9 files changed, 463 insertions, 463 deletions

diff --git a/core/src/main/java/coffee/liz/ecs/DAGWorld.java b/core/src/main/java/coffee/liz/ecs/DAGWorld.java
index b5b54c2..24d5adc 100644
--- a/core/src/main/java/coffee/liz/ecs/DAGWorld.java
+++ b/core/src/main/java/coffee/liz/ecs/DAGWorld.java
@@ -26,140 +26,140 @@ import java.util.stream.Collectors;
 @Log4j2
 @RequiredArgsConstructor
 public class DAGWorld<T> implements World<T> {
-	/** All entities in the world. */
-	protected final Set<Entity> entities = Collections.synchronizedSet(new HashSet<>());
+    /** All entities in the world. */
+    protected final Set<Entity> entities = Collections.synchronizedSet(new HashSet<>());
 
-	/** Cache mapping component types to entities having that component. */
-	private final Map<Class<? extends Component>, Set<Entity>> componentCache = Collections
-			.synchronizedMap(new HashMap<>());
+    /** Cache mapping component types to entities having that component. */
+    private final Map<Class<? extends Component>, Set<Entity>> componentCache = Collections
+            .synchronizedMap(new HashMap<>());
 
-	/** Deterministic ID's for spawned entities. */
-	private final AtomicInteger nextEntityId = new AtomicInteger(0);
+    /** Deterministic ID's for spawned entities. */
+    private final AtomicInteger nextEntityId = new AtomicInteger(0);
 
-	/** All registered systems. */
-	protected final Map<Class<? extends System<T>>, System<T>> systems;
+    /** All registered systems. */
+    protected final Map<Class<? extends System<T>>, System<T>> systems;
 
-	/** Ordered list of systems for execution. */
-	private final List<System<T>> systemExecutionOrder;
+    /** Ordered list of systems for execution. */
+    private final List<System<T>> systemExecutionOrder;
 
-	public DAGWorld(final Map<Class<? extends System<T>>, System<T>> systems) {
-		this.systems = systems;
-		this.systemExecutionOrder = buildExecutionOrder(systems.values().stream().toList());
-		log.debug("Executing in order: {}", systemExecutionOrder);
-	}
+    public DAGWorld(final Map<Class<? extends System<T>>, System<T>> systems) {
+        this.systems = systems;
+        this.systemExecutionOrder = buildExecutionOrder(systems.values().stream().toList());
+        log.debug("Executing in order: {}", systemExecutionOrder);
+    }
 
-	@Override
-	public Entity createEntity() {
-		final Entity entity = Entity.builder().id(nextEntityId.incrementAndGet()).build();
-		entities.add(entity);
-		return entity;
-	}
+    @Override
+    public Entity createEntity() {
+        final Entity entity = Entity.builder().id(nextEntityId.incrementAndGet()).build();
+        entities.add(entity);
+        return entity;
+    }
 
-	@Override
-	public void removeEntity(final Entity entity) {
-		entity.getComponentMap().keySet().forEach(componentType -> {
-			final Set<Entity> cachedEntities = componentCache.get(componentType);
-			if (cachedEntities != null) {
-				cachedEntities.remove(entity);
-			}
-		});
-		entities.remove(entity);
-	}
+    @Override
+    public void removeEntity(final Entity entity) {
+        entity.getComponentMap().keySet().forEach(componentType -> {
+            final Set<Entity> cachedEntities = componentCache.get(componentType);
+            if (cachedEntities != null) {
+                cachedEntities.remove(entity);
+            }
+        });
+        entities.remove(entity);
+    }
 
-	@Override
-	public Set<Entity> query(final Collection<Class<? extends Component>> components) {
-		if (components.isEmpty()) {
-			return Set.copyOf(entities);
-		}
+    @Override
+    public Set<Entity> query(final Collection<Class<? extends Component>> components) {
+        if (components.isEmpty()) {
+            return Set.copyOf(entities);
+        }
 
-		final Class<? extends Component> firstType = components.iterator().next();
-		final Set<Entity> candidates = componentCache.get(firstType);
-		if (candidates == null) {
-			return Collections.emptySet();
-		}
+        final Class<? extends Component> firstType = components.iterator().next();
+        final Set<Entity> candidates = componentCache.get(firstType);
+        if (candidates == null) {
+            return Collections.emptySet();
+        }
 
-		return candidates.stream().filter(entity -> components.stream().allMatch(entity::has))
-				.collect(Collectors.toSet());
-	}
+        return candidates.stream().filter(entity -> components.stream().allMatch(entity::has))
+                .collect(Collectors.toSet());
+    }
 
