Update InputHandler to match changes in imgui_impl_win32.cpp

Dalamud/Interface/ImGuiBackend/InputHandler/Win32InputHandler.cs

@@ -34,11 +34,12 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
     private readonly HCURSOR[] cursors;
 
     private readonly WndProcDelegate wndProcDelegate;
-    private readonly bool[] imguiMouseIsDown;
     private readonly nint platformNamePtr;
 
     private ViewportHandler viewportHandler;
 
+    private int mouseButtonsDown;
+    private bool mouseTracked;
     private long lastTime;
 
     private nint iniPathPtr;
@@ -64,7 +65,8 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
         io.BackendFlags |= ImGuiBackendFlags.HasMouseCursors |
                            ImGuiBackendFlags.HasSetMousePos |
                            ImGuiBackendFlags.RendererHasViewports |
-                           ImGuiBackendFlags.PlatformHasViewports;
+                           ImGuiBackendFlags.PlatformHasViewports |
+                           ImGuiBackendFlags.HasMouseHoveredViewport;
 
         this.platformNamePtr = Marshal.StringToHGlobalAnsi("imgui_impl_win32_c#");
         io.Handle->BackendPlatformName = (byte*)this.platformNamePtr;
@@ -74,8 +76,6 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
         if (io.ConfigFlags.HasFlag(ImGuiConfigFlags.ViewportsEnable))
             this.viewportHandler = new(this);
 
-        this.imguiMouseIsDown = new bool[5];
-
         this.cursors = new HCURSOR[9];
         this.cursors[(int)ImGuiMouseCursor.Arrow] = LoadCursorW(default, IDC.IDC_ARROW);
         this.cursors[(int)ImGuiMouseCursor.TextInput] = LoadCursorW(default, IDC.IDC_IBEAM);
@@ -95,8 +95,6 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
 
     private delegate LRESULT WndProcDelegate(HWND hWnd, uint uMsg, WPARAM wparam, LPARAM lparam);
 
-    private delegate BOOL MonitorEnumProcDelegate(HMONITOR monitor, HDC hdc, RECT* rect, LPARAM lparam);
-
     /// <inheritdoc/>
     public bool UpdateCursor { get; set; } = true;
 
@@ -155,6 +153,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
     public void NewFrame(int targetWidth, int targetHeight)
     {
         var io = ImGui.GetIO();
+        var focusedWindow = GetForegroundWindow();
 
         io.DisplaySize.X = targetWidth;
         io.DisplaySize.Y = targetHeight;
@@ -168,9 +167,9 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
 
         this.viewportHandler.UpdateMonitors();
 
-        this.UpdateMousePos();
+        this.UpdateMouseData(focusedWindow);
 
-        this.ProcessKeyEventsWorkarounds();
+        this.ProcessKeyEventsWorkarounds(focusedWindow);
 
         // TODO: need to figure out some way to unify all this
         // The bottom case works(?) if the caller hooks SetCursor, but otherwise causes fps issues
@@ -224,6 +223,40 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
 
