Fix T83930 and Fix T84659: Walk navigation tablet bugs.

Fixes T83930, allowing walk navigation to continue without jumping back
after repositiong pen.

Fixes T84659, allow walk navigation to start (for Windows Ink) from
keyboard shortcut when pen is in use.

intern/ghost/CMakeLists.txt

@@ -370,6 +370,7 @@ elseif(WIN32)
     intern/GHOST_DropTargetWin32.cpp
     intern/GHOST_SystemWin32.cpp
     intern/GHOST_WindowWin32.cpp
+    intern/GHOST_Wintab.cpp
 
     intern/GHOST_ContextD3D.h
     intern/GHOST_DisplayManagerWin32.h
@@ -377,6 +378,7 @@ elseif(WIN32)
     intern/GHOST_SystemWin32.h
     intern/GHOST_TaskbarWin32.h
     intern/GHOST_WindowWin32.h
+    intern/GHOST_Wintab.h
   )
 
   if(NOT WITH_GL_EGL)

intern/ghost/GHOST_Types.h

@@ -105,7 +105,9 @@ typedef enum {
 
 typedef enum {
   GHOST_kTabletAutomatic = 0,
-  GHOST_kTabletNative,
+  /* Show as Windows Ink to users to match "Use Windows Ink" in tablet utilities, but we use the
+     dependent Windows Pointer API. */
+  GHOST_kTabletWinPointer,
   GHOST_kTabletWintab,
 } GHOST_TTabletAPI;
 

intern/ghost/intern/GHOST_System.h

@@ -239,7 +239,7 @@ class GHOST_System : public GHOST_ISystem {
    * Set which tablet API to use. Only affects Windows, other platforms have a single API.
    * \param api: Enum indicating which API to use.
    */
-  void setTabletAPI(GHOST_TTabletAPI api);
+  virtual void setTabletAPI(GHOST_TTabletAPI api) override;
   GHOST_TTabletAPI getTabletAPI(void);
 
 #ifdef WITH_INPUT_NDOF

intern/ghost/intern/GHOST_SystemWin32.cpp

@@ -866,15 +866,151 @@ GHOST_EventButton *GHOST_SystemWin32::processButtonEvent(GHOST_TEventType type,
 {
   GHOST_SystemWin32 *system = (GHOST_SystemWin32 *)getSystem();
 
-  if (type == GHOST_kEventButtonDown) {
-    window->updateMouseCapture(MousePressed);
-  }
-  else if (type == GHOST_kEventButtonUp) {
-    window->updateMouseCapture(MouseReleased);
+  GHOST_TabletData td = window->getTabletData();
+
+  /* Move mouse to button event position. */
+  if (window->getTabletData().Active != GHOST_kTabletModeNone) {
+    /* Tablet should be handling inbetween mouse moves, only move to event position. */
+    DWORD msgPos = ::GetMessagePos();
+    int msgPosX = GET_X_LPARAM(msgPos);
+    int msgPosY = GET_Y_LPARAM(msgPos);
+    system->pushEvent(new GHOST_EventCursor(
+        ::GetMessageTime(), GHOST_kEventCursorMove, window, msgPosX, msgPosY, td));
   }
 
-  return new GHOST_EventButton(
-      system->getMilliSeconds(), type, window, mask, window->getTabletData());
+  window->updateMouseCapture(type == GHOST_kEventButtonDown ? MousePressed : MouseReleased);
+  return new GHOST_EventButton(system->getMilliSeconds(), type, window, mask, td);
+}
+
+void GHOST_SystemWin32::processWintabEvent(GHOST_WindowWin32 *window)
+{
+  GHOST_Wintab *wt = window->getWintab();
+  if (!wt) {
+    return;
+  }
+
+  GHOST_SystemWin32 *system = (GHOST_SystemWin32 *)getSystem();
+
+  std::vector<GHOST_WintabInfoWin32> wintabInfo;
+  wt->getInput(wintabInfo);
+
+  /* Wintab provided coordinates are untrusted until a Wintab and Win32 button down event match.
+   * This is checked on every button down event, and revoked if there is a mismatch. This can
+   * happen when Wintab incorrectly scales cursor position or is in mouse mode.
+   *
+   * If Wintab was never trusted while processing this Win32 event, a fallback Ghost cursor move
+   * event is created at the position of the Win32 WT_PACKET event. */
+  bool mouseMoveHandled;
+  bool useWintabPos;
+  mouseMoveHandled = useWintabPos = wt->trustCoordinates();
+
+  for (GHOST_WintabInfoWin32 &info : wintabInfo) {
+    switch (info.type) {
+      case GHOST_kEventCursorMove: {
+        if (!useWintabPos) {
+          continue;
+        }
+
+        wt->mapWintabToSysCoordinates(info.x, info.y, info.x, info.y);
+        system->pushEvent(new GHOST_EventCursor(
+            info.time, GHOST_kEventCursorMove, window, info.x, info.y, info.tabletData));
+
+        break;
+      }
+      case GHOST_kEventButtonDown: {
+        UINT message;
+        switch (info.button) {
+          case GHOST_kButtonMaskLeft:
+            message = WM_LBUTTONDOWN;
+            break;
+          case GHOST_kButtonMaskRight:
+            message = WM_RBUTTONDOWN;
+            break;
+          case GHOST_kButtonMaskMiddle:
+            message = WM_MBUTTONDOWN;
+            break;
+          default:
+            continue;
+        }
+
+        /* Wintab buttons are modal, but the API does not inform us what mode a pressed button is
+         * in. Only issue button events if we can steal an equivalent Win32 button event from the
+         * event queue. */
+        MSG msg;
+        if (PeekMessage(&msg, window->getHWND(), message, message, PM_NOYIELD) &&
+            msg.message != WM_QUIT) {
+
+          /* Test for Win32/Wintab button down match. */
+          useWintabPos = wt->testCoordinates(msg.pt.x, msg.pt.y, info.x, info.y);
+          if (!useWintabPos) {
+            continue;
+          }
+
+          /* Steal the Win32 event which was previously peeked. */
+          PeekMessage(&msg, window->getHWND(), message, message, PM_REMOVE | PM_NOYIELD);
+
+          /* Move cursor to button location, to prevent incorrect cursor position when
+           * transitioning from unsynchronized Win32 to Wintab cursor control. */
+          wt->mapWintabToSysCoordinates(info.x, info.y, info.x, info.y);
+          system->pushEvent(new GHOST_EventCursor(
+              info.time, GHOST_kEventCursorMove, window, info.x, info.y, info.tabletData));
+
+          window->updateMouseCapture(MousePressed);
+          system->pushEvent(
+              new GHOST_EventButton(info.time, info.type, window, info.button, info.tabletData));
+
+          mouseMoveHandled = true;
+          break;
+        }
+      }
+      case GHOST_kEventButtonUp: {
+        if (!useWintabPos) {
+          continue;
+        }
+
+        UINT message;
+        switch (info.button) {
+          case GHOST_kButtonMaskLeft:
+            message = WM_LBUTTONUP;
+            break;
+          case GHOST_kButtonMaskRight:
+            message = WM_RBUTTONUP;
+            break;
+          case GHOST_kButtonMaskMiddle:
+            message = WM_MBUTTONUP;
+            break;
+          default:
+            continue;
+        }
+
+        /* Wintab buttons are modal, but the API does not inform us what mode a pressed button is
+         * in. Only issue button events if we can steal an equivalent Win32 button event from the
+         * event queue. */
+        MSG msg;
+        if (PeekMessage(&msg, window->getHWND(), message, message, PM_REMOVE | PM_NOYIELD) &&
+            msg.message != WM_QUIT) {
+
+          window->updateMouseCapture(MouseReleased);
+          system->pushEvent(
+              new GHOST_EventButton(info.time, info.type, window, info.button, info.tabletData));
+        }
+        break;
+      }
+      default:
+        break;
+    }
+  }
+
+  /* Fallback cursor movement if Wintab position were never trusted while processing this event. */
+  if (!mouseMoveHandled) {
+    DWORD pos = GetMessagePos();
+    int x = GET_X_LPARAM(pos);
+    int y = GET_Y_LPARAM(pos);
+
+    /* TODO supply tablet data */
+    system->pushEvent(new GHOST_EventCursor(
+        system->getMilliSeconds(), GHOST_kEventCursorMove, window, x, y, GHOST_TABLET_DATA_NONE));
+  }
 }
 
 void GHOST_SystemWin32::processPointerEvent(
@@ -882,7 +1018,7 @@ void GHOST_SystemWin32::processPointerEvent(
 {
   /* Pointer events might fire when changing windows for a device which is set to use Wintab, even
    * when when Wintab is left enabled but set to the bottom of Wintab overlap order. */
-  if (!window->useTabletAPI(GHOST_kTabletNative)) {
+  if (!window->usingTabletAPI(GHOST_kTabletWinPointer)) {
     return;
   }
 
@@ -893,20 +1029,21 @@ void GHOST_SystemWin32::processPointerEvent(
     return;
   }
 
