compiler/libjpeg/test/rdtarga.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * rdtarga.c
   7  *
   8  * Copyright (C) 1991-1996, Thomas G. Lane.
   9  * This file is part of the Independent JPEG Group's software.
  10  * For conditions of distribution and use, see the accompanying README file.
  11  *
  12  * This file contains routines to read input images in Targa format.
  13  *
  14  * These routines may need modification for non-Unix environments or
  15  * specialized applications.  As they stand, they assume input from
  16  * an ordinary stdio stream.  They further assume that reading begins
  17  * at the start of the file; start_input may need work if the
  18  * user interface has already read some data (e.g., to determine that
  19  * the file is indeed Targa format).
  20  *
  21  * Based on code contributed by Lee Daniel Crocker.
  22  */
  23
  24 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */
  25
  26 #ifdef TARGA_SUPPORTED
  27
  28
  29 /* Macros to deal with unsigned chars as efficiently as compiler allows */
  30
  31 #ifdef HAVE_UNSIGNED_CHAR
  32 typedef unsigned char U_CHAR;
  33 #define UCH(x)  ((int) (x))
  34 #else /* !HAVE_UNSIGNED_CHAR */
  35 #ifdef CHAR_IS_UNSIGNED
  36 typedef char U_CHAR;
  37 #define UCH(x)  ((int) (x))
  38 #else
  39 typedef char U_CHAR;
  40 #define UCH(x)  ((int) (x) & 0xFF)
  41 #endif
  42 #endif /* HAVE_UNSIGNED_CHAR */
  43
  44
  45 #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
  46
  47
  48 /* Private version of data source object */
  49
  50 typedef struct _tga_source_struct * tga_source_ptr;
  51
  52 typedef struct _tga_source_struct {
  53   struct cjpeg_source_struct pub; /* public fields */
  54
  55   j_compress_ptr cinfo;         /* back link saves passing separate parm */
  56
  57   JSAMPARRAY colormap;          /* Targa colormap (converted to my format) */
  58
  59   jvirt_sarray_ptr whole_image; /* Needed if funny input row order */
  60   JDIMENSION current_row;       /* Current logical row number to read */
  61
  62   /* Pointer to routine to extract next Targa pixel from input file */
  63   JMETHOD(void, read_pixel, (tga_source_ptr sinfo));
  64
  65   /* Result of read_pixel is delivered here: */
  66   U_CHAR tga_pixel[4];
  67
  68   int pixel_size;               /* Bytes per Targa pixel (1 to 4) */
  69
  70   /* State info for reading RLE-coded pixels; both counts must be init to 0 */
  71   int block_count;              /* # of pixels remaining in RLE block */
  72   int dup_pixel_count;          /* # of times to duplicate previous pixel */
  73
  74   /* This saves the correct pixel-row-expansion method for preload_image */
  75   JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
  76                                        cjpeg_source_ptr sinfo));
  77 } tga_source_struct;
  78
  79
  80 /* For expanding 5-bit pixel values to 8-bit with best rounding */
  81
  82 static const UINT8 c5to8bits[32] = {
  83     0,   8,  16,  25,  33,  41,  49,  58,
  84    66,  74,  82,  90,  99, 107, 115, 123,
  85   132, 140, 148, 156, 165, 173, 181, 189,
  86   197, 206, 214, 222, 230, 239, 247, 255
  87 };
  88
  89
  90
  91 LOCAL(int)
  92 read_byte (tga_source_ptr sinfo)
  93 /* Read next byte from Targa file */
  94 {
  95   register FILE *infile = sinfo->pub.input_file;
  96   register int c;
  97
  98   if ((c = getc(infile)) == EOF)
  99     ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
 100   return c;
 101 }
 102
 103
 104 LOCAL(void)
 105 read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
 106 /* Read the colormap from a Targa file */
 107 {
 108   int i;
 109
 110   /* Presently only handles 24-bit BGR format */
 111   if (mapentrysize != 24)
 112     ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
 113
 114   for (i = 0; i < cmaplen; i++) {
 115     sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
 116     sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
 117     sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
 118   }
 119 }
 120
 121
 122 /*
 123  * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
 124  */
 125
 126 METHODDEF(void)
 127 read_non_rle_pixel (tga_source_ptr sinfo)
 128 /* Read one Targa pixel from the input file; no RLE expansion */
 129 {
 130   register FILE *infile = sinfo->pub.input_file;
 131   register int i;
 132
 133   for (i = 0; i < sinfo->pixel_size; i++) {
