uniquake/Assets/Scripts/UniQuake.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using UnityEngine;

public class UniQuake: MonoBehaviour
{
    private const string DllName = "uniquake.dll";
    private const int MemSize = 0x4000000;  // 64 MB of heap space
    private const int MaxArgs = 50;     // Corresponds with MAX_NUM_ARGVS in engine

    private QuakeParms quakeParms;
    private SysCalls sysCalls;

    void Start()
    {
        string[] arguments = 
        {
            "",
            "-window",
            "-width", "1440",
            "-height", "1080",
        };

        IntPtr[] argv = new IntPtr[MaxArgs];
        for (int i = 0; i < arguments.Length && i < MaxArgs; ++i)
        {
            argv[i] = Marshal.StringToHGlobalAnsi(arguments[i]);
        }
        
        quakeParms = new QuakeParms
        {
            baseDir = Application.persistentDataPath,
            cacheDir = null,
            argc = arguments.Length,
            argv = argv,
            memBase = Marshal.AllocHGlobal(MemSize),
            memSize = MemSize,
        };

        sysCalls = new SysCalls(this);

        UniQuake_Init(sysCalls.CallbacksPtr, sysCalls.SelfPtr, quakeParms);
    }

    void Update()
    {
        UniQuake_Update(Time.deltaTime);
    }

    private void OnDestroy()
    {
        sysCalls.Destroy();

        if (quakeParms != null)
        {
            if (quakeParms.memBase != IntPtr.Zero)
            {
                Marshal.FreeHGlobal(quakeParms.memBase);
                quakeParms.memBase = IntPtr.Zero;
            }

            if (quakeParms.argv != null)
            {
                for (int i = 0; i < quakeParms.argv.Length; ++i)
                {
                    if (quakeParms.argv[i] != IntPtr.Zero)
                    {
                        Marshal.FreeHGlobal(quakeParms.argv[i]);
                        quakeParms.argv[i] = IntPtr.Zero;
                    }
                }
            }
        }
    }

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    private static extern void UniQuake_Init(IntPtr callbacks, IntPtr callbackTarget, QuakeParms parms);

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    private static extern void UniQuake_Update(float deltaTime);

    [StructLayout(LayoutKind.Sequential, Pack = 0)]
    private class QuakeParms
    {
        [MarshalAs(UnmanagedType.LPStr)]
        public string baseDir;
        
        [MarshalAs(UnmanagedType.LPStr)]
        public string cacheDir;
        
        public int argc;
        
        [MarshalAs(UnmanagedType.LPArray, SizeConst = MaxArgs)] 
        public IntPtr[] argv;
        
        public IntPtr memBase;
        
        public int memSize;
    }
}