Add the ability for custom items to show with an enchantment glint (#3766)

api/src/main/java/org/geysermc/geyser/api/item/custom/NonVanillaCustomItemData.java

@@ -129,6 +129,13 @@ public interface NonVanillaCustomItemData extends CustomItemData {
      */
     boolean isHat();
 
+    /**
+     * Gets if the item is a foil. This is used to determine if the item should be rendered with an enchantment glint effect.
+     *
+     * @return if the item is a foil
+     */
+    boolean isFoil();
+
     /**
      * @deprecated Use {@link #displayHandheld()} instead.
      * Gets if the item is a tool. This is used to set the render type of the item, if the item is handheld.
@@ -174,6 +181,8 @@ public interface NonVanillaCustomItemData extends CustomItemData {
 
         Builder hat(boolean isHat);
 
+        Builder foil(boolean isFoil);
+
         /**
          * @deprecated Use {@link #displayHandheld(boolean)} instead.
          */

core/src/main/java/org/geysermc/geyser/item/GeyserNonVanillaCustomItemData.java

@@ -53,6 +53,7 @@ public final class GeyserNonVanillaCustomItemData extends GeyserCustomItemData i
     private final OptionalInt creativeCategory;
     private final String creativeGroup;
     private final boolean isHat;
+    private final boolean isFoil;
     private final boolean isTool;
 
     public GeyserNonVanillaCustomItemData(NonVanillaCustomItemDataBuilder builder) {
@@ -72,6 +73,7 @@ public final class GeyserNonVanillaCustomItemData extends GeyserCustomItemData i
         this.creativeCategory = builder.creativeCategory;
         this.creativeGroup = builder.creativeGroup;
         this.isHat = builder.hat;
+        this.isFoil = builder.foil;
         this.isTool = builder.tool;
     }
 
@@ -140,6 +142,11 @@ public final class GeyserNonVanillaCustomItemData extends GeyserCustomItemData i
         return isHat;
     }
 
+    @Override
+    public boolean isFoil() {
+        return isFoil;
+    }
+
     public static class NonVanillaCustomItemDataBuilder extends GeyserCustomItemData.CustomItemDataBuilder implements NonVanillaCustomItemData.Builder {
         private String identifier = null;
         private int javaId = -1;
@@ -162,6 +169,7 @@ public final class GeyserNonVanillaCustomItemData extends GeyserCustomItemData i
         private String creativeGroup = null;
 
         private boolean hat = false;
+        private boolean foil = false;
         private boolean tool = false;
 
         @Override
@@ -283,6 +291,12 @@ public final class GeyserNonVanillaCustomItemData extends GeyserCustomItemData i
             return this;
         }
 
+        @Override
+        public NonVanillaCustomItemData.Builder foil(boolean isFoil) {
+            this.foil = isFoil;
+            return this;
+        }
+
         @Override
         public NonVanillaCustomItemData build() {
             if (identifier == null || javaId == -1) {

core/src/main/java/org/geysermc/geyser/registry/populator/CustomItemRegistryPopulator.java

@@ -247,6 +247,10 @@ public class CustomItemRegistryPopulator {
             itemProperties.putInt("creative_category", creativeCategory.getAsInt());
         }
 
+        if (customItemData.isFoil()) {
+            itemProperties.putBoolean("foil", true);
+        }
+
         componentBuilder.putCompound("item_properties", itemProperties.build());
         builder.putCompound("components", componentBuilder.build());