custom entity variant

src/main/java/net/kaupenjoe/tutorialmod/entity/GeckoVariant.java

@@ -0,0 +1,27 @@
+package net.kaupenjoe.tutorialmod.entity;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+public enum GeckoVariant {
+    BLUE(0),
+    GREEN(1),
+    PINK(2),
+    BROWN(3);
+
+    private static final GeckoVariant[] BY_ID = Arrays.stream(values()).sorted(
+            Comparator.comparingInt(GeckoVariant::getId)).toArray(GeckoVariant[]::new);
+    private final int id;
+
+    GeckoVariant(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public static GeckoVariant byId(int id) {
+        return BY_ID[id % BY_ID.length];
+    }
+}

src/main/java/net/kaupenjoe/tutorialmod/entity/client/GeckoRenderer.java

@@ -1,21 +1,38 @@
 package net.kaupenjoe.tutorialmod.entity.client;
 
+import com.google.common.collect.Maps;
 import com.mojang.blaze3d.vertex.PoseStack;
 import net.kaupenjoe.tutorialmod.TutorialMod;
+import net.kaupenjoe.tutorialmod.entity.GeckoVariant;
 import net.kaupenjoe.tutorialmod.entity.custom.GeckoEntity;
+import net.minecraft.Util;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.renderer.entity.EntityRendererProvider;
 import net.minecraft.client.renderer.entity.MobRenderer;
 import net.minecraft.resources.ResourceLocation;
 
+import java.util.Map;
+
 public class GeckoRenderer extends MobRenderer<GeckoEntity, GeckoModel<GeckoEntity>> {
+    private static final Map<GeckoVariant, ResourceLocation> LOCATION_BY_VARIANT =
+            Util.make(Maps.newEnumMap(GeckoVariant.class), map -> {
+                map.put(GeckoVariant.BLUE,
+                        ResourceLocation.fromNamespaceAndPath(TutorialMod.MOD_ID, "textures/entity/gecko/gecko_blue.png"));
+                map.put(GeckoVariant.GREEN,
+                        ResourceLocation.fromNamespaceAndPath(TutorialMod.MOD_ID, "textures/entity/gecko/gecko_green.png"));
+                map.put(GeckoVariant.PINK,
+                        ResourceLocation.fromNamespaceAndPath(TutorialMod.MOD_ID, "textures/entity/gecko/gecko_pink.png"));
+                map.put(GeckoVariant.BROWN,
+                        ResourceLocation.fromNamespaceAndPath(TutorialMod.MOD_ID, "textures/entity/gecko/gecko_brown.png"));
+            });
+
     public GeckoRenderer(EntityRendererProvider.Context context) {
         super(context, new GeckoModel<>(context.bakeLayer(GeckoModel.LAYER_LOCATION)), 0.25f);
     }
 
     @Override
     public ResourceLocation getTextureLocation(GeckoEntity entity) {
-        return ResourceLocation.fromNamespaceAndPath(TutorialMod.MOD_ID, "textures/entity/gecko/gecko_blue.png");
+        return LOCATION_BY_VARIANT.get(entity.getVariant());
     }
 
     @Override

src/main/java/net/kaupenjoe/tutorialmod/entity/custom/GeckoEntity.java

@@ -1,24 +1,33 @@
 package net.kaupenjoe.tutorialmod.entity.custom;
 
+import net.kaupenjoe.tutorialmod.entity.GeckoVariant;
 import net.kaupenjoe.tutorialmod.entity.ModEntities;
 import net.kaupenjoe.tutorialmod.item.ModItems;
+import net.minecraft.Util;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.syncher.EntityDataAccessor;
+import net.minecraft.network.syncher.EntityDataSerializers;
+import net.minecraft.network.syncher.SynchedEntityData;
 import net.minecraft.server.level.ServerLevel;
-import net.minecraft.world.entity.AgeableMob;
-import net.minecraft.world.entity.AnimationState;
-import net.minecraft.world.entity.EntityType;
+import net.minecraft.world.DifficultyInstance;
+import net.minecraft.world.entity.*;
 import net.minecraft.world.entity.ai.attributes.AttributeSupplier;
 import net.minecraft.world.entity.ai.attributes.Attributes;
 import net.minecraft.world.entity.ai.goal.*;
 import net.minecraft.world.entity.animal.Animal;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
+import net.minecraft.world.level.ServerLevelAccessor;
 import org.jetbrains.annotations.Nullable;
 
 public class GeckoEntity extends Animal {
     public final AnimationState idleAnimationState = new AnimationState();
     private int idleAnimationTimeout = 0;
 
+    private static final EntityDataAccessor<Integer> VARIANT =
+            SynchedEntityData.defineId(GeckoEntity.class, EntityDataSerializers.INT);
+
     public GeckoEntity(EntityType<? extends Animal> entityType, Level level) {
         super(entityType, level);
     }
@@ -53,7 +62,10 @@ public boolean isFood(ItemStack stack) {
     @Nullable
     @Override
     public AgeableMob getBreedOffspring(ServerLevel level, AgeableMob otherParent) {
-        return ModEntities.GECKO.get().create(level);
+        GeckoVariant variant = Util.getRandom(GeckoVariant.values(), this.random);
+        GeckoEntity baby = ModEntities.GECKO.get().create(level);
+        baby.setVariant(variant);
+        return baby;
     }
 
     private void setupAnimationStates() {
@@ -73,4 +85,43 @@ public void tick() {
             this.setupAnimationStates();
         }
     }
+
+    /* VARIANT */
+    @Override
+    protected void defineSynchedData(SynchedEntityData.Builder builder) {
+        super.defineSynchedData(builder);
+        builder.define(VARIANT, 0);
+    }
+
+    private int getTypeVariant() {
+        return this.entityData.get(VARIANT);
+    }
+
+    public GeckoVariant getVariant() {
+        return GeckoVariant.byId(this.getTypeVariant() & 255);
+    }
+
+    private void setVariant(GeckoVariant variant) {
+        this.entityData.set(VARIANT, variant.getId() & 255);
+    }
+
+    @Override
+    public void addAdditionalSaveData(CompoundTag compound) {
+        super.addAdditionalSaveData(compound);
+        compound.putInt("Variant", this.getTypeVariant());
+    }
+
+    @Override
+    public void readAdditionalSaveData(CompoundTag compound) {
+        super.readAdditionalSaveData(compound);
+        this.entityData.set(VARIANT, compound.getInt("Variant"));
+    }
+
+    @Override
+    public SpawnGroupData finalizeSpawn(ServerLevelAccessor level, DifficultyInstance difficulty,
+                                        MobSpawnType spawnType, @Nullable SpawnGroupData spawnGroupData) {
+        GeckoVariant variant = Util.getRandom(GeckoVariant.values(), this.random);
+        this.setVariant(variant);
+        return super.finalizeSpawn(level, difficulty, spawnType, spawnGroupData);
+    }
 }