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/src/FreeImage/Source/LibJPEG/rdtarga.c

https://bitbucket.org/cabalistic/ogredeps/
C | 500 lines | 319 code | 88 blank | 93 comment | 51 complexity | b522b32beda6a075f8d1bccfb66aa094 MD5 | raw file
  1/*
  2 * rdtarga.c
  3 *
  4 * Copyright (C) 1991-1996, Thomas G. Lane.
  5 * This file is part of the Independent JPEG Group's software.
  6 * For conditions of distribution and use, see the accompanying README file.
  7 *
  8 * This file contains routines to read input images in Targa format.
  9 *
 10 * These routines may need modification for non-Unix environments or
 11 * specialized applications.  As they stand, they assume input from
 12 * an ordinary stdio stream.  They further assume that reading begins
 13 * at the start of the file; start_input may need work if the
 14 * user interface has already read some data (e.g., to determine that
 15 * the file is indeed Targa format).
 16 *
 17 * Based on code contributed by Lee Daniel Crocker.
 18 */
 19
 20#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
 21
 22#ifdef TARGA_SUPPORTED
 23
 24
 25/* Macros to deal with unsigned chars as efficiently as compiler allows */
 26
 27#ifdef HAVE_UNSIGNED_CHAR
 28typedef unsigned char U_CHAR;
 29#define UCH(x)	((int) (x))
 30#else /* !HAVE_UNSIGNED_CHAR */
 31#ifdef CHAR_IS_UNSIGNED
 32typedef char U_CHAR;
 33#define UCH(x)	((int) (x))
 34#else
 35typedef char U_CHAR;
 36#define UCH(x)	((int) (x) & 0xFF)
 37#endif
 38#endif /* HAVE_UNSIGNED_CHAR */
 39
 40
 41#define	ReadOK(file,buffer,len)	(JFREAD(file,buffer,len) == ((size_t) (len)))
 42
 43
 44/* Private version of data source object */
 45
 46typedef struct _tga_source_struct * tga_source_ptr;
 47
 48typedef struct _tga_source_struct {
 49  struct cjpeg_source_struct pub; /* public fields */
 50
 51  j_compress_ptr cinfo;		/* back link saves passing separate parm */
 52
 53  JSAMPARRAY colormap;		/* Targa colormap (converted to my format) */
 54
 55  jvirt_sarray_ptr whole_image;	/* Needed if funny input row order */
 56  JDIMENSION current_row;	/* Current logical row number to read */
 57
 58  /* Pointer to routine to extract next Targa pixel from input file */
 59  JMETHOD(void, read_pixel, (tga_source_ptr sinfo));
 60
 61  /* Result of read_pixel is delivered here: */
 62  U_CHAR tga_pixel[4];
 63
 64  int pixel_size;		/* Bytes per Targa pixel (1 to 4) */
 65
 66  /* State info for reading RLE-coded pixels; both counts must be init to 0 */
 67  int block_count;		/* # of pixels remaining in RLE block */
 68  int dup_pixel_count;		/* # of times to duplicate previous pixel */
 69
 70  /* This saves the correct pixel-row-expansion method for preload_image */
 71  JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
 72				       cjpeg_source_ptr sinfo));
 73} tga_source_struct;
 74
 75
 76/* For expanding 5-bit pixel values to 8-bit with best rounding */
 77
 78static const UINT8 c5to8bits[32] = {
 79    0,   8,  16,  25,  33,  41,  49,  58,
 80   66,  74,  82,  90,  99, 107, 115, 123,
 81  132, 140, 148, 156, 165, 173, 181, 189,
 82  197, 206, 214, 222, 230, 239, 247, 255
 83};
 84
 85
 86
 87LOCAL(int)
 88read_byte (tga_source_ptr sinfo)
 89/* Read next byte from Targa file */
 90{
 91  register FILE *infile = sinfo->pub.input_file;
 92  register int c;
 93
 94  if ((c = getc(infile)) == EOF)
 95    ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
 96  return c;
 97}
 98
 99
100LOCAL(void)
101read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
102/* Read the colormap from a Targa file */
103{
104  int i;
105
106  /* Presently only handles 24-bit BGR format */
107  if (mapentrysize != 24)
108    ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
109
110  for (i = 0; i < cmaplen; i++) {
111    sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
112    sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
113    sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
114  }
115}
116
117
118/*
119 * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
120 */
121
122METHODDEF(void)
123read_non_rle_pixel (tga_source_ptr sinfo)
124/* Read one Targa pixel from the input file; no RLE expansion */
125{
