PaperMC/nms-patches/EntityEnderDragon.patch

--- a/net/minecraft/server/EntityEnderDragon.java
+++ b/net/minecraft/server/EntityEnderDragon.java
@@ -5,6 +5,17 @@
 import java.util.Iterator;
 import java.util.List;
 
+// CraftBukkit start
+import org.bukkit.block.BlockState;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.craftbukkit.util.BlockStateListPopulator;
+import org.bukkit.event.entity.EntityCreatePortalEvent;
+import org.bukkit.event.entity.EntityExplodeEvent;
+import org.bukkit.event.entity.EntityRegainHealthEvent;
+import org.bukkit.event.entity.EntityTargetEvent;
+import org.bukkit.Bukkit;
+// CraftBukkit end
+
 public class EntityEnderDragon extends EntityInsentient implements IComplex, IMonster {
 
     public double a;
@@ -27,6 +38,7 @@
     public Entity target;
     public int by;
     public EntityEnderCrystal bz;
+    private Explosion explosionSource = new Explosion(null, this, Double.NaN, Double.NaN, Double.NaN, Float.NaN, true, true); // CraftBukkit - reusable source for CraftTNTPrimed.getSource()
 
     public EntityEnderDragon(World world) {
         super(world);
@@ -294,12 +306,21 @@
         if (this.bz != null) {
             if (this.bz.dead) {
                 if (!this.world.isClientSide) {
+                    CraftEventFactory.entityDamage = this.bz; // CraftBukkit
                     this.a(this.bn, DamageSource.explosion((Explosion) null), 10.0F);
+                    CraftEventFactory.entityDamage = null; // CraftBukkit
                 }
 
                 this.bz = null;
             } else if (this.ticksLived % 10 == 0 && this.getHealth() < this.getMaxHealth()) {
-                this.setHealth(this.getHealth() + 1.0F);
+                // CraftBukkit start
+                EntityRegainHealthEvent event = new EntityRegainHealthEvent(this.getBukkitEntity(), 1.0D, EntityRegainHealthEvent.RegainReason.ENDER_CRYSTAL);
+                this.world.getServer().getPluginManager().callEvent(event);
+
+                if (!event.isCancelled()) {
+                    this.setHealth((float) (this.getHealth() + event.getAmount()));
+                }
+                // CraftBukkit end
             }
         }
 
@@ -368,7 +389,19 @@
         }
 
         if (this.random.nextInt(2) == 0 && !arraylist.isEmpty()) {
-            this.target = (Entity) arraylist.get(this.random.nextInt(arraylist.size()));
+            // CraftBukkit start
+            Entity target = (Entity) this.world.players.get(this.random.nextInt(this.world.players.size()));
+            EntityTargetEvent event = new EntityTargetEvent(this.getBukkitEntity(), target.getBukkitEntity(), EntityTargetEvent.TargetReason.RANDOM_TARGET);
+            this.world.getServer().getPluginManager().callEvent(event);
+
+            if (!event.isCancelled()) {
+                if (event.getTarget() == null) {
+                    this.target = null;
+                } else {
+                    this.target = ((org.bukkit.craftbukkit.entity.CraftEntity) event.getTarget()).getHandle();
+                }
+            }
+            // CraftBukkit end
         } else {
             boolean flag;
 
@@ -404,6 +437,11 @@
         boolean flag = false;
         boolean flag1 = false;
 
+        // CraftBukkit start - Create a list to hold all the destroyed blocks
+        List<org.bukkit.block.Block> destroyedBlocks = new java.util.ArrayList<org.bukkit.block.Block>();
+        org.bukkit.craftbukkit.CraftWorld craftWorld = this.world.getWorld();
+        // CraftBukkit end
+
         for (int k1 = i; k1 <= l; ++k1) {
             for (int l1 = j; l1 <= i1; ++l1) {
                 for (int i2 = k; i2 <= j1; ++i2) {
@@ -412,7 +450,11 @@
 
                     if (block.getMaterial() != Material.AIR) {
                         if (block != Blocks.BARRIER && block != Blocks.OBSIDIAN && block != Blocks.END_STONE && block != Blocks.BEDROCK && block != Blocks.COMMAND_BLOCK && this.world.getGameRules().getBoolean("mobGriefing")) {
-                            flag1 = this.world.setAir(blockposition) || flag1;
+                            // CraftBukkit start - Add blocks to list rather than destroying them
+                            // flag1 = this.world.setAir(new BlockPosition(blockposition)) || flag1;
+                            flag1 = true;
+                            destroyedBlocks.add(craftWorld.getBlockAt(k1, l1, i2));
+                            // CraftBukkit end
                         } else {
                             flag = true;
                         }
@@ -422,6 +464,40 @@
         }
 
