/// <summary>
/// Mutates a random connection splitting it with a node.
/// </summary>
public void Mutate_Node()
{
ConnectionGene connectionGene = Connections.GetRandomElement();
if (connectionGene == null)
{
return;
}
NodeGene from = connectionGene.From;
NodeGene to = connectionGene.To;
NodeGene created = NEAT.CreateNode();
created.X = (from.X + to.X) / 2;
created.Y = (from.Y + to.Y) / 2 + random.NextDouble() * 0.1 + .05;
Nodes.Add(created);
ConnectionGene created_connectionGene_1 = NEAT.CreateConnection(from, created);
ConnectionGene created_connectionGene_2 = NEAT.CreateConnection(created, to);
Connections.Remove(connectionGene);
Connections.Add(created_connectionGene_1);
Connections.Add(created_connectionGene_2);
created_connectionGene_1.Weight = 1; //Default weight.
created_connectionGene_2.Weight = connectionGene.Weight; //Old connection's weight.
created_connectionGene_2.Enabled = connectionGene.Enabled; //Old enabled state.
}
/// <summary>
/// Constructs a connection gene with the given innovation number.
/// </summary>
/// <param name="from">The NodeGene to connect from.</param>
/// <param name="to">The NodeGene to connect to.</param>
/// <param name="innovation_number">The innovation number.</param>
public ConnectionGene(NodeGene from, NodeGene to, int innovation_number) :
base(innovation_number)
{
From = from;
To = to;
Enabled = true;
}
/// <summary>
/// Mutates the genome by creating a new connection.
/// </summary>
public void Mutate_Link()
{
for (int i = 0; i < NEAT.LINK_ATTEMPTS; ++i)
{
NodeGene nodeGene_a = Nodes.GetRandomElement();
NodeGene nodeGene_b = Nodes.GetRandomElement();
if (nodeGene_a.X == nodeGene_b.X)
{
continue;
}
ConnectionGene connectionGene;
if (nodeGene_a.X < nodeGene_b.X)
{
connectionGene = new ConnectionGene(nodeGene_a, nodeGene_b, 0); //Temp innovation number.
}
else
{
connectionGene = new ConnectionGene(nodeGene_b, nodeGene_a, 0); //Temp innovation number.
}
if (Connections.Contains(connectionGene))
{
continue;
}
connectionGene = NEAT.CreateConnection(connectionGene.From, connectionGene.To);
connectionGene.Weight = NEAT.WEIGHT_RANDOM + (random.NextDouble() * 2 - 1);
Connections.Add_Sorted_Gene(connectionGene); //This needs to be sorted otherwise something breaks.
return;
}
}