         switch (msg)
         {
+            case WM.WM_MOUSEMOVE:
+            {
+                if (!this.mouseTracked)
+                {
+                    var tme = new TRACKMOUSEEVENT
+                    {
+                        cbSize = (uint)sizeof(TRACKMOUSEEVENT),
+                        dwFlags = TME.TME_LEAVE,
+                        hwndTrack = hWndCurrent,
+                    };
+                    this.mouseTracked = TrackMouseEvent(&tme);
+                }
+
+                var mousePos = new POINT(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
+                if ((io.ConfigFlags & ImGuiConfigFlags.ViewportsEnable) != 0)
+                    ClientToScreen(hWndCurrent, &mousePos);
+                io.AddMousePosEvent(mousePos.x, mousePos.y);
+                break;
+            }
+
+            case WM.WM_MOUSELEAVE:
+            {
+                this.mouseTracked = false;
+                var mouseScreenPos = new POINT(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
+                ClientToScreen(hWndCurrent, &mouseScreenPos);
+                if (this.ViewportFromPoint(mouseScreenPos).IsNull)
+                {
+                    var fltMax = ImGuiNative.GETFLTMAX();
+                    io.AddMousePosEvent(-fltMax, -fltMax);
+                }
+
+                break;
+            }
+
             case WM.WM_LBUTTONDOWN:
             case WM.WM_LBUTTONDBLCLK:
             case WM.WM_RBUTTONDOWN:
@@ -236,11 +269,10 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
                 var button = GetButton(msg, wParam);
                 if (io.WantCaptureMouse)
                 {
-                    if (!ImGui.IsAnyMouseDown() && GetCapture() == nint.Zero)
+                    if (this.mouseButtonsDown == 0 && GetCapture() == nint.Zero)
                         SetCapture(hWndCurrent);
-
+                    this.mouseButtonsDown |= 1 << button;
-                    io.MouseDown[button] = true;
+                    io.AddMouseButtonEvent(button, true);
-                    this.imguiMouseIsDown[button] = true;
                     return default(LRESULT);
                 }
 
@@ -256,13 +288,12 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
             case WM.WM_XBUTTONUP:
             {
                 var button = GetButton(msg, wParam);
-                if (io.WantCaptureMouse && this.imguiMouseIsDown[button])
+                if (io.WantCaptureMouse)
                 {
-                    if (!ImGui.IsAnyMouseDown() && GetCapture() == hWndCurrent)
+                    this.mouseButtonsDown &= ~(1 << button);
+                    if (this.mouseButtonsDown == 0 && GetCapture() == hWndCurrent)
                         ReleaseCapture();
-
+                    io.AddMouseButtonEvent(button, false);
-                    io.MouseDown[button] = false;
-                    this.imguiMouseIsDown[button] = false;
                     return default(LRESULT);
                 }
 
@@ -272,7 +303,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
             case WM.WM_MOUSEWHEEL:
                 if (io.WantCaptureMouse)
                 {
-                    io.MouseWheel += GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+                    io.AddMouseWheelEvent(0, GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA);
                     return default(LRESULT);
                 }
 
@@ -280,7 +311,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
             case WM.WM_MOUSEHWHEEL:
                 if (io.WantCaptureMouse)
                 {
-                    io.MouseWheelH += GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+                    io.AddMouseWheelEvent(GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA, 0);
                     return default(LRESULT);
                 }
 
@@ -374,68 +405,86 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
                 this.viewportHandler.UpdateMonitors();
                 break;
 
-            case WM.WM_KILLFOCUS when hWndCurrent == this.hWnd:
+            case WM.WM_SETFOCUS when hWndCurrent == this.hWnd:
-                if (!ImGui.IsAnyMouseDown() && GetCapture() == hWndCurrent)
+                io.AddFocusEvent(true);
-                    ReleaseCapture();
+                break;
 
-                ImGui.GetIO().WantCaptureMouse = false;
+            case WM.WM_KILLFOCUS when hWndCurrent == this.hWnd:
-                ImGui.ClearWindowFocus();
+                io.AddFocusEvent(false);
+                // if (!ImGui.IsAnyMouseDown() && GetCapture() == hWndCurrent)
+                //     ReleaseCapture();
+                //
+                // ImGui.GetIO().WantCaptureMouse = false;
+                // ImGui.ClearWindowFocus();
                 break;
         }
 
         return null;
     }
 
-    private void UpdateMousePos()
+    private void UpdateMouseData(HWND focusedWindow)
     {
         var io = ImGui.GetIO();
-        var pt = default(POINT);
 
