added nether decay

src/main/java/de/ellpeck/naturesaura/ModConfig.java

@@ -2,13 +2,9 @@ package de.ellpeck.naturesaura;
 
 import de.ellpeck.naturesaura.api.NaturesAuraAPI;
 import de.ellpeck.naturesaura.api.aura.type.BasicAuraType;
-import de.ellpeck.naturesaura.api.aura.type.IAuraType;
 import de.ellpeck.naturesaura.api.misc.WeightedOre;
 import de.ellpeck.naturesaura.chunk.effect.OreSpawnEffect;
-import net.minecraft.block.Block;
 import net.minecraft.entity.EntityType;
-import net.minecraft.tags.BlockTags;
-import net.minecraft.tags.Tag;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.common.ForgeConfigSpec;
 import net.minecraftforge.registries.ForgeRegistries;
@@ -31,6 +27,7 @@ public final class ModConfig {
     public ForgeConfigSpec.ConfigValue<Boolean> rfConverter;
     public ForgeConfigSpec.ConfigValue<Boolean> chunkLoader;
     public ForgeConfigSpec.ConfigValue<Boolean> grassDieEffect;
+    public ForgeConfigSpec.ConfigValue<Boolean> netherDecayEffect;
     public ForgeConfigSpec.ConfigValue<Boolean> plantBoostEffect;
     public ForgeConfigSpec.ConfigValue<Boolean> cacheRechargeEffect;
     public ForgeConfigSpec.ConfigValue<Boolean> explosionEffect;
@@ -94,6 +91,10 @@ public final class ModConfig {
                 .comment("If the Aura Imbalance effect of grass and trees dying in the area if the Aura levels are too low should occur")
                 .translation("config." + NaturesAura.MOD_ID + ".grassDieEffect")
                 .define("grassDieEffect", true);
+        this.netherDecayEffect = builder
+                .comment("If the Aura Imbalance effect of nether blocks degrading in the area if the Aura levels are too low should occur")
+                .translation("config." + NaturesAura.MOD_ID + ".netherDecayEffect")
+                .define("netherDecayEffect", true);
         this.plantBoostEffect = builder
                 .comment("If the Aura Imbalance effect of plant growth being boosted if the Aura levels are high enough should occur")
                 .translation("config." + NaturesAura.MOD_ID + ".plantBoostEffect")
@@ -165,9 +166,8 @@ public final class ModConfig {
     }
 
     public void apply() {
-        if (!this.grassDieEffect.get() && !this.explosionEffect.get() && !this.breathlessEffect.get()) {
+        if (!this.grassDieEffect.get() && !this.netherDecayEffect.get() && !this.explosionEffect.get() && !this.breathlessEffect.get())
             throw new IllegalStateException("Nature's Aura has detected that all negative Aura Imbalance effects are disabled in the config file. This is disallowed behavior. Please enable at least one negative effect.");
-        }
 
         try {
             for (String s : this.additionalBotanistPickaxeConversions.get()) {

src/main/java/de/ellpeck/naturesaura/chunk/effect/DrainSpotEffects.java

@@ -16,6 +16,7 @@ public final class DrainSpotEffects {
         NaturesAuraAPI.DRAIN_SPOT_EFFECTS.put(AnimalEffect.NAME, AnimalEffect::new);
         NaturesAuraAPI.DRAIN_SPOT_EFFECTS.put(OreSpawnEffect.NAME, OreSpawnEffect::new);
         NaturesAuraAPI.DRAIN_SPOT_EFFECTS.put(NetherGrassEffect.NAME, NetherGrassEffect::new);
+        NaturesAuraAPI.DRAIN_SPOT_EFFECTS.put(NetherDecayEffect.NAME, NetherDecayEffect::new);
 
         NaturesAuraAPI.EFFECT_POWDERS.put(PlantBoostEffect.NAME, 0xc2f442);
         NaturesAuraAPI.EFFECT_POWDERS.put(CacheRechargeEffect.NAME, 0x1fb0d1);

