File: image.c

package info (click to toggle)
cups 1.4.4-7+squeeze10
  • links: PTS, VCS
  • area: main
  • in suites: squeeze-lts
  • size: 25,548 kB
  • ctags: 9,583
  • sloc: ansic: 138,214; sh: 37,926; cpp: 25,469; makefile: 3,285; perl: 190; python: 127; php: 28
file content (812 lines) | stat: -rw-r--r-- 19,393 bytes parent folder | download | duplicates (2)
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
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
/*
 * "$Id: image.c 7473 2008-04-21 17:51:58Z mike $"
 *
 *   Base image support for the Common UNIX Printing System (CUPS).
 *
 *   Copyright 2007-2008 by Apple Inc.
 *   Copyright 1993-2005 by Easy Software Products.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Apple Inc. and are protected by Federal copyright
 *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 *   which should have been included with this file.  If this file is
 *   file is missing or damaged, see the license at "http://www.cups.org/".
 *
 *   This file is subject to the Apple OS-Developed Software exception.
 *
 * Contents:
 *
 *   cupsImageClose()         - Close an image file.
 *   cupsImageGetCol()        - Get a column of pixels from an image.
 *   cupsImageGetColorSpace() - Get the image colorspace.
 *   cupsImageGetDepth()      - Get the number of bytes per pixel.
 *   cupsImageGetHeight()     - Get the height of an image.
 *   cupsImageGetRow()        - Get a row of pixels from an image.
 *   cupsImageGetWidth()      - Get the width of an image.
 *   cupsImageGetXPPI()       - Get the horizontal resolution of an image.
 *   cupsImageGetYPPI()       - Get the vertical resolution of an image.
 *   cupsImageOpen()          - Open an image file and read it into memory.
 *   _cupsImagePutCol()       - Put a column of pixels to an image.
 *   _cupsImagePutRow()       - Put a row of pixels to an image.
 *   cupsImageSetMaxTiles()   - Set the maximum number of tiles to cache.
 *   flush_tile()             - Flush the least-recently-used tile in the cache.
 *   get_tile()               - Get a cached tile.
 */

/*
 * Include necessary headers...
 */

#include "image-private.h"


/*
 * Local functions...
 */

static void		flush_tile(cups_image_t *img);
static cups_ib_t	*get_tile(cups_image_t *img, int x, int y);


/*
 * 'cupsImageClose()' - Close an image file.
 */

void
cupsImageClose(cups_image_t *img)	/* I - Image to close */
{
  cups_ic_t	*current,		/* Current cached tile */
		*next;			/* Next cached tile */


 /*
  * Wipe the tile cache file (if any)...
  */

  if (img->cachefile >= 0)
  {
    DEBUG_printf(("Closing/removing swap file \"%s\"...\n", img->cachename));

    close(img->cachefile);
    unlink(img->cachename);
  }

 /*
  * Free the image cache...
  */

  DEBUG_puts("Freeing memory...");

  for (current = img->first, next = NULL; current != NULL; current = next)
  {
    DEBUG_printf(("Freeing cache (%p, next = %p)...\n", current, next));

    next = current->next;
    free(current);
  }

 /*
  * Free the rest of memory...
  */

  if (img->tiles != NULL)
  {
    DEBUG_printf(("Freeing tiles (%p)...\n", img->tiles[0]));

    free(img->tiles[0]);