-	@Override
-	public void update(final T state, final Duration duration) {
-		systemExecutionOrder.forEach(system -> {
-			refreshComponentCache();
-			system.update(this, state, duration);
-		});
-		refreshComponentCache();
-	}
+    @Override
+    public void update(final T state, final Duration duration) {
+        systemExecutionOrder.forEach(system -> {
+            refreshComponentCache();
+            system.update(this, state, duration);
+        });
+        refreshComponentCache();
+    }
 
-	@SuppressWarnings("unchecked")
-	@Override
-	public <S extends System<T>> S getSystem(final Class<S> system) {
-		return (S) systems.get(system);
-	}
+    @SuppressWarnings("unchecked")
+    @Override
+    public <S extends System<T>> S getSystem(final Class<S> system) {
+        return (S) systems.get(system);
+    }
 
-	private void refreshComponentCache() {
-		componentCache.clear();
-		entities.forEach(entity -> entity.getComponentMap().keySet().forEach(
-				componentType -> componentCache.computeIfAbsent(componentType, _ -> new HashSet<>()).add(entity)));
-	}
+    private void refreshComponentCache() {
+        componentCache.clear();
+        entities.forEach(entity -> entity.getComponentMap().keySet().forEach(
+                componentType -> componentCache.computeIfAbsent(componentType, _ -> new HashSet<>()).add(entity)));
+    }
 
-	private List<System<T>> buildExecutionOrder(final Collection<System<T>> systems) {
-		if (systems.isEmpty()) {
-			return Collections.emptyList();
-		}
+    private List<System<T>> buildExecutionOrder(final Collection<System<T>> systems) {
+        if (systems.isEmpty()) {
+            return Collections.emptyList();
+        }
 
-		final Map<Class<?>, System<T>> systemMap = systems.stream()
-				.collect(Collectors.toMap(System::getClass, system -> system));
-		final Map<Class<?>, Integer> inDegree = new HashMap<>();
-		final Map<Class<?>, Set<Class<?>>> adjacencyList = new HashMap<>();
+        final Map<Class<?>, System<T>> systemMap = systems.stream()
+                .collect(Collectors.toMap(System::getClass, system -> system));
+        final Map<Class<?>, Integer> inDegree = new HashMap<>();
+        final Map<Class<?>, Set<Class<?>>> adjacencyList = new HashMap<>();
 
-		systems.forEach(system -> {
-			final Class<?> systemClass = system.getClass();
-			inDegree.put(systemClass, 0);
-			adjacencyList.put(systemClass, new HashSet<>());
-		});
+        systems.forEach(system -> {
+            final Class<?> systemClass = system.getClass();
+            inDegree.put(systemClass, 0);
+            adjacencyList.put(systemClass, new HashSet<>());
+        });
 
-		systems.forEach(system -> {
-			system.getDependencies().forEach(dependency -> {
-				if (systemMap.containsKey(dependency)) {
-					adjacencyList.get(dependency).add(system.getClass());
-					inDegree.merge(system.getClass(), 1, Integer::sum);
-				}
-			});
-		});
+        systems.forEach(system -> {
+            system.getDependencies().forEach(dependency -> {
+                if (systemMap.containsKey(dependency)) {
+                    adjacencyList.get(dependency).add(system.getClass());
+                    inDegree.merge(system.getClass(), 1, Integer::sum);
+                }
+            });
+        });
 
-		// Kahn's algorithm
-		final List<System<T>> result = new ArrayList<>();
+        // Kahn's algorithm
+        final List<System<T>> result = new ArrayList<>();
 
-		final Queue<Class<?>> queue = new LinkedList<>(
-				inDegree.entrySet().stream().filter(entry -> entry.getValue() == 0).map(Map.Entry::getKey).toList());
+        final Queue<Class<?>> queue = new LinkedList<>(
+                inDegree.entrySet().stream().filter(entry -> entry.getValue() == 0).map(Map.Entry::getKey).toList());
 
-		while (!queue.isEmpty()) {
-			final Class<?> currentClass = queue.poll();
-			result.add(systemMap.get(currentClass));
+        while (!queue.isEmpty()) {
+            final Class<?> currentClass = queue.poll();
+            result.add(systemMap.get(currentClass));
 
-			adjacencyList.getOrDefault(currentClass, Collections.emptySet()).forEach(dependent -> {
-				final int newInDegree = inDegree.get(dependent) - 1;
-				inDegree.put(dependent, newInDegree);
-				if (newInDegree == 0) {
-					queue.add(dependent);
-				}
-			});
-		}
+            adjacencyList.getOrDefault(currentClass, Collections.emptySet()).forEach(dependent -> {
+                final int newInDegree = inDegree.get(dependent) - 1;
+                inDegree.put(dependent, newInDegree);
+                if (newInDegree == 0) {
+                    queue.add(dependent);
+                }
+            });
+        }
 
