uniquake/Assets/Scripts/Modules/RenderModule.cs

using System;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using AOT;
using UnityEngine;

public class RenderModule : CallbackHandler<RenderModule>
{
    private const int MaxAliasFrames = 256; // Should match MAXALIASFRAMES
    
    private readonly UniQuake uq;

    public RenderModule(UniQuake uniQuake)
    {
        uq = uniQuake;

        var callbacks = new Callbacks
        {
            target = SelfPtr,

            UploadAliasModel = CreateCallback<UploadAliasModelCallback>(Callback_UploadAliasModel),
        };

        RegisterCallbacks(callbacks);
    }

    /// <summary>
    /// This matches unity_modcalls_t from mod_uniquake.c in native code.
    /// </summary>
    [StructLayout(LayoutKind.Sequential, Pack = 0)]
    private class Callbacks
    {
        public IntPtr target;

        public IntPtr UploadAliasModel;
    }

    [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    private delegate int UploadAliasModelCallback(IntPtr target, [MarshalAs(UnmanagedType.LPStr)] string name,
        QAliasHeader header, IntPtr frames, [MarshalAs(UnmanagedType.LPArray, SizeConst = MaxAliasFrames)]
        IntPtr[] poseVerts, IntPtr triangles, IntPtr stVerts);

    [MonoPInvokeCallback(typeof(UploadAliasModelCallback))]
    private static int Callback_UploadAliasModel(IntPtr target, string name, QAliasHeader header, IntPtr frames, IntPtr[] poseVerts, IntPtr triangles, IntPtr stVerts)
    {
        if (header == null)
        {
            Debug.LogWarning($"Uploading invalid alias model, name = {name}");
            return 0;
        }

        if (frames != IntPtr.Zero)
            header.frames = frames.ToStructArray<QAliasFrameDesc>(header.numFrames);
        
        var poseVertices = new QTriVertex[header.numFrames][];
        for (int i = 0; i < header.numFrames && i < MaxAliasFrames; ++i)
        {
            poseVertices[i] = poseVerts[i].ToStructArray<QTriVertex>(header.numVerts);
        }
        
        return GetSelf(target).UploadAliasModel(name, header, poseVertices,
            triangles.ToStructArray<QTriangle>(header.numTriangles),
            stVerts.ToStructArray<QSTVert>(header.numVerts));
    }

    private int UploadAliasModel(string name, QAliasHeader header, QTriVertex[][] poseVertices, QTriangle[] triangles, QSTVert[] stVertices)
    {
        Debug.Log($"Alias model '{name}' with {header.numVerts} vertices, {header.numTriangles} triangles, {header.numFrames} frame(s)");
        return 1;
    }
}