From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Thu, 20 Aug 2020 11:20:12 -0700
Subject: [PATCH] Add Wandering Trader spawn rate config options

Adds config options for modifying the spawn rates of Wandering Traders.
These values are all easy to understand and configure after a quick read of this
page on the Minecraft wiki: https://minecraft.gamepedia.com/Wandering_Trader#Spawning
Usages of the vanilla WanderingTraderSpawnDelay and WanderingTraderSpawnChance values
in IWorldServerData are removed as they were only used in certain places, with hardcoded
values used in other places.

diff --git a/src/main/java/net/minecraft/world/entity/npc/WanderingTraderSpawner.java b/src/main/java/net/minecraft/world/entity/npc/WanderingTraderSpawner.java
index 83d0db5a9f03ee3ead10d9f61e5f425330eae0e9..ae9f9112ce9bec82e7571f679017f1723d9eb982 100644
--- a/src/main/java/net/minecraft/world/entity/npc/WanderingTraderSpawner.java
+++ b/src/main/java/net/minecraft/world/entity/npc/WanderingTraderSpawner.java
@@ -40,43 +40,54 @@ public class WanderingTraderSpawner implements CustomSpawner {
 
     public WanderingTraderSpawner(ServerLevelData properties) {
         this.serverLevelData = properties;
-        this.tickDelay = 1200;
-        this.spawnDelay = properties.getWanderingTraderSpawnDelay();
-        this.spawnChance = properties.getWanderingTraderSpawnChance();
-        if (this.spawnDelay == 0 && this.spawnChance == 0) {
-            this.spawnDelay = 24000;
-            properties.setWanderingTraderSpawnDelay(this.spawnDelay);
-            this.spawnChance = 25;
-            properties.setWanderingTraderSpawnChance(this.spawnChance);
-        }
+        // Paper start
+        this.tickDelay = Integer.MIN_VALUE;
+        //this.spawnDelay = properties.getWanderingTraderSpawnDelay(); // Paper - This value is read from the world file only for the first spawn, after which vanilla uses a hardcoded value
+        //this.spawnChance = properties.getWanderingTraderSpawnChance(); // Paper - This value is read from the world file only for the first spawn, after which vanilla uses a hardcoded value
+        //if (this.spawnDelay == 0 && this.spawnChance == 0) {
+        //    this.spawnDelay = 24000;
+        //    properties.setWanderingTraderSpawnDelay(this.spawnDelay);
+        //    this.spawnChance = 25;
+        //    properties.setWanderingTraderSpawnChance(this.spawnChance);
+        //}
+        // Paper end
 
     }
 
     @Override
     public int tick(ServerLevel world, boolean spawnMonsters, boolean spawnAnimals) {
+        // Paper start
+        if (this.tickDelay == Integer.MIN_VALUE) {
+            this.tickDelay = world.paperConfig().entities.spawning.wanderingTrader.spawnMinuteLength;
+            this.spawnDelay = world.paperConfig().entities.spawning.wanderingTrader.spawnDayLength;
+            this.spawnChance = world.paperConfig().entities.spawning.wanderingTrader.spawnChanceMin;
+        }
         if (!world.getGameRules().getBoolean(GameRules.RULE_DO_TRADER_SPAWNING)) {
             return 0;
-        } else if (--this.tickDelay > 0) {
+        } else if (this.tickDelay - 1 > 0) {
+            this.tickDelay = this.tickDelay - 1;
             return 0;
         } else {
-            this.tickDelay = 1200;
-            this.spawnDelay -= 1200;
-            this.serverLevelData.setWanderingTraderSpawnDelay(this.spawnDelay);
+            this.tickDelay = world.paperConfig().entities.spawning.wanderingTrader.spawnMinuteLength;
+            this.spawnDelay = this.spawnDelay - world.paperConfig().entities.spawning.wanderingTrader.spawnMinuteLength;
+            //this.serverLevelData.setWanderingTraderSpawnDelay(this.spawnDelay); // Paper - We don't need to save this value to disk if it gets set back to a hardcoded value anyways
             if (this.spawnDelay > 0) {
                 return 0;
             } else {
-                this.spawnDelay = 24000;
+                this.spawnDelay = world.paperConfig().entities.spawning.wanderingTrader.spawnDayLength;
                 if (!world.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING)) {
                     return 0;
                 } else {
                     int i = this.spawnChance;
 
-                    this.spawnChance = Mth.clamp(this.spawnChance + 25, 25, 75);
                     this.serverLevelData.setWanderingTraderSpawnChance(this.spawnChance);
+                    this.spawnChance = Mth.clamp(i + world.paperConfig().entities.spawning.wanderingTrader.spawnChanceFailureIncrement, world.paperConfig().entities.spawning.wanderingTrader.spawnChanceMin, world.paperConfig().entities.spawning.wanderingTrader.spawnChanceMax);
+                    //this.serverLevelData.setWanderingTraderSpawnChance(this.spawnChance); // Paper - We don't need to save this value to disk if it gets set back to a hardcoded value anyways
                     if (this.random.nextInt(100) > i) {
                         return 0;
                     } else if (this.spawn(world)) {
-                        this.spawnChance = 25;
+                        this.spawnChance = world.paperConfig().entities.spawning.wanderingTrader.spawnChanceMin;
+                        // Paper end
                         return 1;
                     } else {
                         return 0;