summaryrefslogtreecommitdiff
path: root/libjava/classpath/java/awt/image/DirectColorModel.java
blob: a464fed305a349a769f74c6c74df7c81471bff52 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
/* DirectColorModel.java --
   Copyright (C) 1999, 2000, 2002, 2004  Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package java.awt.image;

import gnu.java.awt.Buffers;

import java.awt.Point;
import java.awt.Transparency;
import java.awt.color.ColorSpace;

/**
 * @author Rolf W. Rasmussen (rolfwr@ii.uib.no)
 * @author C. Brian Jones (cbj@gnu.org)
 * @author Mark Benvenuto (mcb54@columbia.edu)
 */
public class DirectColorModel extends PackedColorModel
{
  /**
   * For the color model created with this constructor the pixels
   * will have fully opaque alpha components with a value of 255.
   * Each mask should describe a fully contiguous set of bits in the
   * most likely order of alpha, red, green, blue from the most significant
   * byte to the least significant byte.
   *
   * @param pixelBits the number of bits wide used for bit size of pixel values
   * @param rmask the bits describing the red component of a pixel
   * @param gmask the bits describing the green component of a pixel
   * @param bmask the bits describing the blue component of a pixel
   */
  public DirectColorModel(int pixelBits, int rmask, int gmask, int bmask)
  {
    this(ColorSpace.getInstance(ColorSpace.CS_sRGB), pixelBits,
         rmask, gmask, bmask, 0,
         false, // not alpha premultiplied
         Buffers.smallestAppropriateTransferType(pixelBits) // find type
         );
  }

  /**
   * For the color model created with this constructor the pixels
   * will have fully opaque alpha components with a value of 255.
   * Each mask should describe a fully contiguous set of bits in the
   * most likely order of red, green, blue from the most significant
   * byte to the least significant byte.
   *
   * @param pixelBits the number of bits wide used for bit size of pixel values
   * @param rmask the bits describing the red component of a pixel
   * @param gmask the bits describing the green component of a pixel
   * @param bmask the bits describing the blue component of a pixel
   * @param amask the bits describing the alpha component of a pixel
   */
  public DirectColorModel(int pixelBits,
                          int rmask, int gmask, int bmask, int amask)
  {
    this(ColorSpace.getInstance(ColorSpace.CS_sRGB), pixelBits,
         rmask, gmask, bmask, amask,
         false, // not alpha premultiplied
         Buffers.smallestAppropriateTransferType(pixelBits) // find type
         );
  }

  public DirectColorModel(ColorSpace cspace, int pixelBits,
                          int rmask, int gmask, int bmask, int amask,
                          boolean isAlphaPremultiplied,
                          int transferType)
  {
    super(cspace, pixelBits,
          rmask, gmask, bmask, amask, isAlphaPremultiplied,
          ((amask == 0) ? Transparency.OPAQUE : Transparency.TRANSLUCENT),
          transferType);
  }

  public final int getRedMask()
  {
    return getMask(0);
  }

  public final int getGreenMask()
  {
    return getMask(1);
  }

  public final int getBlueMask()
  {
    return getMask(2);
  }

  public final int getAlphaMask()
  {
    return hasAlpha() ? getMask(3) : 0;
  }

  /**
   * Get the red component of the given pixel.
   * <br>
   */
  public final int getRed(int pixel)
  {
    return extractAndNormalizeSample(pixel, 0);
  }

  /**
   * Get the green component of the given pixel.
   * <br>
   */
  public final int getGreen(int pixel)
  {
    return extractAndNormalizeSample(pixel, 1);
  }

  /**
   * Get the blue component of the given pixel.
   * <br>
   */
  public final int getBlue(int pixel)
  {
    return extractAndNormalizeSample(pixel, 2);
  }