-		if (result.size() != systems.size()) {
-			throw new IllegalStateException("Circular dependency detected in systems");
-		}
+        if (result.size() != systems.size()) {
+            throw new IllegalStateException("Circular dependency detected in systems");
+        }
 
-		return Collections.unmodifiableList(result);
-	}
+        return Collections.unmodifiableList(result);
+    }
 
-	@Override
-	public void close() throws Exception {
-		for (final System<T> system : systemExecutionOrder) {
-			system.close();
-		}
-		componentCache.clear();
-		entities.clear();
-	}
+    @Override
+    public void close() throws Exception {
+        for (final System<T> system : systemExecutionOrder) {
+            system.close();
+        }
+        componentCache.clear();
+        entities.clear();
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/math/Mat2.java b/core/src/main/java/coffee/liz/ecs/math/Mat2.java
index 9975227..ed9493c 100644
--- a/core/src/main/java/coffee/liz/ecs/math/Mat2.java
+++ b/core/src/main/java/coffee/liz/ecs/math/Mat2.java
@@ -7,82 +7,82 @@ import java.util.function.Function;
 import java.util.function.Supplier;
 
 public final class Mat2 {
-	private Mat2() {
-	}
+    private Mat2() {
+    }
 
-	/**
-	 * Initializes a mutable 2d matrix of given type.
-	 *
-	 * @param dimensions
-	 *            the dimensions
-	 * @param constructor
-	 *            the constructor
-	 * @return row-indexed 2d matrix of {@param dimensions}
-	 */
-	public static <T> List<List<T>> init(final Vec2<Integer> dimensions, final Function<Vec2<Integer>, T> constructor) {
-		final List<List<T>> rows = new ArrayList<>();
-		for (int y = 0; y < dimensions.getY(); y++) {
-			final List<T> row = new ArrayList<>(dimensions.getX());
-			for (int x = 0; x < dimensions.getX(); x++)
-				row.add(constructor.apply(Vec2i.builder().y(y).x(x).build()));
-			rows.add(row);
-		}
-		return rows;
-	}
+    /**
+     * Initializes a mutable 2d matrix of given type.
+     *
+     * @param dimensions
+     *            the dimensions
+     * @param constructor
+     *            the constructor
+     * @return row-indexed 2d matrix of {@param dimensions}
+     */
+    public static <T> List<List<T>> init(final Vec2<Integer> dimensions, final Function<Vec2<Integer>, T> constructor) {
+        final List<List<T>> rows = new ArrayList<>();
+        for (int y = 0; y < dimensions.getY(); y++) {
+            final List<T> row = new ArrayList<>(dimensions.getX());
+            for (int x = 0; x < dimensions.getX(); x++)
+                row.add(constructor.apply(Vec2i.builder().y(y).x(x).build()));
+            rows.add(row);
+        }
+        return rows;
+    }
 
-	/**
-	 * Convolves a {@link Convolver} across a matrix reaching neighbors around the
-	 * grid like a torus.
-	 *
-	 * @param mat
-	 *            is the row-indexed 2d matrix to convolve.
-	 * @param axes
-	 *            are the x/y major/minor axes.
-	 * @param init
-	 *            is the initial value of the convolution.
-	 * @param convolver
-	 *            is the {@link Convolver}.
-	 * @param finalReduction
-	 *            to apply after {@param convolver}.
-	 * @return result of {@param convolver} applied along axes at each cell.
-	 * @param <T>
-	 *            is the type of the matrix to convolve.
-	 * @param <R>
-	 *            is the type of the resulting type of each convolution.
-	 */
-	public static <T, R, U> List<List<U>> convolveTorus(final List<List<T>> mat, final Vec2<Integer> axes,
-			final Supplier<R> init, final Convolver<T, R> convolver, final BiFunction<T, R, U> finalReduction) {
-		final List<List<R>> rows = new ArrayList<>();
-		for (int y = 0; y < mat.size(); y++) {
-			final List<R> row = new ArrayList<>(mat.get(y).size());
-			for (int x = 0; x < mat.get(y).size(); x++) {
-				final T center = mat.get(y).get(x);
-				R result = init.get();
-				for (int dy = -axes.getY(); dy <= axes.getY(); dy++) {
-					final int ry = Math.floorMod(y + dy, mat.size());
-					for (int dx = -axes.getX(); dx <= axes.getX(); dx++) {
-						final int rx = Math.floorMod(x + dx, mat.get(ry).size());
-						result = convolver.convolve(mat.get(ry).get(rx), Vec2i.builder().x(dx).y(dy).build(), result);
-					}
-				}
-				row.add(result);
-			}
-			rows.add(row);
-		}
+    /**
+     * Convolves a {@link Convolver} across a matrix reaching neighbors around the
+     * grid like a torus.
+     *
+     * @param mat
+     *            is the row-indexed 2d matrix to convolve.
+     * @param axes
+     *            are the x/y major/minor axes.
+     * @param init
+     *            is the initial value of the convolution.
+     * @param convolver
+     *            is the {@link Convolver}.
+     * @param finalReduction
+     *            to apply after {@param convolver}.
+     * @return result of {@param convolver} applied along axes at each cell.
+     * @param <T>
+     *            is the type of the matrix to convolve.
+     * @param <R>
+     *            is the type of the resulting type of each convolution.
+     */
+    public static <T, R, U> List<List<U>> convolveTorus(final List<List<T>> mat, final Vec2<Integer> axes,
+            final Supplier<R> init, final Convolver<T, R> convolver, final BiFunction<T, R, U> finalReduction) {
+        final List<List<R>> rows = new ArrayList<>();
+        for (int y = 0; y < mat.size(); y++) {
+            final List<R> row = new ArrayList<>(mat.get(y).size());
+            for (int x = 0; x < mat.get(y).size(); x++) {
+                final T center = mat.get(y).get(x);
+                R result = init.get();
+                for (int dy = -axes.getY(); dy <= axes.getY(); dy++) {
+                    final int ry = Math.floorMod(y + dy, mat.size());
+                    for (int dx = -axes.getX(); dx <= axes.getX(); dx++) {
+                        final int rx = Math.floorMod(x + dx, mat.get(ry).size());
+                        result = convolver.convolve(mat.get(ry).get(rx), Vec2i.builder().x(dx).y(dy).build(), result);
+                    }
+                }
+                row.add(result);
+            }
+            rows.add(row);
+        }
 