-  if (!pointerInfo[0].isPrimary) {
-    eventHandled = true;
-    return;  // For multi-touch displays we ignore these events
-  }
-
   switch (type) {
-    case WM_POINTERENTER:
-      window->m_tabletInRange = true;
-      system->pushEvent(new GHOST_EventCursor(pointerInfo[0].time,
-                                              GHOST_kEventCursorMove,
-                                              window,
-                                              pointerInfo[0].pixelLocation.x,
-                                              pointerInfo[0].pixelLocation.y,
-                                              pointerInfo[0].tabletData));
+    case WM_POINTERUPDATE:
+      /* Coalesced pointer events are reverse chronological order, reorder chronologically.
+       * Only contiguous move events are coalesced. */
+      for (GHOST_TUns32 i = pointerInfo.size(); i-- > 0;) {
+        system->pushEvent(new GHOST_EventCursor(pointerInfo[i].time,
+                                                GHOST_kEventCursorMove,
+                                                window,
+                                                pointerInfo[i].pixelLocation.x,
+                                                pointerInfo[i].pixelLocation.y,
+                                                pointerInfo[i].tabletData));
+      }
+
+      /* Leave event unhandled so that system cursor is moved. */
+
       break;
     case WM_POINTERDOWN:
       /* Move cursor to point of contact because GHOST_EventButton does not include position. */
@@ -922,18 +1059,10 @@ void GHOST_SystemWin32::processPointerEvent(
                                               pointerInfo[0].buttonMask,
                                               pointerInfo[0].tabletData));
       window->updateMouseCapture(MousePressed);
-      break;
-    case WM_POINTERUPDATE:
-      /* Coalesced pointer events are reverse chronological order, reorder chronologically.
-       * Only contiguous move events are coalesced. */
-      for (GHOST_TUns32 i = pointerInfo.size(); i-- > 0;) {
-        system->pushEvent(new GHOST_EventCursor(pointerInfo[i].time,
-                                                GHOST_kEventCursorMove,
-                                                window,
-                                                pointerInfo[i].pixelLocation.x,
-                                                pointerInfo[i].pixelLocation.y,
-                                                pointerInfo[i].tabletData));
-      }
+
+      /* Mark event handled so that mouse button events are not generated. */
+      eventHandled = true;
+
       break;
     case WM_POINTERUP:
       system->pushEvent(new GHOST_EventButton(pointerInfo[0].time,
@@ -942,16 +1071,14 @@ void GHOST_SystemWin32::processPointerEvent(
                                               pointerInfo[0].buttonMask,
                                               pointerInfo[0].tabletData));
       window->updateMouseCapture(MouseReleased);
-      break;
-    case WM_POINTERLEAVE:
-      window->m_tabletInRange = false;
+
+      /* Mark event handled so that mouse button events are not generated. */
+      eventHandled = true;
+
       break;
     default:
       break;
   }
-
-  eventHandled = true;
-  system->setCursorPosition(pointerInfo[0].pixelLocation.x, pointerInfo[0].pixelLocation.y);
 }
 
 GHOST_EventCursor *GHOST_SystemWin32::processCursorEvent(GHOST_WindowWin32 *window)
@@ -959,18 +1086,14 @@ GHOST_EventCursor *GHOST_SystemWin32::processCursorEvent(GHOST_WindowWin32 *wind
   GHOST_TInt32 x_screen, y_screen;
   GHOST_SystemWin32 *system = (GHOST_SystemWin32 *)getSystem();
 
-  if (window->m_tabletInRange) {
-    if (window->useTabletAPI(GHOST_kTabletNative)) {
-      /* Tablet input handled in WM_POINTER* events. WM_MOUSEMOVE events in response to tablet
-       * input aren't normally generated when using WM_POINTER events, but manually moving the
-       * system cursor as we do in WM_POINTER handling does. */
-      return NULL;
-    }
+  if (window->getTabletData().Active != GHOST_kTabletModeNone) {
+    /* While pen devices are in range, cursor movement is handled by tablet input processing. */
+    return NULL;
   }
 
   system->getCursorPosition(x_screen, y_screen);
 
-  if (window->getCursorGrabModeIsWarp() && !window->m_tabletInRange) {
+  if (window->getCursorGrabModeIsWarp()) {
     GHOST_TInt32 x_new = x_screen;
     GHOST_TInt32 y_new = y_screen;
     GHOST_TInt32 x_accum, y_accum;
@@ -982,7 +1105,7 @@ GHOST_EventCursor *GHOST_SystemWin32::processCursorEvent(GHOST_WindowWin32 *wind
     }
 
     /* Could also clamp to screen bounds wrap with a window outside the view will fail atm.
-     * Use offset of 8 in case the window is at screen bounds. */
+     * Use inset in case the window is at screen bounds. */
     bounds.wrapPoint(x_new, y_new, 2, window->getCursorGrabAxis());
 
     window->getCursorGrabAccum(x_accum, y_accum);
@@ -998,7 +1121,7 @@ GHOST_EventCursor *GHOST_SystemWin32::processCursorEvent(GHOST_WindowWin32 *wind
                                    window,
                                    x_screen + x_accum,
                                    y_screen + y_accum,
-                                   window->getTabletData());
+                                   GHOST_TABLET_DATA_NONE);
     }
   }
   else {
@@ -1007,7 +1130,7 @@ GHOST_EventCursor *GHOST_SystemWin32::processCursorEvent(GHOST_WindowWin32 *wind
                                  window,
                                  x_screen,
                                  y_screen,
-                                 window->getTabletData());
+                                 GHOST_TABLET_DATA_NONE);
   }
   return NULL;
 }
@@ -1117,6 +1240,23 @@ GHOST_EventKey *GHOST_SystemWin32::processKeyEvent(GHOST_WindowWin32 *window, RA
   return event;
 }
 
+GHOST_Event *GHOST_SystemWin32::processWindowSizeEvent(GHOST_WindowWin32 *window)
+{
+  GHOST_SystemWin32 *system = (GHOST_SystemWin32 *)getSystem();
+  GHOST_Event *sizeEvent = new GHOST_Event(
+      system->getMilliSeconds(), GHOST_kEventWindowSize, window);
+
+  /* We get WM_SIZE before we fully init. Do not dispatch before we are continuously resizing. */
+  if (window->m_inLiveResize) {
+    system->pushEvent(sizeEvent);
+    system->dispatchEvents();
+    return NULL;
+  }
+  else {
+    return sizeEvent;
+  }
+}
+
 GHOST_Event *GHOST_SystemWin32::processWindowEvent(GHOST_TEventType type,
                                                    GHOST_WindowWin32 *window)
 {
@@ -1124,7 +1264,6 @@ GHOST_Event *GHOST_SystemWin32::processWindowEvent(GHOST_TEventType type,
 
   if (type == GHOST_kEventWindowActivate) {
     system->getWindowManager()->setActiveWindow(window);
-    window->bringTabletContextToFront();
   }
 
   return new GHOST_Event(system->getMilliSeconds(), type, window);
@@ -1152,6 +1291,31 @@ GHOST_TSuccess GHOST_SystemWin32::pushDragDropEvent(GHOST_TEventType eventType,
       system->getMilliSeconds(), eventType, draggedObjectType, window, mouseX, mouseY, data));
 }
 
