marchaesen/vcxsrv Installation and Configuration X Server Architecture Windows Integration Multiwindow Mode Graphics Rendering Pipeline 2D Graphics (Pixman) 3D Graphics (OpenGL) Direct Rendering Infrastructure (DRI) Windows GLX Implementation Mesa 3D Implementation mhmake Build Tool Makefile Structure Protocol Implementation X11 Protocol and XCB xorg-server/damageext/makefile xorg-server/hw/xwin/InitOutput.c xorg-server/hw/xwin/glx/simpledib.c xorg-server/hw/xwin/makefile xorg-server/hw/xwin/win.h xorg-server/hw/xwin/winclipboardwrappers.c xorg-server/hw/xwin/wincreatewnd.c xorg-server/hw/xwin/windialogs.c xorg-server/hw/xwin/winerror.c xorg-server/hw/xwin/winglobals.c xorg-server/hw/xwin/winglobals.h xorg-server/hw/xwin/winkeybd.c xorg-server/hw/xwin/winmouse.c xorg-server/hw/xwin/winmsgwindow.c xorg-server/hw/xwin/winmultiwindowwindow.c xorg-server/hw/xwin/winmultiwindowwm.c xorg-server/hw/xwin/winmultiwindowwndproc.c xorg-server/hw/xwin/winprefs.c xorg-server/hw/xwin/winprocarg.c xorg-server/hw/xwin/winshadddnl.c xorg-server/hw/xwin/winshadgdi.c xorg-server/hw/xwin/wintrayicon.c xorg-server/hw/xwin/winwindow.h xorg-server/hw/xwin/winwndproc.c xorg-server/hw/xwin/xdmcphostselect.c This page explains how VcXsrv integrates X Window System applications with the Windows desktop environment. It covers the mechanisms for representing X windows as Windows windows, managing window properties, handling input events, and ensuring seamless interaction between the X server and the Windows operating system. For information about multiwindow mode specifically, see Multiwindow Mode . For details on input handling, see Input System . Architecture Overview VcXsrv provides multiple display modes, with the "multi-window" mode being the most integrated with Windows. In this mode, each X window appears as a separate Windows window, allowing X applications to blend naturally with Windows applications. xorg-server/hw/xwin/winmultiwindowwm.c 177-1174 xorg-server/hw/xwin/win.h 66-134 xorg-server/hw/xwin/winwindow.h 32-171 Window Creation and Management When an X client creates a window, VcXsrv creates a corresponding Windows window and establishes a mapping between them. xorg-server/hw/xwin/winmultiwindowwindow.c 99-138 xorg-server/hw/xwin/winmultiwindowwindow.c 342-370 xorg-server/hw/xwin/winmultiwindowwindow.c 447-604 Window Properties Mapping VcXsrv maps X window properties to corresponding Windows window properties: xorg-server/hw/xwin/winmultiwindowwm.c 627-648 xorg-server/hw/xwin/winmultiwindowwm.c 666-689 Thread Architecture The Windows integration is implemented using several threads: Main Server Thread : Handles the core X server functionality Window Manager Thread : Manages window creation, mapping, and property synchronization X Message Thread : Processes X protocol messages for window management Clipboard Thread : Handles clipboard integration (when enabled) xorg-server/hw/xwin/winmultiwindowwm.c 930-1173 xorg-server/hw/xwin/winmultiwindowwm.c 1197-2014 xorg-server/hw/xwin/winclipboardwrappers.c 67-152 Message Processing VcXsrv processes both Windows messages and X11 events, translating between the two systems: Windows to X11 Translation Windows messages are received by the window procedure ( winTopLevelWindowProc ) and translated to X11 events. xorg-server/hw/xwin/winmultiwindowwndproc.c 498-1122 xorg-server/hw/xwin/winwndproc.c 151-779 X11 to Windows Translation X11 events and requests are translated to Windows operations by the window manager thread. xorg-server/hw/xwin/winmultiwindowwm.c 945-1152 Window Styling and Decorations VcXsrv applies appropriate window styles to X windows based on their properties: Normal Windows : Standard window with title bar, borders, and minimize/maximize buttons Dialog Windows : Dialog-style windows with a title bar but no minimize/maximize buttons

