|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
namespace Windows.Win32.Graphics.GdiPlus;
/// <summary>
/// Helper to ensure GDI+ is initialized before making calls.
/// </summary>
internal static partial class GdiPlusInitialization
{
private static readonly nuint s_initToken = Init();
private static unsafe nuint Init()
{
Debug.Assert(s_initToken == 0, "GdiplusInitialization: Initialize should not be called more than once!");
// GDI+ ref counts multiple calls to Startup in the same process, so calls from multiple
// domains are ok, just make sure to pair each w/GdiplusShutdown
nuint token;
GdiplusStartupInputEx startup = GdiplusStartupInputEx.GetDefault();
PInvokeCore.GdiplusStartup(&token, (GdiplusStartupInput*)&startup, null).ThrowIfFailed();
return token;
}
/// <summary>
/// Returns true if GDI+ has been started.
/// </summary>
/// <remarks>
/// <para>
/// This should be called anywhere you make <see cref="PInvokeCore"/> calls to GDI+ where you don't
/// already have a GDI+ handle. In System.Drawing.Common, this is done in the PInvoke static constructor
/// so it is not necessary for methods defined there.
/// </para>
/// <para>
/// We don't do this implicitly in the Core assembly to avoid unnecessary loading of GDI+.
/// </para>
/// <para>
/// https://github.com/microsoft/CsWin32/issues/1308 tracks a proposal to make this more automatic.
/// </para>
/// </remarks>
internal static bool EnsureInitialized() => s_initToken != 0;
}
|