dll/3rdparty/libjpeg/rdtarga.c

   1 /*
   2  * rdtarga.c
   3  *
   4  * Copyright (C) 1991-1996, Thomas G. Lane.
   5  * Modified 2017-2019 by Guido Vollbeding.
   6  * This file is part of the Independent JPEG Group's software.
   7  * For conditions of distribution and use, see the accompanying README file.
   8  *
   9  * This file contains routines to read input images in Targa format.
  10  *
  11  * These routines may need modification for non-Unix environments or
  12  * specialized applications.  As they stand, they assume input from
  13  * an ordinary stdio stream.  They further assume that reading begins
  14  * at the start of the file; start_input may need work if the
  15  * user interface has already read some data (e.g., to determine that
  16  * the file is indeed Targa format).
  17  *
  18  * Based on code contributed by Lee Daniel Crocker.
  19  */
  20
  21 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  22
  23 #ifdef TARGA_SUPPORTED
  24
  25
  26 /* Macros to deal with unsigned chars as efficiently as compiler allows */
  27
  28 #ifdef HAVE_UNSIGNED_CHAR
  29 typedef unsigned char U_CHAR;
  30 #define UCH(x)  ((int) (x))
  31 #else /* !HAVE_UNSIGNED_CHAR */
  32 typedef char U_CHAR;
  33 #ifdef CHAR_IS_UNSIGNED
  34 #define UCH(x)  ((int) (x))
  35 #else
  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
  46 typedef struct _tga_source_struct * tga_source_ptr;
  47
  48 typedef 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   int cmap_length;              /* colormap length */
  66
  67   /* State info for reading RLE-coded pixels; both counts must be init to 0 */
  68   int block_count;              /* # of pixels remaining in RLE block */
  69   int dup_pixel_count;          /* # of times to duplicate previous pixel */
  70
  71   /* This saves the correct pixel-row-expansion method for preload_image */
  72   JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
  73                                        cjpeg_source_ptr sinfo));
  74 } tga_source_struct;
  75
  76
  77 /* For expanding 5-bit pixel values to 8-bit with best rounding */
  78
  79 static const UINT8 c5to8bits[32] = {
  80     0,   8,  16,  25,  33,  41,  49,  58,
  81    66,  74,  82,  90,  99, 107, 115, 123,
  82   132, 140, 148, 156, 165, 173, 181, 189,
  83   197, 206, 214, 222, 230, 239, 247, 255
  84 };
  85
  86
  87
  88 LOCAL(int)
  89 read_byte (tga_source_ptr sinfo)
  90 /* Read next byte from Targa file */
  91 {
  92   register FILE *infile = sinfo->pub.input_file;
  93   register int c;
  94
  95   if ((c = getc(infile)) == EOF)
  96     ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
  97   return c;
  98 }
  99
 100
 101 LOCAL(void)
 102 read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
 103 /* Read the colormap from a Targa file */
 104 {
 105   int i;
 106
 107   /* Presently only handles 24-bit BGR format */
 108   if (mapentrysize != 24)
 109     ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
 110
 111   for (i = 0; i < cmaplen; i++) {
 112     sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
 113     sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
 114     sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
 115   }
 116 }
 117
 118
 119 /*
 120  * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
 121  */
 122
 123 METHODDEF(void)
 124 read_non_rle_pixel (tga_source_ptr sinfo)
 125 /* Read one Targa pixel from the input file; no RLE expansion */
 126 {
 127   register int i;
 128
 129   for (i = 0; i < sinfo->pixel_size; i++) {
 130     sinfo->tga_pixel[i] = (U_CHAR) read_byte(sinfo);
 131   }
 132 }
 133
 134 METHODDEF(void)
 135 read_rle_pixel (tga_source_ptr sinfo)
 136 /* Read one Targa pixel from the input file, expanding RLE data as needed */
 137 {
 138   register int i;
 139
 140   /* Duplicate previously read pixel? */
 141   if (sinfo->dup_pixel_count > 0) {
 142     sinfo->dup_pixel_count--;
 143     return;
 144   }
 145
 146   /* Time to read RLE block header? */
 147   if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
 148     i = read_byte(sinfo);
 149     if (i & 0x80) {             /* Start of duplicate-pixel block? */
 150       sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
 151       sinfo->block_count = 0;   /* then read new block header */
 152     } else {
 153       sinfo->block_count = i & 0x7F; /* number of pixels after this one */
 154     }
 155   }
 156
 157   /* Read next pixel */
 158   for (i = 0; i < sinfo->pixel_size; i++) {
 159     sinfo->tga_pixel[i] = (U_CHAR) read_byte(sinfo);
 160   }
 161 }
 162
 163
 164 /*
 165  * Read one row of pixels.
 166  *
 167  * We provide several different versions depending on input file format.
