better chunk position hashing algo

docs/src/progress/renderertodo.md

@@ -1394,6 +1394,7 @@ Vector pooling
 Simplify WorldOctTree to reduce lag with large node counts
 Increase memory allowance, mostly fixed latency while walking around
 AssetManager streaming budget
+Better chunk position hashing algo
 
 
 

src/main/java/electrosphere/client/block/BlockChunkCache.java

@@ -6,9 +6,10 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.concurrent.locks.ReentrantLock;
 
+import electrosphere.util.math.HashUtils;
+
 /**
  * Caches chunk data on the server
  */
@@ -158,7 +159,7 @@ public class BlockChunkCache {
      * @return The key
      */
     public long getKey(int worldX, int worldY, int worldZ){
-        return Objects.hash(worldX, worldY, worldZ);
+        return HashUtils.hashIVec(worldX, worldY, worldZ);
     }
 
     /**

src/main/java/electrosphere/client/block/ClientBlockManager.java

@@ -7,7 +7,6 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.concurrent.Semaphore;
 
 import org.joml.Vector3i;
@@ -22,6 +21,7 @@ import electrosphere.net.parser.net.message.TerrainMessage;
 import electrosphere.renderer.meshgen.BlockMeshgen.BlockMeshData;
 import electrosphere.server.terrain.manager.ServerTerrainChunk;
 import electrosphere.server.terrain.manager.ServerTerrainManager;
+import electrosphere.util.math.HashUtils;
 
 
 /**
@@ -296,6 +296,6 @@ public class ClientBlockManager {
      * @return The key
      */
     private Long getRequestKey(int worldX, int worldY, int worldZ, int stride){
-        return (long)Objects.hash(worldY, worldZ, worldZ);
+        return (long)HashUtils.hashIVec(worldY, worldZ, worldZ);
     }
 }

src/main/java/electrosphere/client/terrain/cache/ClientTerrainCache.java

@@ -5,11 +5,12 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.concurrent.Semaphore;
 
 import org.joml.Vector3i;
 
+import electrosphere.util.math.HashUtils;
+
 
 
 /**
@@ -151,7 +152,7 @@ public class ClientTerrainCache {
      * @return The cache key
      */
     public long getKey(int worldX, int worldY, int worldZ){
-        return Objects.hash(worldX, worldY, worldZ);
+        return HashUtils.hashIVec(worldX, worldY, worldZ);
     }
     
     /**

src/main/java/electrosphere/client/terrain/manager/ClientTerrainManager.java

@@ -9,7 +9,6 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.UUID;
 import java.util.concurrent.Semaphore;
 
@@ -33,6 +32,7 @@ import electrosphere.renderer.meshgen.TransvoxelModelGeneration;
 import electrosphere.renderer.model.Model;
 import electrosphere.server.terrain.manager.ServerTerrainChunk;
 import electrosphere.server.terrain.manager.ServerTerrainManager;
+import electrosphere.util.math.HashUtils;
 
 /**
  * Manages terrain storage and access on the client
@@ -389,7 +389,7 @@ public class ClientTerrainManager {
      * @return The key
      */
     private Long getRequestKey(int worldX, int worldY, int worldZ, int stride){
-        return (long)Objects.hash(worldY, worldZ, worldZ);
+        return (long)HashUtils.hashIVec(worldY, worldZ, worldZ);
     }
     
 }

src/main/java/electrosphere/server/block/diskmap/ServerBlockChunkDiskMap.java

@@ -6,7 +6,6 @@ import java.nio.ByteBuffer;
 import java.nio.ShortBuffer;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Objects;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.zip.DeflaterOutputStream;
 import java.util.zip.InflaterOutputStream;
@@ -16,6 +15,7 @@ import electrosphere.engine.Globals;
 import electrosphere.logger.LoggerInterface;
 import electrosphere.util.FileUtils;
 import electrosphere.util.annotation.Exclude;
+import electrosphere.util.math.HashUtils;
 
 /**
  * An interface for accessing the disk map of chunk information
@@ -48,7 +48,7 @@ public class ServerBlockChunkDiskMap {
      * @return The key
      */
     private static long getBlockChunkKey(int worldX, int worldY, int worldZ){
-        return Objects.hash(worldX, worldY, worldZ);
+        return HashUtils.hashIVec(worldX, worldY, worldZ);
     }
 
     /**

src/main/java/electrosphere/server/content/ServerContentManager.java

@@ -1,7 +1,6 @@
 package electrosphere.server.content;
 
 import java.util.Collection;
-import java.util.Objects;
 
 import org.joml.Vector3i;
 
@@ -12,6 +11,7 @@ import electrosphere.server.datacell.Realm;
 import electrosphere.server.datacell.ServerDataCell;
 import electrosphere.server.saves.SaveUtils;
 import electrosphere.util.FileUtils;
+import electrosphere.util.math.HashUtils;
 
 public class ServerContentManager {
 
@@ -50,7 +50,7 @@ public class ServerContentManager {
                 contentRaw.hydrateRawContent(realm,cell);
             } else {
                 //else create from scratch
-                ServerContentGenerator.generateContent(realm, cell, worldPos, Objects.hash(worldPos.x, worldPos.y, worldPos.z));
+                ServerContentGenerator.generateContent(realm, cell, worldPos, HashUtils.hashIVec(worldPos.x, worldPos.y, worldPos.z));
             }
         } else {
             //just because content wasn't generated doesn't mean there isn't data saved under that key

src/main/java/electrosphere/server/datacell/gridded/GriddedDataCellManager.java

@@ -7,7 +7,6 @@ import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -42,6 +41,7 @@ import electrosphere.server.fluid.manager.ServerFluidChunk;
 import electrosphere.server.fluid.manager.ServerFluidManager;
 import electrosphere.server.terrain.manager.ServerTerrainManager;
 import electrosphere.server.terrain.models.TerrainModel;
+import electrosphere.util.math.HashUtils;
 import electrosphere.server.terrain.manager.ServerTerrainChunk;
 
 /**
@@ -729,7 +729,7 @@ public class GriddedDataCellManager implements DataCellManager, VoxelCellManager
      * @return The server data cell if it exists, otherwise null
      */
     private Long getServerDataCellKey(Vector3i worldPos){
-        return (long)Objects.hash(worldPos.x, worldPos.y, worldPos.z);
+        return (long)HashUtils.hashIVec(worldPos.x, worldPos.y, worldPos.z);
     }
 
     /**

src/main/java/electrosphere/util/math/HashUtils.java

@@ -0,0 +1,25 @@
+package electrosphere.util.math;
+
+/**
+ * Utilities for hashing things
+ */
+public class HashUtils {
+
+    private static final int SHIFT_Y = 16; // 16 bits per value
+    private static final int SHIFT_Z = 32; // 2 * 16 bits
+    
+    /**
+     * Hashes an integer vector. Must be within the range [0,65536]
+     * @param x The x component
+     * @param y The y component
+     * @param z The z component
+     * @return The hashed value
+     */
+    public static long hashIVec(int x, int y, int z){
+        if (x < 0 || x > 65536 || y < 0 || y > 65536 || z < 0 || z > 65536) {
+            throw new IllegalArgumentException("Values must be in range [0, 65536]");
+        }
+        return ((long) x) | ((long) y << SHIFT_Y) | ((long) z << SHIFT_Z);
+    }
+
+}