-		final List<List<U>> reductions = new ArrayList<>();
-		for (int y = 0; y < mat.size(); y++) {
-			final List<U> reduction = new ArrayList<>(mat.get(y).size());
-			for (int x = 0; x < mat.get(y).size(); x++) {
-				reduction.add(finalReduction.apply(mat.get(y).get(x), rows.get(y).get(x)));
-			}
-			reductions.add(reduction);
-		}
-		return reductions;
-	}
+        final List<List<U>> reductions = new ArrayList<>();
+        for (int y = 0; y < mat.size(); y++) {
+            final List<U> reduction = new ArrayList<>(mat.get(y).size());
+            for (int x = 0; x < mat.get(y).size(); x++) {
+                reduction.add(finalReduction.apply(mat.get(y).get(x), rows.get(y).get(x)));
+            }
+            reductions.add(reduction);
+        }
+        return reductions;
+    }
 
-	@FunctionalInterface
-	public interface Convolver<T, R> {
-		R convolve(final T center, final Vec2<Integer> rel, final R reduction);
-	}
+    @FunctionalInterface
+    public interface Convolver<T, R> {
+        R convolve(final T center, final Vec2<Integer> rel, final R reduction);
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/math/Vec2.java b/core/src/main/java/coffee/liz/ecs/math/Vec2.java
index 7620395..dde6e51 100644
--- a/core/src/main/java/coffee/liz/ecs/math/Vec2.java
+++ b/core/src/main/java/coffee/liz/ecs/math/Vec2.java
@@ -9,80 +9,80 @@ import java.util.function.Function;
  *            the numeric type of vector components
  */
 public interface Vec2<T> {
-	/**
-	 * @return the x coordinate
-	 */
-	T getX();
+    /**
+     * @return the x coordinate
+     */
+    T getX();
 
-	/**
-	 * @return the y coordinate
-	 */
-	T getY();
+    /**
+     * @return the y coordinate
+     */
+    T getY();
 
-	/**
-	 * Adds another vector to this vector.
-	 *
-	 * @param other
-	 *            the vector to add
-	 * @return a new vector with the result
-	 */
-	Vec2<T> plus(final Vec2<T> other);
+    /**
+     * Adds another vector to this vector.
+     *
+     * @param other
+     *            the vector to add
+     * @return a new vector with the result
+     */
+    Vec2<T> plus(final Vec2<T> other);
 
-	/**
-	 * Subtracts another vector from this vector.
-	 *
-	 * @param other
-	 *            the vector to subtract
-	 * @return a new vector with the result
-	 */
-	Vec2<T> minus(final Vec2<T> other);
+    /**
+     * Subtracts another vector from this vector.
+     *
+     * @param other
+     *            the vector to subtract
+     * @return a new vector with the result
+     */
+    Vec2<T> minus(final Vec2<T> other);
 