  /**
   * Get the alpha component of the given pixel.
   * <br>
   */
  public final int getAlpha(int pixel)
  {
    if (!hasAlpha())
      return 255;
    return extractAndScaleSample(pixel, 3);
  }

  private int extractAndNormalizeSample(int pixel, int component)
  {
    int value = extractAndScaleSample(pixel, component);
    if (hasAlpha() && isAlphaPremultiplied() && getAlpha(pixel) != 0)
      value = value*255/getAlpha(pixel);
    return value;
  }

  private int extractAndScaleSample(int pixel, int component)
  {
    int field = pixel & getMask(component);
    int to8BitShift =
      8 - shifts[component] - getComponentSize(component);
    return (to8BitShift>0) ?
      (field << to8BitShift) :
      (field >>> (-to8BitShift));
  }

  /**
   * Get the RGB color value of the given pixel using the default
   * RGB color model.
   * <br>
   *
   * @param pixel a pixel value
   */
  public final int getRGB(int pixel)
  {
    /* FIXME: The Sun docs show that this method is overridden, but I
       don't see any way to improve on the superclass
       implementation. */
    return super.getRGB(pixel);
  }

  public int getRed(Object inData)
  {
    return getRed(getPixelFromArray(inData));
  }

  public int getGreen(Object inData)
  {
    return getGreen(getPixelFromArray(inData));
  }

  public int getBlue(Object inData)
  {
    return getBlue(getPixelFromArray(inData));
  }

  public int getAlpha(Object inData)
  {
    return getAlpha(getPixelFromArray(inData));
  }

  public int getRGB(Object inData)
  {
    return getRGB(getPixelFromArray(inData));
  }

  /**
   * Converts a normalized pixel int value in the sRGB color
   * space to an array containing a single pixel of the color space
   * of the color model.
   *
   * <p>This method performs the inverse function of
   * <code>getRGB(Object inData)</code>.
   *
   * @param rgb pixel as a normalized sRGB, 0xAARRGGBB value.
   *
   * @param pixel to avoid needless creation of arrays, an array to
   * use to return the pixel can be given. If null, a suitable array
   * will be created.
   *
   * @return array of transferType containing a single pixel. The
   * pixel should be encoded in the natural way of the color model.
   *
   * @see #getRGB(Object)
   */
  public Object getDataElements(int rgb, Object pixel)
  {
    // FIXME: handle alpha multiply

    int pixelValue = 0;
    int a = 0;
    if (hasAlpha()) {
      a = (rgb >>> 24) & 0xff;
      pixelValue = valueToField(a, 3, 8);
    }

    if (hasAlpha() && isAlphaPremultiplied())
      {
        int r, g, b;
        /* if r=0xff and a=0xff, then resulting
           value will be (r*a)>>>8 == 0xfe... This seems wrong.
           We should divide by 255 rather than shifting >>>8 after
           multiplying.

           Too bad, shifting is probably less expensive.
           r = ((rgb >>> 16) & 0xff)*a;
           g = ((rgb >>>  8) & 0xff)*a;
           b = ((rgb >>> 0) & 0xff)*a; */
        /* The r, g, b values we calculate are 16 bit. This allows
           us to avoid discarding the lower 8 bits obtained if
           multiplying with the alpha band. */

        // using 16 bit values
        r = ((rgb >>> 8) & 0xff00)*a/255;
        g = ((rgb >>> 0) & 0xff00)*a/255;
        b = ((rgb <<  8) & 0xff00)*a/255;
        pixelValue |=
          valueToField(r, 0, 16) |  // Red
          valueToField(g, 1, 16) |  // Green
          valueToField(b, 2, 16);   // Blue
      }
    else
      {
        int r, g, b;
        // using 8 bit values
        r = (rgb >>> 16) & 0xff;
        g = (rgb >>>  8) & 0xff;
        b = (rgb >>>  0) & 0xff;

        pixelValue |=
          valueToField(r, 0, 8) |  // Red
          valueToField(g, 1, 8) |  // Green
          valueToField(b, 2, 8);   // Blue
      }

    /* In this color model, the whole pixel fits in the first element
       of the array. */
    DataBuffer buffer = Buffers.createBuffer(transferType, pixel, 1);
    buffer.setElem(0, pixelValue);
    return Buffers.getData(buffer);
  }