+void GHOST_SystemWin32::setTabletAPI(GHOST_TTabletAPI api)
+{
+  GHOST_System::setTabletAPI(api);
+
+  /* If API is set to WinPointer (Windows Ink), unload Wintab so that trouble drivers don't disable
+   * Windows Ink. Load Wintab when API is Automatic because decision logic relies on knowing
+   * whether a Wintab device is present. */
+  const bool loadWintab = GHOST_kTabletWinPointer != api;
+  GHOST_WindowManager *wm = getWindowManager();
+
+  for (GHOST_IWindow *win : wm->getWindows()) {
+    GHOST_WindowWin32 *windowWin32 = (GHOST_WindowWin32 *)win;
+    if (loadWintab) {
+      windowWin32->loadWintab(GHOST_kWindowStateMinimized != windowWin32->getState());
+
+      if (windowWin32->usingTabletAPI(GHOST_kTabletWintab)) {
+        windowWin32->resetPointerPenInfo();
+      }
+    }
+    else {
+      windowWin32->closeWintab();
+    }
+  }
+}
+
 void GHOST_SystemWin32::processMinMaxInfo(MINMAXINFO *minmax)
 {
   minmax->ptMinTrackSize.x = 320;
@@ -1386,33 +1550,123 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
             case SC_KEYMENU:
               eventHandled = true;
               break;
-            case SC_RESTORE:
+            case SC_RESTORE: {
               ::ShowWindow(hwnd, SW_RESTORE);
               window->setState(window->getState());
+
+              GHOST_Wintab *wt = window->getWintab();
+              if (wt) {
+                wt->enable();
+              }
+
               eventHandled = true;
               break;
+            }
+            case SC_MAXIMIZE: {
+              GHOST_Wintab *wt = window->getWintab();
+              if (wt) {
+                wt->enable();
+              }
+              /* Don't report event as handled so that default handling occurs. */
+              break;
+            }
+            case SC_MINIMIZE: {
+              GHOST_Wintab *wt = window->getWintab();
+              if (wt) {
+                wt->disable();
+              }
+              /* Don't report event as handled so that default handling occurs. */
+              break;
+            }
           }
           break;
         ////////////////////////////////////////////////////////////////////////
         // Wintab events, processed
         ////////////////////////////////////////////////////////////////////////
-        case WT_PACKET:
-          window->processWin32TabletEvent(wParam, lParam);
+        case WT_CSRCHANGE: {
+          GHOST_Wintab *wt = window->getWintab();
+          if (wt) {
+            wt->updateCursorInfo();
+          }
+          eventHandled = true;
           break;
-        case WT_CSRCHANGE:
-        case WT_PROXIMITY:
-          window->processWin32TabletInitEvent();
+        }
+        case WT_PROXIMITY: {
+          GHOST_Wintab *wt = window->getWintab();
+          if (wt) {
+            bool inRange = LOWORD(lParam);
+            if (inRange) {
+              /* Some devices don't emit WT_CSRCHANGE events, so update cursor info here. */
+              wt->updateCursorInfo();
+            }
+            else {
+              wt->leaveRange();
+
+              /* Send mouse event to signal end of tablet tracking to operators. */
+              DWORD msgPos = ::GetMessagePos();
+              int x = GET_X_LPARAM(msgPos);
+              int y = GET_Y_LPARAM(msgPos);
+              event = new GHOST_EventCursor(system->getMilliSeconds(),
+                                            GHOST_kEventCursorMove,
+                                            window,
+                                            x,
+                                            y,
+                                            GHOST_TABLET_DATA_NONE);
+            }
+          }
+          eventHandled = true;
+          break;
+        }
+        case WT_INFOCHANGE: {
+          GHOST_Wintab *wt = window->getWintab();
+          if (wt) {
+            wt->processInfoChange(lParam);
+
+            if (window->usingTabletAPI(GHOST_kTabletWintab)) {
+              window->resetPointerPenInfo();
+            }
+          }
+          eventHandled = true;
+          break;
+        }
+        case WT_PACKET:
+          processWintabEvent(window);
+          eventHandled = true;
           break;
         ////////////////////////////////////////////////////////////////////////
         // Pointer events, processed
         ////////////////////////////////////////////////////////////////////////
-        case WM_POINTERENTER:
-        case WM_POINTERDOWN:
         case WM_POINTERUPDATE:
+        case WM_POINTERDOWN:
         case WM_POINTERUP:
-        case WM_POINTERLEAVE:
           processPointerEvent(msg, window, wParam, lParam, eventHandled);
           break;
+        case WM_POINTERLEAVE: {
+          GHOST_TUns32 pointerId = GET_POINTERID_WPARAM(wParam);
+          POINTER_INFO pointerInfo;
+          if (!GetPointerInfo(pointerId, &pointerInfo)) {
+            break;
+          }
+
+          /* Reset pointer pen info if pen device has left tracking range. */
+          if (pointerInfo.pointerType == PT_PEN && !IS_POINTER_INRANGE_WPARAM(wParam)) {
+            window->resetPointerPenInfo();
+
+            /* Send mouse event to signal end of tablet tracking to operators. */
+            DWORD msgPos = ::GetMessagePos();
+            int x = GET_X_LPARAM(msgPos);
+            int y = GET_Y_LPARAM(msgPos);
+            event = new GHOST_EventCursor(system->getMilliSeconds(),
+                                          GHOST_kEventCursorMove,
+                                          window,
+                                          x,
+                                          y,
+                                          GHOST_TABLET_DATA_NONE);
+
+            eventHandled = true;
+          }
+          break;
+        }
         ////////////////////////////////////////////////////////////////////////
         // Mouse events, processed
         ////////////////////////////////////////////////////////////////////////
@@ -1451,7 +1705,20 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
           }
           break;
         case WM_MOUSEMOVE:
+          if (!window->m_mousePresent) {
+            TRACKMOUSEEVENT tme = {sizeof(tme)};
+            tme.dwFlags = TME_LEAVE;
+            tme.hwndTrack = hwnd;
+            TrackMouseEvent(&tme);
+            window->m_mousePresent = true;
+            GHOST_Wintab *wt = window->getWintab();
+            if (wt) {
+              wt->gainFocus();
+            }
+          }
+
           event = processCursorEvent(window);
+
           break;
         case WM_MOUSEWHEEL: {
           /* The WM_MOUSEWHEEL message is sent to the focus window
@@ -1486,7 +1753,17 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
             window->loadCursor(true, GHOST_kStandardCursorDefault);
           }
           break;
-
+        case WM_MOUSELEAVE: {
+          window->m_mousePresent = false;
+          if (window->getTabletData().Active == GHOST_kTabletModeNone) {
+            processCursorEvent(window);
+          }
+          GHOST_Wintab *wt = window->getWintab();
+          if (wt) {
+            wt->loseFocus();
+          }
+          break;
+        }
         ////////////////////////////////////////////////////////////////////////
         // Mouse events, ignored
         ////////////////////////////////////////////////////////////////////////
@@ -1534,7 +1811,7 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
              * will not be dispatched to OUR active window if we minimize one of OUR windows. */
             if (LOWORD(wParam) == WA_INACTIVE)
               window->lostMouseCapture();
-            window->processWin32TabletActivateEvent(GET_WM_ACTIVATE_STATE(wParam, lParam));
+
             lResult = ::DefWindowProc(hwnd, msg, wParam, lParam);
             break;
           }
@@ -1576,6 +1853,8 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
           /* Let DefWindowProc handle it. */
           break;
         case WM_SIZING:
+          event = processWindowSizeEvent(window);
+          break;
         case WM_SIZE:
           /* The WM_SIZE message is sent to a window after its size has changed.
            * The WM_SIZE and WM_MOVE messages are not sent if an application handles the
@@ -1583,15 +1862,7 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
            * to perform any move or size change processing during the WM_WINDOWPOSCHANGED
            * message without calling DefWindowProc.
            */
-          /* we get first WM_SIZE before we fully init.
-           * So, do not dispatch before we continuously resizing. */
-          if (window->m_inLiveResize) {
-            system->pushEvent(processWindowEvent(GHOST_kEventWindowSize, window));
-            system->dispatchEvents();
-          }
-          else {
-            event = processWindowEvent(GHOST_kEventWindowSize, window);
-          }
+          event = processWindowSizeEvent(window);
           break;
         case WM_CAPTURECHANGED:
           window->lostMouseCapture();
@@ -1642,6 +1913,24 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
                          SWP_NOZORDER | SWP_NOACTIVATE);
           }
           break;
+        case WM_DISPLAYCHANGE: {
+          GHOST_Wintab *wt = window->getWintab();
+          if (wt) {
+            for (GHOST_IWindow *iter_win : system->getWindowManager()->getWindows()) {
+              GHOST_WindowWin32 *iter_win32win = (GHOST_WindowWin32 *)iter_win;
+              wt->remapCoordinates();
+            }
+          }
+          break;
+        }
+        case WM_KILLFOCUS:
+          /* The WM_KILLFOCUS message is sent to a window immediately before it loses the keyboard
+           * focus. We want to prevent this if a window is still active and it loses focus to
+           * nowhere. */
+          if (!wParam && hwnd == ::GetActiveWindow()) {
+            ::SetFocus(hwnd);
+          }
+          break;
         ////////////////////////////////////////////////////////////////////////
         // Window events, ignored
         ////////////////////////////////////////////////////////////////////////
@@ -1678,12 +1967,6 @@ LRESULT WINAPI GHOST_SystemWin32::s_wndProc(HWND hwnd, UINT msg, WPARAM wParam,
            * object associated with the window.
            */
           break;
-        case WM_KILLFOCUS:
-          /* The WM_KILLFOCUS message is sent to a window immediately before it loses the
-           * keyboard focus. We want to prevent this if a window is still active and it loses
-           * focus to nowhere. */
-          if (!wParam && hwnd == ::GetActiveWindow())
-            ::SetFocus(hwnd);
         case WM_SHOWWINDOW:
         /* The WM_SHOWWINDOW message is sent to a window when the window is
          * about to be hidden or shown. */

intern/ghost/intern/GHOST_SystemWin32.h

@@ -265,6 +265,16 @@ class GHOST_SystemWin32 : public GHOST_System {
                                           int mouseY,
                                           void *data);
 
+  /***************************************************************************************
+   ** Modify tablet API
+   ***************************************************************************************/
+
+  /**
+   * Set which tablet API to use.
+   * \param api: Enum indicating which API to use.
+   */
+  void setTabletAPI(GHOST_TTabletAPI api) override;
+
  protected:
   /**
    * Initializes the system.
@@ -308,6 +318,12 @@ class GHOST_SystemWin32 : public GHOST_System {
                                                GHOST_WindowWin32 *window,
                                                GHOST_TButtonMask mask);
 
+  /**
+   * Creates tablet events from Wintab events.
+   * \param window: The window receiving the event (the active window).
+   */
+  static void processWintabEvent(GHOST_WindowWin32 *window);
+
   /**
    * Creates tablet events from pointer events.
    * \param type: The type of pointer event.
@@ -351,6 +367,13 @@ class GHOST_SystemWin32 : public GHOST_System {
    */
   GHOST_TKey processSpecialKey(short vKey, short scanCode) const;
 
+  /**
+   * Creates a window size event.
+   * \param window: The window receiving the event (the active window).
+   * \return The event created.
+   */
+  static GHOST_Event *processWindowSizeEvent(GHOST_WindowWin32 *window);
+
   /**
    * Creates a window event.
    * \param type: The type of event to create.

intern/ghost/intern/GHOST_WindowWin32.cpp

@@ -21,8 +21,6 @@
  * \ingroup GHOST
  */
 
-#define _USE_MATH_DEFINES
-
 #include "GHOST_WindowWin32.h"
 #include "GHOST_ContextD3D.h"
 #include "GHOST_ContextNone.h"
@@ -72,7 +70,7 @@ GHOST_WindowWin32::GHOST_WindowWin32(GHOST_SystemWin32 *system,
                                      bool is_debug,
                                      bool dialog)
     : GHOST_Window(width, height, state, wantStereoVisual, false),
-      m_tabletInRange(false),
+      m_mousePresent(false),
       m_inLiveResize(false),
       m_system(system),
       m_hDC(0),
@@ -82,6 +80,8 @@ GHOST_WindowWin32::GHOST_WindowWin32(GHOST_SystemWin32 *system,
       m_nPressedButtons(0),
       m_customCursor(0),
       m_wantAlphaBackground(alphaBackground),
+      m_wintab(NULL),
+      m_lastPointerTabletData(GHOST_TABLET_DATA_NONE),
       m_normal_state(GHOST_kWindowStateNormal),
       m_user32(NULL),
       m_parentWindowHwnd(parentwindow ? parentwindow->m_hWnd : HWND_DESKTOP),
@@ -90,10 +90,6 @@ GHOST_WindowWin32::GHOST_WindowWin32(GHOST_SystemWin32 *system,
   wchar_t *title_16 = alloc_utf16_from_8((char *)title, 0);
   RECT win_rect = {left, top, (long)(left + width), (long)(top + height)};
 
