Add ray tracing and bounding box API

src/main/java/org/bukkit/craftbukkit/CraftFluidCollisionMode.java

@@ -0,0 +1,24 @@
+package org.bukkit.craftbukkit;
+
+import org.bukkit.FluidCollisionMode;
+import net.minecraft.server.FluidCollisionOption;
+
+public class CraftFluidCollisionMode {
+
+    private CraftFluidCollisionMode() {}
+
+    public static FluidCollisionOption toNMS(FluidCollisionMode fluidCollisionMode) {
+        if (fluidCollisionMode == null) return null;
+
+        switch (fluidCollisionMode) {
+            case ALWAYS:
+                return FluidCollisionOption.ALWAYS;
+            case SOURCE_ONLY:
+                return FluidCollisionOption.SOURCE_ONLY;
+            case NEVER:
+                return FluidCollisionOption.NEVER;
+            default:
+                return null;
+        }
+    }
+}

src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -12,6 +12,7 @@ import java.util.Iterator;
 import java.util.Random;
 import java.util.Set;
 import java.util.UUID;
+import java.util.function.Predicate;
 
 import net.minecraft.server.*;
 
@@ -22,6 +23,7 @@ import org.bukkit.Chunk;
 import org.bukkit.ChunkSnapshot;
 import org.bukkit.Difficulty;
 import org.bukkit.Effect;
+import org.bukkit.FluidCollisionMode;
 import org.bukkit.GameRule;
 import org.bukkit.Location;
 import org.bukkit.Particle;
@@ -43,6 +45,7 @@ import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.craftbukkit.metadata.BlockMetadataStore;
 import org.bukkit.craftbukkit.potion.CraftPotionUtil;
 import org.bukkit.craftbukkit.util.CraftMagicNumbers;
+import org.bukkit.craftbukkit.util.CraftRayTraceResult;
 import org.bukkit.entity.*;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.minecart.CommandMinecart;
@@ -62,7 +65,9 @@ import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.messaging.StandardMessenger;
 import org.bukkit.potion.PotionData;
 import org.bukkit.potion.PotionType;
+import org.bukkit.util.BoundingBox;
 import org.bukkit.util.Consumer;
+import org.bukkit.util.RayTraceResult;
 import org.bukkit.util.Vector;
 
 public class CraftWorld implements World {
@@ -691,19 +696,162 @@ public class CraftWorld implements World {
 
     @Override
     public Collection<Entity> getNearbyEntities(Location location, double x, double y, double z) {
-        if (location == null || !location.getWorld().equals(this)) {
-            return Collections.emptyList();
+        return this.getNearbyEntities(location, x, y, z, null);
     }
 
-        AxisAlignedBB bb = new AxisAlignedBB(location.getX() - x, location.getY() - y, location.getZ() - z, location.getX() + x, location.getY() + y, location.getZ() + z);
+    @Override
+    public Collection<Entity> getNearbyEntities(Location location, double x, double y, double z, Predicate<Entity> filter) {
+        Validate.notNull(location, "Location is null!");
+        Validate.isTrue(this.equals(location.getWorld()), "Location is from different world!");
+
+        BoundingBox aabb = BoundingBox.of(location, x, y, z);
+        return this.getNearbyEntities(aabb, filter);
+    }
+
+    @Override
+    public Collection<Entity> getNearbyEntities(BoundingBox boundingBox) {
+        return this.getNearbyEntities(boundingBox, null);
+    }
+
+    @Override
+    public Collection<Entity> getNearbyEntities(BoundingBox boundingBox, Predicate<Entity> filter) {
+        Validate.notNull(boundingBox, "Bounding box is null!");
+
+        AxisAlignedBB bb = new AxisAlignedBB(boundingBox.getMinX(), boundingBox.getMinY(), boundingBox.getMinZ(), boundingBox.getMaxX(), boundingBox.getMaxY(), boundingBox.getMaxZ());
         List<net.minecraft.server.Entity> entityList = getHandle().getEntities((net.minecraft.server.Entity) null, bb, null);
         List<Entity> bukkitEntityList = new ArrayList<org.bukkit.entity.Entity>(entityList.size());
-        for (Object entity : entityList) {
-            bukkitEntityList.add(((net.minecraft.server.Entity) entity).getBukkitEntity());
+
+        for (net.minecraft.server.Entity entity : entityList) {
+            Entity bukkitEntity = entity.getBukkitEntity();
+            if (filter == null || filter.test(bukkitEntity)) {
+                bukkitEntityList.add(bukkitEntity);
             }
+        }
+
         return bukkitEntityList;
     }
 