126  register FILE *infile = sinfo->pub.input_file;
127  register int i;
128
129  for (i = 0; i < sinfo->pixel_size; i++) {
130    sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
131  }
132}
133
134
135METHODDEF(void)
136read_rle_pixel (tga_source_ptr sinfo)
137/* Read one Targa pixel from the input file, expanding RLE data as needed */
138{
139  register FILE *infile = sinfo->pub.input_file;
140  register int i;
141
142  /* Duplicate previously read pixel? */
143  if (sinfo->dup_pixel_count > 0) {
144    sinfo->dup_pixel_count--;
145    return;
146  }
147
148  /* Time to read RLE block header? */
149  if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
150    i = read_byte(sinfo);
151    if (i & 0x80) {		/* Start of duplicate-pixel block? */
152      sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
153      sinfo->block_count = 0;	/* then read new block header */
154    } else {
155      sinfo->block_count = i & 0x7F; /* number of pixels after this one */
156    }
157  }
158
159  /* Read next pixel */
160  for (i = 0; i < sinfo->pixel_size; i++) {
161    sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
162  }
163}
164
165
166/*
167 * Read one row of pixels.
168 *
169 * We provide several different versions depending on input file format.
170 */
171
172
173METHODDEF(JDIMENSION)
174get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
175/* This version is for reading 8-bit grayscale pixels */
176{
177  tga_source_ptr source = (tga_source_ptr) sinfo;
178  register JSAMPROW ptr;
179  register JDIMENSION col;
180  
181  ptr = source->pub.buffer[0];
182  for (col = cinfo->image_width; col > 0; col--) {
183    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
184    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
185  }
186  return 1;
187}
188
189METHODDEF(JDIMENSION)
190get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
191/* This version is for reading 8-bit colormap indexes */
192{
193  tga_source_ptr source = (tga_source_ptr) sinfo;
194  register int t;
195  register JSAMPROW ptr;
196  register JDIMENSION col;
197  register JSAMPARRAY colormap = source->colormap;
198
199  ptr = source->pub.buffer[0];
200  for (col = cinfo->image_width; col > 0; col--) {
201    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
202    t = UCH(source->tga_pixel[0]);
203    *ptr++ = colormap[0][t];
204    *ptr++ = colormap[1][t];
205    *ptr++ = colormap[2][t];
206  }
207  return 1;
208}
209
210METHODDEF(JDIMENSION)
211get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
212/* This version is for reading 16-bit pixels */
213{
214  tga_source_ptr source = (tga_source_ptr) sinfo;
215  register int t;
216  register JSAMPROW ptr;
217  register JDIMENSION col;
218  
219  ptr = source->pub.buffer[0];
220  for (col = cinfo->image_width; col > 0; col--) {
221    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
222    t = UCH(source->tga_pixel[0]);
223    t += UCH(source->tga_pixel[1]) << 8;
224    /* We expand 5 bit data to 8 bit sample width.
225     * The format of the 16-bit (LSB first) input word is
226     *     xRRRRRGGGGGBBBBB
227     */
228    ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
229    t >>= 5;
230    ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
231    t >>= 5;
232    ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
233    ptr += 3;
234  }
235  return 1;
236}
237
238METHODDEF(JDIMENSION)
239get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
240/* This version is for reading 24-bit pixels */
241{
242  tga_source_ptr source = (tga_source_ptr) sinfo;
243  register JSAMPROW ptr;
244  register JDIMENSION col;
245  
246  ptr = source->pub.buffer[0];
247  for (col = cinfo->image_width; col > 0; col--) {
248    (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
249    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
250    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
251    *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
252  }
253  return 1;
254}
255
256/*
257 * Targa also defines a 32-bit pixel format with order B,G,R,A.
258 * We presently ignore the attribute byte, so the code for reading
259 * these pixels is identical to the 24-bit routine above.