-  // Initialize tablet variables
-  memset(&m_wintab, 0, sizeof(m_wintab));
-  m_tabletData = GHOST_TABLET_DATA_NONE;
-
   DWORD style = parentwindow ?
                     WS_POPUPWINDOW | WS_CAPTION | WS_MAXIMIZEBOX | WS_MINIMIZEBOX | WS_SIZEBOX :
                     WS_OVERLAPPEDWINDOW;
@@ -218,65 +214,10 @@ GHOST_WindowWin32::GHOST_WindowWin32(GHOST_SystemWin32 *system,
   }
 
   // Initialize Wintab
-  m_wintab.handle = ::LoadLibrary("Wintab32.dll");
-  if (m_wintab.handle && m_system->getTabletAPI() != GHOST_kTabletNative) {
-    // Get API functions
-    m_wintab.info = (GHOST_WIN32_WTInfo)::GetProcAddress(m_wintab.handle, "WTInfoA");
-    m_wintab.open = (GHOST_WIN32_WTOpen)::GetProcAddress(m_wintab.handle, "WTOpenA");
-    m_wintab.close = (GHOST_WIN32_WTClose)::GetProcAddress(m_wintab.handle, "WTClose");
-    m_wintab.packet = (GHOST_WIN32_WTPacket)::GetProcAddress(m_wintab.handle, "WTPacket");
-    m_wintab.enable = (GHOST_WIN32_WTEnable)::GetProcAddress(m_wintab.handle, "WTEnable");
-    m_wintab.overlap = (GHOST_WIN32_WTOverlap)::GetProcAddress(m_wintab.handle, "WTOverlap");
-
-    // Let's see if we can initialize tablet here.
-    // Check if WinTab available by getting system context info.
-    LOGCONTEXT lc = {0};
-    lc.lcOptions |= CXO_SYSTEM;
-    if (m_wintab.open && m_wintab.info && m_wintab.info(WTI_DEFSYSCTX, 0, &lc)) {
-      // Now init the tablet
-      /* The maximum tablet size, pressure and orientation (tilt) */
-      AXIS TabletX, TabletY, Pressure, Orientation[3];
-
-      // Open a Wintab context
-
-      // Open the context
-      lc.lcPktData = PACKETDATA;
-      lc.lcPktMode = PACKETMODE;
-      lc.lcOptions |= CXO_MESSAGES;
-      lc.lcMoveMask = PACKETDATA;
-
-      /* Set the entire tablet as active */
-      m_wintab.info(WTI_DEVICES, DVC_X, &TabletX);
-      m_wintab.info(WTI_DEVICES, DVC_Y, &TabletY);
-
-      /* get the max pressure, to divide into a float */
-      BOOL pressureSupport = m_wintab.info(WTI_DEVICES, DVC_NPRESSURE, &Pressure);
-      if (pressureSupport)
-        m_wintab.maxPressure = Pressure.axMax;
-      else
-        m_wintab.maxPressure = 0;
-
-      /* get the max tilt axes, to divide into floats */
-      BOOL tiltSupport = m_wintab.info(WTI_DEVICES, DVC_ORIENTATION, &Orientation);
-      if (tiltSupport) {
-        /* does the tablet support azimuth ([0]) and altitude ([1]) */
-        if (Orientation[0].axResolution && Orientation[1].axResolution) {
-          /* all this assumes the minimum is 0 */
-          m_wintab.maxAzimuth = Orientation[0].axMax;
-          m_wintab.maxAltitude = Orientation[1].axMax;
-        }
-        else { /* No so don't do tilt stuff. */
-          m_wintab.maxAzimuth = m_wintab.maxAltitude = 0;
-        }
-      }
-
-      // The Wintab spec says we must open the context disabled if we are using cursor masks.
-      m_wintab.tablet = m_wintab.open(m_hWnd, &lc, FALSE);
-      if (m_wintab.enable && m_wintab.tablet) {
-        m_wintab.enable(m_wintab.tablet, TRUE);
-      }
-    }
+  if (system->getTabletAPI() != GHOST_kTabletWinPointer) {
+    loadWintab(GHOST_kWindowStateMinimized != state);
   }
+
   CoCreateInstance(
       CLSID_TaskbarList, NULL, CLSCTX_INPROC_SERVER, IID_ITaskbarList3, (LPVOID *)&m_Bar);
 }
@@ -289,14 +230,7 @@ GHOST_WindowWin32::~GHOST_WindowWin32()
     m_Bar = NULL;
   }
 
-  if (m_wintab.handle) {
-    if (m_wintab.close && m_wintab.tablet) {
-      m_wintab.close(m_wintab.tablet);
-    }
-
-    FreeLibrary(m_wintab.handle);
-    memset(&m_wintab, 0, sizeof(m_wintab));
-  }
+  closeWintab();
 
   if (m_user32) {
     FreeLibrary(m_user32);
@@ -913,20 +847,16 @@ GHOST_TSuccess GHOST_WindowWin32::hasCursorShape(GHOST_TStandardCursor cursorSha
 GHOST_TSuccess GHOST_WindowWin32::getPointerInfo(
     std::vector<GHOST_PointerInfoWin32> &outPointerInfo, WPARAM wParam, LPARAM lParam)
 {
-  if (!useTabletAPI(GHOST_kTabletNative)) {
-    return GHOST_kFailure;
-  }
-
   GHOST_TInt32 pointerId = GET_POINTERID_WPARAM(wParam);
   GHOST_TInt32 isPrimary = IS_POINTER_PRIMARY_WPARAM(wParam);
   GHOST_SystemWin32 *system = (GHOST_SystemWin32 *)GHOST_System::getSystem();
-  GHOST_TUns32 outCount;
+  GHOST_TUns32 outCount = 0;
 
-  if (!(GetPointerInfoHistory(pointerId, &outCount, NULL))) {
+  if (!(GetPointerPenInfoHistory(pointerId, &outCount, NULL))) {
     return GHOST_kFailure;
   }
 
-  auto pointerPenInfo = std::vector<POINTER_PEN_INFO>(outCount);
+  std::vector<POINTER_PEN_INFO> pointerPenInfo(outCount);
   outPointerInfo.resize(outCount);
 
   if (!(GetPointerPenInfoHistory(pointerId, &outCount, pointerPenInfo.data()))) {
@@ -988,148 +918,77 @@ GHOST_TSuccess GHOST_WindowWin32::getPointerInfo(
     }
   }
 
+  if (!outPointerInfo.empty()) {
+    m_lastPointerTabletData = outPointerInfo.back().tabletData;
+  }
+
   return GHOST_kSuccess;
 }
 
-void GHOST_WindowWin32::processWin32TabletActivateEvent(WORD state)
+void GHOST_WindowWin32::resetPointerPenInfo()
 {
-  if (!useTabletAPI(GHOST_kTabletWintab)) {
-    return;
-  }
+  m_lastPointerTabletData = GHOST_TABLET_DATA_NONE;
+}
 
-  if (m_wintab.enable && m_wintab.tablet) {
-    m_wintab.enable(m_wintab.tablet, state);
+GHOST_Wintab *GHOST_WindowWin32::getWintab() const
+{
+  return m_wintab;
+}
 
-    if (m_wintab.overlap && state) {
-      m_wintab.overlap(m_wintab.tablet, TRUE);
+void GHOST_WindowWin32::loadWintab(bool enable)
+{
+  if (!m_wintab) {
+    if (m_wintab = GHOST_Wintab::loadWintab(m_hWnd)) {
+      if (enable) {
+        m_wintab->enable();
+
+        /* Focus Wintab if cursor is inside this window. This ensures Wintab is enabled when the
+         * tablet is used to change the Tablet API. */
+        GHOST_TInt32 x, y;
+        if (m_system->getCursorPosition(x, y)) {
+          GHOST_Rect rect;
+          getClientBounds(rect);
+
+          if (rect.isInside(x, y)) {
+            m_wintab->gainFocus();
+          }
+        }
+      }
     }
   }
 }
 
-bool GHOST_WindowWin32::useTabletAPI(GHOST_TTabletAPI api) const
+void GHOST_WindowWin32::closeWintab()
+{
+  delete m_wintab;
+  m_wintab = NULL;
+}
+
+bool GHOST_WindowWin32::usingTabletAPI(GHOST_TTabletAPI api) const
 {
   if (m_system->getTabletAPI() == api) {
     return true;
   }
   else if (m_system->getTabletAPI() == GHOST_kTabletAutomatic) {
-    if (m_wintab.tablet)
+    if (m_wintab && m_wintab->devicesPresent()) {
       return api == GHOST_kTabletWintab;
-    else
-      return api == GHOST_kTabletNative;
+    }
+    else {
+      return api == GHOST_kTabletWinPointer;
+    }
   }
   else {
     return false;
   }
 }
 