 134     sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
 135   }
 136 }
 137
 138
 139 METHODDEF(void)
 140 read_rle_pixel (tga_source_ptr sinfo)
 141 /* Read one Targa pixel from the input file, expanding RLE data as needed */
 142 {
 143   register FILE *infile = sinfo->pub.input_file;
 144   register int i;
 145
 146   /* Duplicate previously read pixel? */
 147   if (sinfo->dup_pixel_count > 0) {
 148     sinfo->dup_pixel_count--;
 149     return;
 150   }
 151
 152   /* Time to read RLE block header? */
 153   if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
 154     i = read_byte(sinfo);
 155     if (i & 0x80) {             /* Start of duplicate-pixel block? */
 156       sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
 157       sinfo->block_count = 0;   /* then read new block header */
 158     } else {
 159       sinfo->block_count = i & 0x7F; /* number of pixels after this one */
 160     }
 161   }
 162
 163   /* Read next pixel */
 164   for (i = 0; i < sinfo->pixel_size; i++) {
 165     sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
 166   }
 167 }
 168
 169
 170 /*
 171  * Read one row of pixels.
 172  *
 173  * We provide several different versions depending on input file format.
 174  */
 175
 176
 177 METHODDEF(JDIMENSION)
 178 get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 179 /* This version is for reading 8-bit grayscale pixels */
 180 {
 181   tga_source_ptr source = (tga_source_ptr) sinfo;
 182   register JSAMPROW ptr;
 183   register JDIMENSION col;
 184
 185   ptr = source->pub.buffer[0];
 186   for (col = cinfo->image_width; col > 0; col--) {
 187     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 188     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
 189   }
 190   return 1;
 191 }
 192
 193 METHODDEF(JDIMENSION)
 194 get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 195 /* This version is for reading 8-bit colormap indexes */
 196 {
 197   tga_source_ptr source = (tga_source_ptr) sinfo;
 198   register int t;
 199   register JSAMPROW ptr;
 200   register JDIMENSION col;
 201   register JSAMPARRAY colormap = source->colormap;
 202
 203   ptr = source->pub.buffer[0];
 204   for (col = cinfo->image_width; col > 0; col--) {
 205     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 206     t = UCH(source->tga_pixel[0]);
 207     *ptr++ = colormap[0][t];
 208     *ptr++ = colormap[1][t];
 209     *ptr++ = colormap[2][t];
 210   }
 211   return 1;
 212 }
 213
 214 METHODDEF(JDIMENSION)
 215 get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 216 /* This version is for reading 16-bit pixels */
 217 {
 218   tga_source_ptr source = (tga_source_ptr) sinfo;
 219   register int t;
 220   register JSAMPROW ptr;
 221   register JDIMENSION col;
 222
 223   ptr = source->pub.buffer[0];
 224   for (col = cinfo->image_width; col > 0; col--) {
 225     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 226     t = UCH(source->tga_pixel[0]);
 227     t += UCH(source->tga_pixel[1]) << 8;
 228     /* We expand 5 bit data to 8 bit sample width.
 229      * The format of the 16-bit (LSB first) input word is
 230      *     xRRRRRGGGGGBBBBB
 231      */
 232     ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
 233     t >>= 5;
 234     ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
 235     t >>= 5;
 236     ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
 237     ptr += 3;
 238   }
 239   return 1;
 240 }
 241
 242 METHODDEF(JDIMENSION)
 243 get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 244 /* This version is for reading 24-bit pixels */
 245 {
 246   tga_source_ptr source = (tga_source_ptr) sinfo;
 247   register JSAMPROW ptr;
 248   register JDIMENSION col;
 249
 250   ptr = source->pub.buffer[0];
 251   for (col = cinfo->image_width; col > 0; col--) {
 252     (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
 253     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
 254     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
 255     *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
 256   }
 257   return 1;
 258 }
 259
 260 /*
 261  * Targa also defines a 32-bit pixel format with order B,G,R,A.
 262  * We presently ignore the attribute byte, so the code for reading
 263  * these pixels is identical to the 24-bit routine above.
 264  * This works because the actual pixel length is only known to read_pixel.
