Fix new minecart with block breaking furnace minecart display (#717)

This handles DISPLAY_ITEM and related properties separately on furnace minecarts in order to prevent overwriting furnace minecart graphics.

Co-authored-by: DoctorMacc <toy.fighter1@gmail.com>

connector/src/main/java/org/geysermc/connector/entity/FurnaceMinecartEntity.java

@@ -34,6 +34,11 @@ import org.geysermc.connector.network.translators.world.block.BlockTranslator;
 
 public class FurnaceMinecartEntity extends MinecartEntity {
 
+    private int customBlock = 0;
+    private int customBlockOffset = 0;
+    private boolean showCustomBlock = false;
+    private boolean hasFuel = false;
+
     public FurnaceMinecartEntity(long entityId, long geyserId, EntityType entityType, Vector3f position, Vector3f motion, Vector3f rotation) {
         super(entityId, geyserId, entityType, position, motion, rotation);
 
@@ -43,12 +48,39 @@ public class FurnaceMinecartEntity extends MinecartEntity {
 
     @Override
     public void updateBedrockMetadata(EntityMetadata entityMetadata, GeyserSession session) {
-        if (entityMetadata.getId() == 13) {
-            boolean hasFuel = (boolean) entityMetadata.getValue();
 
-            metadata.put(EntityData.DISPLAY_ITEM, BlockTranslator.getBedrockBlockId(hasFuel ? BlockTranslator.JAVA_RUNTIME_FURNACE_LIT_ID : BlockTranslator.JAVA_RUNTIME_FURNACE_ID));
+        // Custom block
+        if (entityMetadata.getId() == 10) {
+            customBlock = (int) entityMetadata.getValue();
+        }
+
+        // Custom block offset
+        if (entityMetadata.getId() == 11) {
+            customBlockOffset = (int) entityMetadata.getValue();
+        }
+
+        // If the custom block should be enabled
+        if (entityMetadata.getId() == 12) {
+            if ((boolean) entityMetadata.getValue()) {
+                showCustomBlock = true;
+                metadata.put(EntityData.DISPLAY_ITEM, BlockTranslator.getBedrockBlockId(customBlock));
+                metadata.put(EntityData.DISPLAY_OFFSET, customBlockOffset);
+            } else {
+                showCustomBlock = false;
+                updateFurnaceMetadata();
+            }
+        }
+
+        if (entityMetadata.getId() == 13 && !showCustomBlock) {
+            hasFuel = (boolean) entityMetadata.getValue();
+            updateFurnaceMetadata();
         }
 
         super.updateBedrockMetadata(entityMetadata, session);
     }
+
+    private void updateFurnaceMetadata() {
+        metadata.put(EntityData.DISPLAY_ITEM, BlockTranslator.getBedrockBlockId(hasFuel ? BlockTranslator.JAVA_RUNTIME_FURNACE_LIT_ID : BlockTranslator.JAVA_RUNTIME_FURNACE_ID));
+        metadata.put(EntityData.DISPLAY_OFFSET, 6);
+    }
 }

connector/src/main/java/org/geysermc/connector/entity/MinecartEntity.java

@@ -55,6 +55,7 @@ public class MinecartEntity extends Entity {
             metadata.put(EntityData.HURT_TIME, Math.min((int) (float) entityMetadata.getValue(), 15));
         }
 
+        if (!(this instanceof FurnaceMinecartEntity)) { // Handled in FurnaceMinecartEntity.java
             // Custom block
             if (entityMetadata.getId() == 10) {
                 metadata.put(EntityData.DISPLAY_ITEM, BlockTranslator.getBedrockBlockId((int) entityMetadata.getValue()));
@@ -70,6 +71,7 @@ public class MinecartEntity extends Entity {
                 // Needs a byte based off of Java's boolean
                 metadata.put(EntityData.HAS_DISPLAY, (byte) ((boolean) entityMetadata.getValue() ? 1 : 0));
             }
+        }
 
         super.updateBedrockMetadata(entityMetadata, session);
     }