-        // Depending on if Viewports are enabled, we have to change how we process
+        var mouseScreenPos = default(POINT);
-        // the cursor position. If viewports are enabled, we pass the absolute cursor
+        var hasMouseScreenPos = GetCursorPos(&mouseScreenPos) != 0;
-        // position to ImGui. Otherwise, we use the old method of passing client-local
+
-        // mouse position to ImGui.
+        var isAppFocused =
-        if (io.ConfigFlags.HasFlag(ImGuiConfigFlags.ViewportsEnable))
+            focusedWindow != default
+            && (focusedWindow == this.hWnd
+                || IsChild(focusedWindow, this.hWnd)
+                || !ImGui.FindViewportByPlatformHandle(focusedWindow).IsNull);
+
+        if (isAppFocused)
         {
+            // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+            // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
             if (io.WantSetMousePos)
             {
-                SetCursorPos((int)io.MousePos.X, (int)io.MousePos.Y);
+                var pos = new POINT((int)io.MousePos.X, (int)io.MousePos.Y);
+                if ((io.ConfigFlags & ImGuiConfigFlags.ViewportsEnable) != 0)
+                    ClientToScreen(this.hWnd, &pos);
+                SetCursorPos(pos.x, pos.y);
             }
 
-            if (GetCursorPos(&pt))
+            // (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
+            if (!io.WantSetMousePos && !this.mouseTracked && hasMouseScreenPos)
             {
-                io.MousePos.X = pt.x;
+                // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
-                io.MousePos.Y = pt.y;
+                // (This is the position you can get with ::GetCursorPos() + ::ScreenToClient() or WM_MOUSEMOVE.)
-            }
+                // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
-            else
+                // (This is the position you can get with ::GetCursorPos() or WM_MOUSEMOVE + ::ClientToScreen(). In theory adding viewport->Pos to a client position would also be the same.)
-            {
+                var mousePos = mouseScreenPos;
-                io.MousePos.X = float.MinValue;
+                if ((io.ConfigFlags & ImGuiConfigFlags.ViewportsEnable) == 0)
-                io.MousePos.Y = float.MinValue;
+                    ClientToScreen(focusedWindow, &mousePos);
+                io.AddMousePosEvent(mousePos.x, mousePos.y);
             }
         }
+
+        // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+        // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+        // - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
+        //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+        //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+        //       by the backend, and use its flawed heuristic to guess the viewport behind.
+        // - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+        if (hasMouseScreenPos)
+        {
+            var viewport = this.ViewportFromPoint(mouseScreenPos);
+            io.AddMouseViewportEvent(!viewport.IsNull ? viewport.ID : 0u);
+        }
         else
         {
-            if (io.WantSetMousePos)
+            io.AddMouseViewportEvent(0);
-            {
-                pt.x = (int)io.MousePos.X;
-                pt.y = (int)io.MousePos.Y;
-                ClientToScreen(this.hWnd, &pt);
-                SetCursorPos(pt.x, pt.y);
-            }
-
-            if (GetCursorPos(&pt) && ScreenToClient(this.hWnd, &pt))
-            {
-                io.MousePos.X = pt.x;
-                io.MousePos.Y = pt.y;
-            }
-            else
-            {
-                io.MousePos.X = float.MinValue;
-                io.MousePos.Y = float.MinValue;
-            }
         }
     }
 
+    private ImGuiViewportPtr ViewportFromPoint(POINT mouseScreenPos)
+    {
+        var hoveredHwnd = WindowFromPoint(mouseScreenPos);
+        return hoveredHwnd != default ? ImGui.FindViewportByPlatformHandle(hoveredHwnd) : default;
+    }
+
     private bool UpdateMouseCursor()
     {
         var io = ImGui.GetIO();
@@ -451,7 +500,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
         return true;
     }
 