-void GHOST_WindowWin32::processWin32TabletInitEvent()
+GHOST_TabletData GHOST_WindowWin32::getTabletData()
 {
-  if (!useTabletAPI(GHOST_kTabletWintab)) {
-    return;
+  if (usingTabletAPI(GHOST_kTabletWintab)) {
+    return m_wintab ? m_wintab->getLastTabletData() : GHOST_TABLET_DATA_NONE;
   }
-
-  // Let's see if we can initialize tablet here
-  if (m_wintab.info && m_wintab.tablet) {
-    AXIS Pressure, Orientation[3]; /* The maximum tablet size */
-
-    BOOL pressureSupport = m_wintab.info(WTI_DEVICES, DVC_NPRESSURE, &Pressure);
-    if (pressureSupport)
-      m_wintab.maxPressure = Pressure.axMax;
-    else
-      m_wintab.maxPressure = 0;
-
-    BOOL tiltSupport = m_wintab.info(WTI_DEVICES, DVC_ORIENTATION, &Orientation);
-    if (tiltSupport) {
-      /* does the tablet support azimuth ([0]) and altitude ([1]) */
-      if (Orientation[0].axResolution && Orientation[1].axResolution) {
-        m_wintab.maxAzimuth = Orientation[0].axMax;
-        m_wintab.maxAltitude = Orientation[1].axMax;
-      }
-      else { /* No so don't do tilt stuff. */
-        m_wintab.maxAzimuth = m_wintab.maxAltitude = 0;
-      }
-    }
-  }
-
-  m_tabletData.Active = GHOST_kTabletModeNone;
-}
-
-void GHOST_WindowWin32::processWin32TabletEvent(WPARAM wParam, LPARAM lParam)
-{
-  if (!useTabletAPI(GHOST_kTabletWintab)) {
-    return;
-  }
-
-  if (m_wintab.packet && m_wintab.tablet) {
-    PACKET pkt;
-    if (m_wintab.packet((HCTX)lParam, wParam, &pkt)) {
-      switch (pkt.pkCursor % 3) { /* % 3 for multiple devices ("DualTrack") */
-        case 0:
-          m_tabletData.Active = GHOST_kTabletModeNone; /* puck - not yet supported */
-          break;
-        case 1:
-          m_tabletData.Active = GHOST_kTabletModeStylus; /* stylus */
-          break;
-        case 2:
-          m_tabletData.Active = GHOST_kTabletModeEraser; /* eraser */
-          break;
-      }
-
-      if (m_wintab.maxPressure > 0) {
-        m_tabletData.Pressure = (float)pkt.pkNormalPressure / (float)m_wintab.maxPressure;
-      }
-      else {
-        m_tabletData.Pressure = 1.0f;
-      }
-
-      if ((m_wintab.maxAzimuth > 0) && (m_wintab.maxAltitude > 0)) {
-        ORIENTATION ort = pkt.pkOrientation;
-        float vecLen;
-        float altRad, azmRad; /* in radians */
-
-        /*
-         * from the wintab spec:
-         * orAzimuth    Specifies the clockwise rotation of the
-         * cursor about the z axis through a full circular range.
-         *
-         * orAltitude   Specifies the angle with the x-y plane
-         * through a signed, semicircular range.  Positive values
-         * specify an angle upward toward the positive z axis;
-         * negative values specify an angle downward toward the negative z axis.
-         *
-         * wintab.h defines .orAltitude as a UINT but documents .orAltitude
-         * as positive for upward angles and negative for downward angles.
-         * WACOM uses negative altitude values to show that the pen is inverted;
-         * therefore we cast .orAltitude as an (int) and then use the absolute value.
-         */
-
-        /* convert raw fixed point data to radians */
-        altRad = (float)((fabs((float)ort.orAltitude) / (float)m_wintab.maxAltitude) * M_PI / 2.0);
-        azmRad = (float)(((float)ort.orAzimuth / (float)m_wintab.maxAzimuth) * M_PI * 2.0);
-
-        /* find length of the stylus' projected vector on the XY plane */
-        vecLen = cos(altRad);
-
-        /* from there calculate X and Y components based on azimuth */
-        m_tabletData.Xtilt = sin(azmRad) * vecLen;
-        m_tabletData.Ytilt = (float)(sin(M_PI / 2.0 - azmRad) * vecLen);
-      }
-      else {
-        m_tabletData.Xtilt = 0.0f;
-        m_tabletData.Ytilt = 0.0f;
-      }
-    }
-  }
-}
-
-void GHOST_WindowWin32::bringTabletContextToFront()
-{
-  if (!useTabletAPI(GHOST_kTabletWintab)) {
-    return;
-  }
-
-  if (m_wintab.overlap && m_wintab.tablet) {
-    m_wintab.overlap(m_wintab.tablet, TRUE);
+  else {
+    return m_lastPointerTabletData;
   }
 }
 

intern/ghost/intern/GHOST_WindowWin32.h

@@ -30,29 +30,16 @@
 
 #include "GHOST_TaskbarWin32.h"
 #include "GHOST_Window.h"
+#include "GHOST_Wintab.h"
 #ifdef WITH_INPUT_IME
 #  include "GHOST_ImeWin32.h"
 #endif
 
 #include <vector>
 
-#include <wintab.h>
-// PACKETDATA and PACKETMODE modify structs in pktdef.h, so make sure they come first
-#define PACKETDATA (PK_BUTTONS | PK_NORMAL_PRESSURE | PK_ORIENTATION | PK_CURSOR)
-#define PACKETMODE PK_BUTTONS
-#include <pktdef.h>
-
 class GHOST_SystemWin32;
 class GHOST_DropTargetWin32;
 
-// typedefs for WinTab functions to allow dynamic loading
-typedef UINT(API *GHOST_WIN32_WTInfo)(UINT, UINT, LPVOID);
-typedef HCTX(API *GHOST_WIN32_WTOpen)(HWND, LPLOGCONTEXTA, BOOL);
-typedef BOOL(API *GHOST_WIN32_WTClose)(HCTX);
-typedef BOOL(API *GHOST_WIN32_WTPacket)(HCTX, UINT, LPVOID);
-typedef BOOL(API *GHOST_WIN32_WTEnable)(HCTX, BOOL);
-typedef BOOL(API *GHOST_WIN32_WTOverlap)(HCTX, BOOL);
-
 // typedefs for user32 functions to allow dynamic loading of Windows 10 DPI scaling functions
 typedef UINT(API *GHOST_WIN32_GetDpiForWindow)(HWND);
 
@@ -62,7 +49,6 @@ struct GHOST_PointerInfoWin32 {
   GHOST_TButtonMask buttonMask;
   POINT pixelLocation;
   GHOST_TUns64 time;
-
   GHOST_TabletData tabletData;
 };
 
@@ -256,16 +242,11 @@ class GHOST_WindowWin32 : public GHOST_Window {
   HCURSOR getStandardCursor(GHOST_TStandardCursor shape) const;
   void loadCursor(bool visible, GHOST_TStandardCursor cursorShape) const;
 
-  const GHOST_TabletData &getTabletData()
-  {
-    return m_tabletData;
-  }
-
   /**
    * Query whether given tablet API should be used.
    * \param api: Tablet API to test.
    */
-  bool useTabletAPI(GHOST_TTabletAPI api) const;
+  bool usingTabletAPI(GHOST_TTabletAPI api) const;
 
   /**
    * Translate WM_POINTER events into GHOST_PointerInfoWin32 structs.
@@ -278,10 +259,34 @@ class GHOST_WindowWin32 : public GHOST_Window {
                                 WPARAM wParam,
                                 LPARAM lParam);
 
-  void processWin32TabletActivateEvent(WORD state);
-  void processWin32TabletInitEvent();
-  void processWin32TabletEvent(WPARAM wParam, LPARAM lParam);
-  void bringTabletContextToFront();
+  /**
+   * Resets pointer pen tablet state.
+   */
+  void resetPointerPenInfo();
+
+  /**
+   * Retrieves pointer to Wintab if Wintab is the set Tablet API.
+   * \return Pointer to Wintab member.
+   */
+  GHOST_Wintab *getWintab() const;
+
+  /**
+   * Loads Wintab context for the window.
+   * \param enable: True if Wintab should be enabled after loading. Wintab should not be enabled if
+   * the window is minimzed.
+   */
+  void loadWintab(bool enable);
+
+  /**
+   * Closes Wintab for the window.
+   */
+  void closeWintab();
+
+  /**
+   * Get the most recent Windows Pointer tablet data.
+   * \return Most recent pointer tablet data.
+   */
+  GHOST_TabletData getTabletData();
 
   GHOST_TSuccess beginFullScreen() const
   {
@@ -295,10 +300,10 @@ class GHOST_WindowWin32 : public GHOST_Window {
 
   GHOST_TUns16 getDPIHint() override;
 
-  /** Whether a tablet stylus is being tracked. */
-  bool m_tabletInRange;
+  /** True if the mouse is either over or captured by the window. */
+  bool m_mousePresent;
 
-  /** if the window currently resizing */
+  /** True if the window currently resizing. */
   bool m_inLiveResize;
 
 #ifdef WITH_INPUT_IME
@@ -382,27 +387,11 @@ class GHOST_WindowWin32 : public GHOST_Window {
   static const wchar_t *s_windowClassName;
   static const int s_maxTitleLength;
 
-  /** Tablet data for GHOST */
-  GHOST_TabletData m_tabletData;
+  /** Pointer to Wintab manager if Wintab is loaded. */
+  GHOST_Wintab *m_wintab;
 
-  /* Wintab API */
-  struct {
-    /** `WinTab.dll` handle. */
-    HMODULE handle = NULL;
-
-    /** API functions */
-    GHOST_WIN32_WTInfo info;
-    GHOST_WIN32_WTOpen open;
-    GHOST_WIN32_WTClose close;
-    GHOST_WIN32_WTPacket packet;
-    GHOST_WIN32_WTEnable enable;
-    GHOST_WIN32_WTOverlap overlap;
-
-    /** Stores the Tablet context if detected Tablet features using `WinTab.dll` */
-    HCTX tablet;
-    LONG maxPressure;
-    LONG maxAzimuth, maxAltitude;
-  } m_wintab;
+  /** Most recent tablet data. */
+  GHOST_TabletData m_lastPointerTabletData;
 