 265  */
 266
 267 #define get_32bit_row  get_24bit_row
 268
 269
 270 /*
 271  * This method is for re-reading the input data in standard top-down
 272  * row order.  The entire image has already been read into whole_image
 273  * with proper conversion of pixel format, but it's in a funny row order.
 274  */
 275
 276 METHODDEF(JDIMENSION)
 277 get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 278 {
 279   tga_source_ptr source = (tga_source_ptr) sinfo;
 280   JDIMENSION source_row;
 281
 282   /* Compute row of source that maps to current_row of normal order */
 283   /* For now, assume image is bottom-up and not interlaced. */
 284   /* NEEDS WORK to support interlaced images! */
 285   source_row = cinfo->image_height - source->current_row - 1;
 286
 287   /* Fetch that row from virtual array */
 288   source->pub.buffer = (*cinfo->mem->access_virt_sarray)
 289     ((j_common_ptr) cinfo, source->whole_image,
 290      source_row, (JDIMENSION) 1, FALSE);
 291
 292   source->current_row++;
 293   return 1;
 294 }
 295
 296
 297 /*
 298  * This method loads the image into whole_image during the first call on
 299  * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
 300  * get_memory_row on subsequent calls.
 301  */
 302
 303 METHODDEF(JDIMENSION)
 304 preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 305 {
 306   tga_source_ptr source = (tga_source_ptr) sinfo;
 307   JDIMENSION row;
 308   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
 309
 310   /* Read the data into a virtual array in input-file row order. */
 311   for (row = 0; row < cinfo->image_height; row++) {
 312     if (progress != NULL) {
 313       progress->pub.pass_counter = (long) row;
 314       progress->pub.pass_limit = (long) cinfo->image_height;
 315       (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
 316     }
 317     source->pub.buffer = (*cinfo->mem->access_virt_sarray)
 318       ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
 319     (*source->get_pixel_rows) (cinfo, sinfo);
 320   }
 321   if (progress != NULL)
 322     progress->completed_extra_passes++;
 323
 324   /* Set up to read from the virtual array in unscrambled order */
 325   source->pub.get_pixel_rows = get_memory_row;
 326   source->current_row = 0;
 327   /* And read the first row */
 328   return get_memory_row(cinfo, sinfo);
 329 }
 330
 331
 332 /*
 333  * Read the file header; return image size and component count.
 334  */
 335
 336 METHODDEF(void)
 337 start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 338 {
 339   tga_source_ptr source = (tga_source_ptr) sinfo;
 340   U_CHAR targaheader[18];
 341   int idlen, cmaptype, subtype, flags, interlace_type, components;
 342   unsigned int width, height, maplen;
 343   boolean is_bottom_up;
 344
 345 #define GET_2B(offset)  ((unsigned int) UCH(targaheader[offset]) + \
 346                          (((unsigned int) UCH(targaheader[offset+1])) << 8))
 347
 348   if (! ReadOK(source->pub.input_file, targaheader, 18))
 349     ERREXIT(cinfo, JERR_INPUT_EOF);
 350
 351   /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
 352   if (targaheader[16] == 15)
 353     targaheader[16] = 16;
 354
 355   idlen = UCH(targaheader[0]);
 356   cmaptype = UCH(targaheader[1]);
 357   subtype = UCH(targaheader[2]);
 358   maplen = GET_2B(5);
 359   width = GET_2B(12);
 360   height = GET_2B(14);
 361   source->pixel_size = UCH(targaheader[16]) >> 3;
 362   flags = UCH(targaheader[17]); /* Image Descriptor byte */
 363
 364   is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
 365   interlace_type = flags >> 6;  /* bits 6/7 are interlace code */
 366
 367   if (cmaptype > 1 ||           /* cmaptype must be 0 or 1 */
 368       source->pixel_size < 1 || source->pixel_size > 4 ||
 369       (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
 370       interlace_type != 0)      /* currently don't allow interlaced image */
 371     ERREXIT(cinfo, JERR_TGA_BADPARMS);
 372
 373   if (subtype > 8) {
 374     /* It's an RLE-coded file */
 375     source->read_pixel = read_rle_pixel;
 376     source->block_count = source->dup_pixel_count = 0;
 377     subtype -= 8;
 378   } else {
 379     /* Non-RLE file */
 380     source->read_pixel = read_non_rle_pixel;
 381   }
 382
 383   /* Now should have subtype 1, 2, or 3 */
