001/*******************************************************************************
002 * Copyright 2011 See AUTHORS file.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *   http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 ******************************************************************************/
016package squidpony.squidmath;
017
018import java.io.Serializable;
019import java.util.Arrays;
020
021/** A resizable, ordered or unordered short variable-length array. Avoids the boxing that occurs with {@code ArrayList<Short>}.
022 * If unordered, this class avoids a memory copy when removing elements (the last element is moved to the removed
023 * element's position). Used internally by CoordPacker, and unlikely to be used outside of it.
024 * <br>
025 * Was called IntArray in libGDX; to avoid confusion with the fixed-length primitive array type, VLA (variable-length
026 * array) was chosen as a different name. Also uses short instead of int, of course.
027 * Copied from LibGDX by Tommy Ettinger on 10/1/2015.
028 * @author Nathan Sweet */
029public class ShortVLA implements Serializable{
030    private static final long serialVersionUID = -2948161891082748626L;
031
032    public short[] items;
033    public int size;
034    public boolean ordered;
035
036    /** Creates an ordered array with a capacity of 16. */
037    public ShortVLA() {
038        this(true, 16);
039    }
040
041    /** Creates an ordered array with the specified capacity. */
042    public ShortVLA(int capacity) {
043        this(true, capacity);
044    }
045
046    /** @param ordered If false, methods that remove elements may change the order of other elements in the array, which avoids a
047     *           memory copy.
048     * @param capacity Any elements added beyond this will cause the backing array to be grown. */
049    public ShortVLA(boolean ordered, int capacity) {
050        this.ordered = ordered;
051        items = new short[capacity];
052    }
053
054    /** Creates a new array containing the elements in the specific array. The new array will be ordered if the specific array is
055     * ordered. The capacity is set to the number of elements, so any subsequent elements added will cause the backing array to be
056     * grown. */
057    public ShortVLA(ShortVLA array) {
058        ordered = array.ordered;
059        size = array.size;
060        items = new short[size];
061        System.arraycopy(array.items, 0, items, 0, size);
062    }
063
064    /** Creates a new ordered array containing the elements in the specified array. The capacity is set to the number of elements,
065     * so any subsequent elements added will cause the backing array to be grown. */
066    public ShortVLA(short[] array) {
067        this(true, array, 0, array.length);
068    }
069
070    /** Creates a new ordered array containing the elements in the specified array, converted to short. The capacity is set to
071     * the number of elements, so any subsequent elements added will cause the backing array to be grown. */
072    public ShortVLA(int[] array) {
073        this(true, array.length);
074        for (int i = 0; i < array.length; i++) {
075            items[size + i] = (short)(array[i]);
076        }
077        size += array.length;
078
079    }
080
081    /** Creates a new array containing the elements in the specified array. The capacity is set to the number of elements, so any
082     * subsequent elements added will cause the backing array to be grown.
083     * @param ordered If false, methods that remove elements may change the order of other elements in the array, which avoids a
084     *           memory copy.
085     */
086    public ShortVLA(boolean ordered, short[] array, int startIndex, int count) {
087        this(ordered, count);
088        size = count;
089        System.arraycopy(array, startIndex, items, 0, count);
090    }
091
092    public void add (short value) {
093        short[] items = this.items;
094        if (size == items.length) items = resize(Math.max(8, (int)(size * 1.75f)));
095        items[size++] = value;
096    }
097    
098    public void addAll (ShortVLA array) {
099        addAll(array, 0, array.size);
100    }
101
102    public void addAll (ShortVLA array, int offset, int length) {
103        if (offset + length > array.size)
104            throw new IllegalArgumentException("offset + length must be <= size: " + offset + " + " + length + " <= " + array.size);
105        addAll(array.items, offset, length);
106    }
107
108    public void addAll (short... array) {
109        addAll(array, 0, array.length);
110    }
111
112    public void addAll (short[] array, int offset, int length) {
113        short[] items = this.items;
114        int sizeNeeded = size + length;
115        if (sizeNeeded > items.length) items = resize(Math.max(8, (int)(sizeNeeded * 1.75f)));
116        System.arraycopy(array, offset, items, size, length);
117        size += length;
118    }
119
120    public void addAll (int[] array) {
121        short[] items = this.items;
122        int sizeNeeded = size + array.length;
123        if (sizeNeeded > items.length) items = resize(Math.max(8, (int)(sizeNeeded * 1.75f)));
124        for (int i = 0; i < array.length; i++) {
125            items[size + i] = (short)(array[i]);
126        }
127        size += array.length;
128    }
129
130    public void addRange (int start, int end) {
131        short[] items = this.items;
132        int sizeNeeded = size + end - start;
133        if (sizeNeeded > items.length) items = resize(Math.max(8, (int)(sizeNeeded * 1.75f)));
134        for(int r = start, i = size; r < end; r++, i++)
135        {
136            items[i] = (short)r;
137        }
138        size += end - start;
139    }
140
141    public void addFractionRange (int start, int end, int fraction) {
142        short[] items = this.items;
143        int sizeNeeded = size + (end - start) / fraction + 2;
144        if (sizeNeeded > items.length) items = resize(Math.max(8, (int)(sizeNeeded * 1.75f)));
145        for(int r = start, i = size; r < end; r = fraction * ((r / fraction) + 1), i++, size++)
146        {
147            items[i] = (short)(r);
148        }
149    }
150
151    public short get (int index) {
152        if (index >= size) throw new IndexOutOfBoundsException("index can't be >= size: " + index + " >= " + size);
153        return items[index];
154    }
155
156    public void set (int index, short value) {
157        if (index >= size) throw new IndexOutOfBoundsException("index can't be >= size: " + index + " >= " + size);
158        items[index] = value;
159    }
160
161    /**
162     * Adds value to the item in the ShortVLA at index. Calling it "add" would overlap with the collection method.
