From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <kfian294ma4@gmail.com>
Date: Sun, 24 Dec 2023 16:54:07 +0000
Subject: [PATCH] Optimise check inside blocks and fluids


diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index f2dab7d69cd26474de88eae95b47f68414232cf6..80dfd159f8f71f9a6de38334d9ec5a50120ed324 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -1763,14 +1763,34 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
         BlockPos blockposition = new BlockPos(axisalignedbb.minX + 0.001D, axisalignedbb.minY + 0.001D, axisalignedbb.minZ + 0.001D);
         BlockPos blockposition1 = new BlockPos(axisalignedbb.maxX - 0.001D, axisalignedbb.maxY - 0.001D, axisalignedbb.maxZ - 0.001D);
 
-        if (this.level.hasChunksAt(blockposition, blockposition1)) {
+        // Sakura start - optimise check inside blocks
+        if (blockposition1.getY() >= this.level.getMinBuildHeight() || blockposition.getY() < this.level.getMaxBuildHeight()) {
             BlockPos.MutableBlockPos blockposition_mutableblockposition = new BlockPos.MutableBlockPos();
 
+            net.minecraft.server.level.ServerChunkCache chunkSource = ((net.minecraft.server.level.ServerLevel) this.level).getChunkSource();
+            net.minecraft.world.level.chunk.ChunkAccess chunk = null;
+            int lastChunkX = Integer.MIN_VALUE;
+            int lastChunkZ = Integer.MIN_VALUE;
+
             for (int i = blockposition.getX(); i <= blockposition1.getX(); ++i) {
-                for (int j = blockposition.getY(); j <= blockposition1.getY(); ++j) {
-                    for (int k = blockposition.getZ(); k <= blockposition1.getZ(); ++k) {
+                int chunkX = i >> 4;
+                for (int k = blockposition.getZ(); k <= blockposition1.getZ(); ++k) {
+                    int chunkZ = k >> 4;
+
+                    if (lastChunkX != chunkX || lastChunkZ != chunkZ) {
+                        chunk = chunkSource.getChunkAtIfLoadedMainThread(chunkX, chunkZ);
+                        lastChunkX = chunkX;
+                        lastChunkZ = chunkZ;
+                    }
+
+                    if (chunk == null) {
+                        continue;
+                    }
+
+                    for (int j = blockposition.getY(); j <= blockposition1.getY(); ++j) {
                         blockposition_mutableblockposition.set(i, j, k);
-                        BlockState iblockdata = this.level.getBlockState(blockposition_mutableblockposition);
+                        BlockState iblockdata = chunk.getBlockState(blockposition_mutableblockposition);
+                        // Sakura end
 
                         try {
                             iblockdata.entityInside(this.level, blockposition_mutableblockposition, this);
@@ -4245,7 +4265,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
     }
 
     public boolean updateFluidHeightAndDoFluidPushing(TagKey<Fluid> tag, double speed) {
-        if (this.touchingUnloadedChunk()) {
+        if (false) { // Sakura
             return false;
         } else {
             AABB axisalignedbb = this.getBoundingBox().deflate(0.001D);
@@ -4262,11 +4282,31 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
             int k1 = 0;
             BlockPos.MutableBlockPos blockposition_mutableblockposition = new BlockPos.MutableBlockPos();
 
+            // Sakura start
+            net.minecraft.server.level.ServerChunkCache chunkSource = ((net.minecraft.server.level.ServerLevel) this.level).getChunkSource();
+            net.minecraft.world.level.chunk.ChunkAccess chunk = null;
+            int lastChunkX = Integer.MIN_VALUE;
+            int lastChunkZ = Integer.MIN_VALUE;
+
             for (int l1 = i; l1 < j; ++l1) {
-                for (int i2 = k; i2 < l; ++i2) {
-                    for (int j2 = i1; j2 < j1; ++j2) {
+                int chunkX = l1 >> 4;
+                for (int j2 = i1; j2 < j1; ++j2) {
+                    int chunkZ = j2 >> 4;
+
+                    if (chunkX != lastChunkX || chunkZ != lastChunkZ) {
+                        chunk = chunkSource.getChunkAtIfLoadedMainThread(chunkX, chunkZ);
+                        lastChunkX = chunkX;
+                        lastChunkZ = chunkZ;
+                    }
+
+                    if (chunk == null) {
+                        return false;
+                    }
+
+                    for (int i2 = k; i2 < l; ++i2) {
                         blockposition_mutableblockposition.set(l1, i2, j2);
-                        FluidState fluid = this.level.getFluidState(blockposition_mutableblockposition);
+                        FluidState fluid = chunk.getFluidState(blockposition_mutableblockposition);
+                        // Sakura end
 
                         if (fluid.is(tag)) {
                             double d2 = (double) ((float) i2 + fluid.getHeight(this.level, blockposition_mutableblockposition));