   GHOST_TWindowState m_normal_state;
 

intern/ghost/intern/GHOST_Wintab.cpp

@@ -0,0 +1,491 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup GHOST
+ */
+
+#define _USE_MATH_DEFINES
+
+#include "GHOST_Wintab.h"
+
+GHOST_Wintab *GHOST_Wintab::loadWintab(HWND hwnd)
+{
+  /* Load Wintab library if available. */
+
+  auto handle = unique_hmodule(::LoadLibrary("Wintab32.dll"), &::FreeLibrary);
+  if (!handle) {
+    return nullptr;
+  }
+
+  /* Get Wintab functions. */
+
+  auto info = (GHOST_WIN32_WTInfo)::GetProcAddress(handle.get(), "WTInfoA");
+  if (!info) {
+    return nullptr;
+  }
+
+  auto open = (GHOST_WIN32_WTOpen)::GetProcAddress(handle.get(), "WTOpenA");
+  if (!open) {
+    return nullptr;
+  }
+
+  auto get = (GHOST_WIN32_WTGet)::GetProcAddress(handle.get(), "WTGetA");
+  if (!get) {
+    return nullptr;
+  }
+
+  auto set = (GHOST_WIN32_WTSet)::GetProcAddress(handle.get(), "WTSetA");
+  if (!set) {
+    return nullptr;
+  }
+
+  auto close = (GHOST_WIN32_WTClose)::GetProcAddress(handle.get(), "WTClose");
+  if (!close) {
+    return nullptr;
+  }
+
+  auto packetsGet = (GHOST_WIN32_WTPacketsGet)::GetProcAddress(handle.get(), "WTPacketsGet");
+  if (!packetsGet) {
+    return nullptr;
+  }
+
+  auto queueSizeGet = (GHOST_WIN32_WTQueueSizeGet)::GetProcAddress(handle.get(), "WTQueueSizeGet");
+  if (!queueSizeGet) {
+    return nullptr;
+  }
+
+  auto queueSizeSet = (GHOST_WIN32_WTQueueSizeSet)::GetProcAddress(handle.get(), "WTQueueSizeSet");
+  if (!queueSizeSet) {
+    return nullptr;
+  }
+
+  auto enable = (GHOST_WIN32_WTEnable)::GetProcAddress(handle.get(), "WTEnable");
+  if (!enable) {
+    return nullptr;
+  }
+
+  auto overlap = (GHOST_WIN32_WTOverlap)::GetProcAddress(handle.get(), "WTOverlap");
+  if (!overlap) {
+    return nullptr;
+  }
+
+  /* Build Wintab context. */
+
+  LOGCONTEXT lc = {0};
+  if (!info(WTI_DEFSYSCTX, 0, &lc)) {
+    return nullptr;
+  }
+
+  Coord tablet, system;
+  extractCoordinates(lc, tablet, system);
+  modifyContext(lc);
+
+  /* The Wintab spec says we must open the context disabled if we are using cursor masks. */
+  auto hctx = unique_hctx(open(hwnd, &lc, FALSE), close);
+  if (!hctx) {
+    return nullptr;
+  }
+
+  /* Wintab provides no way to determine the maximum queue size aside from checking if attempts
+   * to change the queue size are successful. */
+  const int maxQueue = 500;
+  int queueSize = queueSizeGet(hctx.get());
+
+  while (queueSize < maxQueue) {
+    int testSize = min(queueSize + 16, maxQueue);
+    if (queueSizeSet(hctx.get(), testSize)) {
+      queueSize = testSize;
+    }
+    else {
+      /* From Windows Wintab Documentation for WTQueueSizeSet:
+       * "If the return value is zero, the context has no queue because the function deletes the
+       * original queue before attempting to create a new one. The application must continue
+       * calling the function with a smaller queue size until the function returns a non - zero
+       * value."
+       *
+       * In our case we start with a known valid queue size and in the event of failure roll
+       * back to the last valid queue size. The Wintab spec dates back to 16 bit Windows, thus
+       * assumes memory recently deallocated may not be available, which is no longer a practical
+       * concern. */
+      if (!queueSizeSet(hctx.get(), queueSize)) {
+        /* If a previously valid queue size is no longer valid, there is likely something wrong in
+         * the Wintab implementation and we should not use it. */
+        return nullptr;
+      }
+      break;
+    }
+  }
+
+  return new GHOST_Wintab(hwnd,
+                          std::move(handle),
+                          info,
+                          get,
+                          set,
+                          packetsGet,
+                          enable,
+                          overlap,
+                          std::move(hctx),
+                          tablet,
+                          system,
+                          queueSize);
+}
+
+void GHOST_Wintab::modifyContext(LOGCONTEXT &lc)
+{
+  lc.lcPktData = PACKETDATA;
+  lc.lcPktMode = PACKETMODE;
+  lc.lcMoveMask = PACKETDATA;
+  lc.lcOptions |= CXO_CSRMESSAGES | CXO_MESSAGES;
+
+  /* Tablet scaling is handled manually because some drivers don't handle HIDPI or multi-display
+   * correctly; reset tablet scale factors to unscaled tablet coodinates. */
+  lc.lcOutOrgX = lc.lcInOrgX;
+  lc.lcOutOrgY = lc.lcInOrgY;
+  lc.lcOutExtX = lc.lcInExtX;
+  lc.lcOutExtY = lc.lcInExtY;
+}
+
+void GHOST_Wintab::extractCoordinates(LOGCONTEXT &lc, Coord &tablet, Coord &system)
+{
+  tablet.x.org = lc.lcInOrgX;
+  tablet.x.ext = lc.lcInExtX;
+  tablet.y.org = lc.lcInOrgY;
+  tablet.y.ext = lc.lcInExtY;
+
+  system.x.org = lc.lcSysOrgX;
+  system.x.ext = lc.lcSysExtX;
+  system.y.org = lc.lcSysOrgY;
+  /* Wintab maps y origin to the tablet's bottom; invert y to match Windows y origin mapping to the
+   * screen top. */
+  system.y.ext = -lc.lcSysExtY;
+}
+
+GHOST_Wintab::GHOST_Wintab(HWND hwnd,
+                           unique_hmodule handle,
+                           GHOST_WIN32_WTInfo info,
+                           GHOST_WIN32_WTGet get,
+                           GHOST_WIN32_WTSet set,
+                           GHOST_WIN32_WTPacketsGet packetsGet,
+                           GHOST_WIN32_WTEnable enable,
+                           GHOST_WIN32_WTOverlap overlap,
+                           unique_hctx hctx,
+                           Coord tablet,
+                           Coord system,
+                           int queueSize)
+    : m_handle{std::move(handle)},
+      m_fpInfo{info},
+      m_fpGet{get},
+      m_fpSet{set},
+      m_fpPacketsGet{packetsGet},
+      m_fpEnable{enable},
+      m_fpOverlap{overlap},
+      m_context{std::move(hctx)},
+      m_tabletCoord{tablet},
+      m_systemCoord{system},
+      m_pkts{queueSize}
+{
+  m_fpInfo(WTI_INTERFACE, IFC_NDEVICES, &m_numDevices);
+  updateCursorInfo();
+}
+
+void GHOST_Wintab::enable()
+{
+  m_fpEnable(m_context.get(), true);
+  m_enabled = true;
+}
+
+void GHOST_Wintab::disable()
+{
+  if (m_focused) {
+    loseFocus();
+  }
+  m_fpEnable(m_context.get(), false);
+  m_enabled = false;
+}
+
+void GHOST_Wintab::gainFocus()
+{
+  m_fpOverlap(m_context.get(), true);
+  m_focused = true;
+}
+
+void GHOST_Wintab::loseFocus()
+{
+  if (m_lastTabletData.Active != GHOST_kTabletModeNone) {
+    leaveRange();
+  }
+
+  /* Mouse mode of tablet or display layout may change when Wintab or Window is inactive. Don't
+   * trust for mouse movement until re-verified. */
+  m_coordTrusted = false;
+
+  m_fpOverlap(m_context.get(), false);
+  m_focused = false;
+}
+
+void GHOST_Wintab::leaveRange()
+{
+  /* Button state can't be tracked while out of range, reset it. */
+  m_buttons = 0;
+  /* Set to none to indicate tablet is inactive. */
+  m_lastTabletData = GHOST_TABLET_DATA_NONE;
+  /* Clear the packet queue. */
+  m_fpPacketsGet(m_context.get(), m_pkts.size(), m_pkts.data());
+}
+
+void GHOST_Wintab::remapCoordinates()
+{
+  LOGCONTEXT lc = {0};
+
+  if (m_fpInfo(WTI_DEFSYSCTX, 0, &lc)) {
+    extractCoordinates(lc, m_tabletCoord, m_systemCoord);
+    modifyContext(lc);
+
+    m_fpSet(m_context.get(), &lc);
+  }
+}
+
+void GHOST_Wintab::updateCursorInfo()
+{