+    @Override
+    public RayTraceResult rayTraceEntities(Location start, Vector direction, double maxDistance) {
+        return this.rayTraceEntities(start, direction, maxDistance, null);
+    }
+
+    @Override
+    public RayTraceResult rayTraceEntities(Location start, Vector direction, double maxDistance, double raySize) {
+        return this.rayTraceEntities(start, direction, maxDistance, raySize, null);
+    }
+
+    @Override
+    public RayTraceResult rayTraceEntities(Location start, Vector direction, double maxDistance, Predicate<Entity> filter) {
+        return this.rayTraceEntities(start, direction, maxDistance, 0.0D, filter);
+    }
+
+    @Override
+    public RayTraceResult rayTraceEntities(Location start, Vector direction, double maxDistance, double raySize, Predicate<Entity> filter) {
+        Validate.notNull(start, "Start location is null!");
+        Validate.isTrue(this.equals(start.getWorld()), "Start location is from different world!");
+        start.checkFinite();
+
+        Validate.notNull(direction, "Direction is null!");
+        direction.checkFinite();
+
+        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+
+        if (maxDistance < 0.0D) {
+            return null;
+        }
+
+        Vector startPos = start.toVector();
+        Vector dir = direction.clone().normalize().multiply(maxDistance);
+        BoundingBox aabb = BoundingBox.of(startPos, startPos).expandDirectional(dir).expand(raySize);
+        Collection<Entity> entities = this.getNearbyEntities(aabb, filter);
+
+        Entity nearestHitEntity = null;
+        RayTraceResult nearestHitResult = null;
+        double nearestDistanceSq = Double.MAX_VALUE;
+
+        for (Entity entity : entities) {
+            BoundingBox boundingBox = entity.getBoundingBox().expand(raySize);
+            RayTraceResult hitResult = boundingBox.rayTrace(startPos, direction, maxDistance);
+
+            if (hitResult != null) {
+                double distanceSq = startPos.distanceSquared(hitResult.getHitPosition());
+
+                if (distanceSq < nearestDistanceSq) {
+                    nearestHitEntity = entity;
+                    nearestHitResult = hitResult;
+                    nearestDistanceSq = distanceSq;
+                }
+            }
+        }
+
+        return (nearestHitEntity == null) ? null : new RayTraceResult(nearestHitResult.getHitPosition(), nearestHitEntity, nearestHitResult.getHitBlockFace());
+    }
+
+    @Override
+    public RayTraceResult rayTraceBlocks(Location start, Vector direction, double maxDistance) {
+        return this.rayTraceBlocks(start, direction, maxDistance, FluidCollisionMode.NEVER, false);
+    }
+
+    @Override
+    public RayTraceResult rayTraceBlocks(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode) {
+        return this.rayTraceBlocks(start, direction, maxDistance, fluidCollisionMode, false);
+    }
+
+    @Override
+    public RayTraceResult rayTraceBlocks(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode, boolean ignorePassableBlocks) {
+        Validate.notNull(start, "Start location is null!");
+        Validate.isTrue(this.equals(start.getWorld()), "Start location is from different world!");
+        start.checkFinite();
+
+        Validate.notNull(direction, "Direction is null!");
+        direction.checkFinite();
+
+        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+        Validate.notNull(fluidCollisionMode, "Fluid collision mode is null!");
+
+        if (maxDistance < 0.0D) {
+            return null;
+        }
+
+        Vector dir = direction.clone().normalize().multiply(maxDistance);
+        Vec3D startPos = new Vec3D(start.getX(), start.getY(), start.getZ());
+        Vec3D endPos = new Vec3D(start.getX() + dir.getX(), start.getY() + dir.getY(), start.getZ() + dir.getZ());
+        MovingObjectPosition nmsHitResult = this.getHandle().rayTrace(startPos, endPos, CraftFluidCollisionMode.toNMS(fluidCollisionMode), ignorePassableBlocks, false);
+
+        return CraftRayTraceResult.fromNMS(this, nmsHitResult);
+    }
+
+    @Override
+    public RayTraceResult rayTrace(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode, boolean ignorePassableBlocks, double raySize, Predicate<Entity> filter) {
+        RayTraceResult blockHit = this.rayTraceBlocks(start, direction, maxDistance, fluidCollisionMode, ignorePassableBlocks);
+        Vector startVec = null;
+        double blockHitDistance = maxDistance;
+
+        // limiting the entity search range if we found a block hit:
+        if (blockHit != null) {
+            startVec = start.toVector();
+            blockHitDistance = startVec.distance(blockHit.getHitPosition());
+        }
+
+        RayTraceResult entityHit = this.rayTraceEntities(start, direction, blockHitDistance, raySize, filter);
+        if (blockHit == null) {
+            return entityHit;
+        }
+
+        if (entityHit == null) {
+            return blockHit;
+        }
+
+        // Cannot be null as blockHit == null returns above
+        double entityHitDistanceSquared = startVec.distanceSquared(entityHit.getHitPosition());
+        if (entityHitDistanceSquared < (blockHitDistance * blockHitDistance)) {
+            return entityHit;
+        }
+
+        return blockHit;
+    }
+
     public List<Player> getPlayers() {
         List<Player> list = new ArrayList<Player>(world.players.size());
 