    DEBUG_printf(("Freeing tile pointers (%p)...\n", img->tiles));

    free(img->tiles);
  }

  free(img);
}


/*
 * 'cupsImageGetCol()' - Get a column of pixels from an image.
 */

int					/* O - -1 on error, 0 on success */
cupsImageGetCol(cups_image_t *img,	/* I - Image */
        	int          x,		/* I - Column */
        	int          y,		/* I - Start row */
        	int          height,	/* I - Column height */
        	cups_ib_t    *pixels)	/* O - Pixel data */
{
  int			bpp,		/* Bytes per pixel */
			twidth,		/* Tile width */
			count;		/* Number of pixels to get */
  const cups_ib_t	*ib;		/* Pointer into tile */


  if (img == NULL || x < 0 || x >= img->xsize || y >= img->ysize)
    return (-1);

  if (y < 0)
  {
    height += y;
    y = 0;
  }

  if ((y + height) > img->ysize)
    height = img->ysize - y;

  if (height < 1)
    return (-1);

  bpp    = cupsImageGetDepth(img);
  twidth = bpp * (CUPS_TILE_SIZE - 1);

  while (height > 0)
  {
    ib = get_tile(img, x, y);

    if (ib == NULL)
      return (-1);

    count = CUPS_TILE_SIZE - (y & (CUPS_TILE_SIZE - 1));
    if (count > height)
      count = height;

    y      += count;
    height -= count;

    for (; count > 0; count --, ib += twidth)
      switch (bpp)
      {
        case 4 :
            *pixels++ = *ib++;
        case 3 :
            *pixels++ = *ib++;
            *pixels++ = *ib++;
        case 1 :
            *pixels++ = *ib++;
            break;
      }
  }

  return (0);
}


/*
 * 'cupsImageGetColorSpace()' - Get the image colorspace.
 */

cups_icspace_t				/* O - Colorspace */
cupsImageGetColorSpace(
    cups_image_t *img)			/* I - Image */
{
  return (img->colorspace);
}


/*
 * 'cupsImageGetDepth()' - Get the number of bytes per pixel.
 */

int					/* O - Bytes per pixel */
cupsImageGetDepth(cups_image_t *img)	/* I - Image */
{
  return (abs(img->colorspace));
}


/*
 * 'cupsImageGetHeight()' - Get the height of an image.
 */

unsigned				/* O - Height in pixels */
cupsImageGetHeight(cups_image_t *img)	/* I - Image */
{
  return (img->ysize);
}


/*
 * 'cupsImageGetRow()' - Get a row of pixels from an image.
 */

int					/* O - -1 on error, 0 on success */
cupsImageGetRow(cups_image_t *img,	/* I - Image */
                int          x,		/* I - Start column */
                int          y,		/* I - Row */
                int          width,	/* I - Width of row */
                cups_ib_t    *pixels)	/* O - Pixel data */
{
  int			bpp,		/* Bytes per pixel */
			count;		/* Number of pixels to get */
  const cups_ib_t	*ib;		/* Pointer to pixels */


  if (img == NULL || y < 0 || y >= img->ysize || x >= img->xsize)
    return (-1);

  if (x < 0)
  {
    width += x;
    x = 0;
  }

  if ((x + width) > img->xsize)
    width = img->xsize - x;

  if (width < 1)
    return (-1);

  bpp = img->colorspace < 0 ? -img->colorspace : img->colorspace;

  while (width > 0)
  {
    ib = get_tile(img, x, y);

    if (ib == NULL)
      return (-1);

    count = CUPS_TILE_SIZE - (x & (CUPS_TILE_SIZE - 1));
    if (count > width)
      count = width;
    memcpy(pixels, ib, count * bpp);
    pixels += count * bpp;
    x      += count;
    width  -= count;
  }

  return (0);
}


/*
 * 'cupsImageGetWidth()' - Get the width of an image.
 */

unsigned				/* O - Width in pixels */
cupsImageGetWidth(cups_image_t *img)	/* I - Image */
{
  return (img->xsize);
}


/*
 * 'cupsImageGetXPPI()' - Get the horizontal resolution of an image.
 */

unsigned				/* O - Horizontal PPI */
cupsImageGetXPPI(cups_image_t *img)	/* I - Image */
{
  return (img->xppi);
}


/*
 * 'cupsImageGetYPPI()' - Get the vertical resolution of an image.
 */

unsigned				/* O - Vertical PPI */
cupsImageGetYPPI(cups_image_t *img)	/* I - Image */
{
  return (img->yppi);
}


