Introduce support for Minecraft 1.21: Add ReflectionWrapper21, ChunkHider21, and enhance version compatibility across systems.

SpigotCore/SpigotCore_Main/src/de/steamwar/Reflection.java

@@ -157,7 +157,16 @@ public final class Reflection {
 			} else if(MAJOR_VERSION < 21 || MINOR_VERSION < 4) {
 				return Class.forName(spigotClassnames.getOrDefault(name, name));
 			} else {
-				return Class.forName(name);
+				Class<?> clazz = Class.forName(name);
+				if (clazz.getName().equals(name)) {
+					return clazz;
+				}
+
+				try {
+					return Core.class.getClassLoader().getParent().loadClass(name);
+				} catch (ClassNotFoundException e) {
+					return clazz;
+				}
 			}
 		} catch (ClassNotFoundException e) {
 			throw new IllegalArgumentException("Cannot find " + name, e);

SpigotCore/SpigotCore_Main/src/de/steamwar/techhider/ChunkHider.java

@@ -53,6 +53,7 @@ public interface ChunkHider {
 
         private boolean paletted;
         private int bitsPerBlock;
+        private int blockCount;
         private int air;
         private int target;
         private Set<Integer> obfuscate;
@@ -86,7 +87,8 @@ public interface ChunkHider {
         }
 
         public void copyBlockCount() {
-            out.writeShort(in.readShort());
+            this.blockCount = in.readShort();
+            out.writeShort(blockCount);
         }
 
         public void copyBitsPerBlock() {
@@ -140,6 +142,15 @@ public interface ChunkHider {
             out.writeBytes(in, dataArrayLength*8);
         }
 
+        public void skipNewDataArray(int entries) {
+            if (bitsPerBlock == 0) {
+                return;
+            }
+
+            int longs = (int) (((long) entries * bitsPerBlock + 63) >> 6);
+            out.writeBytes(in, longs * Long.BYTES);
+        }
+
         public long[] readDataArray() {
             long[] array = new long[copyVarInt()];
             for(int i = 0; i < array.length; i++)
@@ -148,6 +159,19 @@ public interface ChunkHider {
             return array;
         }
 
+        public long[] readNewDataArray(int entries) {
+            if (bitsPerBlock == 0) {
+                return new long[entries];
+            }
+
+            int longs = (int) (((long) entries * bitsPerBlock + 63) >> 6);
+            long[] array = new long[longs];
+            for(int i = 0; i < longs; i++)
+                array[i] = in.readLong();
+
+            return array;
+        }
+
         public void writeDataArray(long[] array) {
             for(long l : array)
                 out.writeLong(l);

SpigotCore/SpigotCore_Main/src/de/steamwar/techhider/ProtocolUtils.java

@@ -58,6 +58,16 @@ public class ProtocolUtils {
         };
     }
 
+    public static <T> UnaryOperator<T> shallowTypedCloneGenerator(Class<T> clazz) {
+        BiConsumer<Object, Object> filler = shallowFill(clazz);
+
+        return source -> {
+            Object clone = Reflection.newInstance(clazz);
+            filler.accept(source, clone);
+            return (T) clone;
+        };
+    }
+
     private static BiConsumer<Object, Object> shallowFill(Class<?> clazz) {
         if(clazz == null)
             return (source, clone) -> {};

SpigotCore/SpigotCore_Main/src/de/steamwar/techhider/TechHider.java

@@ -79,6 +79,7 @@ public class TechHider {
         techhiders.put(blockChangePacket, this::blockChangeHider);
         techhiders.put(tileEntityDataPacket, this::tileEntityDataHider);
         techhiders.put(multiBlockChangePacket, ProtocolWrapper.impl.multiBlockChangeGenerator(this));
+        System.out.println(ChunkHider.impl.mapChunkPacket().getName());
         techhiders.put(ChunkHider.impl.mapChunkPacket(), ChunkHider.impl.chunkHiderGenerator(this));
 
         if(Core.getVersion() > 12 && Core.getVersion() < 19) {

SpigotCore/SpigotCore_Main/src/plugin.yml

@@ -1,7 +1,7 @@
 name: SpigotCore
 version: "2.0"
 author: Lixfel
-api-version: "1.13"
+api-version: "1.21"
 load: STARTUP
 softdepend:
   - WorldEdit