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1   /*
2    * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package sun.awt.image;
27  import java.awt.image.Raster;
28  import java.awt.image.WritableRaster;
29  import java.awt.image.RasterFormatException;
30  import java.awt.image.SampleModel;
31  import java.awt.image.BandedSampleModel;
32  import java.awt.image.DataBuffer;
33  import java.awt.image.DataBufferUShort;
34  import java.awt.Rectangle;
35  import java.awt.Point;
36  
37  /**
38   * This class defines a Raster with pixels consisting of multiple 16-bit
39   * samples stored in separate arrays for each band.  Operations on
40   * sets of pixels are performed on a given band of each pixel
41   * in the set before moving on to the next band.  The arrays used
42   * for storage may be distinct or shared between some or all of
43   * the bands.
44   * There is only one pixel stride and one scanline stride for all
45   * bands.  This type of Raster can be used with a
46   * ComponentColorModel. This class requires a BandedSampleModel.
47   *
48   */
49  public class ShortBandedRaster extends SunWritableRaster {
50  
51      /** Data offsets for each band of image data. */
52      int[]         dataOffsets;
53  
54      /** Scanline stride of the image data contained in this Raster. */
55      int           scanlineStride;
56  
57      /** The image data array. */
58      short[][]     data;
59  
60      /** A cached copy of minX + width for use in bounds checks. */
61      private int maxX;
62  
63      /** A cached copy of minY + height for use in bounds checks. */
64      private int maxY;
65  
66      /**
67       * Constructs a ShortBandedRaster with the given SampleModel.
68       * The Raster's upper left corner is origin and it is the same
69       * size as the SampleModel.  A DataBuffer large enough to describe the
70       * Raster is automatically created.  SampleModel must be of type
71       * BandedSampleModel.
72       * @param sampleModel     The SampleModel that specifies the layout.
73       * @param origin          The Point that specified the origin.
74       */
75      public ShortBandedRaster(SampleModel sampleModel,
76                                  Point origin) {
77          this(sampleModel,
78               sampleModel.createDataBuffer(),
79               new Rectangle(origin.x,
80                             origin.y,
81                             sampleModel.getWidth(),
82                             sampleModel.getHeight()),
83               origin,
84               null);
85      }
86  
87      /**
88       * Constructs a ShortBandedRaster with the given SampleModel
89       * and DataBuffer.  The Raster's upper left corner is origin and
90       * it is the same size as the SampleModel.  The DataBuffer is not
91       * initialized and must be a DataBufferUShort compatible with SampleModel.
92       * SampleModel must be of type BandedSampleModel.
93       * @param sampleModel     The SampleModel that specifies the layout.
94       * @param dataBuffer      The DataBufferUShort that contains the image data.
95       * @param origin          The Point that specifies the origin.
96       */
97      public ShortBandedRaster(SampleModel sampleModel,
98                                  DataBuffer dataBuffer,
99                                  Point origin) {
100         this(sampleModel, dataBuffer,
101              new Rectangle(origin.x, origin.y,
102                            sampleModel.getWidth(),
103                            sampleModel.getHeight()),
104              origin, null);
105     }
106 
107     /**
108      * Constructs a ShortBandedRaster with the given SampleModel,
109      * DataBuffer, and parent.  DataBuffer must be a DataBufferUShort and
110      * SampleModel must be of type BandedSampleModel.
111      * When translated into the base Raster's
112      * coordinate system, aRegion must be contained by the base Raster.
113      * Origin is the coordinate in the new Raster's coordinate system of
114      * the origin of the base Raster.  (The base Raster is the Raster's
115      * ancestor which has no parent.)
116      *
117      * Note that this constructor should generally be called by other
118      * constructors or create methods, it should not be used directly.
119      * @param sampleModel     The SampleModel that specifies the layout.
120      * @param dataBuffer      The DataBufferUShort that contains the image data.
121      * @param aRegion         The Rectangle that specifies the image area.
122      * @param origin          The Point that specifies the origin.
123      * @param parent          The parent (if any) of this raster.
