dbf-halloween2015

annotate libs/libpng/pngwtran.c @ 1:c3f5c32cb210

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barfed all the libraries in the source tree to make porting easier
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 00:36:56 +0200
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rev   line source
nuclear@1 1
nuclear@1 2 /* pngwtran.c - transforms the data in a row for PNG writers
nuclear@1 3 *
nuclear@1 4 * Last changed in libpng 1.2.9 April 14, 2006
nuclear@1 5 * For conditions of distribution and use, see copyright notice in png.h
nuclear@1 6 * Copyright (c) 1998-2006 Glenn Randers-Pehrson
nuclear@1 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
nuclear@1 8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
nuclear@1 9 */
nuclear@1 10
nuclear@1 11 #define PNG_INTERNAL
nuclear@1 12 #include "png.h"
nuclear@1 13 #ifdef PNG_WRITE_SUPPORTED
nuclear@1 14
nuclear@1 15 /* Transform the data according to the user's wishes. The order of
nuclear@1 16 * transformations is significant.
nuclear@1 17 */
nuclear@1 18 void /* PRIVATE */
nuclear@1 19 png_do_write_transformations(png_structp png_ptr)
nuclear@1 20 {
nuclear@1 21 png_debug(1, "in png_do_write_transformations\n");
nuclear@1 22
nuclear@1 23 if (png_ptr == NULL)
nuclear@1 24 return;
nuclear@1 25
nuclear@1 26 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
nuclear@1 27 if (png_ptr->transformations & PNG_USER_TRANSFORM)
nuclear@1 28 if (png_ptr->write_user_transform_fn != NULL)
nuclear@1 29 (*(png_ptr->write_user_transform_fn)) /* user write transform function */
nuclear@1 30 (png_ptr, /* png_ptr */
nuclear@1 31 &(png_ptr->row_info), /* row_info: */
nuclear@1 32 /* png_uint_32 width; width of row */
nuclear@1 33 /* png_uint_32 rowbytes; number of bytes in row */
nuclear@1 34 /* png_byte color_type; color type of pixels */
nuclear@1 35 /* png_byte bit_depth; bit depth of samples */
nuclear@1 36 /* png_byte channels; number of channels (1-4) */
nuclear@1 37 /* png_byte pixel_depth; bits per pixel (depth*channels) */
nuclear@1 38 png_ptr->row_buf + 1); /* start of pixel data for row */
nuclear@1 39 #endif
nuclear@1 40 #if defined(PNG_WRITE_FILLER_SUPPORTED)
nuclear@1 41 if (png_ptr->transformations & PNG_FILLER)
nuclear@1 42 png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1 43 png_ptr->flags);
nuclear@1 44 #endif
nuclear@1 45 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
nuclear@1 46 if (png_ptr->transformations & PNG_PACKSWAP)
nuclear@1 47 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 48 #endif
nuclear@1 49 #if defined(PNG_WRITE_PACK_SUPPORTED)
nuclear@1 50 if (png_ptr->transformations & PNG_PACK)
nuclear@1 51 png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1 52 (png_uint_32)png_ptr->bit_depth);
nuclear@1 53 #endif
nuclear@1 54 #if defined(PNG_WRITE_SWAP_SUPPORTED)
nuclear@1 55 if (png_ptr->transformations & PNG_SWAP_BYTES)
nuclear@1 56 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 57 #endif
nuclear@1 58 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
nuclear@1 59 if (png_ptr->transformations & PNG_SHIFT)
nuclear@1 60 png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1 61 &(png_ptr->shift));
nuclear@1 62 #endif
nuclear@1 63 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
nuclear@1 64 if (png_ptr->transformations & PNG_SWAP_ALPHA)
nuclear@1 65 png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 66 #endif
nuclear@1 67 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
nuclear@1 68 if (png_ptr->transformations & PNG_INVERT_ALPHA)
nuclear@1 69 png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 70 #endif
nuclear@1 71 #if defined(PNG_WRITE_BGR_SUPPORTED)
nuclear@1 72 if (png_ptr->transformations & PNG_BGR)
nuclear@1 73 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 74 #endif
nuclear@1 75 #if defined(PNG_WRITE_INVERT_SUPPORTED)
nuclear@1 76 if (png_ptr->transformations & PNG_INVERT_MONO)
nuclear@1 77 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1 78 #endif
nuclear@1 79 }
nuclear@1 80
nuclear@1 81 #if defined(PNG_WRITE_PACK_SUPPORTED)
nuclear@1 82 /* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
nuclear@1 83 * row_info bit depth should be 8 (one pixel per byte). The channels
nuclear@1 84 * should be 1 (this only happens on grayscale and paletted images).