-	/**
-	 * Scales this vector by the given factors.
-	 *
-	 * @param scaleX
-	 *            the x scale factor
-	 * @param scaleY
-	 *            the y scale factor
-	 * @return a new scaled vector
-	 */
-	Vec2<T> scale(final T scaleX, final T scaleY);
+    /**
+     * Scales this vector by the given factors.
+     *
+     * @param scaleX
+     *            the x scale factor
+     * @param scaleY
+     *            the y scale factor
+     * @return a new scaled vector
+     */
+    Vec2<T> scale(final T scaleX, final T scaleY);
 
-	/**
-	 * Scales this vector by the given vector.
-	 *
-	 * @param scale
-	 *            scale vec.
-	 * @return a new scaled vector
-	 */
-	default Vec2<T> scale(final Vec2<T> scale) {
-		return scale(scale.getX(), scale.getY());
-	}
+    /**
+     * Scales this vector by the given vector.
+     *
+     * @param scale
+     *            scale vec.
+     * @return a new scaled vector
+     */
+    default Vec2<T> scale(final Vec2<T> scale) {
+        return scale(scale.getX(), scale.getY());
+    }
 
-	/**
-	 * Length of the vector.
-	 *
-	 * @return length.
-	 */
-	float length();
+    /**
+     * Length of the vector.
+     *
+     * @return length.
+     */
+    float length();
 
-	/**
-	 * @return Vec2<Integer> components of {@link Vec2<T>}
-	 */
-	Vec2<Integer> intValue();
+    /**
+     * @return Vec2<Integer> components of {@link Vec2<T>}
+     */
+    Vec2<Integer> intValue();
 
-	/**
-	 * @return Vec2<Float> components of {@link Vec2<T>}
-	 */
-	Vec2<Float> floatValue();
+    /**
+     * @return Vec2<Float> components of {@link Vec2<T>}
+     */
+    Vec2<Float> floatValue();
 
-	/**
-	 * @param xTransform
-	 *            transform of x component.
-	 * @param yTransform
-	 *            transform of y component.
-	 * @return transformed vec applying {@param xTransform} to x component,
-	 *         {@param yTransform} to y component.
-	 */
-	Vec2<T> transform(final Function<T, T> xTransform, final Function<T, T> yTransform);
+    /**
+     * @param xTransform
+     *            transform of x component.
+     * @param yTransform
+     *            transform of y component.
+     * @return transformed vec applying {@param xTransform} to x component,
+     *         {@param yTransform} to y component.
+     */
+    Vec2<T> transform(final Function<T, T> xTransform, final Function<T, T> yTransform);
 }
diff --git a/core/src/main/java/coffee/liz/ecs/math/Vec2f.java b/core/src/main/java/coffee/liz/ecs/math/Vec2f.java
index 5b91a2d..42b73e7 100644
--- a/core/src/main/java/coffee/liz/ecs/math/Vec2f.java
+++ b/core/src/main/java/coffee/liz/ecs/math/Vec2f.java
@@ -15,47 +15,47 @@ import java.util.function.Function;
 @Data
 @Builder
 public final class Vec2f implements Vec2<Float> {
-	/** X coordinate. */
-	private final Float x;
+    /** X coordinate. */
+    private final Float x;
 
-	/** Y coordinate. */
-	private final Float y;
+    /** Y coordinate. */
+    private final Float y;
 
-	@Override
-	public Vec2<Float> plus(final Vec2<Float> other) {
-		return new Vec2f(x + other.getX(), y + other.getY());
-	}
+    @Override
+    public Vec2<Float> plus(final Vec2<Float> other) {
+        return new Vec2f(x + other.getX(), y + other.getY());
+    }
 
-	@Override
-	public Vec2<Float> minus(final Vec2<Float> other) {
-		return new Vec2f(x - other.getX(), y - other.getY());
-	}
+    @Override
+    public Vec2<Float> minus(final Vec2<Float> other) {
+        return new Vec2f(x - other.getX(), y - other.getY());
+    }
 
-	@Override
-	public Vec2<Float> scale(final Float scaleX, final Float scaleY) {
-		return new Vec2f(x * scaleX, y * scaleY);
-	}
+    @Override
+    public Vec2<Float> scale(final Float scaleX, final Float scaleY) {
+        return new Vec2f(x * scaleX, y * scaleY);
+    }
 
-	@Override
-	public float length() {
-		return (float) sqrt(x * x + y * y);
-	}
+    @Override
+    public float length() {
+        return (float) sqrt(x * x + y * y);
+    }
 
-	@Override
-	public Vec2<Float> floatValue() {
-		return this;
-	}
+    @Override
+    public Vec2<Float> floatValue() {
+        return this;
+    }
 
-	@Override
-	public Vec2<Float> transform(final Function<Float, Float> xTransform, final Function<Float, Float> yTransform) {
-		return new Vec2f(xTransform.apply(getX()), yTransform.apply(getY()));
-	}
+    @Override
+    public Vec2<Float> transform(final Function<Float, Float> xTransform, final Function<Float, Float> yTransform) {
+        return new Vec2f(xTransform.apply(getX()), yTransform.apply(getY()));
+    }
 