124      */
125     public ShortBandedRaster(SampleModel sampleModel,
126                                 DataBuffer dataBuffer,
127                                 Rectangle aRegion,
128                                 Point origin,
129                                 ShortBandedRaster parent) {
130 
131         super(sampleModel, dataBuffer, aRegion, origin, parent);
132         this.maxX = minX + width;
133         this.maxY = minY + height;
134         if (!(dataBuffer instanceof DataBufferUShort)) {
135            throw new RasterFormatException("ShortBandedRaster must have " +
136                 "ushort DataBuffers");
137         }
138         DataBufferUShort dbus = (DataBufferUShort)dataBuffer;
139 
140         if (sampleModel instanceof BandedSampleModel) {
141             BandedSampleModel bsm = (BandedSampleModel)sampleModel;
142             this.scanlineStride = bsm.getScanlineStride();
143             int bankIndices[] = bsm.getBankIndices();
144             int bandOffsets[] = bsm.getBandOffsets();
145             int dOffsets[] = dbus.getOffsets();
146             dataOffsets = new int[bankIndices.length];
147             data = new short[bankIndices.length][];
148             int xOffset = aRegion.x - origin.x;
149             int yOffset = aRegion.y - origin.y;
150             for (int i = 0; i < bankIndices.length; i++) {
151                data[i] = stealData(dbus, bankIndices[i]);
152                dataOffsets[i] = dOffsets[bankIndices[i]] +
153                    xOffset + yOffset*scanlineStride + bandOffsets[i];
154             }
155         } else {
156             throw new RasterFormatException("ShortBandedRasters must have "+
157                 "BandedSampleModels");
158         }
159         verify();
160     }
161 
162     /**
163      * Returns a copy of the data offsets array. For each band the data offset
164      * is the index into the band's data array, of the first sample of the
165      * band.
166      */
167     public int[] getDataOffsets() {
168         return (int[]) dataOffsets.clone();
169     }
170 
171     /**
172      * Returns the data offset for the specified band.  The data offset
173      * is the index into the band's data array
174      * in which the first sample of the first scanline is stored.
175      * @param   The band whose offset is returned.
176      */
177     public int getDataOffset(int band) {
178         return dataOffsets[band];
179     }
180 
181     /**
182      * Returns the scanline stride -- the number of data array elements between
183      * a given sample and the sample in the same column
184      * of the next row in the same band.
185      */
186     public int getScanlineStride() {
187         return scanlineStride;
188     }
189 
190     /**
191      * Returns the pixel stride, which is always equal to one for
192      * a Raster with a BandedSampleModel.
193      */
194     public int getPixelStride() {
195         return 1;
196     }
197 
198     /**
199      * Returns a reference to the entire data array.
200      */
201     public short[][] getDataStorage() {
202         return data;
203     }
204 
205     /**
206      * Returns a reference to the specific band data array.
207      */
208     public short[] getDataStorage(int band) {
209         return data[band];
210     }
211 
212     /**
213      * Returns the data elements for all bands at the specified
214      * location.
215      * An ArrayIndexOutOfBounds exception will be thrown at runtime
216      * if the pixel coordinate is out of bounds.
217      * A ClassCastException will be thrown if the input object is non null
218      * and references anything other than an array of transferType.
219      * @param x        The X coordinate of the pixel location.
220      * @param y        The Y coordinate of the pixel location.
221      * @param outData  An object reference to an array of type defined by
222      *                 getTransferType() and length getNumDataElements().
223      *                 If null an array of appropriate type and size will be
224      *                 allocated.
225      * @return         An object reference to an array of type defined by
226      *                 getTransferType() with the request pixel data.
227      */
228     public Object getDataElements(int x, int y, Object obj) {
229         if ((x < this.minX) || (y < this.minY) ||
230             (x >= this.maxX) || (y >= this.maxY)) {
231             throw new ArrayIndexOutOfBoundsException
232                 ("Coordinate out of bounds!");
233         }
234         short outData[];
235         if (obj == null) {
236             outData = new short[numDataElements];
237         } else {
238             outData = (short[])obj;
239         }
240 
241         int off = (y-minY)*scanlineStride + (x-minX);
242 
243         for (int band = 0; band < numDataElements; band++) {
244             outData[band] = data[band][dataOffsets[band] + off];
245         }
246 
247         return outData;
248     }
249 
250     /**
251      * Returns an array  of data elements from the specified rectangular
252      * region.
253      * An ArrayIndexOutOfBounds exception will be thrown at runtime
254      * if the pixel coordinates are out of bounds.