  /**
   * Converts a value to the correct field bits based on the
   * information derived from the field masks.
   *
   * @param highBit the position of the most significant bit in the
   * val parameter.
   */
  private int valueToField(int val, int component, int highBit)
  {
    int toFieldShift =
      getComponentSize(component) + shifts[component] - highBit;
    int ret = (toFieldShift>0) ?
      (val << toFieldShift) :
      (val >>> (-toFieldShift));
    return ret & getMask(component);
  }

  /**
   * Converts a 16 bit value to the correct field bits based on the
   * information derived from the field masks.
   */
  private int value16ToField(int val, int component)
  {
    int toFieldShift = getComponentSize(component) + shifts[component] - 16;
    return (toFieldShift>0) ?
      (val << toFieldShift) :
      (val >>> (-toFieldShift));
  }

  /**
   * Fills an array with the unnormalized component samples from a
   * pixel value. I.e. decompose the pixel, but not perform any
   * color conversion.
   */
  public final int[] getComponents(int pixel, int[] components, int offset)
  {
    int numComponents = getNumComponents();
    if (components == null) components = new int[offset + numComponents];

    for (int b=0; b<numComponents; b++)
      components[offset++] = (pixel&getMask(b)) >>> shifts[b];

    return components;
  }

  public final int[] getComponents(Object pixel, int[] components,
                                   int offset)
  {
    return getComponents(getPixelFromArray(pixel), components, offset);
  }

  /**
   * Creates a <code>WriteableRaster</code> that has a <code>SampleModel</code>
   * that is compatible with this <code>ColorModel</code>.
   *
   * @param w the width of the writeable raster to create
   * @param h the height of the writeable raster to create
   *
   * @throws IllegalArgumentException if <code>w</code> or <code>h</code>
   *         is less than or equal to zero
   */
  public final WritableRaster createCompatibleWritableRaster(int w, int h)
  {
    // Sun also makes this check here.
    if(w <= 0 || h <= 0)
      throw new IllegalArgumentException("width (=" + w + ") and height (="
                                         + h + ") must be > 0");

    SampleModel sm = createCompatibleSampleModel(w, h);
    Point origin = new Point(0, 0);
    return Raster.createWritableRaster(sm, origin);
  }

  public int getDataElement(int[] components, int offset)
  {
    int numComponents = getNumComponents();
    int pixelValue = 0;

    for (int c=0; c<numComponents; c++)
      pixelValue |= (components[offset++] << shifts[c]) & getMask(c);

    return pixelValue;
  }

  public Object getDataElements(int[] components, int offset, Object obj)
  {
    /* In this color model, the whole pixel fits in the first element
       of the array. */
    int pixelValue = getDataElement(components, offset);

    DataBuffer buffer = Buffers.createBuffer(transferType, obj, 1);
    buffer.setElem(0, pixelValue);
    return Buffers.getData(buffer);
  }

  public final ColorModel coerceData (WritableRaster raster,
                                      boolean isAlphaPremultiplied)
  {
    if (this.isAlphaPremultiplied == isAlphaPremultiplied || !hasAlpha())
      return this;

    /* TODO: provide better implementation based on the
       assumptions we can make due to the specific type of the
       color model. */
    coerceDataWorker(raster, isAlphaPremultiplied);

    return new DirectColorModel(cspace, pixel_bits, getRedMask(),
                                getGreenMask(), getBlueMask(), getAlphaMask(),
                                isAlphaPremultiplied, transferType);
  }

  public boolean isCompatibleRaster(Raster raster)
  {
    /* FIXME: the Sun docs say this method is overridden here,
       but I don't see any way to improve upon the implementation
       in ColorModel. */
    return super.isCompatibleRaster(raster);
  }

  String stringParam()
  {
    return super.stringParam() +
      ", redMask=" + Integer.toHexString(getRedMask()) +
      ", greenMask=" + Integer.toHexString(getGreenMask()) +
      ", blueMask=" + Integer.toHexString(getBlueMask()) +
      ", alphaMask=" + Integer.toHexString(getAlphaMask());
  }

  public String toString()
  {
    /* FIXME: Again, docs say override, but how do we improve upon the
       superclass implementation? */
    return super.toString();
  }
}