feat: 项目初始化 + 3D方块世界原型 + AI助搭系统

初始化 monorepo: Go后端(7微服务) + Unity客户端(9模块) + 启动器

HTML5原型: Three.js 3D体素世界, Perlin噪声地形, 原版材质, 22种方块

Minecraft创造模式背包: 双栏布局, 拖拽移动物品, 方向性元件引脚

AI助搭策划文档 + 客户端/服务端骨架 + Docker Compose + CI

launcher/PCL-CE/PCL.Core/Utils/VarIntHelper.cs

@@ -0,0 +1,143 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace PCL.Core.Utils;
+
+public static class VarIntHelper
+{
+    /// <summary>
+    /// 将无符号长整数编码为VarInt字节序列
+    /// </summary>
+    /// <param name="value">要编码的64位无符号整数</param>
+    /// <returns>VarInt字节数组</returns>
+    public static byte[] Encode(ulong value)
+    {
+        using var stream = new MemoryStream();
+        do
+        {
+            var temp = (byte)(value & 0x7F); // 取低7位
+            value >>= 7;                      // 右移7位
+            if (value != 0)                   // 如果还有后续数据
+                temp |= 0x80;                 // 设置最高位为1
+            stream.WriteByte(temp);
+        } while (value != 0);
+        
+        return stream.ToArray();
+    }
+
+    /// <summary>
+    /// 将无符号整数编码为VarInt字节序列
+    /// </summary>
+    /// <param name="value">要编码的32位无符号整数</param>
+    /// <returns>VarInt字节数组</returns>
+    public static byte[] Encode(uint value) => Encode((ulong)value);
+
+    /// <summary>
+    /// 从字节数组中解码无符号长整数
+    /// </summary>
+    /// <param name="bytes">包含VarInt编码的字节数组</param>
+    /// <param name="readLength">读取的字节长度</param>
+    /// <returns>解码后的64位无符号整数</returns>
+    /// <exception cref="ArgumentNullException">输入字节数组为空</exception>
+    /// <exception cref="FormatException">VarInt格式无效或超过最大长度</exception>
+    public static ulong Decode(byte[] bytes, out int readLength)
+    {
+        ArgumentNullException.ThrowIfNull(bytes);
+
+        ulong result = 0;
+        var shift = 0;
+        var bytesRead = 0;
+        const int maxBytes = 10; // ulong最大需要10字节
+        
+        foreach (var b in bytes)
+        {
+            if (bytesRead >= maxBytes)
+                throw new FormatException("VarInt exceeds maximum length");
+            
+            // 取低7位并移位合并
+            result |= (ulong)(b & 0x7F) << shift;
+            bytesRead++;
+            
+            // 检查是否结束
+            if ((b & 0x80) == 0)
+            {
+                readLength = bytesRead;
+                return result;
+            }
+
+            shift += 7;
+        }
+
+        throw new FormatException("Incomplete VarInt encoding");
+    }
+
+    /// <summary>
+    /// 从字节数组中解码无符号整数
+    /// </summary>
+    /// <param name="bytes">包含VarInt编码的字节数组</param>
+    /// <param name="readLength">读取的字节长度</param>
+    /// <returns>解码后的32位无符号整数</returns>
+    public static uint DecodeUInt(byte[] bytes, out int readLength)
+    {
+        var result = Decode(bytes, out readLength);
+        if (result > uint.MaxValue)
+            throw new OverflowException("Decoded value exceeds UInt32 range");
+        return (uint)result;
+    }
+
+    /// <summary>
+    /// 从流中读取并解码无符号长整数，并将流前进所读取的字节数
+    /// </summary>
+    /// <param name="stream">输入流</param>
+    /// <param name="cancellationToken">要监视取消请求的标记</param>
+    /// <returns>解码后的64位无符号整数</returns>
+    /// <exception cref="EndOfStreamException">流提前结束</exception>
+    /// <exception cref="FormatException">VarInt格式无效</exception>
+    public static async Task<ulong> ReadFromStreamAsync(Stream stream, CancellationToken cancellationToken = default)
+    {
+        ulong result = 0;
+        var shift = 0;
+        var bytesRead = 0;
+        const int maxBytes = 10;
+        var buffer = new byte[1];
+        while (true)
+        {
+            var readLength = await stream.ReadAsync(buffer, 0, 1, cancellationToken);
+            if (readLength == 0)
+                throw new EndOfStreamException();
+
+            var b = buffer[0];
+            bytesRead++;
+
+            if (bytesRead > maxBytes)
+                throw new FormatException("VarInt exceeds maximum length");
+
+            result |= (ulong)(b & 0x7F) << shift;
+
+            if ((b & 0x80) == 0)
+                return result;
+
+            shift += 7;
+        }
+    }
+
+    /// <summary>
+    /// 从流中读取并解码无符号整数，并将流前进所读取的字节数
+    /// </summary>
+    /// <param name="stream">输入流</param>
+    /// <param name="cancellationToken"></param>
+    /// <returns>解码后的32位无符号整数</returns>
+    public static async Task<uint> ReadUIntFromStreamAsync(Stream stream, CancellationToken cancellationToken = default)
+    {
+        var result = await ReadFromStreamAsync(stream, cancellationToken);
+        if (result > uint.MaxValue)
+            throw new OverflowException("Decoded value exceeds UInt32 range");
+        return (uint)result;
+    }
+    
+    public static long DecodeZigZag(ulong value) => (long)(value >> 1) ^ -(long)(value & 1);
+
+    public static ulong EncodeZigZag(ulong value) => ((value << 1) ^ (value >> 63));
+}