255      * <pre>
256      *       short[] bandData = (short[])Raster.getDataElements(x, y, w, h, null);
257      *       int numDataElements = Raster.getnumDataElements();
258      *       short[] pixel = new short[numDataElements];
259      *       // To find a data element at location (x2, y2)
260      *       System.arraycopy(bandData, ((y2-y)*w + (x2-x))*numDataElements,
261      *                        pixel, 0, numDataElements);
262      * </pre>
263      * @param x        The X coordinate of the upper left pixel location.
264      * @param y        The Y coordinate of the upper left pixel location.
265      * @param width    Width of the pixel rectangle.
266      * @param height   Height of the pixel rectangle.
267      * @param outData  An object reference to an array of type defined by
268      *                 getTransferType() and length w*h*getNumDataElements().
269      *                 If null an array of appropriate type and size will be
270      *                 allocated.
271      * @return         An object reference to an array of type defined by
272      *                 getTransferType() with the request pixel data.
273      */
274     public Object getDataElements(int x, int y, int w, int h, Object obj) {
275         if ((x < this.minX) || (y < this.minY) ||
276             (x + w > this.maxX) || (y + h > this.maxY)) {
277             throw new ArrayIndexOutOfBoundsException
278                 ("Coordinate out of bounds!");
279         }
280         short outData[];
281         if (obj == null) {
282             outData = new short[numDataElements*w*h];
283         } else {
284             outData = (short[])obj;
285         }
286         int yoff = (y-minY)*scanlineStride + (x-minX);
287 
288         for (int c = 0; c < numDataElements; c++) {
289             int off = c;
290             short[] bank = data[c];
291             int dataOffset = dataOffsets[c];
292 
293             int yoff2 = yoff;
294             for (int ystart=0; ystart < h; ystart++, yoff2 += scanlineStride) {
295                 int xoff = dataOffset + yoff2;
296                 for (int xstart=0; xstart < w; xstart++) {
297                     outData[off] = bank[xoff++];
298                     off += numDataElements;
299                 }
300             }
301         }
302 
303         return outData;
304     }
305 
306     /**
307      * Returns a short array  of data elements from the specified rectangular
308      * region for the specified band.
309      * An ArrayIndexOutOfBounds exception will be thrown at runtime
310      * if the pixel coordinates are out of bounds.
311      * <pre>
312      *       short[] bandData = Raster.getShortData(x, y, w, h, null);
313      *       // To find the data element at location (x2, y2)
314      *       short bandElement = bandData[((y2-y)*w + (x2-x))];
315      * </pre>
316      * @param x        The X coordinate of the upper left pixel location.
317      * @param y        The Y coordinate of the upper left pixel location.
318      * @param width    Width of the pixel rectangle.
319      * @param height   Height of the pixel rectangle.
320      * @param band     The band to return.
321      * @param outData  If non-null, data elements for all bands
322      *                 at the specified location are returned in this array.
323      * @return         Data array with data elements for all bands.
324      */
325     public short[] getShortData(int x, int y, int w, int h,
326                                       int band, short[] outData) {
327         // Bounds check for 'band' will be performed automatically
328         if ((x < this.minX) || (y < this.minY) ||
329             (x + w > this.maxX) || (y + h > this.maxY)) {
330             throw new ArrayIndexOutOfBoundsException
331                 ("Coordinate out of bounds!");
332         }
333         if (outData == null) {
334             outData = new short[scanlineStride*h];
335         }
336         int yoff = (y-minY)*scanlineStride + (x-minX) + dataOffsets[band];
337 
338         if (scanlineStride == w) {
339             System.arraycopy(data[band], yoff, outData, 0, w*h);
340         } else {
341             int off = 0;
342             for (int ystart=0; ystart < h; ystart++, yoff += scanlineStride) {
343                 System.arraycopy(data[band], yoff, outData, off, w);
344                 off += w;
345             }
346         }
347 
348         return outData;
349     }
350 
351     /**
352      * Returns a short array  of data elements from the specified rectangular
353      * region.
354      * An ArrayIndexOutOfBounds exception will be thrown at runtime
355      * if the pixel coordinates are out of bounds.
356      * <pre>
357      *       short[] bandData = Raster.getShortData(x, y, w, h, null);
358      *       int numDataElements = Raster.getnumDataElements();
359      *       short[] pixel = new short[numDataElements];
360      *       // To find a data element at location (x2, y2)
361      *       System.arraycopy(bandData, ((y2-y)*w + (x2-x))*numDataElements,
362      *                        pixel, 0, numDataElements);
363      * </pre>
364      * @param x        The X coordinate of the upper left pixel location.
