Initial CEF and DirectX overlay implementation (PoC, unfinished)

Still pretty unstable, game might crash at times.
Revamp build system and other small fixes

Client/CefHost/CefProcessor.cs

@@ -0,0 +1,128 @@
+using System;
+using System.Drawing;
+using BitmapUtil;
+using CefSharp;
+using CefSharp.Enums;
+using CefSharp.OffScreen;
+using CefSharp.Structs;
+using Size = System.Drawing.Size;
+
+namespace RageCoop.Client.CefHost
+{
+    internal class CefProcessor : IRenderHandler
+    {
+        private readonly CefAdapter _adapter;
+        private readonly BufferMode _mode;
+        private readonly IntPtr _pSharedBuffer;
+        private Rect _rect;
+
+        public CefProcessor(Size size, CefAdapter adapter, IntPtr pSharedBuffer, BufferMode mode)
+        {
+            _adapter = adapter;
+            _rect = new Rect(0, 0, size.Width, size.Height);
+            _pSharedBuffer = pSharedBuffer;
+            _mode = mode;
+            _adapter?.Resized(size);
+        }
+
+        public Size Size
+        {
+            get => new Size(_rect.Width, _rect.Height);
+            set
+            {
+                _rect = new Rect(0, 0, value.Width, value.Height);
+                _adapter?.Resized(value);
+            }
+        }
+
+        public void Dispose()
+        {
+        }
+
+        public ScreenInfo? GetScreenInfo()
+        {
+            return null;
+        }
+
+        public Rect GetViewRect()
+        {
+            return _rect;
+        }
+
+        public bool GetScreenPoint(int viewX, int viewY, out int screenX, out int screenY)
+        {
+            screenX = viewX;
+            screenY = viewY;
+            return true;
+        }
+
+        public void OnAcceleratedPaint(PaintElementType type, Rect dirtyRect, IntPtr sharedHandle)
+        {
+        }
+
+        public void OnPaint(PaintElementType type, Rect dirtyRect, IntPtr buffer, int width, int height)
+        {
+            var dirty = new Rectangle
+            {
+                Width = dirtyRect.Width,
+                Height = dirtyRect.Height,
+                X = dirtyRect.X,
+                Y = dirtyRect.Y
+            };
+            var source = new BitmapInfo
+            {
+                Width = width,
+                Height = height,
+                BytesPerPixel = 4,
+                Scan0 = buffer
+            };
+
+            switch (_mode)
+            {
+                case BufferMode.Dirty:
+                    Unsafe.CopyRegion(source, _pSharedBuffer, dirty);
+                    break;
+                case BufferMode.Full:
+                {
+                    var target = source;
+                    target.Scan0 = _pSharedBuffer;
+                    Unsafe.UpdateRegion(source, target, dirty, dirty.Location);
+                    break;
+                }
+            }
+
+            _adapter?.Paint(dirty);
+        }
+
+        public void OnCursorChange(IntPtr cursor, CursorType type, CursorInfo customCursorInfo)
+        {
+        }
+
+        public bool StartDragging(IDragData dragData, DragOperationsMask mask, int x, int y)
+        {
+            return true;
+        }
+
+        public void UpdateDragCursor(DragOperationsMask operation)
+        {
+        }
+
+        public void OnPopupShow(bool show)
+        {
+        }
+
+        public void OnPopupSize(Rect rect)
+        {
+        }
+
+        public void OnImeCompositionRangeChanged(Range selectedRange, Rect[] characterBounds)
+        {
+            ;
+        }
+
+        public void OnVirtualKeyboardRequested(IBrowser browser, TextInputMode inputMode)
+        {
+            ;
+        }
+    }
+}