Avoid POINT allocations

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndMouseInputProvider.cs

@@ -152,15 +152,15 @@ bool IMouseInputProvider.CaptureMouse()
             // WORKAROUND for the fact that WM_MOUSELEAVE not sent when capture changes
             if (success && !_active)
             {
-                NativeMethods.POINT ptCursor = new NativeMethods.POINT();
+                NativeMethods.POINT ptCursor = default;
 
-                success = UnsafeNativeMethods.TryGetCursorPos(ptCursor);
+                success = UnsafeNativeMethods.TryGetCursorPos(ref ptCursor);
 
                 if(success)
                 {
                     try
                     {
-                        SafeNativeMethods.ScreenToClient(new HandleRef(this, _source.Value.CriticalHandle), ptCursor);
+                        SafeNativeMethods.ScreenToClient(new HandleRef(this, _source.Value.CriticalHandle), ref ptCursor);
                     }
                     catch(System.ComponentModel.Win32Exception)
                     {
@@ -334,7 +334,7 @@ internal IntPtr FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, Int
                 return result;
             }
             /*
-            NativeMethods.POINT ptCursor = new NativeMethods.POINT();
+            NativeMethods.POINT ptCursor = default;
             int messagePos = 0;
             try
             {
@@ -471,7 +471,7 @@ internal IntPtr FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, Int
                     NativeMethods.POINT pt = new NativeMethods.POINT(x,y);
                     try
                     {
-                        SafeNativeMethods.ScreenToClient(new HandleRef(this,hwnd), pt);
+                        SafeNativeMethods.ScreenToClient(new HandleRef(this,hwnd), ref pt);
 
                         x = pt.x;
                         y = pt.y;
@@ -956,7 +956,7 @@ private void PossiblyDeactivate(IntPtr hwndCapture, bool stillActiveIfOverSelf)
                     {
                         NativeMethods.RECT rcClient = new NativeMethods.RECT();
                         SafeNativeMethods.GetClientRect(new HandleRef(this,hwndToCheck), ref rcClient);
-                        SafeNativeMethods.ScreenToClient(new HandleRef(this,hwndToCheck), ptCursor);
+                        SafeNativeMethods.ScreenToClient(new HandleRef(this,hwndToCheck), ref ptCursor);
 
                         if(ptCursor.x < rcClient.left || ptCursor.x >= rcClient.right ||
                            ptCursor.y < rcClient.top || ptCursor.y >= rcClient.bottom)
@@ -1163,10 +1163,10 @@ private bool ReportInput(
                     {
                         // If we get this far, "A" does NOT have capture
                         // - now ensure mouse is over "A"
-                        NativeMethods.POINT ptCursor = new NativeMethods.POINT();
+                        NativeMethods.POINT ptCursor = default;
                         try
                         {
-                            UnsafeNativeMethods.GetCursorPos(ptCursor);
+                            UnsafeNativeMethods.GetCursorPos(ref ptCursor);
                         }
                         catch(System.ComponentModel.Win32Exception)
                         {

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndStylusInputProvider.cs

@@ -100,7 +100,7 @@ IntPtr IStylusInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr
                     NativeMethods.POINT pt1 = new NativeMethods.POINT(
                                             NativeMethods.SignedLOWORD(lParam),
                                             NativeMethods.SignedHIWORD(lParam));
-                    SafeNativeMethods.ScreenToClient(new HandleRef(this, hwnd), pt1);
+                    SafeNativeMethods.ScreenToClient(new HandleRef(this, hwnd), ref pt1);
                     Point ptClient1 = new Point(pt1.x, pt1.y);
 
                     IInputElement inputElement = StylusDevice.LocalHitTest(_source.Value, ptClient1);

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndTarget.cs

@@ -1636,10 +1636,10 @@ private void UpdateWindowAndClientCoordinates()
 
             // Convert the client rect to screen coordinates, adjusting for RTL
             NativeMethods.POINT ptClientTopLeft = new NativeMethods.POINT(rcClient.left, rcClient.top);
-            UnsafeNativeMethods.ClientToScreen(hWnd, ptClientTopLeft);
+            UnsafeNativeMethods.ClientToScreen(hWnd, ref ptClientTopLeft);
 
