  T S
+ *******************************************************************************
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright 2026 OpenTS contributors
+ *
+ * See LICENSE.md for applicable additional terms and warranty disclaimers.
+ ******************************************************************************/
+
+#include "always.h"
+
+#include "gamewindow.h"
+
+#include "_map.h"
+#include "_surface.h"
+#include "_xmouse.h"
+#include "globals.h"
+#include "gscreen.h"
+#include "init.h"
+#include "movies.h"
+#include "video.h"
+
+
+static bool _HandlingMouseWheel = false;
+
+
+/// <summary>
+/// Updates and presents the frame when the application window needs repainting.
+/// </summary>
+void Game_Window_On_Paint(bool update_surface)
+{
+	if (update_surface) {
+		if (MouseCursor != NULL && VisibleSurface != NULL && HiddenSurface != NULL && CompositeSurface != NULL) {
+			if (ScenarioActive == true) {
+				Map.Blit_Sidebar(true);
+				Update_Visible_Surface(CompositeSurface);
+			} else if (Movie_Is_Playing() == true) {
+				Movie_Update_Visible_Surface();
+			} else {
+				Update_Visible_Surface(HiddenSurface);
+			}
+		}
+	}
+	Video_Present_If_Dirty();
+}
+
+
+/// <summary>
+/// Stops tactical scrolling from coasting after the right mouse button is released.
+/// </summary>
+void Game_Window_On_Right_Mouse_Up(void)
+{
+	Map.Set_Scroll_Coasting_Allowed(false);
+}
+
+
+/// <summary>
+/// Applies a mouse wheel step to the sidebar.
+/// </summary>
+void Game_Window_On_Mouse_Wheel(int delta)
+{
+	if (_HandlingMouseWheel) {
+		return;
+	}
+
+	_HandlingMouseWheel = true;
+	Execute_Command(delta < 0 ? "SidebarDown" : "SidebarUp");
+	_HandlingMouseWheel = false;
+}

code/gamewindow.h

@@ -0,0 +1,15 @@
+/*******************************************************************************
+ *                                O P E N  T S
+ *******************************************************************************
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright 2026 OpenTS contributors
+ *
+ * See LICENSE.md for applicable additional terms and warranty disclaimers.
+ ******************************************************************************/
+
+#pragma once
+
+
+void Game_Window_On_Paint(bool update_surface);
+void Game_Window_On_Right_Mouse_Up(void);
+void Game_Window_On_Mouse_Wheel(int delta);

code/video.cpp

@@ -235,10 +235,9 @@ void Video_On_Resize(int drawablewidth, int drawableheight)
 
 
 /// <summary>
-/// Tells the presenter the desktop's display settings changed.
-/// The window may now be on a monitor that refreshes at a different rate.
+/// Sets the refresh rate used to pace presentation.
 /// </summary>
-void Video_On_Display_Change(int refreshrate)
+void Video_Set_Refresh_Rate(int refreshrate)
 {
 	if (!_Initialized) {
 		return;

code/video.h

@@ -43,7 +43,7 @@ void Video_Shutdown(void);
 
 bool Video_Set_Mode(int width, int height);
 void Video_On_Resize(int drawablewidth, int drawableheight);
-void Video_On_Display_Change(int refreshrate);
+void Video_Set_Refresh_Rate(int refreshrate);
 
 void Video_Mark_Dirty(void);
 void Video_Present(void);

code/winstub.cpp

@@ -47,7 +47,6 @@
 #include "_keyboar.h"
 #include "_map.h"
 #include "_rect.h"
-#include "_surface.h"
 #include "_tooltip.h"
 #include "ccfile.h"
 #include "cctooltip.h"
@@ -57,12 +56,11 @@
 #include "dsaudio.h"
 #include "dsurface.h"
 #include "except.h"
+#include "gamewindow.h"
 #include "globals.h"
 #include "goptions.h"
-#include "init.h"
 #include "misc.h"
 #include "movie.h"
-#include "movies.h"
 #include "msgroute.h"
 #include "nativewindow.hh"
 #include "pcx.h"
@@ -88,7 +86,6 @@ HWND	UnusedWindow;
 
 HINSTANCE	ProgramInstance;
 bool _MouseCaptured;
-bool _MouseWheel;
 
 
 //void output(short,short)
@@ -247,19 +244,7 @@ LRESULT CALLBACK /*_export*/ Windows_Procedure(HWND hwnd, UINT message, UINT wPa
 			return(0);
 
 		case WM_PAINT:
-			if (GameInFocus == true || WindowedMode == true) {
-				if (MouseCursor != NULL && VisibleSurface != NULL && HiddenSurface != NULL && CompositeSurface != NULL) {
-					if (ScenarioActive == true) {
-						Map.Blit_Sidebar(true);
-						Update_Visible_Surface(CompositeSurface);
-					} else if (Movie_Is_Playing() == true) {
-						Movie_Update_Visible_Surface();
-					} else {
-						Update_Visible_Surface(HiddenSurface);
-					}
-				}
-			}
-			Video_Present_If_Dirty();
+			Game_Window_On_Paint(GameInFocus == true || WindowedMode == true);
 			ValidateRect(hwnd, NULL);
 			break;
 
@@ -275,15 +260,15 @@ LRESULT CALLBACK /*_export*/ Windows_Procedure(HWND hwnd, UINT message, UINT wPa
 		case WM_SIZE:
 			if (wParam != SIZE_MINIMIZED) {
 				Video_On_Resize(LOWORD(lParam), HIWORD(lParam));
-				Video_On_Display_Change(Win_Window_Refresh_Rate(hwnd));
+				Video_Set_Refresh_Rate(Win_Window_Refresh_Rate(hwnd));
 				if (MouseCursor != NULL) {
 					((WWMouseClass *)MouseCursor)->Calc_Confining_Rect();
 				}
 			}
 			break;
 
 		case WM_DISPLAYCHANGE:
-			Video_On_Display_Change(Win_Window_Refresh_Rate(hwnd));
+			Video_Set_Refresh_Rate(Win_Window_Refresh_Rate(hwnd));
 			break;
 
 		case WM_CLOSE:
@@ -343,22 +328,14 @@ LRESULT CALLBACK /*_export*/ Windows_Procedure(HWND hwnd, UINT message, UINT wPa
 			return(0);
 
 		case WM_RBUTTONUP:
-			Map.Set_Scroll_Coasting_Allowed(false);
+			Game_Window_On_Right_Mouse_Up();
 			break;
 
 		case WM_MOVING:
 			return(On_WM_MOVING(hwnd, wParam, lParam));
 
 		case WM_MOUSEWHEEL:
-			if (!_MouseWheel) {
-				_MouseWheel = true;
-				if (GET_WHEEL_DELTA_WPARAM(wParam) < 0) {
-					Execute_Command("SidebarDown");
-				} else {
-					Execute_Command("SidebarUp");
-				}
-				_MouseWheel = false;
-			}
+			Game_Window_On_Mouse_Wheel(GET_WHEEL_DELTA_WPARAM(wParam));
 			break;
 
 		case WM_SYSCOMMAND:

manual/changes/game-window-event-boundary.md

@@ -0,0 +1,9 @@
+---
+title: Separate game window responses from native events
+category: internal
+release: 0.2.0
+targets: []
+credit: [Krisztiaan]
+---
+
+The Win32 window procedure now translates paint, right-button release, and mouse-wheel messages into native-independent game callbacks. Game responses live with the callbacks, while Win32-specific validation and message decoding remain in the application shell. The video presenter accepts refresh-rate updates directly instead of handling a native display-change event. Controls and rendering configuration are unchanged.