-    private void ProcessKeyEventsWorkarounds()
+    private void ProcessKeyEventsWorkarounds(HWND focusedWindow)
     {
         // Left & right Shift keys: when both are pressed together, Windows tend to not generate the WM_KEYUP event for the first released one.
         if (ImGui.IsKeyDown(ImGuiKey.LeftShift) && !IsVkDown(VK.VK_LSHIFT))
@@ -480,7 +529,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
         {
             // See: https://github.com/goatcorp/ImGuiScene/pull/13
             // > GetForegroundWindow from winuser.h is a surprisingly expensive function.
-            var isForeground = GetForegroundWindow() == this.hWnd;
+            var isForeground = focusedWindow == this.hWnd;
             for (var i = (int)ImGuiKey.NamedKeyBegin; i < (int)ImGuiKey.NamedKeyEnd; i++)
             {
                 // Skip raising modifier keys if the game is focused.
@@ -646,14 +695,7 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
                 return;
 
             var pio = ImGui.GetPlatformIO();
-
+            ImGui.GetPlatformIO().Handle->Monitors.Free();
-            if (ImGui.GetPlatformIO().Handle->Monitors.Data != null)
-            {
-                // We allocated the platform monitor data in OnUpdateMonitors ourselves,
-                // so we have to free it ourselves to ImGui doesn't try to, or else it will crash
-                Marshal.FreeHGlobal(new IntPtr(ImGui.GetPlatformIO().Handle->Monitors.Data));
-                ImGui.GetPlatformIO().Handle->Monitors = default;
-            }
 
             fixed (char* windowClassNamePtr = WindowClassName)
             {
@@ -693,59 +735,50 @@ internal sealed unsafe partial class Win32InputHandler : IImGuiInputHandler
             // Here we use a manual ImVector overload, free the existing monitor data,
             // and allocate our own, as we are responsible for telling ImGui about monitors
             var pio = ImGui.GetPlatformIO();
-            var numMonitors = GetSystemMetrics(SM.SM_CMONITORS);
+            pio.Handle->Monitors.Resize(0);
-            var data = Marshal.AllocHGlobal(Marshal.SizeOf<ImGuiPlatformMonitor>() * numMonitors);
-            if (pio.Handle->Monitors.Data != null)
-                Marshal.FreeHGlobal(new IntPtr(pio.Handle->Monitors.Data));
-            pio.Handle->Monitors = new(numMonitors, numMonitors, (ImGuiPlatformMonitor*)data.ToPointer());
 
-            // ImGuiPlatformIOPtr platformIO = ImGui.GetPlatformIO();
+            EnumDisplayMonitors(default, null, &EnumDisplayMonitorsCallback, default);
-            // Marshal.FreeHGlobal(platformIO.Handle->Monitors.Data);
-            // int numMonitors = GetSystemMetrics(SystemMetric.SM_CMONITORS);
-            // nint data = Marshal.AllocHGlobal(Marshal.SizeOf<ImGuiPlatformMonitor>() * numMonitors);
-            // platformIO.Handle->Monitors = new ImVector(numMonitors, numMonitors, data);
-
-            var monitorIndex = -1;
-            var enumfn = new MonitorEnumProcDelegate(
-                (hMonitor, _, _, _) =>
-                {
-                    monitorIndex++;
-                    var info = new MONITORINFO { cbSize = (uint)sizeof(MONITORINFO) };
-                    if (!GetMonitorInfoW(hMonitor, &info))
-                        return true;
-
-                    var monitorLt = new Vector2(info.rcMonitor.left, info.rcMonitor.top);
-                    var monitorRb = new Vector2(info.rcMonitor.right, info.rcMonitor.bottom);
-                    var workLt = new Vector2(info.rcWork.left, info.rcWork.top);
-                    var workRb = new Vector2(info.rcWork.right, info.rcWork.bottom);
-                    // Give ImGui the info for this display
-
-                    ref var imMonitor = ref ImGui.GetPlatformIO().Monitors.Ref(monitorIndex);
-                    imMonitor.MainPos = monitorLt;
-                    imMonitor.MainSize = monitorRb - monitorLt;
-                    imMonitor.WorkPos = workLt;
-                    imMonitor.WorkSize = workRb - workLt;
-                    imMonitor.DpiScale = 1f;
-                    return true;
-                });
-            EnumDisplayMonitors(
-                default,
-                null,
-                (delegate* unmanaged<HMONITOR, HDC, RECT*, LPARAM, BOOL>)Marshal.GetFunctionPointerForDelegate(enumfn),
-                default);
 