src/main/java/de/ellpeck/naturesaura/chunk/effect/NetherDecayEffect.java

@@ -0,0 +1,103 @@
+package de.ellpeck.naturesaura.chunk.effect;
+
+import de.ellpeck.naturesaura.ModConfig;
+import de.ellpeck.naturesaura.NaturesAura;
+import de.ellpeck.naturesaura.api.NaturesAuraAPI;
+import de.ellpeck.naturesaura.api.aura.chunk.IAuraChunk;
+import de.ellpeck.naturesaura.api.aura.chunk.IDrainSpotEffect;
+import de.ellpeck.naturesaura.api.aura.type.IAuraType;
+import net.minecraft.block.AbstractFireBlock;
+import net.minecraft.block.Block;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.Blocks;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.tags.BlockTags;
+import net.minecraft.util.Direction;
+import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+import net.minecraft.world.chunk.Chunk;
+
+public class NetherDecayEffect implements IDrainSpotEffect {
+
+    public static final ResourceLocation NAME = new ResourceLocation(NaturesAura.MOD_ID, "nether_decay");
+
+    private int amount;
+    private int dist;
+
+    private boolean calcValues(World world, BlockPos pos, Integer spot) {
+        if (spot >= 0)
+            return false;
+        int aura = IAuraChunk.getAuraInArea(world, pos, 50);
+        if (aura >= 0)
+            return false;
+        this.amount = Math.min(300, MathHelper.ceil(Math.abs(aura) / 50000F / IAuraChunk.getSpotAmountInArea(world, pos, 50)));
+        if (this.amount <= 1)
+            return false;
+        this.dist = MathHelper.clamp(Math.abs(aura) / 50000, 5, 75);
+        return true;
+    }
+
+    @Override
+    public ActiveType isActiveHere(PlayerEntity player, Chunk chunk, IAuraChunk auraChunk, BlockPos pos, Integer spot) {
+        if (!this.calcValues(player.world, pos, spot))
+            return ActiveType.INACTIVE;
+        if (player.getDistanceSq(pos.getX(), pos.getY(), pos.getZ()) > this.dist * this.dist)
+            return ActiveType.INACTIVE;
+        return ActiveType.ACTIVE;
+    }
+
+    @Override
+    public ItemStack getDisplayIcon() {
+        return new ItemStack(Items.SOUL_SAND);
+    }
+
+    @Override
+    public void update(World world, Chunk chunk, IAuraChunk auraChunk, BlockPos pos, Integer spot) {
+        if (!this.calcValues(world, pos, spot))
+            return;
+        for (int i = this.amount / 2 + world.rand.nextInt(this.amount / 2); i >= 0; i--) {
+            BlockPos offset = new BlockPos(
+                    pos.getX() + world.rand.nextGaussian() * this.dist,
+                    pos.getY() + world.rand.nextGaussian() * this.dist,
+                    pos.getZ() + world.rand.nextGaussian() * this.dist);
+            if (offset.distanceSq(pos) > this.dist * this.dist || !world.isBlockLoaded(offset))
+                continue;
+
+            // degrade blocks
+            Block degraded = null;
+            BlockState state = world.getBlockState(offset);
+            if (state.getBlock() == Blocks.GLOWSTONE) {
+                degraded = Blocks.NETHERRACK;
+            } else if (state.getBlock().isIn(BlockTags.NYLIUM) || state.getBlock() == Blocks.NETHERRACK) {
+                degraded = Blocks.SOUL_SOIL;
+            } else if (state.getBlock() == Blocks.SOUL_SOIL) {
+                degraded = Blocks.SOUL_SAND;
+            }
+            if (degraded != null) {
+                world.playEvent(2001, offset, Block.getStateId(state));
+                world.setBlockState(offset, degraded.getDefaultState());
+            }
+
+            // ignite blocks
+            if (AbstractFireBlock.canLightBlock(world, offset, Direction.NORTH)) {
+                BlockState fire = AbstractFireBlock.getFireForPlacement(world, offset);
+                world.setBlockState(offset, fire);
+                world.playEvent(1009, offset, 0);
+            }
+        }
+    }
+
+    @Override
+    public boolean appliesHere(Chunk chunk, IAuraChunk auraChunk, IAuraType type) {
+        return ModConfig.instance.netherDecayEffect.get() && type.isSimilar(NaturesAuraAPI.TYPE_NETHER);
+    }
+
+    @Override
+    public ResourceLocation getName() {
+        return NAME;
+    }
+}

src/main/resources/data/naturesaura/patchouli_books/book/en_us/entries/effects/nether_decay.json

@@ -0,0 +1,12 @@
+{
+    "name": "Crimson Decay",
+    "icon": "minecraft:soul_sand",
+    "category": "effects",
+    "advancement": "naturesaura:negative_imbalance",
+    "pages": [
+        {
+            "type": "text",
+            "text": "As it turns out, the effects of $(l:effects/decay)Natural Decay$() extend to the $(thing)nether$() in a way: When the $(aura) levels are low enough, $(item)netherrack$() and other blocks will start to $(thing)decay$() as well. First, they will transform into $(item)soul soil$(), then into $(item)soul sand$(), inevitably making the area truly hard to traverse. Additionally, blocks will also start to $(thing)ignite$() seemingly at random."
+        }
+    ]
+}