-	@Override
-	public Vec2<Integer> intValue() {
-		return Vec2i.builder().x(this.x.intValue()).y(this.y.intValue()).build();
-	}
+    @Override
+    public Vec2<Integer> intValue() {
+        return Vec2i.builder().x(this.x.intValue()).y(this.y.intValue()).build();
+    }
 
-	/** Zero float vec */
-	public static Vec2<Float> ZERO = Vec2f.builder().x(0f).y(0f).build();
+    /** Zero float vec */
+    public static Vec2<Float> ZERO = Vec2f.builder().x(0f).y(0f).build();
 }
diff --git a/core/src/main/java/coffee/liz/ecs/math/Vec2i.java b/core/src/main/java/coffee/liz/ecs/math/Vec2i.java
index b07e481..326a5df 100644
--- a/core/src/main/java/coffee/liz/ecs/math/Vec2i.java
+++ b/core/src/main/java/coffee/liz/ecs/math/Vec2i.java
@@ -15,51 +15,51 @@ import java.util.function.Function;
 @Builder
 @Data
 public final class Vec2i implements Vec2<Integer> {
-	/** X coordinate. */
-	private final Integer x;
+    /** X coordinate. */
+    private final Integer x;
 
-	/** Y coordinate. */
-	private final Integer y;
+    /** Y coordinate. */
+    private final Integer y;
 
-	@Override
-	public Vec2<Integer> plus(final Vec2<Integer> other) {
-		return new Vec2i(x + other.getX(), y + other.getY());
-	}
+    @Override
+    public Vec2<Integer> plus(final Vec2<Integer> other) {
+        return new Vec2i(x + other.getX(), y + other.getY());
+    }
 
-	@Override
-	public Vec2<Integer> minus(final Vec2<Integer> other) {
-		return new Vec2i(x - other.getX(), y - other.getY());
-	}
+    @Override
+    public Vec2<Integer> minus(final Vec2<Integer> other) {
+        return new Vec2i(x - other.getX(), y - other.getY());
+    }
 
-	@Override
-	public Vec2<Integer> scale(final Integer scaleX, final Integer scaleY) {
-		return new Vec2i(x * scaleX, y * scaleY);
-	}
+    @Override
+    public Vec2<Integer> scale(final Integer scaleX, final Integer scaleY) {
+        return new Vec2i(x * scaleX, y * scaleY);
+    }
 
-	@Override
-	public Vec2<Float> floatValue() {
-		return Vec2f.builder().x(this.x.floatValue()).y(this.y.floatValue()).build();
-	}
+    @Override
+    public Vec2<Float> floatValue() {
+        return Vec2f.builder().x(this.x.floatValue()).y(this.y.floatValue()).build();
+    }
 
-	@Override
-	public Vec2<Integer> transform(final Function<Integer, Integer> xTransform,
-			final Function<Integer, Integer> yTransform) {
-		return new Vec2i(xTransform.apply(getX()), yTransform.apply(getY()));
-	}
+    @Override
+    public Vec2<Integer> transform(final Function<Integer, Integer> xTransform,
+            final Function<Integer, Integer> yTransform) {
+        return new Vec2i(xTransform.apply(getX()), yTransform.apply(getY()));
+    }
 
-	@Override
-	public Vec2<Integer> intValue() {
-		return this;
-	}
+    @Override
+    public Vec2<Integer> intValue() {
+        return this;
+    }
 
-	@Override
-	public float length() {
-		return (float) sqrt(x * x + y * y);
-	}
+    @Override
+    public float length() {
+        return (float) sqrt(x * x + y * y);
+    }
 
-	public static final Vec2<Integer> NORTH = new Vec2i(0, 1);
-	public static final Vec2<Integer> SOUTH = new Vec2i(0, -1);
-	public static final Vec2<Integer> EAST = new Vec2i(1, 0);
-	public static final Vec2<Integer> WEST = new Vec2i(-1, 0);
-	public static final Vec2<Integer> ZERO = new Vec2i(0, 0);
+    public static final Vec2<Integer> NORTH = new Vec2i(0, 1);
+    public static final Vec2<Integer> SOUTH = new Vec2i(0, -1);
+    public static final Vec2<Integer> EAST = new Vec2i(1, 0);
+    public static final Vec2<Integer> WEST = new Vec2i(-1, 0);
+    public static final Vec2<Integer> ZERO = new Vec2i(0, 0);
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/Component.java b/core/src/main/java/coffee/liz/ecs/model/Component.java
index f96ba95..2d3a8e7 100644
--- a/core/src/main/java/coffee/liz/ecs/model/Component.java
+++ b/core/src/main/java/coffee/liz/ecs/model/Component.java
@@ -2,7 +2,7 @@ package coffee.liz.ecs.model;
 