nuclear@1 85 */
nuclear@1 86 void /* PRIVATE */
nuclear@1 87 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
nuclear@1 88 {
nuclear@1 89 png_debug(1, "in png_do_pack\n");
nuclear@1 90 if (row_info->bit_depth == 8 &&
nuclear@1 91 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1 92 row != NULL && row_info != NULL &&
nuclear@1 93 #endif
nuclear@1 94 row_info->channels == 1)
nuclear@1 95 {
nuclear@1 96 switch ((int)bit_depth)
nuclear@1 97 {
nuclear@1 98 case 1:
nuclear@1 99 {
nuclear@1 100 png_bytep sp, dp;
nuclear@1 101 int mask, v;
nuclear@1 102 png_uint_32 i;
nuclear@1 103 png_uint_32 row_width = row_info->width;
nuclear@1 104
nuclear@1 105 sp = row;
nuclear@1 106 dp = row;
nuclear@1 107 mask = 0x80;
nuclear@1 108 v = 0;
nuclear@1 109
nuclear@1 110 for (i = 0; i < row_width; i++)
nuclear@1 111 {
nuclear@1 112 if (*sp != 0)
nuclear@1 113 v |= mask;
nuclear@1 114 sp++;
nuclear@1 115 if (mask > 1)
nuclear@1 116 mask >>= 1;
nuclear@1 117 else
nuclear@1 118 {
nuclear@1 119 mask = 0x80;
nuclear@1 120 *dp = (png_byte)v;
nuclear@1 121 dp++;
nuclear@1 122 v = 0;
nuclear@1 123 }
nuclear@1 124 }
nuclear@1 125 if (mask != 0x80)
nuclear@1 126 *dp = (png_byte)v;
nuclear@1 127 break;
nuclear@1 128 }
nuclear@1 129 case 2:
nuclear@1 130 {
nuclear@1 131 png_bytep sp, dp;
nuclear@1 132 int shift, v;
nuclear@1 133 png_uint_32 i;
nuclear@1 134 png_uint_32 row_width = row_info->width;
nuclear@1 135
nuclear@1 136 sp = row;
nuclear@1 137 dp = row;
nuclear@1 138 shift = 6;
nuclear@1 139 v = 0;
nuclear@1 140 for (i = 0; i < row_width; i++)
nuclear@1 141 {
nuclear@1 142 png_byte value;
nuclear@1 143
nuclear@1 144 value = (png_byte)(*sp & 0x03);
nuclear@1 145 v |= (value << shift);
nuclear@1 146 if (shift == 0)
nuclear@1 147 {
nuclear@1 148 shift = 6;
nuclear@1 149 *dp = (png_byte)v;
nuclear@1 150 dp++;
nuclear@1 151 v = 0;
nuclear@1 152 }
nuclear@1 153 else
nuclear@1 154 shift -= 2;
nuclear@1 155 sp++;
nuclear@1 156 }
nuclear@1 157 if (shift != 6)
nuclear@1 158 *dp = (png_byte)v;
nuclear@1 159 break;
nuclear@1 160 }
nuclear@1 161 case 4:
nuclear@1 162 {
nuclear@1 163 png_bytep sp, dp;
nuclear@1 164 int shift, v;
nuclear@1 165 png_uint_32 i;
nuclear@1 166 png_uint_32 row_width = row_info->width;
nuclear@1 167
nuclear@1 168 sp = row;
nuclear@1 169 dp = row;
nuclear@1 170 shift = 4;
nuclear@1 171 v = 0;
nuclear@1 172 for (i = 0; i < row_width; i++)
nuclear@1 173 {
nuclear@1 174 png_byte value;
nuclear@1 175
nuclear@1 176 value = (png_byte)(*sp & 0x0f);
nuclear@1 177 v |= (value << shift);
nuclear@1 178
nuclear@1 179 if (shift == 0)
nuclear@1 180 {
nuclear@1 181 shift = 4;
nuclear@1 182 *dp = (png_byte)v;
nuclear@1 183 dp++;
nuclear@1 184 v = 0;
nuclear@1 185 }
nuclear@1 186 else
nuclear@1 187 shift -= 4;
nuclear@1 188
nuclear@1 189 sp++;
nuclear@1 190 }
nuclear@1 191 if (shift != 4)
nuclear@1 192 *dp = (png_byte)v;
nuclear@1 193 break;
nuclear@1 194 }
nuclear@1 195 }
nuclear@1 196 row_info->bit_depth = (png_byte)bit_depth;
nuclear@1 197 row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
nuclear@1 198 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
nuclear@1 199 row_info->width);
nuclear@1 200 }
nuclear@1 201 }
nuclear@1 202 #endif
nuclear@1 203
nuclear@1 204 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
nuclear@1 205 /* Shift pixel values to take advantage of whole range. Pass the
nuclear@1 206 * true number of bits in bit_depth. The row should be packed
nuclear@1 207 * according to row_info->bit_depth. Thus, if you had a row of
nuclear@1 208 * bit depth 4, but the pixels only had values from 0 to 7, you
nuclear@1 209 * would pass 3 as bit_depth, and this routine would translate the
nuclear@1 210 * data to 0 to 15.