260 * This works because the actual pixel length is only known to read_pixel.
261 */
262
263#define get_32bit_row  get_24bit_row
264
265
266/*
267 * This method is for re-reading the input data in standard top-down
268 * row order.  The entire image has already been read into whole_image
269 * with proper conversion of pixel format, but it's in a funny row order.
270 */
271
272METHODDEF(JDIMENSION)
273get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
274{
275  tga_source_ptr source = (tga_source_ptr) sinfo;
276  JDIMENSION source_row;
277
278  /* Compute row of source that maps to current_row of normal order */
279  /* For now, assume image is bottom-up and not interlaced. */
280  /* NEEDS WORK to support interlaced images! */
281  source_row = cinfo->image_height - source->current_row - 1;
282
283  /* Fetch that row from virtual array */
284  source->pub.buffer = (*cinfo->mem->access_virt_sarray)
285    ((j_common_ptr) cinfo, source->whole_image,
286     source_row, (JDIMENSION) 1, FALSE);
287
288  source->current_row++;
289  return 1;
290}
291
292
293/*
294 * This method loads the image into whole_image during the first call on
295 * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
296 * get_memory_row on subsequent calls.
297 */
298
299METHODDEF(JDIMENSION)
300preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
301{
302  tga_source_ptr source = (tga_source_ptr) sinfo;
303  JDIMENSION row;
304  cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
305
306  /* Read the data into a virtual array in input-file row order. */
307  for (row = 0; row < cinfo->image_height; row++) {
308    if (progress != NULL) {
309      progress->pub.pass_counter = (long) row;
310      progress->pub.pass_limit = (long) cinfo->image_height;
311      (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
312    }
313    source->pub.buffer = (*cinfo->mem->access_virt_sarray)
314      ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
315    (*source->get_pixel_rows) (cinfo, sinfo);
316  }
317  if (progress != NULL)
318    progress->completed_extra_passes++;
319
320  /* Set up to read from the virtual array in unscrambled order */
321  source->pub.get_pixel_rows = get_memory_row;
322  source->current_row = 0;
323  /* And read the first row */
324  return get_memory_row(cinfo, sinfo);
325}
326
327
328/*
329 * Read the file header; return image size and component count.
330 */
331
332METHODDEF(void)
333start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
334{
335  tga_source_ptr source = (tga_source_ptr) sinfo;
336  U_CHAR targaheader[18];
337  int idlen, cmaptype, subtype, flags, interlace_type, components;
338  unsigned int width, height, maplen;
339  boolean is_bottom_up;
340
341#define GET_2B(offset)	((unsigned int) UCH(targaheader[offset]) + \
342			 (((unsigned int) UCH(targaheader[offset+1])) << 8))
343
344  if (! ReadOK(source->pub.input_file, targaheader, 18))
345    ERREXIT(cinfo, JERR_INPUT_EOF);
346
347  /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
348  if (targaheader[16] == 15)
349    targaheader[16] = 16;
350
351  idlen = UCH(targaheader[0]);
352  cmaptype = UCH(targaheader[1]);
353  subtype = UCH(targaheader[2]);
354  maplen = GET_2B(5);
355  width = GET_2B(12);
356  height = GET_2B(14);
357  source->pixel_size = UCH(targaheader[16]) >> 3;
358  flags = UCH(targaheader[17]);	/* Image Descriptor byte */
359
360  is_bottom_up = ((flags & 0x20) == 0);	/* bit 5 set => top-down */
361  interlace_type = flags >> 6;	/* bits 6/7 are interlace code */
362
363  if (cmaptype > 1 ||		/* cmaptype must be 0 or 1 */
364      source->pixel_size < 1 || source->pixel_size > 4 ||
365      (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
366      interlace_type != 0)	/* currently don't allow interlaced image */
367    ERREXIT(cinfo, JERR_TGA_BADPARMS);
368  
369  if (subtype > 8) {
370    /* It's an RLE-coded file */
371    source->read_pixel = read_rle_pixel;
372    source->block_count = source->dup_pixel_count = 0;
373    subtype -= 8;
374  } else {
375    /* Non-RLE file */