365      * @param y        The Y coordinate of the upper left pixel location.
366      * @param width    Width of the pixel rectangle.
367      * @param height   Height of the pixel rectangle.
368      * @param outData  If non-null, data elements for all bands
369      *                 at the specified location are returned in this array.
370      * @return         Data array with data elements for all bands.
371      */
372     public short[] getShortData(int x, int y, int w, int h,
373                                      short[] outData) {
374         if ((x < this.minX) || (y < this.minY) ||
375             (x + w > this.maxX) || (y + h > this.maxY)) {
376             throw new ArrayIndexOutOfBoundsException
377                 ("Coordinate out of bounds!");
378         }
379         if (outData == null) {
380             outData = new short[numDataElements*scanlineStride*h];
381         }
382         int yoff = (y-minY)*scanlineStride + (x-minX);
383 
384         for (int c = 0; c < numDataElements; c++) {
385             int off = c;
386             short[] bank = data[c];
387             int dataOffset = dataOffsets[c];
388 
389             int yoff2 = yoff;
390             for (int ystart=0; ystart < h; ystart++, yoff2 += scanlineStride) {
391                 int xoff = dataOffset + yoff2;
392                 for (int xstart=0; xstart < w; xstart++) {
393                     outData[off] = bank[xoff++];
394                     off += numDataElements;
395                 }
396             }
397         }
398 
399         return outData;
400     }
401 
402     /**
403      * Stores the data element for all bands at the specified location.
404      * An ArrayIndexOutOfBounds exception will be thrown at runtime
405      * if the pixel coordinate is out of bounds.
406      * A ClassCastException will be thrown if the input object is non null
407      * and references anything other than an array of transferType.
408      * @param x        The X coordinate of the pixel location.
409      * @param y        The Y coordinate of the pixel location.
410      * @param inData   An object reference to an array of type defined by
411      *                 getTransferType() and length getNumDataElements()
412      *                 containing the pixel data to place at x,y.
413      */
414     public void setDataElements(int x, int y, Object obj) {
415         if ((x < this.minX) || (y < this.minY) ||
416             (x >= this.maxX) || (y >= this.maxY)) {
417             throw new ArrayIndexOutOfBoundsException
418                 ("Coordinate out of bounds!");
419         }
420         short inData[] = (short[])obj;
421         int off = (y-minY)*scanlineStride + (x-minX);
422         for (int i = 0; i < numDataElements; i++) {
423             data[i][dataOffsets[i] + off] = inData[i];
424         }
425 
426         markDirty();
427     }
428 
429     /**
430      * Stores the Raster data at the specified location.
431      * An ArrayIndexOutOfBounds exception will be thrown at runtime
432      * if the pixel coordinates are out of bounds.
433      * @param x          The X coordinate of the pixel location.
434      * @param y          The Y coordinate of the pixel location.
435      * @param inRaster   Raster of data to place at x,y location.
436      */
437     public void setDataElements(int x, int y, Raster inRaster) {
438         int dstOffX = x + inRaster.getMinX();
439         int dstOffY = y + inRaster.getMinY();
440         int width  = inRaster.getWidth();
441         int height = inRaster.getHeight();
442         if ((dstOffX < this.minX) || (dstOffY < this.minY) ||
443             (dstOffX + width > this.maxX) || (dstOffY + height > this.maxY)) {
444             throw new ArrayIndexOutOfBoundsException
445                 ("Coordinate out of bounds!");
446         }
447 
448         setDataElements(dstOffX, dstOffY, width, height, inRaster);
449     }
450 
451     /**
452      * Stores the Raster data at the specified location.
453      * @param dstX The absolute X coordinate of the destination pixel
454      * that will receive a copy of the upper-left pixel of the
455      * inRaster
456      * @param dstY The absolute Y coordinate of the destination pixel
457      * that will receive a copy of the upper-left pixel of the
458      * inRaster
459      * @param width      The number of pixels to store horizontally
460      * @param height     The number of pixels to store vertically
461      * @param inRaster   Raster of data to place at x,y location.
