From 0d34b02f8821bf114a7ee8e298af6263e7abb8d0 Mon Sep 17 00:00:00 2001
From: Ben Staddon <bs2609@users.noreply.github.com>
Date: Tue, 3 Oct 2017 00:45:58 +0100
Subject: [PATCH] Improve performance of vertex format mapping by caching
 hashcodes (#4370)

---
 .../renderer/vertex/VertexFormat.java.patch   | 38 +++++++++++++++++++
 .../client/model/pipeline/LightUtil.java      | 26 +++++--------
 2 files changed, 48 insertions(+), 16 deletions(-)
 create mode 100644 patches/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java.patch

diff --git a/patches/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java.patch b/patches/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java.patch
new file mode 100644
index 0000000000..e80c6739da
--- /dev/null
+++ b/patches/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java.patch
@@ -0,0 +1,38 @@
+--- ../src-base/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java
++++ ../src-work/minecraft/net/minecraft/client/renderer/vertex/VertexFormat.java
+@@ -17,6 +17,7 @@
+     private int field_177354_e;
+     private final List<Integer> field_177351_f;
+     private int field_177352_g;
++    private int hashCode;
+ 
+     public VertexFormat(VertexFormat p_i46097_1_)
+     {
+@@ -47,6 +48,7 @@
+         this.field_177351_f.clear();
+         this.field_177352_g = -1;
+         this.field_177353_d = 0;
++        this.hashCode = 0;
+     }
+ 
+     @SuppressWarnings("incomplete-switch")
+@@ -75,6 +77,7 @@
+             }
+ 
+             this.field_177353_d += p_181721_1_.func_177368_f();
++            this.hashCode = 0;
+             return this;
+         }
+     }
+@@ -204,9 +207,11 @@
+ 
+     public int hashCode()
+     {
++        if (this.hashCode != 0) return this.hashCode;
+         int i = this.field_177355_b.hashCode();
+         i = 31 * i + this.field_177356_c.hashCode();
+         i = 31 * i + this.field_177353_d;
++        this.hashCode = i;
+         return i;
+     }
+ }
diff --git a/src/main/java/net/minecraftforge/client/model/pipeline/LightUtil.java b/src/main/java/net/minecraftforge/client/model/pipeline/LightUtil.java
index cbdf436e61..21bf325758 100644
--- a/src/main/java/net/minecraftforge/client/model/pipeline/LightUtil.java
+++ b/src/main/java/net/minecraftforge/client/model/pipeline/LightUtil.java
@@ -30,9 +30,8 @@ import net.minecraftforge.client.ForgeHooksClient;
 
 import org.apache.commons.lang3.tuple.Pair;
 
-import com.google.common.cache.CacheBuilder;
-import com.google.common.cache.CacheLoader;
-import com.google.common.cache.LoadingCache;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 
 public class LightUtil
 {
@@ -90,16 +89,7 @@ public class LightUtil
         }
     }
 
-    private static final LoadingCache<Pair<VertexFormat, VertexFormat>, int[]> formatMaps = CacheBuilder.newBuilder()
-        .maximumSize(10)
-        .build(new CacheLoader<Pair<VertexFormat, VertexFormat>, int[]>()
-        {
-            @Override
-            public int[] load(Pair<VertexFormat, VertexFormat> pair)
-            {
-                return mapFormats(pair.getLeft(), pair.getRight());
-            }
-        });
+    private static final ConcurrentMap<Pair<VertexFormat, VertexFormat>, int[]> formatMaps = new ConcurrentHashMap<>();
 
     public static void putBakedQuad(IVertexConsumer consumer, BakedQuad quad)
     {
@@ -110,20 +100,19 @@ public class LightUtil
             consumer.setQuadTint(quad.getTintIndex());
         }
         consumer.setApplyDiffuseLighting(quad.shouldApplyDiffuseLighting());
-        //int[] eMap = mapFormats(consumer.getVertexFormat(), DefaultVertexFormats.ITEM);
         float[] data = new float[4];
         VertexFormat formatFrom = consumer.getVertexFormat();
         VertexFormat formatTo = quad.getFormat();
         int countFrom = formatFrom.getElementCount();
         int countTo = formatTo.getElementCount();
-        int[] eMap = formatMaps.getUnchecked(Pair.of(formatFrom, formatTo));
+        int[] eMap = mapFormats(formatFrom, formatTo);
         for(int v = 0; v < 4; v++)
         {
             for(int e = 0; e < countFrom; e++)
             {
                 if(eMap[e] != countTo)
                 {
-                    unpack(quad.getVertexData(), data, quad.getFormat(), v, eMap[e]);
+                    unpack(quad.getVertexData(), data, formatTo, v, eMap[e]);
                     consumer.put(e, data);
                 }
                 else
@@ -135,6 +124,11 @@ public class LightUtil
     }
 
     public static int[] mapFormats(VertexFormat from, VertexFormat to)
+    {
+        return formatMaps.computeIfAbsent(Pair.of(from, to), pair -> generateMapping(pair.getLeft(), pair.getRight()));
+    }
+
+    private static int[] generateMapping(VertexFormat from, VertexFormat to)
     {
         int fromCount = from.getElementCount();
         int toCount = to.getElementCount();