/*
 * 'cupsImageOpen()' - Open an image file and read it into memory.
 */

cups_image_t *				/* O - New image */
cupsImageOpen(
    const char      *filename,		/* I - Filename of image */
    cups_icspace_t  primary,		/* I - Primary colorspace needed */
    cups_icspace_t  secondary,		/* I - Secondary colorspace if primary no good */
    int             saturation,		/* I - Color saturation level */
    int             hue,		/* I - Color hue adjustment */
    const cups_ib_t *lut)		/* I - RGB gamma/brightness LUT */
{
  FILE		*fp;			/* File pointer */
  unsigned char	header[16],		/* First 16 bytes of file */
		header2[16];		/* Bytes 2048-2064 (PhotoCD) */
  cups_image_t	*img;			/* New image buffer */
  int		status;			/* Status of load... */


  DEBUG_printf(("cupsImageOpen(\"%s\", %d, %d, %d, %d, %p)\n",
        	filename ? filename : "(null)", primary, secondary,
		saturation, hue, lut));

 /*
  * Figure out the file type...
  */

  if ((fp = fopen(filename, "r")) == NULL)
    return (NULL);

  if (fread(header, 1, sizeof(header), fp) == 0)
  {
    fclose(fp);
    return (NULL);
  }

  fseek(fp, 2048, SEEK_SET);
  memset(header2, 0, sizeof(header2));
  fread(header2, 1, sizeof(header2), fp);
  fseek(fp, 0, SEEK_SET);

 /*
  * Allocate memory...
  */

  img = calloc(sizeof(cups_image_t), 1);

  if (img == NULL)
  {
    fclose(fp);
    return (NULL);
  }

 /*
  * Load the image as appropriate...
  */

  img->max_ics = CUPS_TILE_MINIMUM;
  img->xppi    = 128;
  img->yppi    = 128;

  if (!memcmp(header, "GIF87a", 6) || !memcmp(header, "GIF89a", 6))
    status = _cupsImageReadGIF(img, fp, primary, secondary, saturation, hue,
                               lut);
  else if (!memcmp(header, "BM", 2))
    status = _cupsImageReadBMP(img, fp, primary, secondary, saturation, hue,
                               lut);
  else if (header[0] == 0x01 && header[1] == 0xda)
    status = _cupsImageReadSGI(img, fp, primary, secondary, saturation, hue,
                               lut);
  else if (header[0] == 0x59 && header[1] == 0xa6 &&
           header[2] == 0x6a && header[3] == 0x95)
    status = _cupsImageReadSunRaster(img, fp, primary, secondary, saturation,
                                     hue, lut);
  else if (header[0] == 'P' && header[1] >= '1' && header[1] <= '6')
    status = _cupsImageReadPNM(img, fp, primary, secondary, saturation, hue,
                               lut);
  else if (!memcmp(header2, "PCD_IPI", 7))
    status = _cupsImageReadPhotoCD(img, fp, primary, secondary, saturation,
                                   hue, lut);
  else if (!memcmp(header + 8, "\000\010", 2) ||
           !memcmp(header + 8, "\000\030", 2))
    status = _cupsImageReadPIX(img, fp, primary, secondary, saturation, hue,
                               lut);
#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
  else if (!memcmp(header, "\211PNG", 4))
    status = _cupsImageReadPNG(img, fp, primary, secondary, saturation, hue,
                               lut);
#endif /* HAVE_LIBPNG && HAVE_LIBZ */
#ifdef HAVE_LIBJPEG
  else if (!memcmp(header, "\377\330\377", 3) &&	/* Start-of-Image */
	   header[3] >= 0xe0 && header[3] <= 0xef)	/* APPn */
    status = _cupsImageReadJPEG(img, fp, primary, secondary, saturation, hue,
                                lut);
#endif /* HAVE_LIBJPEG */
#ifdef HAVE_LIBTIFF
  else if (!memcmp(header, "MM\000\052", 4) ||
           !memcmp(header, "II\052\000", 4))
    status = _cupsImageReadTIFF(img, fp, primary, secondary, saturation, hue,
                                lut);
#endif /* HAVE_LIBTIFF */
  else
  {
    fclose(fp);
    status = -1;
  }

