CursorOverlayNativeMethods.cs

using System.Runtime.InteropServices;

namespace SwitchifyPc.Windows.CursorOverlay;

internal static partial class CursorOverlayNativeMethods
{
    internal const int WS_EX_LAYERED = 0x00080000;
    internal const int WS_EX_TRANSPARENT = 0x00000020;
    internal const int WS_EX_TOPMOST = 0x00000008;
    internal const int WS_EX_TOOLWINDOW = 0x00000080;
    internal const int WS_EX_NOACTIVATE = 0x08000000;
    internal const uint SWP_NOSIZE = 0x0001;
    internal const uint SWP_NOMOVE = 0x0002;
    internal const uint SWP_NOACTIVATE = 0x0010;
    internal const uint SWP_SHOWWINDOW = 0x0040;
    internal const int ULW_ALPHA = 0x00000002;
    internal const byte AC_SRC_OVER = 0x00;
    internal const byte AC_SRC_ALPHA = 0x01;
    internal static readonly IntPtr HWND_TOPMOST = new(-1);

    [StructLayout(LayoutKind.Sequential)]
    internal struct Point(int x, int y)
    {
        internal int X = x;
        internal int Y = y;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct Size(int cx, int cy)
    {
        internal int Cx = cx;
        internal int Cy = cy;
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    internal struct BlendFunction
    {
        internal byte BlendOp;
        internal byte BlendFlags;
        internal byte SourceConstantAlpha;
        internal byte AlphaFormat;
    }

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, uint uFlags);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool UpdateLayeredWindow(
        IntPtr hWnd,
        IntPtr hdcDst,
        ref Point pptDst,
        ref Size psize,
        IntPtr hdcSrc,
        ref Point pptSrc,
        int crKey,
        ref BlendFunction pblend,
        int dwFlags);

    [DllImport("user32.dll")]
    internal static extern IntPtr GetDC(IntPtr hWnd);

    [DllImport("user32.dll")]
    internal static extern int ReleaseDC(IntPtr hWnd, IntPtr hdc);

    [DllImport("gdi32.dll")]
    internal static extern IntPtr CreateCompatibleDC(IntPtr hdc);

    [DllImport("gdi32.dll")]
    internal static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj);

    [DllImport("gdi32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool DeleteObject(IntPtr hObject);

    [DllImport("gdi32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool DeleteDC(IntPtr hdc);
}