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/*******************************************************************************
* 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 java.util.BitSet;
import com.badlogic.gdx.math.MathUtils;
/** A resizable, ordered or unordered boolean array. Avoids the boxing that occurs with ArrayList. 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;
}
/** 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 and returns the last item. */
public boolean pop () {
return items[--size];
}
/** Returns the last item. */
public boolean peek () {
return items[size - 1];
}
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(items.length, 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 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();
}
}
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