Genetics: GenomeTemplate (per-organism gene allotment) + breed override

Adds the species/organism layer on top of the gene foundation. GenomeTemplate carries which GeneDefs an individual has plus the per-organism base value and spread its alleles are drawn around (and an optional discrete-variant override), so the same shared GeneDef expresses different centres for different species — Generate() draws an individual, Registry() feeds breeding and trait computation. Genome.Breed gains an optional mutationChance that overrides every gene's fixed MutationChance, so a caller can drive mutation from an evolvable trait. Allele sampling (numeric spread+clamp, weighted discrete pick) is factored into a shared GeneSampling used by both Generate paths. Covered by GenomeTemplateTests (per-species centres, registry-driven breeding, mutation override on/off). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-12 23:51:02 +03:00
parent bc18db5df6
commit ead22517ee
4 changed files with 240 additions and 51 deletions
@@ -0,0 +1,106 @@
+using MrGameEng.Genetics;
+using Xunit;
+
+namespace MrGameEng.Genetics.Tests;
+
+public class GenomeTemplateTests
+{
+    private static GeneDef Numeric(string name, float min, float max) =>
+        new()
+        {
+            DefName = name,
+            Kind = GeneKind.Numeric,
+            Min = min,
+            Max = max,
+        };
+
+    private static GeneDef Discrete(string name, int variants = 2) =>
+        new()
+        {
+            DefName = name,
+            Kind = GeneKind.Discrete,
+            Variants = variants,
+        };
+
+    [Fact]
+    public void Generate_UsesPerEntryBaseAndSpread_NotGeneDefault()
+    {
+        var gene = Numeric("opt", min: 0f, max: 100f); // GeneDef.Default is 0
+        var template = new GenomeTemplate([
+            new GenomeTemplate.Entry(gene, Base: 50f, Spread: 0.1f),
+        ]);
+        var random = new Random(3);
+
+        for (var i = 0; i < 200; i++)
+        {
+            var allele = template.Generate(random)["opt"];
+            Assert.InRange(allele.A, 45f, 55f); // around the template base, not 0
+            Assert.InRange(allele.B, 45f, 55f);
+        }
+    }
+
+    [Fact]
+    public void Generate_TwoSpecies_DifferInCentre()
+    {
+        var gene = Numeric("opt", 0f, 100f);
+        var oak = new GenomeTemplate([new GenomeTemplate.Entry(gene, 20f, 0f)]);
+        var grass = new GenomeTemplate([new GenomeTemplate.Entry(gene, 80f, 0f)]);
+
+        Assert.Equal(20f, oak.Generate(new Random(1)).Express(gene), 3);
+        Assert.Equal(80f, grass.Generate(new Random(1)).Express(gene), 3);
+    }
+
+    [Fact]
+    public void Registry_CoversEntries_AndDrivesBreeding()
+    {
+        var template = new GenomeTemplate([
+            new GenomeTemplate.Entry(Numeric("a", 0f, 10f), 5f, 0.1f),
+            new GenomeTemplate.Entry(Discrete("morph"), 0f, 0f),
+        ]);
+        var random = new Random(9);
+        var a = template.Generate(random);
+        var b = template.Generate(random);
+
+        var child = Genome.Breed(a, b, template.Registry, random);
+
+        Assert.True(child.Has("a"));
+        Assert.True(child.Has("morph"));
+    }
+
+    [Fact]
+    public void Breed_MutationChanceOverride_ForcesMutation()
+    {
+        var gene = Numeric("a", min: -100f, max: 100f);
+        var registry = new Dictionary<string, GeneDef> { ["a"] = gene };
+        var parent = new Genome { ["a"] = new Allele(10f, 10f) };
+
+        // Override chance to 1 → every inherited allele mutates away from 10.
+        var moved = false;
+        for (var seed = 0; seed < 30 && !moved; seed++)
+        {
+            var child = Genome.Breed(
+                parent,
+                parent,
+                registry,
+                new Random(seed),
+                mutationChance: 1f
+            );
+            moved = child["a"].A != 10f || child["a"].B != 10f;
+        }
+
+        Assert.True(moved, "with overridden mutationChance=1 the allele should mutate");
+    }
+
+    [Fact]
+    public void Breed_MutationChanceZero_KeepsAlleles()
+    {
+        var gene = Numeric("a", -100f, 100f);
+        var registry = new Dictionary<string, GeneDef> { ["a"] = gene };
+        var parent = new Genome { ["a"] = new Allele(10f, 10f) };
+
+        var child = Genome.Breed(parent, parent, registry, new Random(5), mutationChance: 0f);
+
+        Assert.Equal(10f, child["a"].A);
+        Assert.Equal(10f, child["a"].B);
+    }
+}