         if (flag1) {
+            // CraftBukkit start - Set off an EntityExplodeEvent for the dragon exploding all these blocks
+            org.bukkit.entity.Entity bukkitEntity = this.getBukkitEntity();
+            EntityExplodeEvent event = new EntityExplodeEvent(bukkitEntity, bukkitEntity.getLocation(), destroyedBlocks, 0F);
+            Bukkit.getPluginManager().callEvent(event);
+            if (event.isCancelled()) {
+                // This flag literally means 'Dragon hit something hard' (Obsidian, White Stone or Bedrock) and will cause the dragon to slow down.
+                // We should consider adding an event extension for it, or perhaps returning true if the event is cancelled.
+                return flag;
+            } else if (event.getYield() == 0F) {
+                // Yield zero ==> no drops
+                for (org.bukkit.block.Block block : event.blockList()) {
+                    this.world.setAir(new BlockPosition(block.getX(), block.getY(), block.getZ()));
+                }
+            } else {
+                for (org.bukkit.block.Block block : event.blockList()) {
+                    org.bukkit.Material blockId = block.getType();
+                    if (blockId == org.bukkit.Material.AIR) {
+                        continue;
+                    }
+
+                    int blockX = block.getX();
+                    int blockY = block.getY();
+                    int blockZ = block.getZ();
+
+                    Block nmsBlock = org.bukkit.craftbukkit.util.CraftMagicNumbers.getBlock(blockId);
+                    if (nmsBlock.a(explosionSource)) {
+                        nmsBlock.dropNaturally(this.world, new BlockPosition(blockX, blockY, blockZ), nmsBlock.fromLegacyData(block.getData()), event.getYield(), 0);
+                    }
+                    nmsBlock.wasExploded(world, new BlockPosition(blockX, blockY, blockZ), explosionSource);
+
+                    this.world.setAir(new BlockPosition(blockX, blockY, blockZ));
+                }
+            }
+            // CraftBukkit end
             double d0 = axisalignedbb.a + (axisalignedbb.d - axisalignedbb.a) * (double) this.random.nextFloat();
             double d1 = axisalignedbb.b + (axisalignedbb.e - axisalignedbb.b) * (double) this.random.nextFloat();
             double d2 = axisalignedbb.c + (axisalignedbb.f - axisalignedbb.c) * (double) this.random.nextFloat();
@@ -469,6 +545,7 @@
     }
 
     protected void aZ() {
+        if (this.dead) return; // CraftBukkit - can't kill what's already dead
         ++this.by;
         if (this.by >= 180 && this.by <= 200) {
             float f = (this.random.nextFloat() - 0.5F) * 8.0F;
@@ -484,7 +561,7 @@
 
         if (!this.world.isClientSide) {
             if (this.by > 150 && this.by % 5 == 0 && flag) {
-                i = 1000;
+                i = this.expToDrop / 12; // CraftBukkit - drop experience as dragon falls from sky. use experience drop from death event. This is now set in getExpReward()
 
                 while (i > 0) {
                     j = EntityExperienceOrb.getOrbValue(i);
@@ -494,7 +571,23 @@
             }
 
             if (this.by == 1) {
-                this.world.a(1018, new BlockPosition(this), 0);
+                // CraftBukkit start - Use relative location for far away sounds
+                // this.world.a(1018, new BlockPosition(this), 0);
+                int viewDistance = ((WorldServer) this.world).getServer().getViewDistance() * 16;
+                for (EntityPlayer player : (List<EntityPlayer>) MinecraftServer.getServer().getPlayerList().players) {
+                    double deltaX = this.locX - player.locX;
+                    double deltaZ = this.locZ - player.locZ;
+                    double distanceSquared = deltaX * deltaX + deltaZ * deltaZ;
+                    if (distanceSquared > viewDistance * viewDistance) {
+                        double deltaLength = Math.sqrt(distanceSquared);
+                        double relativeX = player.locX + (deltaX / deltaLength) * viewDistance;
+                        double relativeZ = player.locZ + (deltaZ / deltaLength) * viewDistance;
+                        player.playerConnection.sendPacket(new PacketPlayOutWorldEvent(1018, new BlockPosition((int) relativeX, (int) this.locY, (int) relativeZ), 0, true));
+                    } else {
+                        player.playerConnection.sendPacket(new PacketPlayOutWorldEvent(1018, new BlockPosition((int) this.locX, (int) this.locY, (int) this.locZ), 0, true));
+                    }
+                }
+                // CraftBukkit end
             }
         }
 
@@ -502,7 +595,7 @@
         this.aI = this.yaw += 20.0F;
         if (this.by == 200 && !this.world.isClientSide) {
             if (flag) {
-                i = 2000;
+                i = this.expToDrop - (10 * this.expToDrop / 12); // CraftBukkit - drop the remaining experience
 
                 while (i > 0) {
                     j = EntityExperienceOrb.getOrbValue(i);
@@ -522,6 +615,9 @@
         double d0 = 12.25D;
         double d1 = 6.25D;
 