             NativeMethods.POINT ptClientBottomRight = new NativeMethods.POINT(rcClient.right, rcClient.bottom);
-            UnsafeNativeMethods.ClientToScreen(hWnd, ptClientBottomRight);
+            UnsafeNativeMethods.ClientToScreen(hWnd, ref ptClientBottomRight);
 
             if(ptClientBottomRight.x >= ptClientTopLeft.x)
             {
@@ -2201,7 +2201,10 @@ private void UpdateWindowSettings(bool enableRenderTarget, DUCE.ChannelSet? chan
                 NativeMethods.BLENDFUNCTION blend = new NativeMethods.BLENDFUNCTION();
                 blend.BlendOp = NativeMethods.AC_SRC_OVER;
                 blend.SourceConstantAlpha = 0; // transparent
-                UnsafeNativeMethods.UpdateLayeredWindow(_hWnd.h, IntPtr.Zero, null, null, IntPtr.Zero, null, 0, ref blend, NativeMethods.ULW_ALPHA);
+                unsafe
+                {
+                    UnsafeNativeMethods.UpdateLayeredWindow(_hWnd.h, IntPtr.Zero, null, null, IntPtr.Zero, null, 0, ref blend, NativeMethods.ULW_ALPHA);
+                }
             }
             isLayered = (flags != MILTransparencyFlags.Opaque);
 

src/Microsoft.DotNet.Wpf/src/PresentationFramework/MS/Internal/Controls/ActiveXSite.cs

@@ -69,7 +69,7 @@ int UnsafeNativeMethods.IOleControlSite.GetExtendedControl(out object ppDisp)
             return NativeMethods.E_NOTIMPL;
         }
 
-        int UnsafeNativeMethods.IOleControlSite.TransformCoords(NativeMethods.POINT pPtlHimetric, NativeMethods.POINTF pPtfContainer, int dwFlags)
+        int UnsafeNativeMethods.IOleControlSite.TransformCoords(ref NativeMethods.POINT pPtlHimetric, ref NativeMethods.POINTF pPtfContainer, int dwFlags)
         {
             if ((dwFlags & NativeMethods.XFORMCOORDS_HIMETRICTOCONTAINER) != 0)
             {

src/Microsoft.DotNet.Wpf/src/PresentationFramework/MS/Internal/Controls/webbrowsersite.cs

@@ -65,7 +65,7 @@ internal WebBrowserSite(WebBrowser host) : base(host)
 
         #region IDocHostUIHandler Implementation
 
-        int UnsafeNativeMethods.IDocHostUIHandler.ShowContextMenu(int dwID, NativeMethods.POINT pt, object pcmdtReserved, object pdispReserved)
+        int UnsafeNativeMethods.IDocHostUIHandler.ShowContextMenu(int dwID, ref NativeMethods.POINT pt, object pcmdtReserved, object pdispReserved)
         {
             //
             // Returning S_FALSE will allow the native control to do default processing,

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Controls/Primitives/Popup.cs

@@ -1595,7 +1595,7 @@ private void BuildWindow(Visual targetVisual)
             // the Display on which the PopupRoot is situated, and return that value here. 
             var origin =
                 _positionInfo != null
-                ? new NativeMethods.POINTSTRUCT(_positionInfo.X, _positionInfo.Y)
+                ? new NativeMethods.POINT(_positionInfo.X, _positionInfo.Y)
                 : PopupInitialPlacementHelper.GetPlacementOrigin(this);
 
             _secHelper.BuildWindow(origin.x, origin.y, targetVisual, IsTransparent, PopupFilterMessage, OnWindowResize, OnDpiChanged);
@@ -3057,7 +3057,7 @@ internal NativeMethods.POINT GetMouseCursorPos(Visual targetVisual)
                 // This is a fallback if we couldn't convert Mouse.GetPosition
                 NativeMethods.POINT mousePoint = new NativeMethods.POINT(0, 0);
 
