From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Encode42 <me@encode42.dev>
Date: Tue, 23 Mar 2021 15:40:45 -0400
Subject: [PATCH] Config to disable hostile mob spawn on ice


diff --git a/src/main/java/net/minecraft/world/entity/monster/Monster.java b/src/main/java/net/minecraft/world/entity/monster/Monster.java
index 37539f7680013ab99ed3313b82f9829617d17a71..01eb60c7086be32c64f119a1c492a11cd070a073 100644
--- a/src/main/java/net/minecraft/world/entity/monster/Monster.java
+++ b/src/main/java/net/minecraft/world/entity/monster/Monster.java
@@ -89,6 +89,14 @@ public abstract class Monster extends PathfinderMob implements Enemy {
     }
 
     public static boolean isDarkEnoughToSpawn(ServerLevelAccessor world, BlockPos pos, RandomSource random) {
+        // Purpur start
+        if (!world.getMinecraftWorld().purpurConfig.mobsSpawnOnPackedIce || !world.getMinecraftWorld().purpurConfig.mobsSpawnOnBlueIce) {
+            net.minecraft.world.level.block.state.BlockState spawnBlock = world.getBlockState(pos.below());
+            if ((!world.getMinecraftWorld().purpurConfig.mobsSpawnOnPackedIce && spawnBlock.is(net.minecraft.world.level.block.Blocks.PACKED_ICE)) || (!world.getMinecraftWorld().purpurConfig.mobsSpawnOnBlueIce && spawnBlock.is(net.minecraft.world.level.block.Blocks.BLUE_ICE))) {
+                return false;
+            }
+        }
+        // Purpur end
         if (world.getBrightness(LightLayer.SKY, pos) > random.nextInt(32)) {
             return false;
         } else {
diff --git a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
index 7a7a5ffbee371d92899beb3defee9e6ebf8a9e71..28cfb198b936c24bdad05ce5603847811335d911 100644
--- a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
+++ b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
@@ -540,6 +540,13 @@ public class PurpurWorldConfig {
         furnaceUseLavaFromUnderneath = getBoolean("blocks.furnace.use-lava-from-underneath", furnaceUseLavaFromUnderneath);
     }
 
+    public boolean mobsSpawnOnPackedIce = true;
+    public boolean mobsSpawnOnBlueIce = true;
+    private void iceSettings() {
+        mobsSpawnOnPackedIce = getBoolean("blocks.packed_ice.allow-mob-spawns", mobsSpawnOnPackedIce);
+        mobsSpawnOnBlueIce = getBoolean("blocks.blue_ice.allow-mob-spawns", mobsSpawnOnBlueIce);
+    }
+
     public boolean lavaInfinite = false;
     public int lavaInfiniteRequiredSources = 2;
     public int lavaSpeedNether = 10;