+        // CraftBukkit start - Replace any "this.world" in the following with just "world"!
+        BlockStateListPopulator world = new BlockStateListPopulator(this.world.getWorld());
+
         for (int i = -1; i <= 32; ++i) {
             for (int j = -4; j <= 4; ++j) {
                 for (int k = -4; k <= 4; ++k) {
@@ -532,31 +628,51 @@
 
                         if (i < 0) {
                             if (d2 <= 6.25D) {
-                                this.world.setTypeUpdate(blockposition1, Blocks.BEDROCK.getBlockData());
+                                world.setTypeUpdate(blockposition1, Blocks.BEDROCK.getBlockData());
                             }
                         } else if (i > 0) {
-                            this.world.setTypeUpdate(blockposition1, Blocks.AIR.getBlockData());
+                            world.setTypeUpdate(blockposition1, Blocks.AIR.getBlockData());
                         } else if (d2 > 6.25D) {
-                            this.world.setTypeUpdate(blockposition1, Blocks.BEDROCK.getBlockData());
+                            world.setTypeUpdate(blockposition1, Blocks.BEDROCK.getBlockData());
                         } else {
-                            this.world.setTypeUpdate(blockposition1, Blocks.END_PORTAL.getBlockData());
+                            world.setTypeUpdate(blockposition1, Blocks.END_PORTAL.getBlockData());
                         }
                     }
                 }
             }
         }
 
-        this.world.setTypeUpdate(blockposition, Blocks.BEDROCK.getBlockData());
-        this.world.setTypeUpdate(blockposition.up(), Blocks.BEDROCK.getBlockData());
+        world.setTypeUpdate(blockposition, Blocks.BEDROCK.getBlockData());
+        world.setTypeUpdate(blockposition.up(), Blocks.BEDROCK.getBlockData());
         BlockPosition blockposition2 = blockposition.up(2);
 
-        this.world.setTypeUpdate(blockposition2, Blocks.BEDROCK.getBlockData());
-        this.world.setTypeUpdate(blockposition2.west(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.EAST));
-        this.world.setTypeUpdate(blockposition2.east(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.WEST));
-        this.world.setTypeUpdate(blockposition2.north(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.SOUTH));
-        this.world.setTypeUpdate(blockposition2.south(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.NORTH));
-        this.world.setTypeUpdate(blockposition.up(3), Blocks.BEDROCK.getBlockData());
-        this.world.setTypeUpdate(blockposition.up(4), Blocks.DRAGON_EGG.getBlockData());
+        world.setTypeUpdate(blockposition2, Blocks.BEDROCK.getBlockData());
+        world.setTypeUpdate(blockposition2.west(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.EAST));
+        world.setTypeUpdate(blockposition2.east(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.WEST));
+        world.setTypeUpdate(blockposition2.north(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.SOUTH));
+        world.setTypeUpdate(blockposition2.south(), Blocks.TORCH.getBlockData().set(BlockTorch.FACING, EnumDirection.NORTH));
+        world.setTypeUpdate(blockposition.up(3), Blocks.BEDROCK.getBlockData());
+        world.setTypeUpdate(blockposition.up(4), Blocks.DRAGON_EGG.getBlockData());
+
+        EntityCreatePortalEvent event = new EntityCreatePortalEvent((org.bukkit.entity.LivingEntity) this.getBukkitEntity(), java.util.Collections.unmodifiableList(world.getList()), org.bukkit.PortalType.ENDER);
+        this.world.getServer().getPluginManager().callEvent(event);
+
+        if (!event.isCancelled()) {
+            for (BlockState state : event.getBlocks()) {
+                state.update(true);
+            }
+        } else {
+            for (BlockState state : event.getBlocks()) {
+                PacketPlayOutBlockChange packet = new PacketPlayOutBlockChange(this.world, new BlockPosition(state.getX(), state.getY(), state.getZ()));
+                for (Iterator it = this.world.players.iterator(); it.hasNext();) {
+                    EntityHuman entity = (EntityHuman) it.next();
+                    if (entity instanceof EntityPlayer) {
+                        ((EntityPlayer) entity).playerConnection.sendPacket(packet);
+                    }
+                }
+            }
+        }
+        // CraftBukkit end
     }
 
     protected void D() {}
@@ -584,4 +700,12 @@
     protected float bB() {
         return 5.0F;
     }
+
+    // CraftBukkit start
+    public int getExpReward() {
+        // This value is equal to the amount of experience dropped while falling from the sky (10 * 1000)
+        // plus what is dropped when the dragon hits the ground (2000)
+        return 12000;
+    }
+    // CraftBukkit end
 }