462      */
463     private void setDataElements(int dstX, int dstY,
464                                  int width, int height,
465                                  Raster inRaster) {
466         // Assume bounds checking has been performed previously
467         if (width <= 0 || height <= 0) {
468             return;
469         }
470 
471         // Write inRaster (minX, minY) to (dstX, dstY)
472 
473         int srcOffX = inRaster.getMinX();
474         int srcOffY = inRaster.getMinY();
475         Object tdata = null;
476 
477 //      // REMIND: Do something faster!
478 //      if (inRaster instanceof ShortBandedRaster) {
479 //      }
480 
481         for (int startY=0; startY < height; startY++) {
482             // Grab one scanline at a time
483             tdata = inRaster.getDataElements(srcOffX, srcOffY+startY,
484                                              width, 1, tdata);
485             setDataElements(dstX, dstY + startY, width, 1, tdata);
486         }
487     }
488 
489     /**
490      * Stores an array of data elements into the specified rectangular
491      * region.
492      * An ArrayIndexOutOfBounds exception will be thrown at runtime
493      * if the pixel coordinates are out of bounds.
494      * A ClassCastException will be thrown if the input object is non null
495      * and references anything other than an array of transferType.
496      * The data elements in the
497      * data array are assumed to be packed.  That is, a data element
498      * for the nth band at location (x2, y2) would be found at:
499      * <pre>
500      *      inData[((y2-y)*w + (x2-x))*numDataElements + n]
501      * </pre>
502      * @param x        The X coordinate of the upper left pixel location.
503      * @param y        The Y coordinate of the upper left pixel location.
504      * @param w        Width of the pixel rectangle.
505      * @param h        Height of the pixel rectangle.
506      * @param inData   An object reference to an array of type defined by
507      *                 getTransferType() and length w*h*getNumDataElements()
508      *                 containing the pixel data to place between x,y and
509      *                 x+h, y+h.
510      */
511     public void setDataElements(int x, int y, int w, int h, Object obj) {
512         if ((x < this.minX) || (y < this.minY) ||
513             (x + w > this.maxX) || (y + h > this.maxY)) {
514             throw new ArrayIndexOutOfBoundsException
515                 ("Coordinate out of bounds!");
516         }
517         short inData[] = (short[])obj;
518         int yoff = (y-minY)*scanlineStride + (x-minX);
519 
520         for (int c = 0; c < numDataElements; c++) {
521             int off = c;
522             short[] bank = data[c];
523             int dataOffset = dataOffsets[c];
524 
525             int yoff2 = yoff;
526             for (int ystart=0; ystart < h; ystart++, yoff2 += scanlineStride) {
527                 int xoff = dataOffset + yoff2;
528                 for (int xstart=0; xstart < w; xstart++) {
529                     bank[xoff++] = inData[off];
530                     off += numDataElements;
531                 }
532             }
533         }
534 
535         markDirty();
536     }
537 
538     /**
539      * Stores a short array of data elements into the specified
540      * rectangular region for the specified band.
541      * An ArrayIndexOutOfBounds exception will be thrown at runtime
542      * if the pixel coordinates are out of bounds.
543      * The data elements in the
544      * data array are assumed to be packed.  That is, a data element
545      * at location (x2, y2) would be found at:
546      * <pre>
547      *      inData[((y2-y)*w + (x2-x))]
548      * </pre>
549      * @param x        The X coordinate of the upper left pixel location.
550      * @param y        The Y coordinate of the upper left pixel location.
551      * @param w        Width of the pixel rectangle.
552      * @param h        Height of the pixel rectangle.
553      * @param band     The band to set.
554      * @param inData   The data elements to be stored.
555      */
556     public void putShortData(int x, int y, int w, int h,
557                                    int band, short[] inData) {
558         // Bounds check for 'band' will be performed automatically
559         if ((x < this.minX) || (y < this.minY) ||
560             (x + w > this.maxX) || (y + h > this.maxY)) {
561             throw new ArrayIndexOutOfBoundsException
562                 ("Coordinate out of bounds!");
563         }
564         int yoff = (y-minY)*scanlineStride + (x-minX) + dataOffsets[band];
565         int xoff;
566         int off = 0;
567         int xstart;
568         int ystart;
569 
570         if (scanlineStride == w) {
571             System.arraycopy(inData, 0, data[band], yoff, w*h);
572         } else {
573             for (ystart=0; ystart < h; ystart++, yoff += scanlineStride) {
574                 System.arraycopy(inData, off, data[band], yoff, w);
575                 off += w;
576             }
577         }
578 
579         markDirty();
580     }
581 
582     /**
583      * Stores a short integer array of data elements into the specified
584      * rectangular region.
