feat: adding VarDoublePacker

same as VarFloatPacker, but for double

Assets/Mirage/Runtime/Serialization/Packers/VarDoublePacker.cs

@@ -0,0 +1,59 @@
+/*
+MIT License
+
+Copyright (c) 2021 James Frowen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+using System;
+
+namespace Mirage.Serialization
+{
+    /// <summary>
+    /// Packs a double using <see cref="ZigZag"/> and <see cref="VarIntBlocksPacker"/>
+    /// </summary>
+    public sealed class VarDoublePacker
+    {
+        private readonly int _blockSize;
+        private readonly double _precision;
+        private readonly double _inversePrecision;
+
+        public VarDoublePacker(double precision, int blockSize)
+        {
+            _precision = precision;
+            _blockSize = blockSize;
+            _inversePrecision = 1 / precision;
+        }
+
+        public void Pack(NetworkWriter writer, double value)
+        {
+            var scaled = (long)Math.Round(value * _inversePrecision);
+            var zig = ZigZag.Encode(scaled);
+            VarIntBlocksPacker.Pack(writer, zig, _blockSize);
+        }
+
+        public double Unpack(NetworkReader reader)
+        {
+            var zig = VarIntBlocksPacker.Unpack(reader, _blockSize);
+            var scaled = ZigZag.Decode(zig);
+            return scaled * _precision;
+        }
+    }
+}