             Log.Information("Monitors set up!");
-            for (var i = 0; i < numMonitors; i++)
+            foreach (ref var monitor in pio.Handle->Monitors)
             {
-                var monitor = pio.Handle->Monitors[i];
                 Log.Information(
-                    "Monitor {Index}: {MainPos} {MainSize} {WorkPos} {WorkSize}",
+                    "Monitor: {MainPos} {MainSize} {WorkPos} {WorkSize}",
-                    i,
                     monitor.MainPos,
                     monitor.MainSize,
                     monitor.WorkPos,
                     monitor.WorkSize);
             }
+
+            return;
+
+            [UnmanagedCallersOnly]
+            static BOOL EnumDisplayMonitorsCallback(HMONITOR hMonitor, HDC hdc, RECT* rect, LPARAM lParam)
+            {
+                var info = new MONITORINFO { cbSize = (uint)sizeof(MONITORINFO) };
+                if (!GetMonitorInfoW(hMonitor, &info))
+                    return true;
+
+                var monitorLt = new Vector2(info.rcMonitor.left, info.rcMonitor.top);
+                var monitorRb = new Vector2(info.rcMonitor.right, info.rcMonitor.bottom);
+                var workLt = new Vector2(info.rcWork.left, info.rcWork.top);
+                var workRb = new Vector2(info.rcWork.right, info.rcWork.bottom);
+
+                // Give ImGui the info for this display
+                var imMonitor = new ImGuiPlatformMonitor
+                {
+                    MainPos = monitorLt,
+                    MainSize = monitorRb - monitorLt,
+                    WorkPos = workLt,
+                    WorkSize = workRb - workLt,
+                    DpiScale = 1f,
+                };
+                if ((info.dwFlags & MONITORINFOF_PRIMARY) != 0)
+                    ImGui.GetPlatformIO().Monitors.PushFront(imMonitor);
+                else
+                    ImGui.GetPlatformIO().Monitors.PushBack(imMonitor);
+                return true;
+            }
         }
 
         [UnmanagedCallersOnly(CallConvs = [typeof(CallConvCdecl)])]

Dalamud/Interface/Internal/Windows/TitleScreenMenuWindow.cs

@@ -86,7 +86,8 @@ internal class TitleScreenMenuWindow : Window, IDisposable
         : base(
             "TitleScreenMenuOverlay",
             ImGuiWindowFlags.NoTitleBar | ImGuiWindowFlags.AlwaysAutoResize | ImGuiWindowFlags.NoScrollbar |
-            ImGuiWindowFlags.NoBackground | ImGuiWindowFlags.NoFocusOnAppearing | ImGuiWindowFlags.NoNavFocus)
+            ImGuiWindowFlags.NoBackground | ImGuiWindowFlags.NoFocusOnAppearing | ImGuiWindowFlags.NoNavFocus |
+            ImGuiWindowFlags.NoDocking)
     {
         this.showTsm = consoleManager.AddVariable("dalamud.show_tsm", "Show the Title Screen Menu", true);
 

imgui/Dalamud.Bindings.ImGui/ImVector.cs

@@ -1,7 +1,12 @@
-using System.Runtime.CompilerServices;
+using System.Collections;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Dalamud.Bindings.ImGui;
 
+/// <summary>
+/// A structure representing a dynamic array for unmanaged types.
+/// </summary>
 public unsafe struct ImVector
 {
     public readonly int Size;
@@ -15,23 +20,23 @@ public unsafe struct ImVector
         Data = data;
     }
 
