/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
******************************************************************************/
package com.badlogic.gdx.utils;
import com.badlogic.gdx.math.MathUtils;
import java.util.BitSet;
/**
* A resizable, ordered or unordered boolean array. Avoids the boxing that occurs with ArrayList<Boolean>. It is less
* memory efficient than {@link BitSet}, except for very small sizes. It more CPU efficient than {@link BitSet}, except
* for very large sizes or if BitSet functionality such as and, or, xor, etc are needed. If unordered, this class avoids
* a memory copy when removing elements (the last element is moved to the removed element's position).
*
* @author Nathan Sweet
*/
public class BooleanArray {
public boolean[] items;
public int size;
public boolean ordered;
/** Creates an ordered array with a capacity of 16. */
public BooleanArray() {
this(true, 16);
}
/** Creates an ordered array with the specified capacity. */
public BooleanArray(int capacity) {
this(true, capacity);
}
/**
* @param ordered
* If false, methods that remove elements may change the order of other elements in the array, which
* avoids a memory copy.
* @param capacity
* Any elements added beyond this will cause the backing array to be grown.
*/
public BooleanArray(boolean ordered, int capacity) {
this.ordered = ordered;
items = new boolean[capacity];
}
/**
* Creates a new array containing the elements in the specific array. The new array will be ordered if the specific
* array is ordered. The capacity is set to the number of elements, so any subsequent elements added will cause the
* backing array to be grown.
*/
public BooleanArray(BooleanArray array) {
this.ordered = array.ordered;
size = array.size;
items = new boolean[size];
System.arraycopy(array.items, 0, items, 0, size);
}
/**
* Creates a new ordered array containing the elements in the specified array. The capacity is set to the number of
* elements, so any subsequent elements added will cause the backing array to be grown.
*/
public BooleanArray(boolean[] array) {
this(true, array);
}
/**
* Creates a new array containing the elements in the specified array. The capacity is set to the number of
* elements, so any subsequent elements added will cause the backing array to be grown.
*
* @param ordered
* If false, methods that remove elements may change the order of other elements in the array, which
* avoids a memory copy.
*/
public BooleanArray(boolean ordered, boolean[] array) {
this(ordered, array.length);
size = array.length;
System.arraycopy(array, 0, items, 0, size);
}
public void add(boolean value) {
boolean[] items = this.items;
if (size == items.length)
items = resize(Math.max(8, (int) (size * 1.75f)));
items[size++] = value;
}
public void addAll(BooleanArray array) {
addAll(array, 0, array.size);
}
public void addAll(BooleanArray array, int offset, int length) {
if (offset + length > array.size)
throw new IllegalArgumentException("offset + length must be <= size: " + offset + " + " + length + " <= "
+ array.size);
addAll(array.items, offset, length);
}
public void addAll(boolean[] array) {
addAll(array, 0, array.length);
}
public void addAll(boolean[] array, int offset, int length) {
boolean[] items = this.items;
int sizeNeeded = size + length - offset;
if (sizeNeeded >= items.length)
items = resize(Math.max(8, (int) (sizeNeeded * 1.75f)));
System.arraycopy(array, offset, items, size, length);
size += length;
}
public boolean get(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
return items[index];
}
public void set(int index, boolean value) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
items[index] = value;
}
public void insert(int index, boolean value) {
boolean[] items = this.items;
if (size == items.length)
items = resize(Math.max(8, (int) (size * 1.75f)));
if (ordered)
System.arraycopy(items, index, items, index + 1, size - index);
else
items[size] = items[index];
size++;
items[index] = value;
}
public void swap(int first, int second) {
if (first >= size)
throw new IndexOutOfBoundsException(String.valueOf(first));
if (second >= size)
throw new IndexOutOfBoundsException(String.valueOf(second));
boolean[] items = this.items;
boolean firstValue = items[first];
items[first] = items[second];
items[second] = firstValue;
}
/** Removes and returns the item at the specified index. */
public boolean removeIndex(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
boolean[] items = this.items;
boolean value = items[index];
size--;
if (ordered)
System.arraycopy(items, index + 1, items, index, size - index);
else
items[index] = items[size];
return value;
}
/**
* Removes from this array all of elements contained in the specified array.
*
* @return true if this array was modified.
*/
public boolean removeAll(BooleanArray array) {
int size = this.size;
int startSize = size;
boolean[] items = this.items;
for (int i = 0, n = array.size; i < n; i++) {
boolean item = array.get(i);
for (int ii = 0; ii < size; ii++) {
if (item == items[ii]) {
removeIndex(ii);
size--;
break;
}
}
}
return size != startSize;
}
/** Removes and returns the last item. */
public boolean pop() {
return items[--size];
}
/** Returns the last item. */
public boolean peek() {
return items[size - 1];
}
/** Returns the first item. */
public boolean first() {
return items[0];
}
public void clear() {
size = 0;
}
/**
* Reduces the size of the backing array to the size of the actual items. This is useful to release memory when many
* items have been removed, or if it is known that more items will not be added.
*/
public void shrink() {
resize(size);
}
/**
* Increases the size of the backing array to acommodate the specified number of additional items. Useful before
* adding many items to avoid multiple backing array resizes.
*
* @return {@link #items}
*/
public boolean[] ensureCapacity(int additionalCapacity) {
int sizeNeeded = size + additionalCapacity;
if (sizeNeeded >= items.length)
resize(Math.max(8, sizeNeeded));
return items;
}
protected boolean[] resize(int newSize) {
boolean[] newItems = new boolean[newSize];
boolean[] items = this.items;
System.arraycopy(items, 0, newItems, 0, Math.min(size, newItems.length));
this.items = newItems;
return newItems;
}
public void reverse() {
for (int i = 0, lastIndex = size - 1, n = size / 2; i < n; i++) {
int ii = lastIndex - i;
boolean temp = items[i];
items[i] = items[ii];
items[ii] = temp;
}
}
public void shuffle() {
for (int i = size - 1; i >= 0; i--) {
int ii = MathUtils.random(i);
boolean temp = items[i];
items[i] = items[ii];
items[ii] = temp;
}
}
/**
* Reduces the size of the array to the specified size. If the array is already smaller than the specified size, no
* action is taken.
*/
public void truncate(int newSize) {
if (size > newSize)
size = newSize;
}
/** Returns a random item from the array, or false if the array is empty. */
public boolean random() {
if (size == 0)
return false;
return items[MathUtils.random(0, size - 1)];
}
public boolean[] toArray() {
boolean[] array = new boolean[size];
System.arraycopy(items, 0, array, 0, size);
return array;
}
public boolean equals(Object object) {
if (object == this)
return true;
if (!(object instanceof BooleanArray))
return false;
BooleanArray array = (BooleanArray) object;
int n = size;
if (n != array.size)
return false;
for (int i = 0; i < n; i++)
if (items[i] != array.items[i])
return false;
return true;
}
public String toString() {
if (size == 0)
return "[]";
boolean[] items = this.items;
StringBuilder buffer = new StringBuilder(32);
buffer.append('[');
buffer.append(items[0]);
for (int i = 1; i < size; i++) {
buffer.append(", ");
buffer.append(items[i]);
}
buffer.append(']');
return buffer.toString();
}
public String toString(String separator) {
if (size == 0)
return "";
boolean[] items = this.items;
StringBuilder buffer = new StringBuilder(32);
buffer.append(items[0]);
for (int i = 1; i < size; i++) {
buffer.append(separator);
buffer.append(items[i]);
}
return buffer.toString();
}
}