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Source/Engine/Engine/Windows/WindowsGame.cpp

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_WINDOWS && !USE_EDITOR
+
+#include "WindowsGame.h"
+#include "Engine/Engine/Globals.h"
+#include "Engine/Engine/CommandLine.h"
+#include "Engine/Core/Config/PlatformSettings.h"
+
+void WindowsGame::InitMainWindowSettings(CreateWindowSettings& settings)
+{
+    // TODO: restore window size and fullscreen mode from the cached local settings saved after previous session
+
+    const auto platformSettings = WindowsPlatformSettings::Instance();
+    auto windowMode = platformSettings->WindowMode;
+
+    // Use command line switches
+    if (CommandLine::Options.Fullscreen.IsTrue())
+        windowMode = GameWindowMode::Fullscreen;
+    else if (CommandLine::Options.Windowed.IsTrue())
+        windowMode = GameWindowMode::Windowed;
+
+    settings.Fullscreen = windowMode == GameWindowMode::Fullscreen;
+    settings.HasSizingFrame = platformSettings->ResizableWindow;
+
+    // Fullscreen - put window to cover the whole desktop area
+    if (windowMode == GameWindowMode::FullscreenBorderless ||
+        windowMode == GameWindowMode::Fullscreen)
+    {
+        settings.Size = Platform::GetDesktopSize();
+        settings.Position = Vector2::Zero;
+    }
+        // Not fullscreen - put window in the middle of the screen
+    else if (windowMode == GameWindowMode::Windowed ||
+        windowMode == GameWindowMode::Borderless)
+    {
+        settings.Size = Vector2((float)platformSettings->ScreenWidth, (float)platformSettings->ScreenHeight);
+        settings.Position = (Platform::GetDesktopSize() - settings.Size) / 2;
+    }
+
+    // Windowed mode
+    settings.HasBorder = windowMode == GameWindowMode::Windowed || windowMode == GameWindowMode::Fullscreen;
+    settings.AllowMinimize = platformSettings->ResizableWindow;
+}
+
+bool WindowsGame::Init()
+{
+    const auto platformSettings = WindowsPlatformSettings::Instance();
+
+    // Create mutex if need to
+    if (platformSettings->ForceSingleInstance)
+    {
+        if (Platform::CreateMutex(*Globals::ProductName))
+        {
+            Platform::ReleaseMutex();
+            Platform::Error(String::Format(TEXT("Only one instance of {0} can be run at the same time."), Globals::ProductName));
+            return true;
+        }
+    }
+
+    return GameBase::Init();
+}
+
+void WindowsGame::BeforeExit()
+{
+    Platform::ReleaseMutex();
+
+    GameBase::BeforeExit();
+}
+
+#endif