 /** Component of an {@link Entity}. */
 public interface Component {
-	default Class<? extends Component> getKey() {
-		return getClass();
-	}
+    default Class<? extends Component> getKey() {
+        return getClass();
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/Entity.java b/core/src/main/java/coffee/liz/ecs/model/Entity.java
index e820e57..7dab667 100644
--- a/core/src/main/java/coffee/liz/ecs/model/Entity.java
+++ b/core/src/main/java/coffee/liz/ecs/model/Entity.java
@@ -18,88 +18,88 @@ import java.util.Set;
 @AllArgsConstructor
 @Data
 public class Entity {
-	/** Unique id. */
-	private final int id;
+    /** Unique id. */
+    private final int id;
 
-	/** Instances of {@link Component}s. */
-	@Builder.Default
-	private Map<Class<? extends Component>, Component> componentMap = Collections.synchronizedMap(new HashMap<>());
+    /** Instances of {@link Component}s. */
+    @Builder.Default
+    private Map<Class<? extends Component>, Component> componentMap = Collections.synchronizedMap(new HashMap<>());
 
-	/**
-	 * Check if entity has component type.
-	 *
-	 * @param componentType
-	 *            the {@link Component} class
-	 * @return true if component exists
-	 */
-	public boolean has(final Class<? extends Component> componentType) {
-		return componentMap.containsKey(componentType);
-	}
+    /**
+     * Check if entity has component type.
+     *
+     * @param componentType
+     *            the {@link Component} class
+     * @return true if component exists
+     */
+    public boolean has(final Class<? extends Component> componentType) {
+        return componentMap.containsKey(componentType);
+    }
 
-	/**
-	 * Check if entity has all component types.
-	 *
-	 * @param components
-	 *            collection of {@link Component} classes
-	 * @return true if all components exist
-	 */
-	public boolean hasAll(final Collection<Class<? extends Component>> components) {
-		return components.stream().allMatch(this::has);
-	}
+    /**
+     * Check if entity has all component types.
+     *
+     * @param components
+     *            collection of {@link Component} classes
+     * @return true if all components exist
+     */
+    public boolean hasAll(final Collection<Class<? extends Component>> components) {
+        return components.stream().allMatch(this::has);
+    }
 
-	/**
-	 * Get component by type.
-	 *
-	 * @param componentType
-	 *            the {@link Component} class
-	 * @param <C>
-	 *            component type
-	 * @return the component or throw {@link IllegalArgumentException}
-	 */
-	@SuppressWarnings("unchecked")
-	public <C extends Component> C get(final Class<C> componentType) {
-		final C component = (C) componentMap.get(componentType);
-		if (component == null) {
-			throw new IllegalArgumentException(
-					"Entity with id " + getId() + " does not have required component " + componentType.getSimpleName());
-		}
-		return component;
-	}
+    /**
+     * Get component by type.
+     *
+     * @param componentType
+     *            the {@link Component} class
+     * @param <C>
+     *            component type
+     * @return the component or throw {@link IllegalArgumentException}
+     */
+    @SuppressWarnings("unchecked")
+    public <C extends Component> C get(final Class<C> componentType) {
+        final C component = (C) componentMap.get(componentType);
+        if (component == null) {
+            throw new IllegalArgumentException(
+                    "Entity with id " + getId() + " does not have required component " + componentType.getSimpleName());
+        }
+        return component;
+    }
 
-	/**
-	 * Add component to entity.
-	 *
-	 * @param component
-	 *            the {@link Component} to add
-	 * @param <C>
-	 *            component type
-	 * @return this {@link Entity} for chaining
-	 */
-	public <C extends Component> Entity add(final C component) {
-		componentMap.put(component.getKey(), component);
-		return this;
-	}
+    /**
+     * Add component to entity.
+     *
+     * @param component
+     *            the {@link Component} to add
+     * @param <C>
+     *            component type
+     * @return this {@link Entity} for chaining
+     */
+    public <C extends Component> Entity add(final C component) {
+        componentMap.put(component.getKey(), component);
+        return this;
+    }
 
-	/**
-	 * Remove component from entity.
-	 *
-	 * @param componentType
-	 *            the {@link Component} class to remove
-	 * @param <C>
-	 *            component type
-	 * @return this {@link Entity} for chaining
-	 */
-	public <C extends Component> Entity remove(final Class<C> componentType) {
-		componentMap.remove(componentType);
-		return this;
-	}
+    /**
+     * Remove component from entity.
+     *
+     * @param componentType
+     *            the {@link Component} class to remove
+     * @param <C>
+     *            component type
+     * @return this {@link Entity} for chaining
+     */
+    public <C extends Component> Entity remove(final Class<C> componentType) {
+        componentMap.remove(componentType);
+        return this;
+    }
 
