private NeatGenome <T> CreateGenomeInner(NeatGenome <T> parent1, NeatGenome <T> parent2)
{
// Randomly select one parent as being the primary parent.
if (_rng.NextBool())
{
VariableUtils.Swap(ref parent1, ref parent2);
}
// Enumerate over the connection genes in both parents.
foreach (var geneIndexPair in EnumerateParentGenes(parent1.ConnectionGenes, parent2.ConnectionGenes))
{
// Create a connection gene based on the current position in both parents.
ConnectionGene <T>?connGene = CreateConnectionGene(
parent1.ConnectionGenes, parent2.ConnectionGenes,
geneIndexPair.Item1, geneIndexPair.Item2,
out bool isSecondaryGene);
if (connGene.HasValue)
{
// Attempt to add the gene to the child genome we are building.
_builder.TryAddGene(connGene.Value, isSecondaryGene);
}
}
// Convert the genes to the structure required by NeatGenome.
var connGenes = _builder.ToConnectionGenes();
// Create and return a new genome.
return(_genomeBuilder.Create(
_genomeIdSeq.Next(),
_generationSeq.Peek,
connGenes));
}
private NeatGenome <T> CreateGenomeInner(
NeatGenome <T> parent1,
NeatGenome <T> parent2,
IRandomSource rng)
{
// Resolve a flag that determines if *all* disjoint genes from the secondary parent will be included in the child genome, or not.
// This approach is from SharpNEAT v2.x and is preserved to act as baseline in v4.x, but better strategies may exist.
bool includeSecondaryParentGene = DiscreteDistribution.SampleBernoulli(rng, _secondaryParentGeneProbability);
// Enumerate over the connection genes in both parents.
foreach (var geneIndexPair in EnumerateParentGenes(parent1.ConnectionGenes, parent2.ConnectionGenes))
{
// Create a connection gene based on the current position in both parents.
ConnectionGene <T>?connGene = CreateConnectionGene(
parent1.ConnectionGenes, parent2.ConnectionGenes,
geneIndexPair.Item1, geneIndexPair.Item2,
includeSecondaryParentGene, rng);
if (connGene.HasValue)
{ // Attempt to add the gene to the child genome we are building.
_connGeneListBuilder.TryAddGene(connGene.Value);
}
}
// Convert the genes to the structure required by NeatGenome.
ConnectionGenes <T> connGenes = _connGeneListBuilder.ToConnectionGenes();
// Create and return a new genome.
return(_genomeBuilder.Create(
_genomeIdSeq.Next(),
_generationSeq.Peek,
connGenes));
}