163     * @param index
164     * @param value
165     */
166    public void incr (int index, short value) {
167        if (index >= size) throw new IndexOutOfBoundsException("index can't be >= size: " + index + " >= " + size);
168        items[index] += value;
169    }
170
171    public void mul (int index, short value) {
172        if (index >= size) throw new IndexOutOfBoundsException("index can't be >= size: " + index + " >= " + size);
173        items[index] *= value;
174    }
175
176    public void insert (int index, short value) {
177        if (index > size) throw new IndexOutOfBoundsException("index can't be > size: " + index + " > " + size);
178        short[] items = this.items;
179        if (size == items.length) items = resize(Math.max(8, (int)(size * 1.75f)));
180        if (ordered)
181            System.arraycopy(items, index, items, index + 1, size - index);
182        else
183            items[size] = items[index];
184        size++;
185        items[index] = value;
186    }
187
188    public void swap (int first, int second) {
189        if (first >= size) throw new IndexOutOfBoundsException("first can't be >= size: " + first + " >= " + size);
190        if (second >= size) throw new IndexOutOfBoundsException("second can't be >= size: " + second + " >= " + size);
191        short[] items = this.items;
192        short firstValue = items[first];
193        items[first] = items[second];
194        items[second] = firstValue;
195    }
196
197    public boolean contains (short value) {
198        int i = size - 1;
199        short[] items = this.items;
200        while (i >= 0)
201            if (items[i--] == value) return true;
202        return false;
203    }
204
205    public int indexOf (short value) {
206        short[] items = this.items;
207        for (int i = 0, n = size; i < n; i++)
208            if (items[i] == value) return i;
209        return -1;
210    }
211
212    public int lastIndexOf (short value) {
213        short[] items = this.items;
214        for (int i = size - 1; i >= 0; i--)
215            if (items[i] == value) return i;
216        return -1;
217    }
218
219    public boolean removeValue (short value) {
220        short[] items = this.items;
221        for (int i = 0, n = size; i < n; i++) {
222            if (items[i] == value) {
223                removeIndex(i);
224                return true;
225            }
226        }
227        return false;
228    }
229
230    /** Removes and returns the item at the specified index. */
231    public short removeIndex (int index) {
232        if (index >= size) throw new IndexOutOfBoundsException("index can't be >= size: " + index + " >= " + size);
233        short[] items = this.items;
234        short value = items[index];
235        size--;
236        if (ordered)
237            System.arraycopy(items, index + 1, items, index, size - index);
238        else
239            items[index] = items[size];
240        return value;
241    }
242
243    /** Removes the items between the specified indices, inclusive. */
244    public void removeRange (int start, int end) {
245        if (end >= size) throw new IndexOutOfBoundsException("end can't be >= size: " + end + " >= " + size);
246        if (start > end) throw new IndexOutOfBoundsException("start can't be > end: " + start + " > " + end);
247        short[] items = this.items;
248        int count = end - start + 1;
249        if (ordered)
250            System.arraycopy(items, start + count, items, start, size - (start + count));
251        else {
252            int lastIndex = size - 1;
253            for (int i = 0; i < count; i++)
254                items[start + i] = items[lastIndex - i];
255        }
256        size -= count;
257    }
258
259    /** Removes from this array all of elements contained in the specified array.