+  AXIS Pressure, Orientation[3];
+
+  BOOL pressureSupport = m_fpInfo(WTI_DEVICES, DVC_NPRESSURE, &Pressure);
+  m_maxPressure = pressureSupport ? Pressure.axMax : 0;
+
+  BOOL tiltSupport = m_fpInfo(WTI_DEVICES, DVC_ORIENTATION, &Orientation);
+  /* Check if tablet supports azimuth [0] and altitude [1], encoded in axResolution. */
+  if (tiltSupport && Orientation[0].axResolution && Orientation[1].axResolution) {
+    m_maxAzimuth = Orientation[0].axMax;
+    m_maxAltitude = Orientation[1].axMax;
+  }
+  else {
+    m_maxAzimuth = m_maxAltitude = 0;
+  }
+}
+
+void GHOST_Wintab::processInfoChange(LPARAM lParam)
+{
+  /* Update number of connected Wintab digitizers. */
+  if (LOWORD(lParam) == WTI_INTERFACE && HIWORD(lParam) == IFC_NDEVICES) {
+    m_fpInfo(WTI_INTERFACE, IFC_NDEVICES, &m_numDevices);
+  }
+}
+
+bool GHOST_Wintab::devicesPresent()
+{
+  return m_numDevices > 0;
+}
+
+GHOST_TabletData GHOST_Wintab::getLastTabletData()
+{
+  return m_lastTabletData;
+}
+
+void GHOST_Wintab::getInput(std::vector<GHOST_WintabInfoWin32> &outWintabInfo)
+{
+  const int numPackets = m_fpPacketsGet(m_context.get(), m_pkts.size(), m_pkts.data());
+  outWintabInfo.resize(numPackets);
+  size_t outExtent = 0;
+
+  for (int i = 0; i < numPackets; i++) {
+    PACKET pkt = m_pkts[i];
+    GHOST_WintabInfoWin32 &out = outWintabInfo[i + outExtent];
+
+    out.tabletData = GHOST_TABLET_DATA_NONE;
+    /* % 3 for multiple devices ("DualTrack"). */
+    switch (pkt.pkCursor % 3) {
+      case 0:
+        /* Puck - processed as mouse. */
+        out.tabletData.Active = GHOST_kTabletModeNone;
+        break;
+      case 1:
+        out.tabletData.Active = GHOST_kTabletModeStylus;
+        break;
+      case 2:
+        out.tabletData.Active = GHOST_kTabletModeEraser;
+        break;
+    }
+
+    out.x = pkt.pkX;
+    out.y = pkt.pkY;
+
+    if (m_maxPressure > 0) {
+      out.tabletData.Pressure = (float)pkt.pkNormalPressure / (float)m_maxPressure;
+    }
+
+    if ((m_maxAzimuth > 0) && (m_maxAltitude > 0)) {
+      ORIENTATION ort = pkt.pkOrientation;
+      float vecLen;
+      float altRad, azmRad; /* In radians. */
+
+      /*
+       * From the wintab spec:
+       * orAzimuth: Specifies the clockwise rotation of the cursor about the z axis through a
+       * full circular range.
+       * orAltitude: Specifies the angle with the x-y plane through a signed, semicircular range.
+       * Positive values specify an angle upward toward the positive z axis; negative values
+       * specify an angle downward toward the negative z axis.
+       *
+       * wintab.h defines orAltitude as a UINT but documents orAltitude as positive for upward
+       * angles and negative for downward angles. WACOM uses negative altitude values to show that
+       * the pen is inverted; therefore we cast orAltitude as an (int) and then use the absolute
+       * value.
+       */
+
+      /* Convert raw fixed point data to radians. */
+      altRad = (float)((fabs((float)ort.orAltitude) / (float)m_maxAltitude) * M_PI / 2.0);
+      azmRad = (float)(((float)ort.orAzimuth / (float)m_maxAzimuth) * M_PI * 2.0);
+
+      /* Find length of the stylus' projected vector on the XY plane. */
+      vecLen = cos(altRad);
+
+      /* From there calculate X and Y components based on azimuth. */
+      out.tabletData.Xtilt = sin(azmRad) * vecLen;
+      out.tabletData.Ytilt = (float)(sin(M_PI / 2.0 - azmRad) * vecLen);
+    }
+
+    out.time = pkt.pkTime;
+
+    /* Some Wintab libraries don't handle relative button input, so we track button presses
+     * manually. */
+    out.button = GHOST_kButtonMaskNone;
+    out.type = GHOST_kEventCursorMove;
+
+    DWORD buttonsChanged = m_buttons ^ pkt.pkButtons;
+    WORD buttonIndex = 0;
+    GHOST_WintabInfoWin32 buttonRef = out;
+    int buttons = 0;
+
+    while (buttonsChanged) {
+      if (buttonsChanged & 1) {
+        /* Find the index for the changed button from the button map. */
+        GHOST_TButtonMask button = mapWintabToGhostButton(pkt.pkCursor, buttonIndex);
+
+        if (button != GHOST_kButtonMaskNone) {
+          /* Extend output if multiple buttons are pressed. We don't extend input until we confirm
+           * a Wintab buttons maps to a system button. */
+          if (buttons > 0) {
+            outWintabInfo.resize(outWintabInfo.size() + 1);
+            outExtent++;
+            GHOST_WintabInfoWin32 &out = outWintabInfo[i + outExtent];
+            out = buttonRef;
+          }
+          buttons++;
+
+          out.button = button;
+          if (buttonsChanged & pkt.pkButtons) {
+            out.type = GHOST_kEventButtonDown;
+          }
+          else {
+            out.type = GHOST_kEventButtonUp;
+          }
+        }
+
+        m_buttons ^= 1 << buttonIndex;
+      }
+
+      buttonsChanged >>= 1;
+      buttonIndex++;
+    }
+  }
+
+  if (!outWintabInfo.empty()) {
+    m_lastTabletData = outWintabInfo.back().tabletData;
+  }
+}
+
+GHOST_TButtonMask GHOST_Wintab::mapWintabToGhostButton(UINT cursor, WORD physicalButton)
+{
+  const WORD numButtons = 32;
+  BYTE logicalButtons[numButtons] = {0};
+  BYTE systemButtons[numButtons] = {0};
+
+  if (!m_fpInfo(WTI_CURSORS + cursor, CSR_BUTTONMAP, &logicalButtons) ||
+      !m_fpInfo(WTI_CURSORS + cursor, CSR_SYSBTNMAP, &systemButtons)) {
+    return GHOST_kButtonMaskNone;
+  }
+
+  if (physicalButton >= numButtons) {
+    return GHOST_kButtonMaskNone;
+  }
+
+  BYTE lb = logicalButtons[physicalButton];
+
+  if (lb >= numButtons) {
+    return GHOST_kButtonMaskNone;
+  }
+
+  switch (systemButtons[lb]) {
+    case SBN_LCLICK:
+      return GHOST_kButtonMaskLeft;
+    case SBN_RCLICK:
+      return GHOST_kButtonMaskRight;
+    case SBN_MCLICK:
+      return GHOST_kButtonMaskMiddle;
+    default:
+      return GHOST_kButtonMaskNone;
+  }
+}
+
+void GHOST_Wintab::mapWintabToSysCoordinates(int x_in, int y_in, int &x_out, int &y_out)
+{
+  /* Maps from range [in.org, in.org + abs(in.ext)] to [out.org, out.org + abs(out.ext)], in
+   * reverse if in.ext and out.ext have differing sign. */
+  auto remap = [](int inPoint, Range in, Range out) -> int {
+    int absInExt = abs(in.ext);
+    int absOutExt = abs(out.ext);
+
+    /* Translate input from range [in.org, in.org + absInExt] to [0, absInExt] */
+    int inMagnitude = inPoint - in.org;
+
+    /* If signs of extents differ, reverse input over range. */
+    if ((in.ext < 0) != (out.ext < 0)) {
+      inMagnitude = absInExt - inMagnitude;
+    }
+
+    /* Scale from [0, absInExt] to [0, absOutExt]. */
+    int outMagnitude = inMagnitude * absOutExt / absInExt;
+
+    /* Translate from range [0, absOutExt] to [out.org, out.org + absOutExt]. */
+    int outPoint = outMagnitude + out.org;
+
+    return outPoint;
+  };
+
+  x_out = remap(x_in, m_tabletCoord.x, m_systemCoord.x);
+  y_out = remap(y_in, m_tabletCoord.y, m_systemCoord.y);
+}
+
+bool GHOST_Wintab::trustCoordinates()
+{
+  return m_coordTrusted;
+}
+
+bool GHOST_Wintab::testCoordinates(int sysX, int sysY, int wtX, int wtY)
+{
+  mapWintabToSysCoordinates(wtX, wtY, wtX, wtY);
+
+  /* Allow off by one pixel tolerance in case of rounding error. */
+  if (abs(sysX - wtX) <= 1 && abs(sysY - wtY) <= 1) {
+    m_coordTrusted = true;
+    return true;
+  }
+  else {
+    m_coordTrusted = false;
+    return false;
+  }
+}