src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java

@@ -8,7 +8,9 @@ import java.util.List;
 
 import net.minecraft.server.*;
 
+import org.apache.commons.lang.Validate;
 import org.bukkit.Chunk;
+import org.bukkit.FluidCollisionMode;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.World;
@@ -18,15 +20,18 @@ import org.bukkit.block.BlockFace;
 import org.bukkit.block.BlockState;
 import org.bukkit.block.PistonMoveReaction;
 import org.bukkit.block.data.BlockData;
-import org.bukkit.craftbukkit.CraftChunk;
+import org.bukkit.craftbukkit.CraftFluidCollisionMode;
 import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.block.data.CraftBlockData;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.craftbukkit.util.CraftMagicNumbers;
+import org.bukkit.craftbukkit.util.CraftRayTraceResult;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.metadata.MetadataValue;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.util.BlockVector;
+import org.bukkit.util.RayTraceResult;
+import org.bukkit.util.Vector;
 
 public class CraftBlock implements Block {
     private final net.minecraft.server.GeneratorAccess world;
@@ -602,4 +607,45 @@ public class CraftBlock implements Block {
     public boolean isPassable() {
         return this.getData0().getCollisionShape(world, position).isEmpty();
     }
+
+    @Override
+    public RayTraceResult rayTrace(Location start, Vector direction, double maxDistance, FluidCollisionMode fluidCollisionMode) {
+        Validate.notNull(start, "Start location is null!");
+        Validate.isTrue(this.getWorld().equals(start.getWorld()), "Start location is from different world!");
+        start.checkFinite();
+
+        Validate.notNull(direction, "Direction is null!");
+        direction.checkFinite();
+        Validate.isTrue(direction.lengthSquared() > 0, "Direction's magnitude is 0!");
+
+        Validate.notNull(fluidCollisionMode, "Fluid collision mode is null!");
+        if (maxDistance < 0.0D) {
+            return null;
+        }
+
+        Vector dir = direction.clone().normalize().multiply(maxDistance);
+        Vec3D startPos = new Vec3D(start.getX(), start.getY(), start.getZ());
+        Vec3D endPos = new Vec3D(start.getX() + dir.getX(), start.getY() + dir.getY(), start.getZ() + dir.getZ());
+
+        // Similar to to nms.World#rayTrace:
+        IBlockData blockData = world.getType(position);
+        Fluid fluid = world.b(position); // PAIL getFluid
+        boolean collidableBlock = blockData.getBlock().d(blockData); // PAIL isCollidable
+        boolean collideWithFluid = CraftFluidCollisionMode.toNMS(fluidCollisionMode).d.test(fluid); // PAIL predicate
+
+        if (!collidableBlock && !collideWithFluid) {
+            return null;
+        }
+
+        MovingObjectPosition nmsHitResult = null;
+        if (collidableBlock) {
+            nmsHitResult = net.minecraft.server.Block.a(blockData, world.getMinecraftWorld(), position, startPos, endPos); // PAIL rayTrace
+        }
+
+        if (nmsHitResult == null && collideWithFluid) {
+            nmsHitResult = VoxelShapes.a(0.0D, 0.0D, 0.0D, 1.0D, (double) fluid.f(), 1.0D).a(startPos, endPos, position); // PAIL create, getHeight, rayTrace
+        }
+
+        return CraftRayTraceResult.fromNMS(this.getWorld(), nmsHitResult);
+    }
 }

src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -28,6 +28,7 @@ import org.bukkit.permissions.PermissionAttachment;
 import org.bukkit.permissions.PermissionAttachmentInfo;
 import org.bukkit.permissions.ServerOperator;
 import org.bukkit.plugin.Plugin;
+import org.bukkit.util.BoundingBox;
 import org.bukkit.util.Vector;
 
 public abstract class CraftEntity implements org.bukkit.entity.Entity {
@@ -273,6 +274,12 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         return getHandle().width;
     }
 
