using StgSharp.Envitronment.Win32;
using StgSharp.Graphics;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http.Headers;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

#if Windows
#pragma warning disable CA1416

using Windows.Win32.Graphics.Gdi;
using Windows.Win32.Graphics.OpenGL;


namespace StgSharpDebug.Environment
{
    public static unsafe class wglEx
    {

        private static delegate* unmanaged[Stdcall]<HDC, int*, float*, uint, int*, uint*, bool> wglChoosePixelFormatARBpointer;
        private static delegate* unmanaged[Stdcall]<HDC, HGLRC, int*, HGLRC> wglCreateContextAttribsARBpointer;

        public static unsafe bool glChoosePixelFormatARB(
            DeviceContextHandle hdc,
            int[] pixelIntAttributeList,
            out int piFormats,
            out uint piFormatCount)
        {
            if ((ulong)wglChoosePixelFormatARBpointer < 10)
            {
                piFormats = 0;
                piFormatCount = 0;
                return false;
            }
            pixelIntAttributeList = pixelIntAttributeList.Concat([0]).ToArray();
            int pf;
            uint nf;
            fixed (int* pial = pixelIntAttributeList)
            {
                bool ret = wglChoosePixelFormatARBpointer(new HDC(hdc.Value), pial, (float*)0, 1, &pf, &nf);
                piFormats = pf;
                piFormatCount = nf;
                return ret;
            }
        }

        public static unsafe GlRenderContextHandle wglCreateContextAttribsARB(
                            DeviceContextHandle hdc,
            GlRenderContextHandle hglrc,
            int[] pixelFormat)
        {
            if ((ulong)wglCreateContextAttribsARBpointer < 10)
            {
                return default;
            }
            HGLRC h, h_share = new HGLRC(hglrc.Value);
            HDC h_dc = new HDC(hdc.Value);
            fixed (int* format = pixelFormat)
            {
                h = wglCreateContextAttribsARBpointer(h_dc, h_share, format);
                return new GlRenderContextHandle(h);
            }
        }

        internal static void LoadWGLex()
        {
            wglChoosePixelFormatARBpointer = (delegate* unmanaged[Stdcall]<HDC, int*, float*, uint, int*, uint*, bool>)glManager.LoadGLfunc("wglChoosePixelFormatARB");
            wglCreateContextAttribsARBpointer = (delegate* unmanaged[Stdcall]<HDC, HGLRC, int*, HGLRC>)glManager.LoadGLfunc("wglCreateContextAttribsARB");
        }
    }

}

#pragma warning restore CA1416 // 验证平台兼容性
#endif