-    public ref T Ref<T>(int index)
+    public readonly ref T Ref<T>(int index) => ref Unsafe.AsRef<T>((byte*)this.Data + (index * Unsafe.SizeOf<T>()));
-    {
-        return ref Unsafe.AsRef<T>((byte*)Data + index * Unsafe.SizeOf<T>());
-    }
 
-    public IntPtr Address<T>(int index)
+    public readonly nint Address<T>(int index) => (nint)((byte*)this.Data + (index * Unsafe.SizeOf<T>()));
-    {
-        return (IntPtr)((byte*)Data + index * Unsafe.SizeOf<T>());
-    }
 }
 
 /// <summary>
 /// A structure representing a dynamic array for unmanaged types.
 /// </summary>
 /// <typeparam name="T">The type of elements in the vector, must be unmanaged.</typeparam>
-public unsafe struct ImVector<T> where T : unmanaged
+[StructLayout(LayoutKind.Sequential)]
+public unsafe struct ImVector<T> : IEnumerable<T>
+    where T : unmanaged
 {
+    private int size;
+    private int capacity;
+    private T* data;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="ImVector{T}"/> struct with the specified size, capacity, and data pointer.
     /// </summary>
@@ -45,11 +50,6 @@ public unsafe struct ImVector<T> where T : unmanaged
         this.data = data;
     }
 
-    private int size;
-    private int capacity;
-    private unsafe T* data;
-
-
     /// <summary>
     /// Gets or sets the element at the specified index.
     /// </summary>
@@ -58,80 +58,72 @@ public unsafe struct ImVector<T> where T : unmanaged
     /// <exception cref="IndexOutOfRangeException">Thrown when the index is out of range.</exception>
     public T this[int index]
     {
-        get
+        readonly get
         {
-            if (index < 0 || index >= size)
+            if (index < 0 || index >= this.size)
-            {
                 throw new IndexOutOfRangeException();
-            }
+            return this.data[index];
-            return data[index];
         }
         set
         {
-            if (index < 0 || index >= size)
+            if (index < 0 || index >= this.size)
-            {
                 throw new IndexOutOfRangeException();
-            }
+            this.data[index] = value;
-            data[index] = value;
         }
     }
 
     /// <summary>
     /// Gets a pointer to the first element of the vector.
     /// </summary>
-    public readonly T* Data => data;
+    public readonly T* Data => this.data;
 
     /// <summary>
     /// Gets a pointer to the first element of the vector.
     /// </summary>
-    public readonly T* Front => data;
+    public readonly T* Front => this.data;
 
     /// <summary>
     /// Gets a pointer to the last element of the vector.
     /// </summary>
-    public readonly T* Back => size > 0 ? data + size - 1 : null;
+    public readonly T* Back => this.size > 0 ? this.data + this.size - 1 : null;
 
     /// <summary>
     /// Gets or sets the capacity of the vector.
     /// </summary>
     public int Capacity
     {
-        readonly get => capacity;
+        readonly get => this.capacity;
         set
         {
-            if (capacity == value)
+            ArgumentOutOfRangeException.ThrowIfLessThan(value, this.size, nameof(Capacity));
-            {
+            if (this.capacity == value)
                 return;
-            }
 
-            if (data == null)
+            if (this.data == null)
             {
-                data = (T*)ImGui.MemAlloc((nuint)(value * sizeof(T)));
+                this.data = (T*)ImGui.MemAlloc((nuint)(value * sizeof(T)));
             }
             else
             {
-                int newSize = Math.Min(size, value);
+                var newSize = Math.Min(this.size, value);
-                T* newData = (T*)ImGui.MemAlloc((nuint)(value * sizeof(T)));
+                var newData = (T*)ImGui.MemAlloc((nuint)(value * sizeof(T)));
-                Buffer.MemoryCopy(data, newData, (nuint)(value * sizeof(T)), (nuint)(newSize * sizeof(T)));
+                Buffer.MemoryCopy(this.data, newData, (nuint)(value * sizeof(T)), (nuint)(newSize * sizeof(T)));
-                ImGui.MemFree(data);
+                ImGui.MemFree(this.data);
-                data = newData;
+                this.data = newData;
-                size = newSize;
+                this.size = newSize;
             }
 
