DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (409f3966645a)

VCS Links

Line Code
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

/* pngwtran.c - transforms the data in a row for PNG writers
 *
 * Last changed in libpng 1.6.26 [October 20, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
 */

#include "pngpriv.h"

#ifdef PNG_WRITE_SUPPORTED
#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED

#ifdef PNG_WRITE_PACK_SUPPORTED
/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
 * row_info bit depth should be 8 (one pixel per byte).  The channels
 * should be 1 (this only happens on grayscale and paletted images).
 */
static void
png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
{
   png_debug(1, "in png_do_pack");

   if (row_info->bit_depth == 8 &&
      row_info->channels == 1)
   {
      switch ((int)bit_depth)
      {
         case 1:
         {
            png_bytep sp, dp;
            int mask, v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            mask = 0x80;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               if (*sp != 0)
                  v |= mask;

               sp++;

               if (mask > 1)
                  mask >>= 1;

               else
               {
                  mask = 0x80;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }
            }

            if (mask != 0x80)
               *dp = (png_byte)v;

            break;
         }

         case 2:
         {
            png_bytep sp, dp;
            unsigned int shift;
            int v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            shift = 6;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               png_byte value;

               value = (png_byte)(*sp & 0x03);
               v |= (value << shift);

               if (shift == 0)
               {
                  shift = 6;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }

               else
                  shift -= 2;

               sp++;
            }

            if (shift != 6)
               *dp = (png_byte)v;

            break;
         }

         case 4:
         {
            png_bytep sp, dp;
            unsigned int shift;
            int v;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            sp = row;
            dp = row;
            shift = 4;
            v = 0;

            for (i = 0; i < row_width; i++)
            {
               png_byte value;

               value = (png_byte)(*sp & 0x0f);
               v |= (value << shift);

               if (shift == 0)
               {
                  shift = 4;
                  *dp = (png_byte)v;
                  dp++;
                  v = 0;
               }

               else
                  shift -= 4;

               sp++;
            }

            if (shift != 4)
               *dp = (png_byte)v;

            break;
         }

         default:
            break;
      }

      row_info->bit_depth = (png_byte)bit_depth;
      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
          row_info->width);
   }
}
#endif

#ifdef PNG_WRITE_SHIFT_SUPPORTED
/* Shift pixel values to take advantage of whole range.  Pass the
 * true number of bits in bit_depth.  The row should be packed
 * according to row_info->bit_depth.  Thus, if you had a row of
 * bit depth 4, but the pixels only had values from 0 to 7, you
 * would pass 3 as bit_depth, and this routine would translate the
 * data to 0 to 15.
 */
static void
png_do_shift(png_row_infop row_info, png_bytep row,
    png_const_color_8p bit_depth)
{
   png_debug(1, "in png_do_shift");

   if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
   {
      int shift_start[4], shift_dec[4];
      unsigned int channels = 0;

      if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->red;
         shift_dec[channels] = bit_depth->red;
         channels++;

         shift_start[channels] = row_info->bit_depth - bit_depth->green;
         shift_dec[channels] = bit_depth->green;
         channels++;

         shift_start[channels] = row_info->bit_depth - bit_depth->blue;
         shift_dec[channels] = bit_depth->blue;
         channels++;
      }

      else
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->gray;
         shift_dec[channels] = bit_depth->gray;
         channels++;
      }

      if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
      {
         shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
         shift_dec[channels] = bit_depth->alpha;
         channels++;
      }

      /* With low row depths, could only be grayscale, so one channel */
      if (row_info->bit_depth < 8)
      {
         png_bytep bp = row;
         png_size_t i;
         unsigned int mask;
         png_size_t row_bytes = row_info->rowbytes;

         if (bit_depth->gray == 1 && row_info->bit_depth == 2)
            mask = 0x55;

         else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
            mask = 0x11;

         else
            mask = 0xff;

         for (i = 0; i < row_bytes; i++, bp++)
         {
            int j;
            unsigned int v, out;

            v = *bp;
            out = 0;

            for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
            {
               if (j > 0)
                  out |= v << j;

               else
                  out |= (v >> (-j)) & mask;
            }

            *bp = (png_byte)(out & 0xff);
         }
      }

      else if (row_info->bit_depth == 8)
      {
         png_bytep bp = row;
         png_uint_32 i;
         png_uint_32 istop = channels * row_info->width;

         for (i = 0; i < istop; i++, bp++)
         {

            const unsigned int c = i%channels;
            int j;
            unsigned int v, out;

            v = *bp;
            out = 0;