  if (status)
  {
    free(img);
    return (NULL);
  }
  else
    return (img);
}


/*
 * '_cupsImagePutCol()' - Put a column of pixels to an image.
 */

int					/* O - -1 on error, 0 on success */
_cupsImagePutCol(
    cups_image_t    *img,		/* I - Image */
    int             x,			/* I - Column */
    int             y,			/* I - Start row */
    int             height,		/* I - Column height */
    const cups_ib_t *pixels)		/* I - Pixels to put */
{
  int		bpp,			/* Bytes per pixel */
		twidth,			/* Width of tile */
		count;			/* Number of pixels to put */
  int		tilex,			/* Column within tile */
		tiley;			/* Row within tile */
  cups_ib_t	*ib;			/* Pointer to pixels in tile */


  if (img == NULL || x < 0 || x >= img->xsize || y >= img->ysize)
    return (-1);

  if (y < 0)
  {
    height += y;
    y = 0;
  }

  if ((y + height) > img->ysize)
    height = img->ysize - y;

  if (height < 1)
    return (-1);

  bpp    = cupsImageGetDepth(img);
  twidth = bpp * (CUPS_TILE_SIZE - 1);
  tilex  = x / CUPS_TILE_SIZE;
  tiley  = y / CUPS_TILE_SIZE;

  while (height > 0)
  {
    ib = get_tile(img, x, y);

    if (ib == NULL)
      return (-1);

    img->tiles[tiley][tilex].dirty = 1;
    tiley ++;

    count = CUPS_TILE_SIZE - (y & (CUPS_TILE_SIZE - 1));
    if (count > height)
      count = height;

    y      += count;
    height -= count;

    for (; count > 0; count --, ib += twidth)
      switch (bpp)
      {
        case 4 :
            *ib++ = *pixels++;
        case 3 :
            *ib++ = *pixels++;
            *ib++ = *pixels++;
        case 1 :
            *ib++ = *pixels++;
            break;
      }
  }

  return (0);
}


/*
 * '_cupsImagePutRow()' - Put a row of pixels to an image.
 */

int					/* O - -1 on error, 0 on success */
_cupsImagePutRow(
    cups_image_t    *img,		/* I - Image */
    int             x,			/* I - Start column */
    int             y,			/* I - Row */
    int             width,		/* I - Row width */
    const cups_ib_t *pixels)		/* I - Pixel data */
{
  int		bpp,			/* Bytes per pixel */
		count;			/* Number of pixels to put */
  int		tilex,			/* Column within tile */
		tiley;			/* Row within tile */
  cups_ib_t	*ib;			/* Pointer to pixels in tile */


  if (img == NULL || y < 0 || y >= img->ysize || x >= img->xsize)
    return (-1);

  if (x < 0)
  {
    width += x;
    x = 0;
  }

  if ((x + width) > img->xsize)
    width = img->xsize - x;

  if (width < 1)
    return (-1);

  bpp   = img->colorspace < 0 ? -img->colorspace : img->colorspace;
  tilex = x / CUPS_TILE_SIZE;
  tiley = y / CUPS_TILE_SIZE;

  while (width > 0)
  {
    ib = get_tile(img, x, y);

    if (ib == NULL)
      return (-1);

    img->tiles[tiley][tilex].dirty = 1;

    count = CUPS_TILE_SIZE - (x & (CUPS_TILE_SIZE - 1));
    if (count > width)
      count = width;
    memcpy(ib, pixels, count * bpp);
    pixels += count * bpp;
    x      += count;
    width  -= count;
    tilex  ++;
  }