585      * An ArrayIndexOutOfBounds exception will be thrown at runtime
586      * if the pixel coordinates are out of bounds.
587      * The data elements in the
588      * data array are assumed to be packed.  That is, a data element
589      * for the nth band at location (x2, y2) would be found at:
590      * <pre>
591      *      inData[((y2-y)*w + (x2-x))*numDataElements + n]
592      * </pre>
593      * @param x        The X coordinate of the upper left pixel location.
594      * @param y        The Y coordinate of the upper left pixel location.
595      * @param w        Width of the pixel rectangle.
596      * @param h        Height of the pixel rectangle.
597      * @param inData   The data elements to be stored.
598      */
599     public void putShortData(int x, int y, int w, int h, short[] inData) {
600         if ((x < this.minX) || (y < this.minY) ||
601             (x + w > this.maxX) || (y + h > this.maxY)) {
602             throw new ArrayIndexOutOfBoundsException
603                 ("Coordinate out of bounds!");
604         }
605         int yoff = (y-minY)*scanlineStride + (x-minX);
606 
607         for (int c = 0; c < numDataElements; c++) {
608             int off = c;
609             short[] bank = data[c];
610             int dataOffset = dataOffsets[c];
611 
612             int yoff2 = yoff;
613             for (int ystart=0; ystart < h; ystart++, yoff2 += scanlineStride) {
614                 int xoff = dataOffset + yoff2;
615                 for (int xstart=0; xstart < w; xstart++) {
616                     bank[xoff++] = inData[off];
617                     off += numDataElements;
618                 }
619             }
620         }
621 
622         markDirty();
623     }
624 
625     /**
626      * Creates a Writable subRaster given a region of the Raster.  The x and y
627      * coordinates specify the horizontal and vertical offsets
628      * from the upper-left corner of this Raster to the upper-left corner
629      * of the subRaster.  A subset of the bands of the parent Raster may
630      * be specified.  If this is null, then all the bands are present in the
631      * subRaster. A translation to the subRaster may also be specified.
632      * Note that the subRaster will reference the same
633      * DataBuffers as the parent Raster, but using different offsets.
634      * @param x               X offset.
635      * @param y               Y offset.
636      * @param width           Width (in pixels) of the subraster.
637      * @param height          Height (in pixels) of the subraster.
638      * @param x0              Translated X origin of the subraster.
639      * @param y0              Translated Y origin of the subraster.
640      * @param bandList        Array of band indices.
641      * @exception RasterFormatException
642      *            if the specified bounding box is outside of the parent Raster.
643      */
644     public WritableRaster createWritableChild(int x, int y,
645                                               int width, int height,
646                                               int x0, int y0,
647                                               int bandList[]) {
648 
649         if (x < this.minX) {
650             throw new RasterFormatException("x lies outside raster");
651         }
652         if (y < this.minY) {
653             throw new RasterFormatException("y lies outside raster");
654         }
655         if ((x+width < x) || (x+width > this.minX + this.width)) {
656             throw new RasterFormatException("(x + width) is outside of Raster");
657         }
658         if ((y+height < y) || (y+height > this.minY + this.height)) {
659             throw new RasterFormatException("(y + height) is outside of Raster");
660         }
661 
662         SampleModel sm;
663 
664         if (bandList != null)
665             sm = sampleModel.createSubsetSampleModel(bandList);
666         else
667             sm = sampleModel;
668 
669         int deltaX = x0 - x;
670         int deltaY = y0 - y;
671 
672         return new ShortBandedRaster(sm,
673                                      dataBuffer,
674                                      new Rectangle(x0, y0, width, height),
675                                      new Point(sampleModelTranslateX+deltaX,
676                                                sampleModelTranslateY+deltaY),
677                                      this);
678 
679     }
680 
681     /**
682      * Creates a subraster given a region of the raster.  The x and y
683      * coordinates specify the horizontal and vertical offsets
684      * from the upper-left corner of this raster to the upper-left corner
685      * of the subraster.  A subset of the bands of the parent Raster may
686      * be specified.  If this is null, then all the bands are present in the
687      * subRaster. A translation to the subRaster may also be specified.