 168  */
 169
 170 METHODDEF(JDIMENSION)
 171 get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 172 /* This version is for reading 8-bit grayscale pixels */
 173 {
 174   tga_source_ptr source = (tga_source_ptr) sinfo;
 175   register JSAMPROW ptr;
 176   register JDIMENSION col;
 177
 178   ptr = source->pub.buffer[0];
 179   for (col = cinfo->image_width; col > 0; col--) {
 180     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 181     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
 182   }
 183   return 1;
 184 }
 185
 186 METHODDEF(JDIMENSION)
 187 get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 188 /* This version is for reading 8-bit colormap indexes */
 189 {
 190   tga_source_ptr source = (tga_source_ptr) sinfo;
 191   register JSAMPROW ptr;
 192   register JSAMPARRAY colormap;
 193   register JDIMENSION col;
 194   register int t;
 195   int cmaplen;
 196
 197   ptr = source->pub.buffer[0];
 198   colormap = source->colormap;
 199   cmaplen = source->cmap_length;
 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     if (t >= cmaplen)
 204       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 205     *ptr++ = colormap[0][t];
 206     *ptr++ = colormap[1][t];
 207     *ptr++ = colormap[2][t];
 208   }
 209   return 1;
 210 }
 211
 212 METHODDEF(JDIMENSION)
 213 get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 214 /* This version is for reading 16-bit pixels */
 215 {
 216   tga_source_ptr source = (tga_source_ptr) sinfo;
 217   register int t;
 218   register JSAMPROW ptr;
 219   register JDIMENSION col;
 220
 221   ptr = source->pub.buffer[0];
 222   for (col = cinfo->image_width; col > 0; col--) {
 223     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 224     t = UCH(source->tga_pixel[0]);
 225     t += UCH(source->tga_pixel[1]) << 8;
 226     /* We expand 5 bit data to 8 bit sample width.
 227      * The format of the 16-bit (LSB first) input word is
 228      *     xRRRRRGGGGGBBBBB
 229      */
 230     ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
 231     t >>= 5;
 232     ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
 233     t >>= 5;
 234     ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
 235     ptr += 3;
 236   }
 237   return 1;
 238 }
 239
 240 METHODDEF(JDIMENSION)
 241 get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 242 /* This version is for reading 24-bit pixels */
 243 {
 244   tga_source_ptr source = (tga_source_ptr) sinfo;
 245   register JSAMPROW ptr;
 246   register JDIMENSION col;
 247
 248   ptr = source->pub.buffer[0];
 249   for (col = cinfo->image_width; col > 0; col--) {
 250     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 251     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
 252     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
 253     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
 254   }
 255   return 1;
 256 }
 257
 258 /*
 259  * Targa also defines a 32-bit pixel format with order B,G,R,A.
 260  * We presently ignore the attribute byte, so the code for reading
 261  * these pixels is identical to the 24-bit routine above.
 262  * This works because the actual pixel length is only known to read_pixel.
 263  */
 264
 265 #define get_32bit_row  get_24bit_row
 266
 267
 268 /*
 269  * This method is for re-reading the input data in standard top-down
 270  * row order.  The entire image has already been read into whole_image
 271  * with proper conversion of pixel format, but it's in a funny row order.
 272  */
 273
 274 METHODDEF(JDIMENSION)
 275 get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 276 {
 277   tga_source_ptr source = (tga_source_ptr) sinfo;
 278   JDIMENSION source_row;
 279
 280   /* Compute row of source that maps to current_row of normal order */
 281   /* For now, assume image is bottom-up and not interlaced. */
 282   /* NEEDS WORK to support interlaced images! */
 283   source_row = cinfo->image_height - source->current_row - 1;
 284
 285   /* Fetch that row from virtual array */
 286   source->pub.buffer = (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,
 287     source->whole_image, source_row, (JDIMENSION) 1, FALSE);
 288
 289   source->current_row++;
 290   return 1;
 291 }
 292
 293
 294 /*
 295  * This method loads the image into whole_image during the first call on
 296  * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
 297  * get_memory_row on subsequent calls.
 298  */
 299
 300 METHODDEF(JDIMENSION)
 301 preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 302 {
 303   tga_source_ptr source = (tga_source_ptr) sinfo;
 304   JDIMENSION row;
 305   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
 306
 307   /* Read the data into a virtual array in input-file row order. */
 308   for (row = 0; row < cinfo->image_height; row++) {
 309     if (progress != NULL) {
 310       progress->pub.pass_counter = (long) row;
 311       progress->pub.pass_limit = (long) cinfo->image_height;
 312       (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
 313     }
 314     source->pub.buffer = (*cinfo->mem->access_virt_sarray)
 315       ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
 316     (*source->get_pixel_rows) (cinfo, sinfo);
 317   }
 318   if (progress != NULL)
 319     progress->completed_extra_passes++;
 320
 321   /* Set up to read from the virtual array in unscrambled order */
 322   source->pub.get_pixel_rows = get_memory_row;
 323   source->current_row = 0;
 324   /* And read the first row */
 325   return get_memory_row(cinfo, sinfo);
 326 }
 327
 328
 329 /*
 330  * Read the file header; return image size and component count.