+    @Override
+    public BoundingBox getBoundingBox() {
+        AxisAlignedBB bb = getHandle().getBoundingBox();
+        return new BoundingBox(bb.minX, bb.minY, bb.minZ, bb.maxX, bb.maxY, bb.maxZ);
+    }
+
     public boolean isOnGround() {
         if (entity instanceof EntityArrow) {
             return ((EntityArrow) entity).inGround;

src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java

@@ -36,6 +36,7 @@ import net.minecraft.server.MobEffect;
 import net.minecraft.server.MobEffectList;
 
 import org.apache.commons.lang.Validate;
+import org.bukkit.FluidCollisionMode;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.attribute.Attribute;
@@ -78,6 +79,7 @@ import org.bukkit.potion.PotionEffect;
 import org.bukkit.potion.PotionEffectType;
 import org.bukkit.potion.PotionType;
 import org.bukkit.util.BlockIterator;
+import org.bukkit.util.RayTraceResult;
 import org.bukkit.util.Vector;
 
 public class CraftLivingEntity extends CraftEntity implements LivingEntity {
@@ -170,6 +172,29 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
         return getLineOfSight(transparent, maxDistance, 2);
     }
 
+    @Override
+    public Block getTargetBlockExact(int maxDistance) {
+        return this.getTargetBlockExact(maxDistance, FluidCollisionMode.NEVER);
+    }
+
+    @Override
+    public Block getTargetBlockExact(int maxDistance, FluidCollisionMode fluidCollisionMode) {
+        RayTraceResult hitResult = this.rayTraceBlocks(maxDistance, fluidCollisionMode);
+        return (hitResult != null ? hitResult.getHitBlock() : null);
+    }
+
+    @Override
+    public RayTraceResult rayTraceBlocks(double maxDistance) {
+        return this.rayTraceBlocks(maxDistance, FluidCollisionMode.NEVER);
+    }
+
+    @Override
+    public RayTraceResult rayTraceBlocks(double maxDistance, FluidCollisionMode fluidCollisionMode) {
+        Location eyeLocation = this.getEyeLocation();
+        Vector direction = eyeLocation.getDirection();
+        return this.getWorld().rayTraceBlocks(eyeLocation, direction, maxDistance, fluidCollisionMode, false);
+    }
+
     public int getRemainingAir() {
         return getHandle().getAirTicks();
     }

src/main/java/org/bukkit/craftbukkit/util/CraftRayTraceResult.java

@@ -0,0 +1,42 @@
+package org.bukkit.craftbukkit.util;
+
+import org.bukkit.World;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.craftbukkit.block.CraftBlock;
+import org.bukkit.entity.Entity;
+import org.bukkit.util.RayTraceResult;
+import org.bukkit.util.Vector;
+import net.minecraft.server.BlockPosition;
+import net.minecraft.server.MovingObjectPosition;
+import net.minecraft.server.MovingObjectPosition.EnumMovingObjectType;
+import net.minecraft.server.Vec3D;
+
+public class CraftRayTraceResult {
+
+    private CraftRayTraceResult() {}
+
+    public static RayTraceResult fromNMS(World world, MovingObjectPosition nmsHitResult) {
+        if (nmsHitResult == null || nmsHitResult.type == EnumMovingObjectType.MISS) return null;
+
+        Vec3D nmsHitPos = nmsHitResult.pos;
+        Vector hitPosition = new Vector(nmsHitPos.x, nmsHitPos.y, nmsHitPos.z);
+        BlockFace hitBlockFace = null;
+
+        if (nmsHitResult.direction != null) {
+            hitBlockFace = CraftBlock.notchToBlockFace(nmsHitResult.direction);
+        }
+
+        if (nmsHitResult.entity != null) {
+            Entity hitEntity = nmsHitResult.entity.getBukkitEntity();
+            return new RayTraceResult(hitPosition, hitEntity, hitBlockFace);
+        }
+
+        Block hitBlock = null;
+        BlockPosition nmsBlockPos = nmsHitResult.a(); // PAIL: getBlockPosition
+        if (nmsBlockPos != null && world != null) {
+            hitBlock = world.getBlockAt(nmsBlockPos.getX(), nmsBlockPos.getY(), nmsBlockPos.getZ());
+        }
+        return new RayTraceResult(hitPosition, hitBlock, hitBlockFace);
+    }
+}