Paper/Spigot-Server-Patches/0091-Optimized-Light-Level-Comparisons.patch

From 40da4eaa1b6515d51742dc8a7bb9960666a75299 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 18 Mar 2016 21:22:56 -0400
Subject: [PATCH] Optimized Light Level Comparisons

Use an optimized method to test if a block position meets a desired light level.

This method benefits from returning as soon as the desired light level matches.

diff --git a/src/main/java/net/minecraft/server/BlockCrops.java b/src/main/java/net/minecraft/server/BlockCrops.java
index 5f8bffe..ab8d18e 100644
--- a/src/main/java/net/minecraft/server/BlockCrops.java
+++ b/src/main/java/net/minecraft/server/BlockCrops.java
@@ -48,7 +48,7 @@ public class BlockCrops extends BlockPlant implements IBlockFragilePlantElement
 
     public void b(World world, BlockPosition blockposition, IBlockData iblockdata, Random random) {
         super.b(world, blockposition, iblockdata, random);
-        if (world.getLightLevel(blockposition.up()) >= 9) {
+        if (world.isLightLevel(blockposition.up(), 9)) { // Paper
             int i = this.x(iblockdata);
 
             if (i < this.g()) {
diff --git a/src/main/java/net/minecraft/server/BlockGrass.java b/src/main/java/net/minecraft/server/BlockGrass.java
index fe55848..8fc736d 100644
--- a/src/main/java/net/minecraft/server/BlockGrass.java
+++ b/src/main/java/net/minecraft/server/BlockGrass.java
@@ -29,7 +29,8 @@ public class BlockGrass extends Block implements IBlockFragilePlantElement {
 
     public void b(World world, BlockPosition blockposition, IBlockData iblockdata, Random random) {
         if (!world.isClientSide) {
-            if (world.getLightLevel(blockposition.up()) < 4 && world.getType(blockposition.up()).c() > 2) {
+            int lightLevel = -1; // Paper
+            if (world.getType(blockposition.up()).c() > 2 && (lightLevel = world.getLightLevel(blockposition.up())) < 4) { // Paper - move light check to end to avoid unneeded light lookups
                 // CraftBukkit start
                 // world.setTypeUpdate(blockposition, Blocks.DIRT.getBlockData());
                 org.bukkit.World bworld = world.getWorld();
@@ -44,18 +45,25 @@ public class BlockGrass extends Block implements IBlockFragilePlantElement {
                 }
                 // CraftBukkit end
             } else {
-                if (world.getLightLevel(blockposition.up()) >= 9) {
+                // Paper start
+                // If light was calculated above, reuse it, else grab it
+                if (lightLevel == -1) {
+                    lightLevel = world.getLightLevel(blockposition.up());
+                }
+                if (lightLevel >= 9) {
+                    // Paper end
                     for (int i = 0; i < 4; ++i) {
                         BlockPosition blockposition1 = blockposition.a(random.nextInt(3) - 1, random.nextInt(5) - 3, random.nextInt(3) - 1);
 
-                        if (blockposition1.getY() >= 0 && blockposition1.getY() < 256 && !world.isLoaded(blockposition1)) {
+                        IBlockData iblockdata2 = world.getTypeIfLoaded(blockposition1); // Paper - moved up
+                        if (iblockdata2 == null) { // Paper
                             return;
                         }
 
                         IBlockData iblockdata1 = world.getType(blockposition1.up());
-                        IBlockData iblockdata2 = world.getType(blockposition1);
+                        //IBlockData iblockdata2 = world.getTypeIfLoaded(blockposition1); // Paper - moved up
 