nuclear@1 211 */
nuclear@1 212 void /* PRIVATE */
nuclear@1 213 png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
nuclear@1 214 {
nuclear@1 215 png_debug(1, "in png_do_shift\n");
nuclear@1 216 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1 217 if (row != NULL && row_info != NULL &&
nuclear@1 218 #else
nuclear@1 219 if (
nuclear@1 220 #endif
nuclear@1 221 row_info->color_type != PNG_COLOR_TYPE_PALETTE)
nuclear@1 222 {
nuclear@1 223 int shift_start[4], shift_dec[4];
nuclear@1 224 int channels = 0;
nuclear@1 225
nuclear@1 226 if (row_info->color_type & PNG_COLOR_MASK_COLOR)
nuclear@1 227 {
nuclear@1 228 shift_start[channels] = row_info->bit_depth - bit_depth->red;
nuclear@1 229 shift_dec[channels] = bit_depth->red;
nuclear@1 230 channels++;
nuclear@1 231 shift_start[channels] = row_info->bit_depth - bit_depth->green;
nuclear@1 232 shift_dec[channels] = bit_depth->green;
nuclear@1 233 channels++;
nuclear@1 234 shift_start[channels] = row_info->bit_depth - bit_depth->blue;
nuclear@1 235 shift_dec[channels] = bit_depth->blue;
nuclear@1 236 channels++;
nuclear@1 237 }
nuclear@1 238 else
nuclear@1 239 {
nuclear@1 240 shift_start[channels] = row_info->bit_depth - bit_depth->gray;
nuclear@1 241 shift_dec[channels] = bit_depth->gray;
nuclear@1 242 channels++;
nuclear@1 243 }
nuclear@1 244 if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
nuclear@1 245 {
nuclear@1 246 shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
nuclear@1 247 shift_dec[channels] = bit_depth->alpha;
nuclear@1 248 channels++;
nuclear@1 249 }
nuclear@1 250
nuclear@1 251 /* with low row depths, could only be grayscale, so one channel */
nuclear@1 252 if (row_info->bit_depth < 8)
nuclear@1 253 {
nuclear@1 254 png_bytep bp = row;
nuclear@1 255 png_uint_32 i;
nuclear@1 256 png_byte mask;
nuclear@1 257 png_uint_32 row_bytes = row_info->rowbytes;
nuclear@1 258
nuclear@1 259 if (bit_depth->gray == 1 && row_info->bit_depth == 2)
nuclear@1 260 mask = 0x55;
nuclear@1 261 else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
nuclear@1 262 mask = 0x11;
nuclear@1 263 else
nuclear@1 264 mask = 0xff;
nuclear@1 265
nuclear@1 266 for (i = 0; i < row_bytes; i++, bp++)
nuclear@1 267 {
nuclear@1 268 png_uint_16 v;
nuclear@1 269 int j;
nuclear@1 270
nuclear@1 271 v = *bp;
nuclear@1 272 *bp = 0;
nuclear@1 273 for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
nuclear@1 274 {
nuclear@1 275 if (j > 0)
nuclear@1 276 *bp |= (png_byte)((v << j) & 0xff);
nuclear@1 277 else
nuclear@1 278 *bp |= (png_byte)((v >> (-j)) & mask);
nuclear@1 279 }
nuclear@1 280 }
nuclear@1 281 }
nuclear@1 282 else if (row_info->bit_depth == 8)
nuclear@1 283 {
nuclear@1 284 png_bytep bp = row;
nuclear@1 285 png_uint_32 i;
nuclear@1 286 png_uint_32 istop = channels * row_info->width;
nuclear@1 287
nuclear@1 288 for (i = 0; i < istop; i++, bp++)
nuclear@1 289 {
nuclear@1 290
nuclear@1 291 png_uint_16 v;
nuclear@1 292 int j;
nuclear@1 293 int c = (int)(i%channels);
nuclear@1 294
nuclear@1 295 v = *bp;
