intern/ghost/intern/GHOST_WindowWin32.cpp

@@ -93,7 +93,7 @@ GHOST_WindowWin32::GHOST_WindowWin32(GHOST_SystemWin32 *system,
   }
 
   RECT win_rect = {left, top, long(left + width), long(top + height)};
-  adjustWindowRectForClosestMonitor(&win_rect, style, extended_style);
+  adjustWindowRectForDesktop(&win_rect, style, extended_style);
 
   wchar_t *title_16 = alloc_utf16_from_8((char *)title, 0);
   m_hWnd = ::CreateWindowExW(extended_style,                 /* window extended style */
@@ -298,24 +298,52 @@ GHOST_WindowWin32::~GHOST_WindowWin32()
   m_directManipulationHelper = NULL;
 }
 
-void GHOST_WindowWin32::adjustWindowRectForClosestMonitor(LPRECT win_rect,
-                                                          DWORD dwStyle,
-                                                          DWORD dwExStyle)
+void GHOST_WindowWin32::adjustWindowRectForDesktop(LPRECT win_rect, DWORD dwStyle, DWORD dwExStyle)
 {
-  /* Get Details of the closest monitor. */
-  HMONITOR hmonitor = MonitorFromRect(win_rect, MONITOR_DEFAULTTONEAREST);
+  /* Windows can span multiple monitors, but must be usable. The desktop can have a larger
+   * surface than all monitors combined, for example when two monitors are aligned diagonally.
+   * Therefore we ensure that all the window's corners are within some monitor's Work area. */
+
+  POINT pt;
+  HMONITOR hmonitor;
   MONITORINFOEX monitor;
   monitor.cbSize = sizeof(MONITORINFOEX);
   monitor.dwFlags = 0;
-  GetMonitorInfo(hmonitor, &monitor);
 
-  /* Constrain requested size and position to fit within this monitor. */
-  LONG width = min(monitor.rcWork.right - monitor.rcWork.left, win_rect->right - win_rect->left);
-  LONG height = min(monitor.rcWork.bottom - monitor.rcWork.top, win_rect->bottom - win_rect->top);
-  win_rect->left = min(max(monitor.rcWork.left, win_rect->left), monitor.rcWork.right - width);
-  win_rect->right = win_rect->left + width;
-  win_rect->top = min(max(monitor.rcWork.top, win_rect->top), monitor.rcWork.bottom - height);
-  win_rect->bottom = win_rect->top + height;
+  /* Note that with MonitorFromPoint using MONITOR_DEFAULTTONEAREST, it will return
+   * the exact monitor if there is one at the location or the nearest monitor if not. */
+
+  /* Top-left. */
+  pt.x = win_rect->left;
+  pt.y = win_rect->top;
+  hmonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONEAREST);
+  GetMonitorInfo(hmonitor, &monitor);
+  win_rect->top = max(win_rect->top, monitor.rcWork.top);
+  win_rect->left = max(win_rect->left, monitor.rcWork.left);
+
+  /* Top-right. */
+  pt.x = win_rect->right;
+  pt.y = win_rect->top;
+  hmonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONEAREST);
+  GetMonitorInfo(hmonitor, &monitor);
+  win_rect->top = max(win_rect->top, monitor.rcWork.top);
+  win_rect->right = min(win_rect->right, monitor.rcWork.right);
+
+  /* Bottom-left. */
+  pt.x = win_rect->left;
+  pt.y = win_rect->bottom;
+  hmonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONEAREST);
+  GetMonitorInfo(hmonitor, &monitor);
+  win_rect->bottom = min(win_rect->bottom, monitor.rcWork.bottom);
+  win_rect->left = max(win_rect->left, monitor.rcWork.left);
+
+  /* Bottom-right. */
+  pt.x = win_rect->right;
+  pt.y = win_rect->bottom;
+  hmonitor = MonitorFromPoint(pt, MONITOR_DEFAULTTONEAREST);
+  GetMonitorInfo(hmonitor, &monitor);
+  win_rect->bottom = min(win_rect->bottom, monitor.rcWork.bottom);
+  win_rect->right = min(win_rect->right, monitor.rcWork.right);
 
   /* With Windows 10 and newer we can adjust for chrome that differs with DPI and scale. */
   GHOST_WIN32_AdjustWindowRectExForDpi fpAdjustWindowRectExForDpi = nullptr;
@@ -334,9 +362,6 @@ void GHOST_WindowWin32::adjustWindowRectForClosestMonitor(LPRECT win_rect,
   else {
     AdjustWindowRectEx(win_rect, dwStyle & ~WS_OVERLAPPED, FALSE, dwExStyle);
   }
-
-  /* But never allow a top position that can hide part of the title bar. */
-  win_rect->top = max(monitor.rcWork.top, win_rect->top);
 }
 
 bool GHOST_WindowWin32::getValid() const

intern/ghost/intern/GHOST_WindowWin32.h

@@ -87,12 +87,12 @@ class GHOST_WindowWin32 : public GHOST_Window {
   ~GHOST_WindowWin32();
 
   /**
-   * Adjusts a requested window rect to fit and position correctly in monitor.
+   * Adjusts a requested window rect to fit and position within the desktop.
    * \param win_rect: pointer to rectangle that will be modified.
    * \param dwStyle: The Window Style of the window whose required size is to be calculated.
    * \param dwExStyle: The Extended Window Style of the window.
    */
-  void adjustWindowRectForClosestMonitor(LPRECT win_rect, DWORD dwStyle, DWORD dwExStyle);
+  void adjustWindowRectForDesktop(LPRECT win_rect, DWORD dwStyle, DWORD dwExStyle);
 
   /**
    * Returns indication as to whether the window is valid.