populationEntity[] crossover2(populationEntity left, populationEntity right)
{
int[] leftNetworkStructure = left.networkStructure;
populationEntity[] crossover = new populationEntity[2];
for (int h = 1; h < leftNetworkStructure.Length; h++)
{
float randi = Random.Range(0, leftNetworkStructure[h - 1]);
float randj = Random.Range(0, leftNetworkStructure[h]);
for (int i = 0; i < leftNetworkStructure[h]; i++)
{
for (int j = 0; j < leftNetworkStructure[h - 1]; j++)
{
if (i < randi || (i == randi && j <= randj))
{
float tempw1 = left.weights[h - 1][i, j];
left.weights[h - 1][i, j] = right.weights[h - 1][i, j];
right.weights[h - 1][i, j] = tempw1;
}
}
}
}
crossover[0] = left;
crossover[1] = right;
//bias?
return(crossover);
}
populationEntity[] crossover(populationEntity left, populationEntity right)
{
int[] leftNetworkStructure = left.networkStructure;
populationEntity[] crossover = new populationEntity[2];
for (int h = 1; h < leftNetworkStructure.Length; h++)
{
for (int i = 0; i < leftNetworkStructure[h]; i++)
{
for (int j = 0; j < leftNetworkStructure[h - 1]; j++)
{
if (Random.Range(0f, 1f) < crossOverProbability)
{
float tempw1 = left.weights[h - 1][i, j];
left.weights[h - 1][i, j] = right.weights[h - 1][i, j];
right.weights[h - 1][i, j] = tempw1;
}
}
}
}
crossover[0] = left;
crossover[1] = right;
//bias?
return(crossover);
}
populationEntity[] selection(populationEntity[] pop, float[] probabilities)
{
populationEntity[] selection = new populationEntity[2];
selection[0] = pop[getRandomIntWithProbability(probabilities)];
selection[1] = pop[getRandomIntWithProbability(probabilities)];
return(selection);
}
// Update is called once per frame
void Update()
{
if (!currentSnake.GetComponent <ISnake>().isAlive())
{
population[currentSnakeNumber].score = currentSnake.GetComponent <ISnake>().getScore();
population[currentSnakeNumber].timeAlive = currentSnake.GetComponent <ISnake>().getTimeAlive();
population[currentSnakeNumber].collidedWithWall = currentSnake.GetComponent <ISnake>().isCollidedWithWall();
population[currentSnakeNumber].distanceFromFood = currentSnake.GetComponent <ISnake>().getDistanceFromFood();
population[currentSnakeNumber].fitness = getSurvivalScore(population[currentSnakeNumber]);
currentTotal += population[currentSnakeNumber].score;
averageCurrentGeneration = currentTotal / (currentSnakeNumber + 1);
if (population[currentSnakeNumber].fitness > highestFitness)
{
highestFitness = population[currentSnakeNumber].fitness;
bestSnake = population[currentSnakeNumber];
}
if (population[currentSnakeNumber].score > best)
{
best = population[currentSnakeNumber].score;
}
if (population[currentSnakeNumber].score > bestCurrentGeneration)
{
bestCurrentGeneration = population[currentSnakeNumber].score;
}
foreach (GameObject tailPart in currentSnake.GetComponent <ISnake>().getSnake())
{
Destroy(tailPart);
}
Destroy(currentSnake);
GameObject food = GameObject.Find("FoodSpawner").GetComponent <FoodSpawner>().food;
Destroy(food);
GameObject.Find("FoodSpawner").GetComponent <FoodSpawner>().Spawn();
currentSnake = nextInPopulation();
currentSnake.GetComponent <ISnake>().Initialize(population[currentSnakeNumber].weights, population[currentSnakeNumber].biases, population[currentSnakeNumber].networkStructure, population[currentSnakeNumber].color);
}
}
void Start()
{
Vector2 map = GameObject.Find("Map").GetComponent <MapGenerator>().mapSize;
top = (int)map.y / 2 - 1;
bottom = (int)-map.y / 2 + 1;
right = (int)map.x / 2 - 1;
left = (int)-map.x / 2 + 1;
population = new populationEntity[populationSize];
for (int i = 0; i < populationSize; i++)
{
population[i] = new populationEntity(networkStructure);
}
currentSnakeNumber = 0;
currentGeneration = 0;
currentSnake = Instantiate(snakePrefab, new Vector3(0, 0.5f, 0), Quaternion.identity);
currentSnake.GetComponent <ISnake>().Initialize(population[currentSnakeNumber].weights, population[currentSnakeNumber].biases, population[currentSnakeNumber].networkStructure, population[currentSnakeNumber].color);
}
populationEntity mutate(populationEntity populationEntity)
{
int[] popNetworkStructure = populationEntity.networkStructure;
for (int h = 1; h < popNetworkStructure.Length; h++)
{
for (int i = 0; i < popNetworkStructure[h]; i++)
{
for (int j = 0; j < popNetworkStructure[h - 1]; j++)
{
if (Random.Range(0f, 1f) < mutationProbability)
{
populationEntity.weights[h - 1][i, j] += gaussian(0f, mutationRate) / 5;
//clamp?
}
}
}
}
//Bias?
return(populationEntity);
}
GameObject nextInPopulation()
{
if (currentSnakeNumber != populationSize - 1)
{
currentSnakeNumber += 1;
}
else
{
currentGeneration += 1;
currentSnakeNumber = 0;
float totalScore = 0f;
bestCurrentGeneration = 0f;
if (averageCurrentGeneration > bestAverage)
{
bestAverage = averageCurrentGeneration;
}
averageCurrentGeneration = 0f;
currentTotal = 0f;
foreach (populationEntity pop in population.OrderByDescending(x => getSurvivalScore(x)))
{
totalScore += getSurvivalScore(pop);
}
float[] probabilities = new float[populationSize];
for (int i = 0; i < populationSize; i++)
{
//probabilities[i] = linearRanking(populationSize,i,1.75f);
//Smoothing
probabilities[i] = (getSurvivalScore(population[i]) + smoothing) / (totalScore + populationSize * smoothing);
}
for (int i = elites; i < populationSize - randoms; i++)
{
populationEntity[] sel = selection(population, probabilities);
populationEntity[] cv = crossover2(sel[0], sel[1]);
population[i] = mutate(cv[0]);
}
for (int i = populationSize - randoms; i < populationSize; i++)
{
population[i] = new populationEntity(networkStructure);
}
for (int i = 0; i < elites; i++)
{
population[i] = bestSnake;
}
}
int xc = (int)Random.Range(left, right);
int z = (int)Random.Range(bottom, top);
// xc = 0;
// z = 0;
return(Instantiate(snakePrefab, new Vector3(xc, 0.5f, z), Quaternion.identity));
}
float getSurvivalScore(populationEntity popEnt)
{
float score = Mathf.Pow(2, popEnt.score) + Mathf.Pow(popEnt.timeAlive, 2);
return(score);
}