-                UnsafeNativeMethods.TryGetCursorPos(mousePoint);
+                UnsafeNativeMethods.TryGetCursorPos(ref mousePoint);
 
                 return mousePoint;
             }
@@ -3527,7 +3527,7 @@ internal static bool IsPerMonitorDpiScalingActive
             /// <summary>
             /// Finds the screen coordinates of the PlacementTarget's (left, top)
             /// </summary>
-            private static NativeMethods.POINTSTRUCT? GetPlacementTargetOriginInScreenCoordinates(Popup popup)
+            private static NativeMethods.POINT? GetPlacementTargetOriginInScreenCoordinates(Popup popup)
             {
                 var target = popup?.GetTarget() as UIElement;
                 if (target != null)
@@ -3541,7 +3541,7 @@ internal static bool IsPerMonitorDpiScalingActive
                     if (targetToClientTransform.TryTransform(new Point(0, 0), out ptPlacementTargetOrigin))
                     {
                         var screenOrigin = popup._secHelper.ClientToScreen(rootVisual, ptPlacementTargetOrigin);
-                        return new NativeMethods.POINTSTRUCT((int)screenOrigin.X, (int)screenOrigin.Y);
+                        return new NativeMethods.POINT((int)screenOrigin.X, (int)screenOrigin.Y);
                     }
                 }
 
@@ -3551,13 +3551,13 @@ internal static bool IsPerMonitorDpiScalingActive
             /// <summary>
             /// Finds the (top,left) screen coordinates of the monitor that contains the placement target
             /// </summary>
-            internal static NativeMethods.POINTSTRUCT GetPlacementOrigin(Popup popup)
+            internal static NativeMethods.POINT GetPlacementOrigin(Popup popup)
             {
-                var placementOrigin = new NativeMethods.POINTSTRUCT(0, 0);
+                NativeMethods.POINT placementOrigin = default;
 
                 if (IsPerMonitorDpiScalingActive)
                 {
-                    var screenOrigin = GetPlacementTargetOriginInScreenCoordinates(popup);
+                    NativeMethods.POINT? screenOrigin = GetPlacementTargetOriginInScreenCoordinates(popup);
                     if (screenOrigin.HasValue)
                     {
                         try

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Documents/ImmComposition.cs

@@ -606,7 +606,7 @@ private void OnWmImeNotify(IntPtr hwnd, IntPtr wParam)
                         candform.rcArea.right = 0;
                         candform.rcArea.top = 0;
                         candform.rcArea.bottom = 0;
-                        candform.ptCurrentPos = new NativeMethods.POINT(0, 0);
+                        candform.ptCurrentPos = default;
                     }
                     else
                     {

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Documents/TextStore.cs

@@ -793,7 +793,7 @@ public void GetACPFromPoint(int viewCookie, ref UnsafeNativeMethods.POINT tsfPoi
             compositionTarget = source.CompositionTarget;
 
             // Convert to client coordinates.
-            SafeNativeMethods.ScreenToClient(new HandleRef(null,win32Window.Handle), point);
+            SafeNativeMethods.ScreenToClient(new HandleRef(null, win32Window.Handle), ref point);
 
             // Convert to mil measure units.
             milPoint = new Point(point.x, point.y);
@@ -2347,8 +2347,8 @@ private static UnsafeNativeMethods.RECT TransformRootRectToScreenCoordinates(Poi
             hwnd = win32Window.Handle;
 
             // Transform to screen coords.
-            clientPoint = new NativeMethods.POINT();
-            UnsafeNativeMethods.ClientToScreen(new HandleRef(null, hwnd), /* ref by interop */ clientPoint);
+            clientPoint = default;
+            UnsafeNativeMethods.ClientToScreen(new HandleRef(null, hwnd), ref clientPoint);
 
             rect.left = (int)(clientPoint.x + milPointTopLeft.X);
             rect.right = (int)(clientPoint.x + milPointBottomRight.X);

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Standard/NativeMethods.cs

@@ -3212,10 +3212,10 @@ public static void UnregisterClass(string lpClassName, IntPtr hInstance)
         private static extern bool _UpdateLayeredWindow(
             IntPtr hwnd,
             SafeDC hdcDst,
-            [In] ref POINT pptDst,
-            [In] ref SIZE psize,
+            ref POINT pptDst,
+            ref SIZE psize,
             SafeDC hdcSrc,
-            [In] ref POINT pptSrc,
+            ref POINT pptSrc,
             int crKey,
             ref BLENDFUNCTION pblend,
             ULW dwFlags);