            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
            {
               if (j > 0)
                  out |= v << j;

               else
                  out |= v >> (-j);
            }

            *bp = (png_byte)(out & 0xff);
         }
      }

      else
      {
         png_bytep bp;
         png_uint_32 i;
         png_uint_32 istop = channels * row_info->width;

         for (bp = row, i = 0; i < istop; i++)
         {
            const unsigned int c = i%channels;
            int j;
            unsigned int value, v;

            v = png_get_uint_16(bp);
            value = 0;

            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
            {
               if (j > 0)
                  value |= v << j;

               else
                  value |= v >> (-j);
            }
            *bp++ = (png_byte)((value >> 8) & 0xff);
            *bp++ = (png_byte)(value & 0xff);
         }
      }
   }
}
#endif

#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
static void
png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
{
   png_debug(1, "in png_do_write_swap_alpha");

   {
      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This converts from ARGB to RGBA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save;
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This converts from AARRGGBB to RRGGBBAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save[2];
               save[0] = *(sp++);
               save[1] = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save[0];
               *(dp++) = save[1];
            }
         }
#endif /* WRITE_16BIT */
      }

      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This converts from AG to GA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save;
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This converts from AAGG to GGAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               png_byte save[2];
               save[0] = *(sp++);
               save[1] = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = save[0];
               *(dp++) = save[1];
            }
         }
#endif /* WRITE_16BIT */
      }
   }
}
#endif

#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
static void
png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
{
   png_debug(1, "in png_do_write_invert_alpha");

   {
      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This inverts the alpha channel in RGBA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=3; dp = sp;
               *dp = (png_byte)(255 - *(sp++));
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This inverts the alpha channel in RRGGBBAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=6; dp = sp;
               *(dp++) = (png_byte)(255 - *(sp++));
               *dp     = (png_byte)(255 - *(sp++));
            }
         }
#endif /* WRITE_16BIT */
      }

      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
      {
         if (row_info->bit_depth == 8)
         {
            /* This inverts the alpha channel in GA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               *(dp++) = *(sp++);
               *(dp++) = (png_byte)(255 - *(sp++));
            }
         }

#ifdef PNG_WRITE_16BIT_SUPPORTED
         else
         {
            /* This inverts the alpha channel in GGAA */
            png_bytep sp, dp;
            png_uint_32 i;
            png_uint_32 row_width = row_info->width;

            for (i = 0, sp = dp = row; i < row_width; i++)
            {
               /* Does nothing
               *(dp++) = *(sp++);
               *(dp++) = *(sp++);
               */
               sp+=2; dp = sp;
               *(dp++) = (png_byte)(255 - *(sp++));
               *dp     = (png_byte)(255 - *(sp++));
            }
         }
#endif /* WRITE_16BIT */
      }
   }
}
#endif

/* Transform the data according to the user's wishes.  The order of
 * transformations is significant.
 */
void /* PRIVATE */
png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
{
   png_debug(1, "in png_do_write_transformations");

   if (png_ptr == NULL)
      return;

#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
      if (png_ptr->write_user_transform_fn != NULL)
         (*(png_ptr->write_user_transform_fn)) /* User write transform
                                                 function */
             (png_ptr,  /* png_ptr */
             row_info,  /* row_info: */
                /*  png_uint_32 width;       width of row */
                /*  png_size_t rowbytes;     number of bytes in row */
                /*  png_byte color_type;     color type of pixels */
                /*  png_byte bit_depth;      bit depth of samples */
                /*  png_byte channels;       number of channels (1-4) */
                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
             png_ptr->row_buf + 1);      /* start of pixel data for row */
#endif

#ifdef PNG_WRITE_FILLER_SUPPORTED
   if ((png_ptr->transformations & PNG_FILLER) != 0)
      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
          !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
#endif

#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
      png_do_packswap(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_PACK_SUPPORTED
   if ((png_ptr->transformations & PNG_PACK) != 0)
      png_do_pack(row_info, png_ptr->row_buf + 1,
          (png_uint_32)png_ptr->bit_depth);
#endif

#ifdef PNG_WRITE_SWAP_SUPPORTED
#  ifdef PNG_16BIT_SUPPORTED
   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
      png_do_swap(row_info, png_ptr->row_buf + 1);
#  endif
#endif

#ifdef PNG_WRITE_SHIFT_SUPPORTED
   if ((png_ptr->transformations & PNG_SHIFT) != 0)
      png_do_shift(row_info, png_ptr->row_buf + 1,
           &(png_ptr->shift));
#endif

#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_BGR_SUPPORTED
   if ((png_ptr->transformations & PNG_BGR) != 0)
      png_do_bgr(row_info, png_ptr->row_buf + 1);
#endif

#ifdef PNG_WRITE_INVERT_SUPPORTED
   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
      png_do_invert(row_info, png_ptr->row_buf + 1);
#endif
}
#endif /* WRITE_TRANSFORMS */
#endif /* WRITE */