-	/**
-	 * Get all component types.
-	 *
-	 * @return set of {@link Component} classes
-	 */
-	public Set<Class<? extends Component>> componentTypes() {
-		return componentMap.keySet();
-	}
+    /**
+     * Get all component types.
+     *
+     * @return set of {@link Component} classes
+     */
+    public Set<Class<? extends Component>> componentTypes() {
+        return componentMap.keySet();
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/System.java b/core/src/main/java/coffee/liz/ecs/model/System.java
index ac99818..c4b0bc0 100644
--- a/core/src/main/java/coffee/liz/ecs/model/System.java
+++ b/core/src/main/java/coffee/liz/ecs/model/System.java
@@ -10,24 +10,24 @@ import java.util.Collection;
  *            is the state of the stuff outside the {@link World}.
  */
 public interface System<T> extends AutoCloseable {
-	/**
-	 * {@link System} clazzes that must run before this system.
-	 *
-	 * @return {@link Collection} of dependencies.
-	 */
-	Collection<Class<? extends System<T>>> getDependencies();
+    /**
+     * {@link System} clazzes that must run before this system.
+     *
+     * @return {@link Collection} of dependencies.
+     */
+    Collection<Class<? extends System<T>>> getDependencies();
 
-	/**
-	 * @param world
-	 *            Is the {@link World}.
-	 * @param state
-	 *            Is the {@link T} state outside the {@param world}.
-	 * @param dt
-	 *            Is the timestep.
-	 */
-	void update(final World<T> world, final T state, final Duration dt);
+    /**
+     * @param world
+     *            Is the {@link World}.
+     * @param state
+     *            Is the {@link T} state outside the {@param world}.
+     * @param dt
+     *            Is the timestep.
+     */
+    void update(final World<T> world, final T state, final Duration dt);
 
-	@Override
-	default void close() {
-	}
+    @Override
+    default void close() {
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/World.java b/core/src/main/java/coffee/liz/ecs/model/World.java
index 05363e8..c59a0d7 100644
--- a/core/src/main/java/coffee/liz/ecs/model/World.java
+++ b/core/src/main/java/coffee/liz/ecs/model/World.java
@@ -11,48 +11,48 @@ import java.util.Set;
  *            is the state of the stuff outside the world.
  */
 public interface World<T> extends AutoCloseable {
-	/**
-	 * Create unique {@link Entity} in the {@link World}.
-	 *
-	 * @return created {@link Entity}.
-	 */
-	Entity createEntity();
+    /**
+     * Create unique {@link Entity} in the {@link World}.
+     *
+     * @return created {@link Entity}.
+     */
+    Entity createEntity();
 
-	/**
-	 * Remove an entity from the {@link World}.
-	 *
-	 * @param entity
-	 *            to remove.
-	 */
-	void removeEntity(final Entity entity);
+    /**
+     * Remove an entity from the {@link World}.
+     *
+     * @param entity
+     *            to remove.
+     */
+    void removeEntity(final Entity entity);
 
-	/**
-	 * Get entities with {@link Component}s.
-	 *
-	 * @param components
-	 *            to query for.
-	 * @return All entities with all {@param components}.
-	 */
-	Set<Entity> query(final Collection<Class<? extends Component>> components);
+    /**
+     * Get entities with {@link Component}s.
+     *
+     * @param components
+     *            to query for.
+     * @return All entities with all {@param components}.
+     */
+    Set<Entity> query(final Collection<Class<? extends Component>> components);
 
-	/**
-	 * Integrate the {@link World}.
-	 *
-	 * @param state
-	 *            Is the state outside the world.
-	 * @param duration
-	 *            Is the time step.
-	 */
-	void update(final T state, final Duration duration);
+    /**
+     * Integrate the {@link World}.
+     *
+     * @param state
+     *            Is the state outside the world.
+     * @param duration
+     *            Is the time step.
+     */
+    void update(final T state, final Duration duration);
 
-	/**
-	 * Get world {@link System}.
-	 *
-	 * @param system
-	 *            is the Clazz.
-	 * @param <S>
-	 *            is the {@link System} type.
-	 * @return {@link System} instance of {@param system}.
-	 */
-	<S extends System<T>> S getSystem(final Class<S> system);
+    /**
+     * Get world {@link System}.
+     *
+     * @param system
+     *            is the Clazz.
+     * @param <S>
+     *            is the {@link System} type.
+     * @return {@link System} instance of {@param system}.
+     */
+    <S extends System<T>> S getSystem(final Class<S> system);
 }