688      * Note that the subraster will reference the same
689      * DataBuffers as the parent raster, but using different offsets.
690      * @param x               X offset.
691      * @param y               Y offset.
692      * @param width           Width (in pixels) of the subraster.
693      * @param height          Height (in pixels) of the subraster.
694      * @param x0              Translated X origin of the subraster.
695      * @param y0              Translated Y origin of the subraster.
696      * @param bandList        Array of band indices.
697      * @exception RasterFormatException
698      *            if the specified bounding box is outside of the parent raster.
699      */
700     public Raster createChild (int x, int y,
701                                int width, int height,
702                                int x0, int y0,
703                                int bandList[]) {
704         return createWritableChild(x, y, width, height, x0, y0, bandList);
705     }
706 
707     /**
708      * Creates a Raster with the same layout but using a different
709      * width and height, and with new zeroed data arrays.
710      */
711     public WritableRaster createCompatibleWritableRaster(int w, int h) {
712         if (w <= 0 || h <=0) {
713             throw new RasterFormatException("negative "+
714                                             ((w <= 0) ? "width" : "height"));
715         }
716 
717         SampleModel sm = sampleModel.createCompatibleSampleModel(w,h);
718 
719         return new ShortBandedRaster(sm, new Point(0,0));
720     }
721 
722     /**
723      * Creates a Raster with the same layout and the same
724      * width and height, and with new zeroed data arrays.  If
725      * the Raster is a subRaster, this will call
726      * createCompatibleRaster(width, height).
727      */
728     public WritableRaster createCompatibleWritableRaster() {
729        return createCompatibleWritableRaster(width,height);
730     }
731 
732     /**
733      * Verify that the layout parameters are consistent with the data.
734      * Verifies whether the data buffer has enough data for the raster,
735      * taking into account offsets, after ensuring all offsets are >=0.
736      * @throws RasterFormatException if a problem is detected.
737      */
738     private void verify() {
739 
740         /* Need to re-verify the dimensions since a sample model may be
741          * specified to the constructor
742          */
743         if (width <= 0 || height <= 0 ||
744             height > (Integer.MAX_VALUE / width))
745         {
746             throw new RasterFormatException("Invalid raster dimension");
747         }
748 
749         if (scanlineStride < 0 ||
750             scanlineStride > (Integer.MAX_VALUE / height))
751         {
752             // integer overflow
753             throw new RasterFormatException("Incorrect scanline stride: "
754                     + scanlineStride);
755         }
756 
757         for (int i = 0; i < data.length; i++) {
758             if (scanlineStride > data[i].length) {
759                 throw new RasterFormatException("Incorrect scanline stride: "
760                     + scanlineStride);
761             }
762         }
763 
764         // Make sure data for Raster is in a legal range
765         for (int i=0; i < dataOffsets.length; i++) {
766             if (dataOffsets[i] < 0) {
767                 throw new RasterFormatException("Data offsets for band "+i+
768                                                 "("+dataOffsets[i]+
769                                                 ") must be >= 0");
770             }
771         }
772 
773         int lastScanOffset = (height - 1) * scanlineStride;
774         if ((width - 1) > (Integer.MAX_VALUE - lastScanOffset)) {
775             throw new RasterFormatException("Invalid raster dimension");
776         }
777         int lastPixelOffset = lastScanOffset + (width - 1);
778 
779         int maxIndex = 0;
780         int index;
781 
782         for (int i=0; i < numDataElements; i++) {
783             if (dataOffsets[i] > (Integer.MAX_VALUE - lastPixelOffset)) {
784                 throw new RasterFormatException("Invalid raster dimension");
785             }
786             index = lastPixelOffset + dataOffsets[i];
787             if (index > maxIndex) {
788                 maxIndex = index;
789             }
790         }
791         for (int i=0; i < numDataElements; i++) {
792             if (data[i].length <= maxIndex) {
793                 throw new RasterFormatException("Data array too small " +
794                       "(should be > "+ maxIndex+" )");
795             }
796         }
797     }
798 
799     public String toString() {
800         return new String ("ShortBandedRaster: width = "+width+" height = "
801                            + height
802                            +" #numBands " + numBands
803                            +" #dataElements "+numDataElements);
804 
805     }
806 
807 }