  return (0);
}


/*
 * 'cupsImageSetMaxTiles()' - Set the maximum number of tiles to cache.
 *
 * If the "max_tiles" argument is 0 then the maximum number of tiles is
 * computed from the image size or the RIP_CACHE environment variable.
 */

void
cupsImageSetMaxTiles(
    cups_image_t *img,			/* I - Image to set */
    int          max_tiles)		/* I - Number of tiles to cache */
{
  int	cache_size,			/* Size of tile cache in bytes */
	min_tiles,			/* Minimum number of tiles to cache */
	max_size;			/* Maximum cache size in bytes */
  char	*cache_env,			/* Cache size environment variable */
	cache_units[255];		/* Cache size units */


  min_tiles = max(CUPS_TILE_MINIMUM,
                  1 + max((img->xsize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE,
                          (img->ysize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE));

  if (max_tiles == 0)
    max_tiles = ((img->xsize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE) *
                ((img->ysize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE);

  cache_size = max_tiles * CUPS_TILE_SIZE * CUPS_TILE_SIZE *
               cupsImageGetDepth(img);

  if ((cache_env = getenv("RIP_MAX_CACHE")) != NULL)
  {
    switch (sscanf(cache_env, "%d%254s", &max_size, cache_units))
    {
      case 0 :
          max_size = 32 * 1024 * 1024;
	  break;
      case 1 :
          max_size *= 4 * CUPS_TILE_SIZE * CUPS_TILE_SIZE;
	  break;
      case 2 :
          if (tolower(cache_units[0] & 255) == 'g')
	    max_size *= 1024 * 1024 * 1024;
          else if (tolower(cache_units[0] & 255) == 'm')
	    max_size *= 1024 * 1024;
	  else if (tolower(cache_units[0] & 255) == 'k')
	    max_size *= 1024;
	  else if (tolower(cache_units[0] & 255) == 't')
	    max_size *= 4 * CUPS_TILE_SIZE * CUPS_TILE_SIZE;
	  break;
    }
  }
  else
    max_size = 32 * 1024 * 1024;

  if (cache_size > max_size)
    max_tiles = max_size / CUPS_TILE_SIZE / CUPS_TILE_SIZE /
                cupsImageGetDepth(img);

  if (max_tiles < min_tiles)
    max_tiles = min_tiles;

  img->max_ics = max_tiles;

  DEBUG_printf(("max_ics=%d...\n", img->max_ics));
}


/*
 * 'flush_tile()' - Flush the least-recently-used tile in the cache.
 */

static void
flush_tile(cups_image_t *img)		/* I - Image */
{
  int		bpp;			/* Bytes per pixel */
  cups_itile_t	*tile;			/* Pointer to tile */


  bpp  = cupsImageGetDepth(img);
  tile = img->first->tile;

  if (!tile->dirty)
  {
    tile->ic = NULL;
    return;
  }

  if (img->cachefile < 0)
  {
    if ((img->cachefile = cupsTempFd(img->cachename,
                                     sizeof(img->cachename))) < 0)
    {
      tile->ic    = NULL;
      tile->dirty = 0;
      return;
    }

    DEBUG_printf(("Created swap file \"%s\"...\n", img->cachename));
  }

  if (tile->pos >= 0)
  {
    if (lseek(img->cachefile, tile->pos, SEEK_SET) != tile->pos)
    {
      tile->ic    = NULL;
      tile->dirty = 0;
      return;
    }
  }
  else
  {
    if ((tile->pos = lseek(img->cachefile, 0, SEEK_END)) < 0)
    {
      tile->ic    = NULL;
      tile->dirty = 0;
      return;
    }
  }

  write(img->cachefile, tile->ic->pixels, bpp * CUPS_TILE_SIZE * CUPS_TILE_SIZE);