Utility Windows : Small windows with minimal decorations Override-redirect Windows : Windows without decorations (popup menus, tooltips) The window styles are determined by examining X window properties including: Motif WM hints (decoration flags) Window type atoms (_NET_WM_WINDOW_TYPE) Window state (_NET_WM_STATE) xorg-server/hw/xwin/winmultiwindowwm.c 191-193 xorg-server/hw/xwin/winmultiwindowwm.c 694-736 Alpha Channel/Transparency Support VcXsrv supports alpha channel/transparency for X windows with 32-bit depth, using different Windows APIs depending on the Windows version: For Windows 10 and later: SetWindowCompositionAttribute For Windows 7 and Vista: DwmEnableBlurBehindWindow This allows X windows with transparency to blend properly with the Windows desktop. xorg-server/hw/xwin/winmultiwindowwndproc.c 373-456 System Tray Integration VcXsrv adds an icon to the Windows system tray (notification area) to provide quick access to server controls and to show server status. The tray icon provides a menu with options like: Custom menu items from configuration files xorg-server/hw/xwin/wintrayicon.c 1-205 xorg-server/hw/xwin/winwndproc.c 188-226 xorg-server/hw/xwin/winglobals.c 63-64 Desktop Integration Multi-Monitor Support VcXsrv supports multiple monitors, allowing X windows to be positioned correctly across different monitors. It detects monitor configuration changes and adjusts the X screen size and position accordingly. When the desktop configuration changes (monitor added/removed or resolution changed), VcXsrv receives a WM_DISPLAYCHANGE message and updates the X screen configuration to match. xorg-server/hw/xwin/winwndproc.c 228-381 xorg-server/hw/xwin/winmultiwindowwindow.c 157-279 Window Activation and Focus VcXsrv manages window activation and focus by: Translating Windows WM_SETFOCUS events to X focus events Setting the X input focus when a window is activated Handling the WM_ACTIVATE message to notify X clients xorg-server/hw/xwin/winmultiwindowwndproc.c 856-901 xorg-server/hw/xwin/winmultiwindowwm.c 1047-1089 Configuration Options VcXsrv provides several command-line options to control Windows integration: xorg-server/hw/xwin/winprocarg.c 457-892 xorg-server/hw/xwin/winglobals.c 60-82 Technical Implementation Details Windows windows and X windows are mapped to each other using window properties: WIN_WINDOW_PROP : Stores a pointer to the X window structure WIN_WID_PROP : Stores the X window ID WIN_STATE_PROP : Stores the window state (normal, maximized, minimized) WIN_SCR_PROP : Stores a pointer to the screen structure xorg-server/hw/xwin/winglobals.c 103-107 xorg-server/hw/xwin/winmultiwindowwindow.c 605-607 Window Message Communication Communication between threads is done using custom window messages: WM_WM_MOVE : Window moved WM_WM_SIZE : Window resized WM_WM_RAISE : Raise window WM_WM_LOWER : Lower window WM_WM_ACTIVATE : Activate window WM_WM_KILL : Close window WM_WM_NAME_EVENT : Window name changed WM_WM_HINTS_EVENT : Window hints changed xorg-server/hw/xwin/winwindow.h 98-110 xorg-server/hw/xwin/winmultiwindowwm.c 945-1152 The Windows integration in VcXsrv provides a seamless experience for running X applications on Windows. By carefully mapping X windows to Windows windows and translating events between the two systems, VcXsrv makes X applications appear and behave like native Windows applications while maintaining compatibility with the X11 protocol. Refresh this wiki Windows Integration Architecture Overview Window Creation and Management Window Properties Mapping Thread Architecture Message Processing Windows to X11 Translation X11 to Windows Translation Window Styling and Decorations Alpha Channel/Transparency Support System Tray Integration Desktop Integration Multi-Monitor Support Window Activation and Focus Configuration Options Technical Implementation Details Window Message Communication