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Window.cs

@@ -3582,12 +3582,11 @@ private void SetIWindowService()
         IntPtr GetCurrentMonitorFromMousePosition()
         {
             // center on the screen on which the mouse is on
-            NativeMethods.POINT pt = new NativeMethods.POINT();
+            NativeMethods.POINT pt = default;
 
-            UnsafeNativeMethods.TryGetCursorPos(pt);
+            UnsafeNativeMethods.TryGetCursorPos(ref pt);
 
-            NativeMethods.POINTSTRUCT ptStruct = new NativeMethods.POINTSTRUCT(pt.x, pt.y);
-            return SafeNativeMethods.MonitorFromPoint(ptStruct, NativeMethods.MONITOR_DEFAULTTONEAREST);
+            return SafeNativeMethods.MonitorFromPoint(pt, NativeMethods.MONITOR_DEFAULTTONEAREST);
         }
 
         // <summary>
@@ -4699,7 +4698,11 @@ internal virtual void WmMoveChangedHelper()
 
         private bool WmGetMinMaxInfo( IntPtr lParam )
         {
-            NativeMethods.MINMAXINFO mmi = (NativeMethods.MINMAXINFO)UnsafeNativeMethods.PtrToStructure( lParam, typeof(NativeMethods.MINMAXINFO));
+            NativeMethods.MINMAXINFO mmi;
+            unsafe
+            {
+                mmi = *(NativeMethods.MINMAXINFO*)lParam;
+            }
 
             //
             // For Bug 1380569: Window SizeToContent does not work after changing Max size properties
@@ -4760,7 +4763,10 @@ private bool WmGetMinMaxInfo( IntPtr lParam )
 
                 // Notify Win32 of the new Min/Max value for this HWND.
 
-                Marshal.StructureToPtr(mmi, lParam, true);
+                unsafe
+                {
+                    *(NativeMethods.MINMAXINFO*)lParam = mmi;
+                }
             }
 
             return true;
@@ -7277,7 +7283,7 @@ internal NativeMethods.RECT WindowBounds
                 private NativeMethods.POINT GetWindowScreenLocation(FlowDirection flowDirection)
                 {
                     Debug.Assert(IsSourceWindowNull != true, "IsSourceWindowNull cannot be true here");
-                    NativeMethods.POINT pt = new NativeMethods.POINT(0, 0);
+                    NativeMethods.POINT pt = default;
                     if (flowDirection == FlowDirection.RightToLeft)
                     {
                         NativeMethods.RECT rc = new NativeMethods.RECT(0, 0, 0, 0);
@@ -7288,7 +7294,7 @@ private NativeMethods.POINT GetWindowScreenLocation(FlowDirection flowDirection)
                         // note that we use rc.right here for the RTL case and client to screen that point
                         pt = new NativeMethods.POINT(rc.right, rc.top);
                     }
-                    UnsafeNativeMethods.ClientToScreen(new HandleRef(this, _sourceWindow.CriticalHandle), pt);
+                    UnsafeNativeMethods.ClientToScreen(new HandleRef(this, _sourceWindow.CriticalHandle), ref pt);
 
                     return pt;
                 }

src/Microsoft.DotNet.Wpf/src/Shared/MS/Internal/PointUtil.cs

@@ -178,7 +178,7 @@ public static Point ClientToScreen(Point pointClient, PresentationSource present
             NativeMethods.POINT ptClient            = FromPoint(pointClient);
             NativeMethods.POINT ptClientRTLAdjusted = AdjustForRightToLeft(ptClient, handleRef);
 
-            UnsafeNativeMethods.ClientToScreen(handleRef, ptClientRTLAdjusted);
+            UnsafeNativeMethods.ClientToScreen(handleRef, ref ptClientRTLAdjusted);
 
             return ToPoint(ptClientRTLAdjusted);
         }
@@ -200,7 +200,7 @@ internal static Point ScreenToClient(Point pointScreen, PresentationSource prese
 