 384   components = 3;               /* until proven different */
 385   cinfo->in_color_space = JCS_RGB;
 386
 387   switch (subtype) {
 388   case 1:                       /* Colormapped image */
 389     if (source->pixel_size == 1 && cmaptype == 1)
 390       source->get_pixel_rows = get_8bit_row;
 391     else
 392       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 393     TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
 394     break;
 395   case 2:                       /* RGB image */
 396     switch (source->pixel_size) {
 397     case 2:
 398       source->get_pixel_rows = get_16bit_row;
 399       break;
 400     case 3:
 401       source->get_pixel_rows = get_24bit_row;
 402       break;
 403     case 4:
 404       source->get_pixel_rows = get_32bit_row;
 405       break;
 406     default:
 407       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 408       break;
 409     }
 410     TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
 411     break;
 412   case 3:                       /* Grayscale image */
 413     components = 1;
 414     cinfo->in_color_space = JCS_GRAYSCALE;
 415     if (source->pixel_size == 1)
 416       source->get_pixel_rows = get_8bit_gray_row;
 417     else
 418       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 419     TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
 420     break;
 421   default:
 422     ERREXIT(cinfo, JERR_TGA_BADPARMS);
 423     break;
 424   }
 425
 426   if (is_bottom_up) {
 427     /* Create a virtual array to buffer the upside-down image. */
 428     source->whole_image = (*cinfo->mem->request_virt_sarray)
 429       ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
 430        (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
 431     if (cinfo->progress != NULL) {
 432       cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
 433       progress->total_extra_passes++; /* count file input as separate pass */
 434     }
 435     /* source->pub.buffer will point to the virtual array. */
 436     source->pub.buffer_height = 1; /* in case anyone looks at it */
 437     source->pub.get_pixel_rows = preload_image;
 438   } else {
 439     /* Don't need a virtual array, but do need a one-row input buffer. */
 440     source->whole_image = NULL;
 441     source->pub.buffer = (*cinfo->mem->alloc_sarray)
 442       ((j_common_ptr) cinfo, JPOOL_IMAGE,
 443        (JDIMENSION) width * components, (JDIMENSION) 1);
 444     source->pub.buffer_height = 1;
 445     source->pub.get_pixel_rows = source->get_pixel_rows;
 446   }
 447
 448   while (idlen--)               /* Throw away ID field */
 449     (void) read_byte(source);
 450
 451   if (maplen > 0) {
 452     if (maplen > 256 || GET_2B(3) != 0)
 453       ERREXIT(cinfo, JERR_TGA_BADCMAP);
 454     /* Allocate space to store the colormap */
 455     source->colormap = (*cinfo->mem->alloc_sarray)
 456       ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
 457     /* and read it from the file */
 458     read_colormap(source, (int) maplen, UCH(targaheader[7]));
 459   } else {
 460     if (cmaptype)               /* but you promised a cmap! */
 461       ERREXIT(cinfo, JERR_TGA_BADPARMS);
 462     source->colormap = NULL;
 463   }
 464
 465   cinfo->input_components = components;
 466   cinfo->data_precision = 8;
 467   cinfo->image_width = width;
 468   cinfo->image_height = height;
 469 }
 470
 471
 472 /*
 473  * Finish up at the end of the file.
 474  */
 475
 476 METHODDEF(void)
 477 finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 478 {
 479   /* no work */
 480 }
 481
 482
 483 /*
 484  * The module selection routine for Targa format input.
 485  */
 486
 487 JGLOBAL(cjpeg_source_ptr)
 488 jinit_read_targa (j_compress_ptr cinfo)
 489 {
 490   tga_source_ptr source;
 491
 492   /* Create module interface object */
 493   source = (tga_source_ptr)
 494       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 495                                   SIZEOF(tga_source_struct));
 496   source->cinfo = cinfo;        /* make back link for subroutines */
 497   /* Fill in method ptrs, except get_pixel_rows which start_input sets */
 498   source->pub.start_input = start_input_tga;
 499   source->pub.finish_input = finish_input_tga;
 500
 501   return (cjpeg_source_ptr) source;
 502 }
 503
 504 #endif /* TARGA_SUPPORTED */