Implement drop rates for world monster drops

src/main/java/emu/lunarcore/data/excel/MappingInfoExcel.java

@@ -25,6 +25,7 @@ public class MappingInfoExcel extends GameResource {
     private String FarmType; // is enum
     private List<ItemParam> DisplayItemList;
     
+    // Temp solution for handling drop tables
     private transient List<DropParam> dropList;
     
     @Override
@@ -35,7 +36,12 @@ public class MappingInfoExcel extends GameResource {
     @Override
     public void onLoad() {
         // Temp way to pre-calculate drop list
-        this.dropList = new ArrayList<>(this.getDisplayItemList().size());
+        if (this.DisplayItemList == null || DisplayItemList.size() == 0) {
+            this.dropList = new ArrayList<>(0);
+            return;
+        }
+        
+        this.dropList = new ArrayList<>(DisplayItemList.size());
         
         var equipmentDrops = new IntArrayList();
         var relicDrops = new Int2ObjectOpenHashMap<IntList>();

src/main/java/emu/lunarcore/data/excel/MonsterDropExcel.java

@@ -1,24 +1,80 @@
 package emu.lunarcore.data.excel;
 
+import java.util.ArrayList;
 import java.util.List;
 
+import emu.lunarcore.GameConstants;
+import emu.lunarcore.data.GameData;
 import emu.lunarcore.data.GameResource;
 import emu.lunarcore.data.ResourceType;
+import emu.lunarcore.data.ResourceType.LoadPriority;
 import emu.lunarcore.data.common.ItemParam;
+import emu.lunarcore.game.drops.DropParam;
 import lombok.Getter;
 
 @Getter
-@ResourceType(name = {"MonsterDrop.json"})
+@ResourceType(name = {"MonsterDrop.json"}, loadPriority = LoadPriority.LOW)
 public class MonsterDropExcel extends GameResource {
     private int MonsterTemplateID;
     private int WorldLevel;
     private int AvatarExpReward;
 
     private List<ItemParam> DisplayItemList;
+    
+    // Temp solution for handling drop tables
+    private transient List<DropParam> dropList;
 
     @Override
     public int getId() {
         return (MonsterTemplateID << 4) + WorldLevel;
     }
 
+    @Override
+    public void onLoad() {
+        // Temp way to pre-calculate drop list
+        if (this.getDisplayItemList() == null || this.getDisplayItemList().size() == 0) {
+            this.dropList = new ArrayList<>(0);
+            return;
+        }
+        
+        this.dropList = new ArrayList<>(this.getDisplayItemList().size());
+        
+        for (var itemParam : this.getDisplayItemList()) {
+            // Add item param if the amount is already set in the excel
+            if (itemParam.getCount() > 0) {
+                dropList.add(new DropParam(itemParam.getId(), itemParam.getCount()));
+                continue;
+            }
+            
+            // TODO drop rate is not correct
+            if (itemParam.getId() == GameConstants.MATERIAL_COIN_ID) {
+                dropList.add(new DropParam(itemParam.getId(), getAvatarExpReward()));
+                continue;
+            }
+            
+            // Get item excel
+            ItemExcel itemExcel = GameData.getItemExcelMap().get(itemParam.getId());
+            if (itemExcel == null) continue;
+            
+            // TODO drop rate is not correct
+            double mod = switch (itemExcel.getRarity()) {
+                case NotNormal -> 0.8;
+                case Rare -> 0.3;
+                case VeryRare -> 0.125;
+                case SuperRare -> 0;
+                default -> 1.0;
+            };
+            
+            double baseAmount = this.getWorldLevel() + 3;
+            
+            // Create drop param
+            var drop = new DropParam(itemParam.getId(), 1);
+            drop.setMaxCount((int) Math.ceil(baseAmount * mod));
+            drop.setMinCount((int) Math.floor(baseAmount * mod * 0.5));
+            
+            if (drop.getMaxCount() > 0) {
+                dropList.add(drop);
+            }
+        }
+    }
 }

src/main/java/emu/lunarcore/game/drops/DropService.java

@@ -5,7 +5,6 @@ import java.util.List;
 
 import emu.lunarcore.GameConstants;
 import emu.lunarcore.data.GameData;
-import emu.lunarcore.data.common.ItemParam;
 import emu.lunarcore.data.excel.ItemExcel;
 import emu.lunarcore.game.battle.Battle;
 import emu.lunarcore.game.inventory.GameItem;
@@ -28,19 +27,10 @@ public class DropService extends BaseGameService {
         // Calculate drops from monsters
         for (EntityMonster monster : battle.getNpcMonsters()) {
             var dropExcel = GameData.getMonsterDropExcel(monster.getExcel().getId(), monster.getWorldLevel());
-            if (dropExcel == null || dropExcel.getDisplayItemList() == null) {
-                continue;
-            }
+            if (dropExcel == null) continue;
             
-            for (ItemParam param : dropExcel.getDisplayItemList()) {
-                int id = param.getId();
-                int count = Utils.randomRange(0, 3);
-                
-                if (id == 2) {
-                    count = dropExcel.getAvatarExpReward();
-                }
-                
-                dropMap.addTo(id, count);
+            for (var dropParam : dropExcel.getDropList()) {
+                dropParam.roll(dropMap);
             }
         }
         

src/main/java/emu/lunarcore/game/enums/ItemRarity.java

@@ -4,12 +4,12 @@ import lombok.Getter;
 
 @Getter
 public enum ItemRarity {
-    Unknown (0),
-    Normal (1),
-    NotNormal (2),
-    Rare (3),
-    VeryRare (4),
-    SuperRare (5);
+    Unknown     (0),
+    Normal      (1),
+    NotNormal   (2),
+    Rare        (3),
+    VeryRare    (4),
+    SuperRare   (5);
 
     private int val;