Added target block ray trace functionality.

By: Raphfrk <raphfrk@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java

@@ -9,11 +9,18 @@ import net.minecraft.server.EntitySnowball;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.CraftWorld;
 
+import org.bukkit.block.Block;
 import org.bukkit.entity.Arrow;
 import org.bukkit.entity.Egg;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Snowball;
 import org.bukkit.entity.Vehicle;
+import org.bukkit.util.BlockIterator;
+
+import java.util.List;
+import java.util.HashSet;
+import java.util.ArrayList;
+import java.util.Iterator;
 
 public class CraftLivingEntity extends CraftEntity implements LivingEntity {
     private EntityLiving entity;
@@ -64,6 +71,53 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
         return (Snowball) snowball.getBukkitEntity();
     }
 
+    public double getEyeHeight() {
+        return 1.0D;
+    }
+
+    public double getEyeHeight(boolean ignoreSneaking) {
+        return getEyeHeight();
+    }
+
+    private List<Block> getLineOfSight(HashSet<Byte> transparent, int maxDistance, int maxLength) {
+        if (maxDistance > 120) {
+            maxDistance = 120;
+        }
+        ArrayList<Block> blocks = new ArrayList();
+        Iterator<Block> itr = new BlockIterator(this, maxDistance);
+        while (itr.hasNext()) {
+            Block block = itr.next();
+            blocks.add(block);
+            if (maxLength != 0 && blocks.size() > maxLength) {
+                blocks.remove(0);
+            }
+            int id = block.getTypeId();
+            if (transparent == null) {
+                if (id != 0) {
+                    break;
+                }
+            } else {
+                if (!transparent.contains((byte)id)) {
+                    break;
+                }
+            }
+        }
+        return blocks;
+    }
+
+    public List<Block> getLineOfSight(HashSet<Byte> transparent, int maxDistance) {
+        return getLineOfSight(transparent, maxDistance, 0);
+    }
+
+    public Block getTargetBlock(HashSet<Byte> transparent, int maxDistance) {
+        List<Block> blocks = getLineOfSight(transparent, maxDistance, 1);
+        return blocks.get(0);
+    }
+
+    public List<Block> getLastTwoTargetBlocks(HashSet<Byte> transparent, int maxDistance) {
+        return getLineOfSight(transparent, maxDistance, 2);
+    }
+
     public Arrow shootArrow() {
         net.minecraft.server.World world = ((CraftWorld)getWorld()).getHandle();
         EntityArrow arrow = new EntityArrow(world, entity);

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java

@@ -58,6 +58,22 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         return entity;
     }
 
+    public double getEyeHeight() {
+        return getEyeHeight(false);
+    }
+
+    public double getEyeHeight(boolean ignoreSneaking) {
+        if(ignoreSneaking) {
+            return 1.62D;
+        } else {
+            if (isSneaking()) {
+                return 1.42D;
+            } else {
+                return 1.62D;
+            }
+        }
+    }
+
     public void setHandle(final EntityPlayer entity) {
         super.setHandle((EntityHuman) entity);
         this.entity = entity;