260     * @return true if this array was modified. */
261    public boolean removeAll (ShortVLA array) {
262        int size = this.size;
263        int startSize = size;
264        short[] items = this.items;
265        for (int i = 0, n = array.size; i < n; i++) {
266            short item = array.get(i);
267            for (int ii = 0; ii < size; ii++) {
268                if (item == items[ii]) {
269                    removeIndex(ii);
270                    size--;
271                    break;
272                }
273            }
274        }
275        return size != startSize;
276    }
277
278    /** Removes and returns the last item. */
279    public short pop () {
280        return items[--size];
281    }
282
283    /** Returns the last item. */
284    public short peek () {
285        return items[size - 1];
286    }
287
288    /** Returns the first item. */
289    public short first () {
290        if (size == 0) throw new IllegalStateException("IntVLA is empty.");
291        return items[0];
292    }
293
294    public void clear () {
295        size = 0;
296    }
297
298    /** Reduces the size of the backing array to the size of the actual items. This is useful to release memory when many items have
299     * been removed, or if it is known that more items will not be added.
300     * @return {@link #items} */
301    public short[] shrink () {
302        if (items.length != size) resize(size);
303        return items;
304    }
305
306    /** Increases the size of the backing array to accommodate the specified number of additional items. Useful before adding many
307     * items to avoid multiple backing array resizes.
308     * @return {@link #items} */
309    public short[] ensureCapacity (int additionalCapacity) {
310        int sizeNeeded = size + additionalCapacity;
311        if (sizeNeeded > items.length) resize(Math.max(8, sizeNeeded));
312        return items;
313    }
314
315    protected short[] resize (int newSize) {
316        short[] newItems = new short[newSize];
317        short[] items = this.items;
318        System.arraycopy(items, 0, newItems, 0, Math.min(size, newItems.length));
319        this.items = newItems;
320        return newItems;
321    }
322
323    public int[] asInts () {
324        int[] newItems = new int[size];
325        short[] items = this.items;
326        for (int i = 0; i < size; i++) {
327            newItems[i] = items[i] & 0xffff;
328        }
329        return newItems;
330    }
331
332    public void sort () {
333        Arrays.sort(items, 0, size);
334    }
335
336    public void reverse () {
337        short[] items = this.items;
338        for (int i = 0, lastIndex = size - 1, n = size / 2; i < n; i++) {
339            int ii = lastIndex - i;
340            short temp = items[i];
341            items[i] = items[ii];
342            items[ii] = temp;
343        }
344    }
345
346    /** Reduces the size of the array to the specified size. If the array is already smaller than the specified size, no action is
347     * taken. */
348    public void truncate (int newSize) {
349        if (size > newSize) size = newSize;
350    }
351
352
353    public short[] toArray () {
354        short[] array = new short[size];
355        System.arraycopy(items, 0, array, 0, size);
356        return array;
357    }
358
359    @Override
360        public int hashCode () {
361        if (!ordered) return super.hashCode();
362        short[] items = this.items;
363        int h = 1;
364        for (int i = 0, n = size; i < n; i++)
365            h = h * 31 + items[i];
366        return h;
367    }
368
369    @Override
370        public boolean equals (Object object) {
371        if (object == this) return true;
372        if (!ordered) return false;
373        if (!(object instanceof ShortVLA)) return false;
374        ShortVLA array = (ShortVLA)object;
375        if (!array.ordered) return false;
376        int n = size;
377        if (n != array.size) return false;
378        for (int i = 0; i < n; i++)
379            if (items[i] != array.items[i]) return false;
380        return true;
381    }
382
383    @Override
384        public String toString () {
385        if (size == 0) return "[]";
386        short[] items = this.items;
387        StringBuilder buffer = new StringBuilder(32);
388        buffer.append('[');
389        buffer.append(items[0]);
390        for (int i = 1; i < size; i++) {
391            buffer.append(", ");
392            buffer.append(items[i]);
393        }
394        buffer.append(']');
395        return buffer.toString();
396    }
397
398    public String toString (String separator) {
399        if (size == 0) return "";
400        short[] items = this.items;
401        StringBuilder buffer = new StringBuilder(32);
402        buffer.append(items[0]);
403        for (int i = 1; i < size; i++) {
404            buffer.append(separator);
405            buffer.append(items[i]);
406        }
407        return buffer.toString();
408    }
409
410    /** @see #ShortVLA(short[]) */
411    public static ShortVLA with (short... array) {
412        return new ShortVLA(array);
413    }
414}