  tile->ic    = NULL;
  tile->dirty = 0;
}


/*
 * 'get_tile()' - Get a cached tile.
 */

static cups_ib_t *			/* O - Pointer to tile or NULL */
get_tile(cups_image_t *img,		/* I - Image */
         int          x,		/* I - Column in image */
         int          y)		/* I - Row in image */
{
  int		bpp,			/* Bytes per pixel */
		tilex,			/* Column within tile */
		tiley,			/* Row within tile */
		xtiles,			/* Number of tiles horizontally */
		ytiles;			/* Number of tiles vertically */
  cups_ic_t	*ic;			/* Cache pointer */
  cups_itile_t	*tile;			/* Tile pointer */


  if (img->tiles == NULL)
  {
    xtiles = (img->xsize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE;
    ytiles = (img->ysize + CUPS_TILE_SIZE - 1) / CUPS_TILE_SIZE;

    DEBUG_printf(("Creating tile array (%dx%d)\n", xtiles, ytiles));

    if ((img->tiles = calloc(sizeof(cups_itile_t *), ytiles)) == NULL)
      return (NULL);

    if ((tile = calloc(xtiles * sizeof(cups_itile_t), ytiles)) == NULL)
      return (NULL);

    for (tiley = 0; tiley < ytiles; tiley ++)
    {
      img->tiles[tiley] = tile;
      for (tilex = xtiles; tilex > 0; tilex --, tile ++)
        tile->pos = -1;
    }
  }

  bpp   = cupsImageGetDepth(img);
  tilex = x / CUPS_TILE_SIZE;
  tiley = y / CUPS_TILE_SIZE;
  tile  = img->tiles[tiley] + tilex;
  x     &= (CUPS_TILE_SIZE - 1);
  y     &= (CUPS_TILE_SIZE - 1);

  if ((ic = tile->ic) == NULL)
  {
    if (img->num_ics < img->max_ics)
    {
      if ((ic = calloc(sizeof(cups_ic_t) +
                       bpp * CUPS_TILE_SIZE * CUPS_TILE_SIZE, 1)) == NULL)
      {
        if (img->num_ics == 0)
	  return (NULL);

        flush_tile(img);
	ic = img->first;
      }
      else
      {
	ic->pixels = ((cups_ib_t *)ic) + sizeof(cups_ic_t);

	img->num_ics ++;

	DEBUG_printf(("Allocated cache tile %d (%p)...\n", img->num_ics, ic));
      }
    }
    else
    {
      DEBUG_printf(("Flushing old cache tile (%p)...\n", img->first));

      flush_tile(img);
      ic = img->first;
    }

    ic->tile = tile;
    tile->ic = ic;

    if (tile->pos >= 0)
    {
      DEBUG_printf(("Loading cache tile from file position " CUPS_LLFMT "...\n",
                    CUPS_LLCAST tile->pos));

      lseek(img->cachefile, tile->pos, SEEK_SET);
      read(img->cachefile, ic->pixels, bpp * CUPS_TILE_SIZE * CUPS_TILE_SIZE);
    }
    else
    {
      DEBUG_puts("Clearing cache tile...");

      memset(ic->pixels, 0, bpp * CUPS_TILE_SIZE * CUPS_TILE_SIZE);
    }
  }

  if (ic == img->first)
  {
    if (ic->next != NULL)
      ic->next->prev = NULL;

    img->first = ic->next;
    ic->next   = NULL;
    ic->prev   = NULL;
  }
  else if (img->first == NULL)
    img->first = ic;

  if (ic != img->last)
  {
   /*
    * Remove the cache entry from the list...
    */

    if (ic->prev != NULL)
      ic->prev->next = ic->next;
    if (ic->next != NULL)
      ic->next->prev = ic->prev;

   /*
    * And add it to the end...
    */

    if (img->last != NULL)
      img->last->next = ic;

    ic->prev  = img->last;
    img->last = ic;
  }

  ic->next = NULL;

  return (ic->pixels + bpp * (y * CUPS_TILE_SIZE + x));
}


/*
 * End of "$Id: image.c 7473 2008-04-21 17:51:58Z mike $".
 */