/// <summary>
/// runs the main brain a few times after mutating it and returns its average score
/// </summary>
/// <param name="mutateMagnitude">The magnitude by which mutations can happen</param>
/// <param name="iterations">The number of times the snake plays the game before returning the average score.</param>
/// <param name="mutateNRR">Determines how much mutation magnitude distrubution conforms to a normal distribution.</param>
/// <returns>the average score</returns>
private double ModeTrainAI(double mutateMagnitude = .1, int mutateNRR = 4, int iterations = 100, int mutationChance = 5)
{
SnakeBrain.Mutate(mutateMagnitude, mutateNRR, mutationChance);
double averageScore = 0;
for (int i = 0; i < iterations; i++)
{
NewBoard(i);
while (Board1.Progress1Tick())
{
RunBrain();
}
averageScore += CalculateScore();
}
return(averageScore / iterations);
}
/// <summary>
/// runs the main brain a few times after mutating it and returns its average score
/// </summary>
/// <param name="mutateMagnitude">The magnitude by which mutations can happen</param>
/// <param name="iterations">The number of times the snake plays the game before returning the average score.</param>
/// <param name="mutateNRR">Determines how much mutation magnitude distrubution conforms to a normal distribution.</param>
/// <param name="randomly">Whether or not to use deterministic brain changes</param>
/// <param name="incrementor">if non-random then this must should increment by 1 each call</param>
/// <returns>the average score</returns>
private double ModeTrainAI(double mutateMagnitude = .1, int mutateNRR = 4, int iterations = 100, int nrOfMutations = 2, bool randomly = false, int incrementor = 0)
{
if (randomly)
{
SnakeBrain.Mutate(mutateMagnitude, mutateNRR, nrOfMutations);
}
double averageScore = 0;
for (int i = 0; i < iterations; i++)
{
NewBoard(i);
while (Board1.Progress1Tick())
{
RunBrain(Board1, SnakeBrain);
}
averageScore += CalculateScore(Board1);
}
return(averageScore / iterations);
}
private void RunBrain()
{
double[] tailDistances = new double[4] {
Board1.WidthHeight - 1,
Board1.WidthHeight - 1,
Board1.WidthHeight - 1,
Board1.WidthHeight - 1
};
for (int i = 0; i < Board1.TailLength; i++)
{
if (Board1.TailY[i] == Board1.SnakeHeadY)
{
tailDistances[0] = Math.Min(tailDistances[0], Board1.DistanceLeft(Board1.SnakeHeadX, Board1.TailX[i]));
tailDistances[2] = Math.Min(tailDistances[2], Board1.DistanceRight(Board1.SnakeHeadX, Board1.TailX[i]));
}
if (Board1.TailX[i] == Board1.SnakeHeadX)
{
tailDistances[1] = Math.Min(tailDistances[1], Board1.DistanceUp(Board1.SnakeHeadY, Board1.TailY[i]));
tailDistances[3] = Math.Min(tailDistances[3], Board1.DistanceDown(Board1.SnakeHeadY, Board1.TailY[i]));
}
}
int[] foodDistances = new int[4] {
Board1.DistanceLeft(Board1.SnakeHeadX, Board1.FoodX),
Board1.DistanceUp(Board1.SnakeHeadY, Board1.FoodY),
Board1.DistanceRight(Board1.SnakeHeadX, Board1.FoodX),
Board1.DistanceDown(Board1.SnakeHeadY, Board1.FoodY)
};
int k = (int)Board1.SnakeDirection;
int horizontalDistance;
int verticalDistance;
if (foodDistances[k] > foodDistances[(k + 2) % 4])
{
verticalDistance = -foodDistances[(k + 2) % 4];
}
else
{
verticalDistance = foodDistances[k];
}
if (foodDistances[(k + 1) % 4] > foodDistances[(k + 3) % 4])
{
horizontalDistance = -foodDistances[(k + 3) % 4];
}
else
{
horizontalDistance = foodDistances[(k + 1) % 4];
}
double[] perceptronsValues = new double[4]
{
//a bearing value to the next food piece relative to the current snake heading.
//vertical goes into the x argument to make sure that a dead ahead food direction leads to a value of 0
Math.Atan2(horizontalDistance, verticalDistance),
//whether or not a tail piece is ahead of, to the left of or to the right of the snake head
tailDistances[k],
tailDistances[(k + 3) % 4],
tailDistances[(k + 1) % 4],
};
//calculate what the brain "thinks" that it should do
double[] brainThoughts = SnakeBrain.InputToOutput(perceptronsValues);
double maxvalue = brainThoughts.Max();
for (int i = 0; i < 3; i++)
{
if (maxvalue == brainThoughts[i])
{
if (i == 1)
{
Board1.ChangeDirection(Board.Direction.right);
}
else if (i == 2)
{
Board1.ChangeDirection(Board.Direction.left);
}
}
}
}