376    source->read_pixel = read_non_rle_pixel;
377  }
378
379  /* Now should have subtype 1, 2, or 3 */
380  components = 3;		/* until proven different */
381  cinfo->in_color_space = JCS_RGB;
382
383  switch (subtype) {
384  case 1:			/* Colormapped image */
385    if (source->pixel_size == 1 && cmaptype == 1)
386      source->get_pixel_rows = get_8bit_row;
387    else
388      ERREXIT(cinfo, JERR_TGA_BADPARMS);
389    TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
390    break;
391  case 2:			/* RGB image */
392    switch (source->pixel_size) {
393    case 2:
394      source->get_pixel_rows = get_16bit_row;
395      break;
396    case 3:
397      source->get_pixel_rows = get_24bit_row;
398      break;
399    case 4:
400      source->get_pixel_rows = get_32bit_row;
401      break;
402    default:
403      ERREXIT(cinfo, JERR_TGA_BADPARMS);
404      break;
405    }
406    TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
407    break;
408  case 3:			/* Grayscale image */
409    components = 1;
410    cinfo->in_color_space = JCS_GRAYSCALE;
411    if (source->pixel_size == 1)
412      source->get_pixel_rows = get_8bit_gray_row;
413    else
414      ERREXIT(cinfo, JERR_TGA_BADPARMS);
415    TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
416    break;
417  default:
418    ERREXIT(cinfo, JERR_TGA_BADPARMS);
419    break;
420  }
421
422  if (is_bottom_up) {
423    /* Create a virtual array to buffer the upside-down image. */
424    source->whole_image = (*cinfo->mem->request_virt_sarray)
425      ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
426       (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
427    if (cinfo->progress != NULL) {
428      cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
429      progress->total_extra_passes++; /* count file input as separate pass */
430    }
431    /* source->pub.buffer will point to the virtual array. */
432    source->pub.buffer_height = 1; /* in case anyone looks at it */
433    source->pub.get_pixel_rows = preload_image;
434  } else {
435    /* Don't need a virtual array, but do need a one-row input buffer. */
436    source->whole_image = NULL;
437    source->pub.buffer = (*cinfo->mem->alloc_sarray)
438      ((j_common_ptr) cinfo, JPOOL_IMAGE,
439       (JDIMENSION) width * components, (JDIMENSION) 1);
440    source->pub.buffer_height = 1;
441    source->pub.get_pixel_rows = source->get_pixel_rows;
442  }
443  
444  while (idlen--)		/* Throw away ID field */
445    (void) read_byte(source);
446
447  if (maplen > 0) {
448    if (maplen > 256 || GET_2B(3) != 0)
449      ERREXIT(cinfo, JERR_TGA_BADCMAP);
450    /* Allocate space to store the colormap */
451    source->colormap = (*cinfo->mem->alloc_sarray)
452      ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
453    /* and read it from the file */
454    read_colormap(source, (int) maplen, UCH(targaheader[7]));
455  } else {
456    if (cmaptype)		/* but you promised a cmap! */
457      ERREXIT(cinfo, JERR_TGA_BADPARMS);
458    source->colormap = NULL;
459  }
460
461  cinfo->input_components = components;
462  cinfo->data_precision = 8;
463  cinfo->image_width = width;
464  cinfo->image_height = height;
465}
466
467
468/*
469 * Finish up at the end of the file.
470 */
471
472METHODDEF(void)
473finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
474{
475  /* no work */
476}
477
478
479/*
480 * The module selection routine for Targa format input.
481 */
482
483GLOBAL(cjpeg_source_ptr)
484jinit_read_targa (j_compress_ptr cinfo)
485{
486  tga_source_ptr source;
487
488  /* Create module interface object */
489  source = (tga_source_ptr)
490      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
491				  SIZEOF(tga_source_struct));
492  source->cinfo = cinfo;	/* make back link for subroutines */
493  /* Fill in method ptrs, except get_pixel_rows which start_input sets */
494  source->pub.start_input = start_input_tga;
495  source->pub.finish_input = finish_input_tga;
496
497  return (cjpeg_source_ptr) source;
498}
499
500#endif /* TARGA_SUPPORTED */