intern/ghost/intern/GHOST_Wintab.h

@@ -0,0 +1,250 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup GHOST
+ * Declaration of GHOST_WintabWin32 class.
+ */
+
+/* Wacom's Wintab documentation is periodically offline, moved, and increasingly hidden away. You
+ * can find a (painstakingly) archived copy of the documentation at
+ * https://web.archive.org/web/20201122230125/https://developer-docs-legacy.wacom.com/display/DevDocs/Windows+Wintab+Documentation
+ */
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include <wtypes.h>
+
+#include "GHOST_Types.h"
+
+#include <wintab.h>
+/* PACKETDATA and PACKETMODE modify structs in pktdef.h, so make sure they come first. */
+#define PACKETDATA \
+  (PK_BUTTONS | PK_NORMAL_PRESSURE | PK_ORIENTATION | PK_CURSOR | PK_X | PK_Y | PK_TIME)
+#define PACKETMODE 0
+#include <pktdef.h>
+
+/* Typedefs for Wintab functions to allow dynamic loading. */
+typedef UINT(API *GHOST_WIN32_WTInfo)(UINT, UINT, LPVOID);
+typedef BOOL(API *GHOST_WIN32_WTGet)(HCTX, LPLOGCONTEXTA);
+typedef BOOL(API *GHOST_WIN32_WTSet)(HCTX, LPLOGCONTEXTA);
+typedef HCTX(API *GHOST_WIN32_WTOpen)(HWND, LPLOGCONTEXTA, BOOL);
+typedef BOOL(API *GHOST_WIN32_WTClose)(HCTX);
+typedef int(API *GHOST_WIN32_WTPacketsGet)(HCTX, int, LPVOID);
+typedef int(API *GHOST_WIN32_WTQueueSizeGet)(HCTX);
+typedef BOOL(API *GHOST_WIN32_WTQueueSizeSet)(HCTX, int);
+typedef BOOL(API *GHOST_WIN32_WTEnable)(HCTX, BOOL);
+typedef BOOL(API *GHOST_WIN32_WTOverlap)(HCTX, BOOL);
+
+/* Typedefs for Wintab and Windows resource management. */
+typedef std::unique_ptr<std::remove_pointer_t<HMODULE>, decltype(&::FreeLibrary)> unique_hmodule;
+typedef std::unique_ptr<std::remove_pointer_t<HCTX>, GHOST_WIN32_WTClose> unique_hctx;
+
+struct GHOST_WintabInfoWin32 {
+  GHOST_TInt32 x, y;
+  GHOST_TEventType type;
+  GHOST_TButtonMask button;
+  GHOST_TUns64 time;
+  GHOST_TabletData tabletData;
+};
+
+class GHOST_Wintab {
+ public:
+  /**
+   * Loads Wintab if available.
+   * \param hwnd: Window to attach Wintab context to.
+   */
+  static GHOST_Wintab *loadWintab(HWND hwnd);
+
+  /**
+   * Enables Wintab context.
+   */
+  void enable();
+
+  /**
+   * Disables the Wintab context and unwinds Wintab state.
+   */
+  void disable();
+
+  /**
+   * Brings Wintab context to the top of the overlap order.
+   */
+  void gainFocus();
+
+  /**
+   * Puts Wintab context at bottom of overlap order and unwinds Wintab state.
+   */
+  void loseFocus();
+
+  /**
+   * Clean up when Wintab leaves tracking range.
+   */
+  void leaveRange();
+
+  /**
+   * Handle Wintab coordinate changes when DisplayChange events occur.
+   */
+  void remapCoordinates();
+
+  /**
+   * Maps Wintab to Win32 display coordinates.
+   * \param x_in: The tablet x coordinate.
+   * \param y_in: The tablet y coordinate.
+   * \param x_out: Output for the Win32 mapped x coordinate.
+   * \param y_out: Output for the Win32 mapped y coordiante.
+   */
+  void mapWintabToSysCoordinates(int x_in, int y_in, int &x_out, int &y_out);
+
+  /**
+   * Updates cached Wintab properties for current cursor.
+   */
+  void updateCursorInfo();
+
+  /**
+   * Handle Wintab info changes such as change in number of connected tablets.
+   * \param lParam: LPARAM of the event.
+   */
+  void processInfoChange(LPARAM lParam);
+
+  /**
+   * Whether Wintab devices are present.
+   * \return True if Wintab devices are present.
+   */
+  bool devicesPresent();
+
+  /**
+   * Translate Wintab packets into GHOST_WintabInfoWin32 structs.
+   * \param outWintabInfo: Storage to return resulting GHOST_WintabInfoWin32 data.
+   */
+  void getInput(std::vector<GHOST_WintabInfoWin32> &outWintabInfo);
+
+  /**
+   * Whether Wintab coordinates should be trusted.
+   * \return True if Wintab coordinates should be trusted.
+   */
+  bool trustCoordinates();
+
+  /**
+   * Tests whether Wintab coordinates can be trusted by comparing Win32 and Wintab reported curser
+   * position.
+   * \param sysX: System cursor x position.
+   * \param sysY: System cursor y position.
+   * \param wtX: Wintab cursor x position.
+   * \param wtY: Wintab cursor y position.
+   * \return True if Win32 and Wintab cursor positions match within tolerance.
+   *
+   * Note: Only test coordiantes on button press, not release. This prevents issues when async
+   * mismatch causes mouse movement to replay and snap back, which is only an issue while drawing.
+   */
+  bool testCoordinates(int sysX, int sysY, int wtX, int wtY);
+
+  /**
+   * Retrieve the most recent tablet data, or none if pen is not in range.
+   * \return Most recent tablet data, or none if pen is not in range.
+   */
+  GHOST_TabletData getLastTabletData();
+
+ private:
+  /** Wintab dll handle. */
+  unique_hmodule m_handle;
+  /** Wintab API functions. */
+  GHOST_WIN32_WTInfo m_fpInfo = nullptr;
+  GHOST_WIN32_WTGet m_fpGet = nullptr;
+  GHOST_WIN32_WTSet m_fpSet = nullptr;
+  GHOST_WIN32_WTPacketsGet m_fpPacketsGet = nullptr;
+  GHOST_WIN32_WTEnable m_fpEnable = nullptr;
+  GHOST_WIN32_WTOverlap m_fpOverlap = nullptr;
+
+  /** Stores the Wintab tablet context. */
+  unique_hctx m_context;
+  /** Whether the context is enabled. */
+  bool m_enabled = false;
+  /** Whether the context has focus and is at the top of overlap order. */
+  bool m_focused = false;
+
+  /** Pressed button map. */
+  GHOST_TUns8 m_buttons = 0;
+
+  /** Range of a coodinate space. */
+  struct Range {
+    /** Origin of range. */
+    int org = 0;
+    /** Extent of range. */
+    int ext = 1;
+  };
+
+  /** 2D Coordinate space. */
+  struct Coord {
+    /** Range of x. */
+    Range x = {};
+    /** Range of y. */
+    Range y = {};
+  };
+  /** Whether Wintab coordinates are trusted. */
+  bool m_coordTrusted = false;
+  /** Tablet input range. */
+  Coord m_tabletCoord = {};
+  /** System output range. */
+  Coord m_systemCoord = {};
+
+  int m_maxPressure = 0;
+  int m_maxAzimuth = 0;
+  int m_maxAltitude = 0;
+
+  /** Number of connected Wintab devices. */
+  UINT m_numDevices = 0;
+  /** Reusable buffer to read in Wintab packets. */
+  std::vector<PACKET> m_pkts;
+  /** Most recently received tablet data, or none if pen is not in range. */
+  GHOST_TabletData m_lastTabletData = GHOST_TABLET_DATA_NONE;
+
+  GHOST_Wintab(HWND hwnd,
+               unique_hmodule handle,
+               GHOST_WIN32_WTInfo info,
+               GHOST_WIN32_WTGet get,
+               GHOST_WIN32_WTSet set,
+               GHOST_WIN32_WTPacketsGet packetsGet,
+               GHOST_WIN32_WTEnable enable,
+               GHOST_WIN32_WTOverlap overlap,
+               unique_hctx hctx,
+               Coord tablet,
+               Coord system,
+               int queueSize);
+
+  /**
+   * Convert Wintab system mapped (mouse) buttons into Ghost button mask.
+   * \param cursor: The Wintab cursor associated to the button.
+   * \param physicalButton: The physical button ID to inspect.
+   * \return The system mapped button.
+   */
+  GHOST_TButtonMask mapWintabToGhostButton(UINT cursor, WORD physicalButton);
+
+  /**
+   * Applies common modifications to Wintab context.
+   * \param lc: Wintab context to modify.
+   */
+  static void modifyContext(LOGCONTEXT &lc);
+
+  /**
+   * Extracts tablet and system coordinates from Wintab context.
+   * \param lc: Wintab context to extract coordinates from.
+   * \param tablet: Tablet coordinates.
+   * \param system: System coordinates.
+   */
+  static void extractCoordinates(LOGCONTEXT &lc, Coord &tablet, Coord &system);
+};

source/blender/editors/space_view3d/view3d_walk.c

@@ -693,6 +693,9 @@ static void walkEvent(bContext *C, WalkInfo *walk, const wmEvent *event)
       if ((walk->center_mval[0] == event->mval[0]) && (walk->center_mval[1] == event->mval[1])) {
         walk->is_cursor_first = false;
       }
+      else if (event->tablet.is_motion_absolute) {
+        walk->is_cursor_first = false;
+      }
       else {
         /* note, its possible the system isn't giving us the warp event
          * ideally we shouldn't have to worry about this, see: T45361 */
@@ -704,13 +707,19 @@ static void walkEvent(bContext *C, WalkInfo *walk, const wmEvent *event)
       return;
     }
 
-    if ((walk->is_cursor_absolute == false) && event->tablet.is_motion_absolute) {
+    if (!walk->is_cursor_absolute && event->tablet.is_motion_absolute) {
       walk->is_cursor_absolute = true;
       copy_v2_v2_int(walk->prev_mval, event->mval);
       copy_v2_v2_int(walk->center_mval, event->mval);
       /* Without this we can't turn 180d with the default speed of 1.0. */
       walk->mouse_speed *= 4.0f;
     }
+    else if (walk->is_cursor_absolute && !event->tablet.is_motion_absolute) {
+        walk->is_cursor_absolute = false;
+        walk->is_cursor_first = true;
+        /* Return walk speed to normal. */
+        walk->mouse_speed = U.walk_navigation.mouse_speed;
+    }
 #endif /* USE_TABLET_SUPPORT */
 
     walk->moffset[0] += event->mval[0] - walk->prev_mval[0];

source/blender/windowmanager/intern/wm_window.c

@@ -2080,7 +2080,7 @@ void WM_init_tablet_api(void)
   if (g_system) {
     switch (U.tablet_api) {
       case USER_TABLET_NATIVE:
-        GHOST_SetTabletAPI(g_system, GHOST_kTabletNative);
+        GHOST_SetTabletAPI(g_system, GHOST_kTabletWinPointer);
         break;
       case USER_TABLET_WINTAB:
         GHOST_SetTabletAPI(g_system, GHOST_kTabletWintab);