optimized faces

FaceData.cs

@@ -2,25 +2,42 @@
 
 namespace Voxel
 {
+    [StructLayout(LayoutKind.Sequential, Pack = 1)]
     public struct FaceData
     {
-        public Orientation Facing;
-        public byte X, Y, Z;
-        public Textures Texture;
-        public byte LightLevel;
+        public uint _data;
+
+        // Bit layout:
+        // [31-24]: Y (8 bits) 0-255
+        // [23-20]: Z (4 bits) 0-15
+        // [19-16]: X (4 bits) 0-15
+        // [15-10]: Texture (6 bits) 0-63
+        // [9-7]:   Facing (3 bits) 0-7
+        // [6-3]:   Light (4 bits) 0-15
+        // [2-0]:   unused (3 bits)
+
+        public FaceData(byte x, byte y, byte z, Orientation facing, Textures texture, byte lightLevel)
+        {
+            _data = (uint)(
+                ((y & 0xFF) << 24) |      // 8 bits
+                ((z & 0x0F) << 20) |      // 4 bits
+                ((x & 0x0F) << 16) |      // 4 bits
+                (((byte)texture & 0x3F) << 10) | // 6 bits (0-63)
+                (((byte)facing & 0x07) << 7) |   // 3 bits
+                ((lightLevel & 0x0F) << 3)       // 4 bits
+            );
+        }
+
+        public byte X => (byte)((_data >> 16) & 0x0F);
+        public byte Y => (byte)((_data >> 24) & 0xFF);
+        public byte Z => (byte)((_data >> 20) & 0x0F);
+        public Orientation Facing => (Orientation)((_data >> 7) & 0x07);
+        public Textures Texture => (Textures)((_data >> 10) & 0x3F);
+        public byte LightLevel => (byte)((_data >> 3) & 0x0F);
 
         public byte[] Pack()
         {
-            return new byte[]
-            {
-                X,
-                Y,
-                Z,
-                (byte)Facing,
-                (byte)Texture,
-                LightLevel,
-                0,0 // two bits empty
-            };
+            return BitConverter.GetBytes(_data);
         }
     }
 }