feature: first

CringeLauncher/ImGuiHandler.cs

@@ -0,0 +1,93 @@
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.UI.WindowsAndMessaging;
+using CringePlugins.Abstractions;
+using CringePlugins.Render;
+using ImGuiNET;
+using SharpDX.Direct3D11;
+using static ImGuiNET.ImGui;
+
+namespace CringeLauncher;
+
+internal class ImGuiHandler : IDisposable
+{
+    private readonly DeviceContext _deviceContext;
+    private static nint _wndproc;
+
+    public static ImGuiHandler? Instance;
+    
+    public static RenderTargetView? Rtv;
+    private readonly IRootRenderComponent _renderHandler;
+
+    public ImGuiHandler(nint windowHandle, Device1 device, DeviceContext deviceContext)
+    {
+        _deviceContext = deviceContext;
+
+        _renderHandler = new RenderHandler();
+        
+        CreateContext();
+        
+        var io = GetIO();
+
+        io.ConfigWindowsMoveFromTitleBarOnly = true;
+        io.ConfigFlags |= ImGuiConfigFlags.DockingEnable | ImGuiConfigFlags.ViewportsEnable;
+        
+        ImGui_ImplWin32_Init(windowHandle);
+        ImGui_ImplDX11_Init(device.NativePointer, deviceContext.NativePointer);
+    }
+
+    public void HookWindow(HWND windowHandle)
+    {
+        _wndproc = PInvoke.GetWindowLongPtr(windowHandle, WINDOW_LONG_PTR_INDEX.GWL_WNDPROC);
+
+        unsafe
+        {
+            delegate* unmanaged[Stdcall]<HWND, int, nint, nint, int> wndProcHook = &WndProcHook;
+            
+            PInvoke.SetWindowLongPtr(windowHandle, WINDOW_LONG_PTR_INDEX.GWL_WNDPROC, (nint)wndProcHook);
+        }
+    }
+
+    public void DoRender()
+    {
+        if (Rtv is null)
+            throw new InvalidOperationException("Rtv is null");
+        
+        ImGui_ImplDX11_NewFrame();
+        ImGui_ImplWin32_NewFrame();
+        NewFrame();
+        
+        _renderHandler.OnFrame();
+        
+        Render();
+        
+        _deviceContext.ClearState();
+        _deviceContext.OutputMerger.SetRenderTargets(Rtv);
+        
+        ImGui_ImplDX11_RenderDrawData(GetDrawData());
+        
+        UpdatePlatformWindows();
+        RenderPlatformWindowsDefault();
+    }
+    
+    [UnmanagedCallersOnly(CallConvs = [typeof(CallConvStdcall)])]
+    private static int WndProcHook(HWND hWnd, int msg, nint wParam, nint lParam)
+    {
+        var hookResult = ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam);
+        return hookResult == 0 ? CallWindowProc(_wndproc, hWnd, msg, wParam, lParam) : hookResult;
+    }
+        
+    [DllImport("USER32.dll", ExactSpelling = true, EntryPoint = "CallWindowProcW")]
+    [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
+    [SupportedOSPlatform("windows5.0")]
+    private static extern int CallWindowProc(nint lpPrevWndFunc, HWND hWnd, int msg, nint wParam, nint lParam);
+
+    public void Dispose()
+    {
+        _deviceContext.Dispose();
+        _renderHandler.Dispose();
+    }
+}