-            capacity = value;
+            this.capacity = value;
 
             // Clear the rest of the data
-            for (int i = size; i < capacity; i++)
+            new Span<T>(this.data + this.size, this.capacity - this.size).Clear();
-            {
-                data[i] = default;
-            }
         }
     }
 
     /// <summary>
     /// Gets the number of elements in the vector.
     /// </summary>
-    public readonly int Size => size;
+    public readonly int Size => this.size;
 
     /// <summary>
     /// Grows the capacity of the vector to at least the specified value.
@@ -139,10 +131,8 @@ public unsafe struct ImVector<T> where T : unmanaged
     /// <param name="newCapacity">The new capacity.</param>
     public void Grow(int newCapacity)
     {
-        if (newCapacity > capacity)
+        var newCapacity2 = this.capacity > 0 ? this.capacity + (this.capacity / 2) : 8;
-        {
+        this.Capacity = newCapacity2 > newCapacity ? newCapacity2 : newCapacity;
-            Capacity = newCapacity * 2;
-        }
     }
 
     /// <summary>
@@ -151,10 +141,8 @@ public unsafe struct ImVector<T> where T : unmanaged
     /// <param name="size">The minimum capacity required.</param>
     public void EnsureCapacity(int size)
     {
-        if (size > capacity)
+        if (size > this.capacity)
-        {
             Grow(size);
-        }
     }
 
     /// <summary>
@@ -164,25 +152,46 @@ public unsafe struct ImVector<T> where T : unmanaged
     public void Resize(int newSize)
     {
         EnsureCapacity(newSize);
-        size = newSize;
+        this.size = newSize;
     }
 
     /// <summary>
     /// Clears all elements from the vector.
     /// </summary>
-    public void Clear()
+    public void Clear() => this.size = 0;
+
+    /// <summary>
+    /// Adds an element to the end of the vector.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    [OverloadResolutionPriority(1)]
+    public void PushBack(T value)
     {
-        size = 0;
+        this.EnsureCapacity(this.size + 1);
+        this.data[this.size++] = value;
     }
 
     /// <summary>
     /// Adds an element to the end of the vector.
     /// </summary>
     /// <param name="value">The value to add.</param>
-    public void PushBack(T value)
+    [OverloadResolutionPriority(2)]
+    public void PushBack(in T value)
     {
-        EnsureCapacity(size + 1);
+        EnsureCapacity(this.size + 1);
-        data[size++] = value;
+        this.data[this.size++] = value;
+    }
+
+    /// <summary>
+    /// Adds an element to the front of the vector.
+    /// </summary>
+    /// <param name="value">The value to add.</param>
+    public void PushFront(in T value)
+    {
+        if (this.size == 0)
+            this.PushBack(value);
+        else
+            this.Insert(0, value);
     }
 
     /// <summary>
@@ -190,48 +199,126 @@ public unsafe struct ImVector<T> where T : unmanaged
     /// </summary>
     public void PopBack()
     {
-        if (size > 0)
+        if (this.size > 0)
         {
-            size--;
+            this.size--;
         }
     }
 
