Feature: Enhanced AI logic and stats tracking for Pong game.

Author: deanthecoder

G33kShell.Desktop/Console/Screensavers/Pong/Brain.cs

@@ -9,40 +9,36 @@
 //
 // THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND.
 
-using System.Numerics;
+using System;
 using CSharp.Core;
 using G33kShell.Desktop.Console.Screensavers.AI;
 
 namespace G33kShell.Desktop.Console.Screensavers.Pong;
 
 public class Brain : AiBrainBase
 {
-    public Brain() : base(GetInputSize(), [10], 6)
+    public const int BrainInputCount = 8;
+
+    public Brain() : base(BrainInputCount, [16], 4)
     {
     }
 
     private Brain(Brain brain) : base(brain)
     {
     }
-
-    private static int GetInputSize() =>
-        new GameState([Vector2.One, Vector2.One], Vector2.One, Vector2.One, 1, 1).ToInputVector().Length;
-
     public (Direction LeftBat, Direction RightBat) ChooseMoves(IAiGameState state)
     {
         var outputs = GetOutputs(state);
 
         var leftBatDirection = Direction.Left; // No move.
-        if (outputs[0] > outputs[1] && outputs[0] > outputs[2])
-            leftBatDirection = Direction.Up;
-        else if (outputs[2] > outputs[0] && outputs[2] > outputs[1])
-            leftBatDirection = Direction.Down;
+        var diff = outputs[0] - outputs[1];
+        if (Math.Abs(diff) > 0.2) // Apply a threshold for a move.
+            leftBatDirection = diff > 0 ? Direction.Up : Direction.Down;
 
         var rightBatDirection = Direction.Left; // No move.
-        if (outputs[3] > outputs[4] && outputs[3] > outputs[5])
-            rightBatDirection = Direction.Up;
-        else if (outputs[5] > outputs[3] && outputs[5] > outputs[4])
-            rightBatDirection = Direction.Down;
+        diff = outputs[2] - outputs[3];
+        if (Math.Abs(diff) > 0.2)
+            rightBatDirection = diff > 0 ? Direction.Up : Direction.Down;
 
         return (leftBatDirection, rightBatDirection);
     }

G33kShell.Desktop/Console/Screensavers/Pong/Game.cs

@@ -23,6 +23,7 @@ public class Game : AiGameBase
 {
     private const int ScoreToWin = 10;
     private const float BatSpeed = 0.22f;
+    private readonly int[] m_batMoves = new int[2];
     private Vector2 m_ballVelocity;
     private int m_ballMoves;
     private int m_rallies;
@@ -36,12 +37,11 @@ public override double Rating
     {
         get
         {
-            if (Scores[0] + Scores[1] == 0)
+            if (Scores[0] * Scores[1] == 0)
                 return 0.0; // No score - rubbish game.
-            return m_rallies * 0.2                                    // Reward rallies.
-                   + m_ballMoves * 0.01                             // ...and long games.
-                   + (ScoreToWin - Math.Abs(Scores[0] - Scores[1])) // Reward balanced scores.
-                   + (Scores[0] + Scores[1]) / (2.0 * ScoreToWin);  // Reward high score. (Note: Might be small if game times-out.)
+            if (Math.Min(m_batMoves[0], m_batMoves[1]) < 300)
+                return 0.0; // No moves - rubbish game.
+            return m_rallies * (Scores[0] + Scores[1]);
         }
     }
 
@@ -50,7 +50,12 @@ public override double Rating
 
     public override IEnumerable<(string Name, string Value)> ExtraGameStats()
     {
-        yield break;
+        yield return ("Ticks", m_ballMoves.ToString());
+        yield return ("Score1", Scores[0].ToString());
+        yield return ("Score2", Scores[1].ToString());
+        yield return ("LeftMoves", m_batMoves[0].ToString());
+        yield return ("RightMoves", m_batMoves[1].ToString());
+        yield return ("Rallies", m_rallies.ToString());
     }
 
     public Game(int arenaWidth, int arenaHeight) : base(arenaWidth, arenaHeight, new Brain())
@@ -65,6 +70,7 @@ public override AiGameBase ResetGame()
         Scores[0] = Scores[1] = 0;
         m_rallies = 0;
         m_ballMoves = 0;
+        m_batMoves[0] = m_batMoves[1] = 0;
 
         return this;
     }
@@ -139,15 +145,21 @@ public override void Tick()
             _ => 0
         };
         if (nextY >= BatHeight / 2.0f && nextY < ArenaHeight - BatHeight / 2.0f)
+        {
             BatPositions[0].Y = nextY;
+            m_batMoves[0]++;
+        }
         nextY = BatPositions[1].Y + BatSpeed * newDirections.RightBat switch
         {
             Direction.Up => -1,
             Direction.Down => 1,
             _ => 0
         };
         if (nextY >= BatHeight / 2.0f && nextY < ArenaHeight - BatHeight / 2.0f)
+        {
             BatPositions[1].Y = nextY;
+            m_batMoves[1]++;
+        }
     }
 
     private void NormalizeBallVelocity() =>

G33kShell.Desktop/Console/Screensavers/Pong/GameState.cs

@@ -8,7 +8,6 @@
 // about your modifications. Your contributions are valued!
 // 
 // THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND.
-using System.Collections.Generic;
 using System.Numerics;
 using CSharp.Core.Extensions;
 using G33kShell.Desktop.Console.Screensavers.AI;
@@ -37,18 +36,21 @@ public GameState(Vector2[] bats, Vector2 ballPosition, Vector2 ballVelocity, int
 
     public double[] ToInputVector()
     {
-        var inputVector = new List<double>();
+        var inputVector = new double[Brain.BrainInputCount];
 
         // Encode bat positions.
-        inputVector.Add(m_bats[0].Y / m_arenaHeight * 2.0f - 1.0f);
-        inputVector.Add(m_bats[1].Y / m_arenaHeight * 2.0f - 1.0f);
-        
+        inputVector[0] = m_bats[0].Y / m_arenaHeight * 2.0f - 1.0f;
+        inputVector[1] = m_bats[1].Y / m_arenaHeight * 2.0f - 1.0f;
+
+        inputVector[2] = (m_bats[0].Y - m_ballPosition.Y) / m_arenaHeight * 2.0f;
+        inputVector[3] = (m_bats[1].Y - m_ballPosition.Y) / m_arenaHeight * 2.0f;
+
         // Encode ball state.
-        inputVector.Add(m_ballPosition.X / m_arenaWidth * 2.0f - 1.0f);
-        inputVector.Add(m_ballPosition.Y / m_arenaHeight * 2.0f - 1.0f);
-        inputVector.Add(m_ballVelocity.X.Clamp(-1.0f, 1.0f));
-        inputVector.Add(m_ballVelocity.Y.Clamp(-1.0f, 1.0f));
+        inputVector[4] = m_ballPosition.X / m_arenaWidth * 2.0f - 1.0f;
+        inputVector[5] = m_ballPosition.Y / m_arenaHeight * 2.0f - 1.0f;
+        inputVector[6] = m_ballVelocity.X.Clamp(-1.0f, 1.0f);
+        inputVector[7] = m_ballVelocity.Y.Clamp(-1.0f, 1.0f);
 
-        return inputVector.ToArray();
+        return inputVector;
     }
 }