-                        if (iblockdata2.getBlock() == Blocks.DIRT && iblockdata2.get(BlockDirt.VARIANT) == BlockDirt.EnumDirtVariant.DIRT && world.getLightLevel(blockposition1.up()) >= 4 && iblockdata1.c() <= 2) {
+                        if (iblockdata2.getBlock() == Blocks.DIRT && iblockdata2.get(BlockDirt.VARIANT) == BlockDirt.EnumDirtVariant.DIRT && iblockdata1.c() <= 2 && world.isLightLevel(blockposition1.up(), 4)) { // Paper - move last check before isLightLevel to avoid unneeded light checks
                             // CraftBukkit start
                             // world.setTypeUpdate(blockposition1, Blocks.GRASS.getBlockData());
                             org.bukkit.World bworld = world.getWorld();
diff --git a/src/main/java/net/minecraft/server/BlockSapling.java b/src/main/java/net/minecraft/server/BlockSapling.java
index 76b13a3..b7776fb 100644
--- a/src/main/java/net/minecraft/server/BlockSapling.java
+++ b/src/main/java/net/minecraft/server/BlockSapling.java
@@ -34,7 +34,7 @@ public class BlockSapling extends BlockPlant implements IBlockFragilePlantElemen
     public void b(World world, BlockPosition blockposition, IBlockData iblockdata, Random random) {
         if (!world.isClientSide) {
             super.b(world, blockposition, iblockdata, random);
-            if (world.getLightLevel(blockposition.up()) >= 9 && random.nextInt(Math.max(2, (int) (((100.0F / world.spigotConfig.saplingModifier) * 7) + 0.5F))) == 0) { // Spigot
+            if (world.isLightLevel(blockposition.up(), 9) && random.nextInt(Math.max(2, (int) (((100.0F / world.spigotConfig.saplingModifier) * 7) + 0.5F))) == 0) { // Spigot // Paper
                 // CraftBukkit start
                 world.captureTreeGeneration = true;
                 // CraftBukkit end
diff --git a/src/main/java/net/minecraft/server/BlockStem.java b/src/main/java/net/minecraft/server/BlockStem.java
index 73e68d8..439a77e 100644
--- a/src/main/java/net/minecraft/server/BlockStem.java
+++ b/src/main/java/net/minecraft/server/BlockStem.java
@@ -47,7 +47,7 @@ public class BlockStem extends BlockPlant implements IBlockFragilePlantElement {
 
     public void b(World world, BlockPosition blockposition, IBlockData iblockdata, Random random) {
         super.b(world, blockposition, iblockdata, random);
-        if (world.getLightLevel(blockposition.up()) >= 9) {
+        if (world.isLightLevel(blockposition.up(), 9)) { // Paper
             float f = BlockCrops.a((Block) this, world, blockposition);
 
             if (random.nextInt((int) ((100.0F / (this == Blocks.PUMPKIN_STEM ? world.spigotConfig.pumpkinModifier : world.spigotConfig.melonModifier)) * (25.0F / f)) + 1) == 0) { // Spigot
diff --git a/src/main/java/net/minecraft/server/EntityMonster.java b/src/main/java/net/minecraft/server/EntityMonster.java
index f477036..23826fe 100644
--- a/src/main/java/net/minecraft/server/EntityMonster.java
+++ b/src/main/java/net/minecraft/server/EntityMonster.java
@@ -118,17 +118,17 @@ public abstract class EntityMonster extends EntityCreature implements IMonster {
         if (this.world.b(EnumSkyBlock.SKY, blockposition) > this.random.nextInt(32)) {
             return false;
         } else {
-            int i = this.world.getLightLevel(blockposition);
-
+            //int i = this.world.getLightLevel(blockposition); // Paper
+            boolean passes; // Paper
             if (this.world.V()) {
                 int j = this.world.af();
 
                 this.world.c(10);
-                i = this.world.getLightLevel(blockposition);
+                passes = !world.isLightLevel(blockposition, this.random.nextInt(9)); // Paper
                 this.world.c(j);
-            }
+            } else { passes = !world.isLightLevel(blockposition, this.random.nextInt(9)); } // Paper
 
-            return i <= this.random.nextInt(8);
+            return passes; // Paper
         }
     }
 
diff --git a/src/main/java/net/minecraft/server/EntityZombie.java b/src/main/java/net/minecraft/server/EntityZombie.java
index 7a5b053..0b0eef3 100644
--- a/src/main/java/net/minecraft/server/EntityZombie.java
+++ b/src/main/java/net/minecraft/server/EntityZombie.java
@@ -194,7 +194,7 @@ public class EntityZombie extends EntityMonster {
                     int j1 = j + MathHelper.nextInt(this.random, 7, 40) * MathHelper.nextInt(this.random, -1, 1);
                     int k1 = k + MathHelper.nextInt(this.random, 7, 40) * MathHelper.nextInt(this.random, -1, 1);
 
-                    if (this.world.getType(new BlockPosition(i1, j1 - 1, k1)).q() && this.world.getLightLevel(new BlockPosition(i1, j1, k1)) < 10) {
+                    if (this.world.getType(new BlockPosition(i1, j1 - 1, k1)).q() && !this.world.isLightLevel(new BlockPosition(i1, j1, k1), 10)) { // Paper
                         entityzombie.setPosition((double) i1, (double) j1, (double) k1);
                         if (!this.world.isPlayerNearby((double) i1, (double) j1, (double) k1, 7.0D) && this.world.a(entityzombie.getBoundingBox(), (Entity) entityzombie) && this.world.getCubes(entityzombie, entityzombie.getBoundingBox()).isEmpty() && !this.world.containsLiquid(entityzombie.getBoundingBox())) {
                             this.world.addEntity(entityzombie, CreatureSpawnEvent.SpawnReason.REINFORCEMENTS); // CraftBukkit
-- 
2.8.0