+    public ref T Insert(int index, in T v) {
+        ArgumentOutOfRangeException.ThrowIfNegative(index, nameof(index));
+        ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(index, this.size, nameof(index));
+        this.EnsureCapacity(this.size + 1);
+        if (index < this.size)
+        {
+            Buffer.MemoryCopy(
+                this.data + index,
+                this.data + index + 1,
+                (this.size - index) * sizeof(T),
+                (this.size - index) * sizeof(T));
+        }
+
+        this.data[index] = v;
+        this.size++;
+        return ref this.data[index];
+    }
+
+    public Span<T> InsertRange(int index, ReadOnlySpan<T> v)
+    {
+        ArgumentOutOfRangeException.ThrowIfNegative(index, nameof(index));
+        ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(index, this.size, nameof(index));
+        this.EnsureCapacity(this.size + v.Length);
+        if (index < this.size)
+        {
+            Buffer.MemoryCopy(
+                this.data + index,
+                this.data + index + v.Length,
+                (this.size - index) * sizeof(T),
+                (this.size - index) * sizeof(T));
+        }
+
+        var dstSpan = new Span<T>(this.data + index, v.Length);
+        v.CopyTo(new(this.data + index, v.Length));
+        this.size += v.Length;
+        return dstSpan;
+    }
+
     /// <summary>
     /// Frees the memory allocated for the vector.
     /// </summary>
     public void Free()
     {
-        if (data != null)
+        if (this.data != null)
         {
-            ImGui.MemFree(data);
+            ImGui.MemFree(this.data);
-            data = null;
+            this.data = null;
-            size = 0;
+            this.size = 0;
-            capacity = 0;
+            this.capacity = 0;
         }
     }
 
-    public ref T Ref(int index)
+    public readonly ref T Ref(int index)
     {
-        return ref Unsafe.AsRef<T>((byte*)Data + index * Unsafe.SizeOf<T>());
+        return ref Unsafe.AsRef<T>((byte*)Data + (index * Unsafe.SizeOf<T>()));
     }
 
-    public ref TCast Ref<TCast>(int index)
+    public readonly ref TCast Ref<TCast>(int index)
     {
-        return ref Unsafe.AsRef<TCast>((byte*)Data + index * Unsafe.SizeOf<TCast>());
+        return ref Unsafe.AsRef<TCast>((byte*)Data + (index * Unsafe.SizeOf<TCast>()));
     }
 
-    public void* Address(int index)
+    public readonly void* Address(int index)
     {
-        return (byte*)Data + index * Unsafe.SizeOf<T>();
+        return (byte*)Data + (index * Unsafe.SizeOf<T>());
     }
 
-    public void* Address<TCast>(int index)
+    public readonly void* Address<TCast>(int index)
     {
-        return (byte*)Data + index * Unsafe.SizeOf<TCast>();
+        return (byte*)Data + (index * Unsafe.SizeOf<TCast>());
     }
 
-    public ImVector* ToUntyped()
+    public readonly ImVector* ToUntyped()
     {
-        return (ImVector*)Unsafe.AsPointer(ref this);
+        return (ImVector*)Unsafe.AsPointer(ref Unsafe.AsRef(in this));
+    }
+
+    public readonly Span<T> AsSpan() => new(this.data, this.size);
+
+    public readonly Enumerator GetEnumerator() => new(this.data, this.data + this.size);
+
+    readonly IEnumerator<T> IEnumerable<T>.GetEnumerator() => this.GetEnumerator();
+
+    readonly IEnumerator IEnumerable.GetEnumerator() => this.GetEnumerator();
+
+    public struct Enumerator(T* begin, T* end) : IEnumerator<T>, IEnumerable<T>
+    {
+        private T* current = null;
+
+        public readonly ref T Current => ref *this.current;
+
+        readonly T IEnumerator<T>.Current => this.Current;
+
+        readonly object IEnumerator.Current => this.Current;
+
+        public bool MoveNext()
+        {
+            var next = this.current == null ? begin : this.current + 1;
+            if (next == end)
+                return false;
+            this.current = next;
+            return true;
+        }
+
+        public void Reset() => this.current = null;
+
+        public readonly Enumerator GetEnumerator() => new(begin, end);
+
+        readonly void IDisposable.Dispose()
+        {
+        }
+
+        readonly IEnumerator<T> IEnumerable<T>.GetEnumerator() => this.GetEnumerator();
+
+        readonly IEnumerator IEnumerable.GetEnumerator() => this.GetEnumerator();
     }
 }