 331  */
 332
 333 METHODDEF(void)
 334 start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 335 {
 336   tga_source_ptr source = (tga_source_ptr) sinfo;
 337   U_CHAR targaheader[18];
 338   int idlen, cmaptype, subtype, flags, interlace_type, components;
 339   unsigned int width, height, maplen;
 340   boolean is_bottom_up;
 341
 342 #define GET_2B(offset)  ((unsigned int) UCH(targaheader[offset]) + \
 343                          (((unsigned int) UCH(targaheader[offset+1])) << 8))
 344
 345   if (! ReadOK(source->pub.input_file, targaheader, 18))
 346     ERREXIT(cinfo, JERR_INPUT_EOF);
 347
 348   /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
 349   if (targaheader[16] == 15)
 350     targaheader[16] = 16;
 351
 352   idlen = UCH(targaheader[0]);
 353   cmaptype = UCH(targaheader[1]);
 354   subtype = UCH(targaheader[2]);
 355   maplen = GET_2B(5);
 356   width = GET_2B(12);
 357   height = GET_2B(14);
 358   source->pixel_size = UCH(targaheader[16]) >> 3;
 359   flags = UCH(targaheader[17]); /* Image Descriptor byte */
 360
 361   is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
 362   interlace_type = flags >> 6;  /* bits 6/7 are interlace code */
 363
 364   if (cmaptype > 1 ||           /* cmaptype must be 0 or 1 */
 365       width <= 0 || height <= 0 ||
 366       source->pixel_size < 1 || source->pixel_size > 4 ||
 367       (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
 368       interlace_type != 0)      /* currently don't allow interlaced image */
 369     ERREXIT(cinfo, JERR_TGA_BADPARMS);
 370
 371   if (subtype > 8) {
 372     /* It's an RLE-coded file */
 373     source->read_pixel = read_rle_pixel;
 374     source->block_count = source->dup_pixel_count = 0;
 375     subtype -= 8;
 376   } else {
 377     /* Non-RLE file */
 378     source->read_pixel = read_non_rle_pixel;
 379   }
 380
 381   /* Now should have subtype 1, 2, or 3 */
 382   components = 3;               /* until proven different */
 383   cinfo->in_color_space = JCS_RGB;
 384
 385   switch (subtype) {
 386   case 1:                       /* Colormapped image */
 387     if (source->pixel_size == 1 && cmaptype == 1)
 388       source->get_pixel_rows = get_8bit_row;
 389     else
 390       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 391     TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
 392     break;
 393   case 2:                       /* RGB image */
 394     switch (source->pixel_size) {
 395     case 2:
 396       source->get_pixel_rows = get_16bit_row;
 397       break;
 398     case 3:
 399       source->get_pixel_rows = get_24bit_row;
 400       break;
 401     case 4:
 402       source->get_pixel_rows = get_32bit_row;
 403       break;
 404     default:
 405       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 406     }
 407     TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
 408     break;
 409   case 3:                       /* Grayscale image */
 410     components = 1;
 411     cinfo->in_color_space = JCS_GRAYSCALE;
 412     if (source->pixel_size == 1)
 413       source->get_pixel_rows = get_8bit_gray_row;
 414     else
 415       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 416     TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
 417     break;
 418   default:
 419     ERREXIT(cinfo, JERR_TGA_BADPARMS);
 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) ((j_common_ptr) cinfo,
 438       JPOOL_IMAGE, (JDIMENSION) width * components, (JDIMENSION) 1);
 439     source->pub.buffer_height = 1;
 440     source->pub.get_pixel_rows = source->get_pixel_rows;
 441   }
 442
 443   while (idlen--)               /* Throw away ID field */
 444     (void) read_byte(source);
 445
 446   if (maplen > 0) {
 447     if (maplen > 256 || GET_2B(3) != 0)
 448       ERREXIT(cinfo, JERR_TGA_BADCMAP);
 449     /* Allocate space to store the colormap */
 450     source->colormap = (*cinfo->mem->alloc_sarray) ((j_common_ptr) cinfo,
 451       JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
 452     source->cmap_length = (int) maplen;
 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     source->cmap_length = 0;
 460   }
 461
 462   cinfo->input_components = components;
 463   cinfo->data_precision = 8;
 464   cinfo->image_width = width;
 465   cinfo->image_height = height;
 466 }
 467
 468
 469 /*
 470  * Finish up at the end of the file.
 471  */
 472
 473 METHODDEF(void)
 474 finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 475 {
 476   /* no work */
 477 }
 478
 479
 480 /*
 481  * The module selection routine for Targa format input.
 482  */
 483
 484 GLOBAL(cjpeg_source_ptr)
 485 jinit_read_targa (j_compress_ptr cinfo)
 486 {
 487   tga_source_ptr source;
 488
 489   /* Create module interface object */
 490   source = (tga_source_ptr) (*cinfo->mem->alloc_small)
 491     ((j_common_ptr) cinfo, JPOOL_IMAGE, 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 &source->pub;
 498 }
 499
 500 #endif /* TARGA_SUPPORTED */