             NativeMethods.POINT ptClient = FromPoint(pointScreen);
 
-            SafeNativeMethods.ScreenToClient(handleRef, ptClient);
+            SafeNativeMethods.ScreenToClient(handleRef, ref ptClient);
 
             ptClient = AdjustForRightToLeft(ptClient, handleRef);
 

src/Microsoft.DotNet.Wpf/src/Shared/MS/Win32/NativeMethodsCLR.cs

@@ -2996,13 +2996,10 @@ private static int SizeOf()
         }
 
         [StructLayout(LayoutKind.Sequential)]
-        public class POINT {
+        public struct POINT {
             public int x;
             public int y;
 
-            public POINT() {
-            }
-
             public POINT(int x, int y) {
                 this.x = x;
                 this.y = y;
@@ -3014,18 +3011,6 @@ public override string ToString() {
 #endif
         }
 
-        // use this in cases where the Native API takes a POINT not a POINT*
-        // classes marshal by ref.
-        [StructLayout(LayoutKind.Sequential)]
-        public struct POINTSTRUCT {
-            public int x;
-            public int y;
-            public POINTSTRUCT(int x, int y) {
-              this.x = x;
-              this.y = y;
-            }
-      }
-
         public delegate IntPtr WndProc(IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam);
 
 
@@ -4216,14 +4201,11 @@ public void Disconnect(bool release) {
 #endif
 
         [StructLayout(LayoutKind.Sequential)/*leftover(noAutoOffset)*/]
-        public sealed class POINTF
+        public struct POINTF
         {
-          [MarshalAs(UnmanagedType.R4)/*leftover(offset=0, x)*/]
           public float x;
-
-          [MarshalAs(UnmanagedType.R4)/*leftover(offset=4, y)*/]
           public float y;
-}
+        }
 
         [StructLayout(LayoutKind.Sequential)/*leftover(noAutoOffset)*/]
         public sealed class OLEINPLACEFRAMEINFO
@@ -4237,7 +4219,7 @@ public sealed class OLEINPLACEFRAMEINFO
 
           [MarshalAs(UnmanagedType.U4)/*leftover(offset=16, cAccelEntries)*/]
           public uint cAccelEntries;
-}
+        }
 
 #if never
         [StructLayout(LayoutKind.Sequential)]
@@ -5216,12 +5198,12 @@ public class ACCEL {
 #endif
 
         [StructLayout(LayoutKind.Sequential)]
-        public class MINMAXINFO {
-            public POINT ptReserved = new POINT();
-            public POINT ptMaxSize = new POINT();
-            public POINT ptMaxPosition = new POINT();
-            public POINT ptMinTrackSize = new POINT();
-            public POINT ptMaxTrackSize = new POINT();
+        public struct MINMAXINFO {
+            public POINT ptReserved;
+            public POINT ptMaxSize;
+            public POINT ptMaxPosition;
+            public POINT ptMinTrackSize;
+            public POINT ptMaxTrackSize;
         }
 #if never
         [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]

src/Microsoft.DotNet.Wpf/src/Shared/MS/Win32/NativeMethodsSetLastError.cs

@@ -63,7 +63,7 @@ internal static class NativeMethodsSetLastError
         public static extern int MapWindowPoints(NativeMethods.HWND hWndFrom, NativeMethods.HWND hWndTo, [In, Out] ref NativeMethods.RECT rect, int cPoints);
 
         [DllImport(PresentationNativeDll, EntryPoint="MapWindowPointsWrapper", SetLastError = true, ExactSpelling=true, CharSet=CharSet.Auto)]
-        public static extern int MapWindowPoints(NativeMethods.HWND hWndFrom, NativeMethods.HWND hWndTo, [In, Out] ref NativeMethods.POINT pt, int cPoints);
+        public static extern int MapWindowPoints(NativeMethods.HWND hWndFrom, NativeMethods.HWND hWndTo, ref NativeMethods.POINT pt, int cPoints);
 
 #elif UIAUTOMATIONCLIENTSIDEPROVIDERS   // UIAutomationClientSideProviders