send scores to big display

TanksServer/ServicePointDisplay/FixedSizeCharGridView.cs

@@ -0,0 +1,39 @@
+using System.Text;
+
+namespace TanksServer.ServicePointDisplay;
+
+internal sealed class FixedSizeCharGridView(Memory<byte> data, ushort rowLength, ushort rowCount)
+{
+    public char this[int x, int y]
+    {
+        get => (char)data.Span[x + y * rowLength];
+        set => data.Span[x + y * rowLength] = CharToByte(value);
+    }
+
+    public string this[int row]
+    {
+        get
+        {
+            var rowStart = row * rowLength;
+            return Encoding.UTF8.GetString(data[rowStart..(rowStart + rowLength)].Span);
+        }
+        set
+        {
+            ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(row, rowCount, nameof(row));
+            ArgumentOutOfRangeException.ThrowIfGreaterThan(value.Length, rowLength, nameof(value));
+            var x = 0;
+            for (; x < value.Length; x++)
+                this[x, row] = value[x];
+            for (; x < rowLength; x++)
+                this[x, row] = ' ';
+        }
+    }
+
+    private static byte CharToByte(char c)
+    {
+        ArgumentOutOfRangeException.ThrowIfNegative(c);
+        ArgumentOutOfRangeException.ThrowIfGreaterThan(c, (char)byte.MaxValue, nameof(c));
+        // c# strings are UTF-16
+        return (byte)c;
+    }
+}