nuclear@1 296 *bp = 0;
nuclear@1 297 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
nuclear@1 298 {
nuclear@1 299 if (j > 0)
nuclear@1 300 *bp |= (png_byte)((v << j) & 0xff);
nuclear@1 301 else
nuclear@1 302 *bp |= (png_byte)((v >> (-j)) & 0xff);
nuclear@1 303 }
nuclear@1 304 }
nuclear@1 305 }
nuclear@1 306 else
nuclear@1 307 {
nuclear@1 308 png_bytep bp;
nuclear@1 309 png_uint_32 i;
nuclear@1 310 png_uint_32 istop = channels * row_info->width;
nuclear@1 311
nuclear@1 312 for (bp = row, i = 0; i < istop; i++)
nuclear@1 313 {
nuclear@1 314 int c = (int)(i%channels);
nuclear@1 315 png_uint_16 value, v;
nuclear@1 316 int j;
nuclear@1 317
nuclear@1 318 v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
nuclear@1 319 value = 0;
nuclear@1 320 for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
nuclear@1 321 {
nuclear@1 322 if (j > 0)
nuclear@1 323 value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
nuclear@1 324 else
nuclear@1 325 value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
nuclear@1 326 }
nuclear@1 327 *bp++ = (png_byte)(value >> 8);
nuclear@1 328 *bp++ = (png_byte)(value & 0xff);
nuclear@1 329 }
nuclear@1 330 }
nuclear@1 331 }
nuclear@1 332 }
nuclear@1 333 #endif
nuclear@1 334
nuclear@1 335 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
nuclear@1 336 void /* PRIVATE */
nuclear@1 337 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
nuclear@1 338 {
nuclear@1 339 png_debug(1, "in png_do_write_swap_alpha\n");
nuclear@1 340 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1 341 if (row != NULL && row_info != NULL)
nuclear@1 342 #endif
nuclear@1 343 {
nuclear@1 344 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1 345 {
nuclear@1 346 /* This converts from ARGB to RGBA */
nuclear@1 347 if (row_info->bit_depth == 8)
nuclear@1 348 {
nuclear@1 349 png_bytep sp, dp;
nuclear@1 350 png_uint_32 i;
nuclear@1 351 png_uint_32 row_width = row_info->width;
nuclear@1 352 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 353 {
nuclear@1 354 png_byte save = *(sp++);
nuclear@1 355 *(dp++) = *(sp++);
nuclear@1 356 *(dp++) = *(sp++);
nuclear@1 357 *(dp++) = *(sp++);
nuclear@1 358 *(dp++) = save;
nuclear@1 359 }
nuclear@1 360 }
nuclear@1 361 /* This converts from AARRGGBB to RRGGBBAA */
nuclear@1 362 else
nuclear@1 363 {
nuclear@1 364 png_bytep sp, dp;
nuclear@1 365 png_uint_32 i;
nuclear@1 366 png_uint_32 row_width = row_info->width;
nuclear@1 367
nuclear@1 368 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 369 {
nuclear@1 370 png_byte save[2];
nuclear@1 371 save[0] = *(sp++);
nuclear@1 372 save[1] = *(sp++);
nuclear@1 373 *(dp++) = *(sp++);
nuclear@1 374 *(dp++) = *(sp++);
nuclear@1 375 *(dp++) = *(sp++);
nuclear@1 376 *(dp++) = *(sp++);
nuclear@1 377 *(dp++) = *(sp++);
nuclear@1 378 *(dp++) = *(sp++);
nuclear@1 379 *(dp++) = save[0];
nuclear@1 380 *(dp++) = save[1];
nuclear@1 381 }
nuclear@1 382 }
nuclear@1 383 }
nuclear@1 384 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@1 385 {
nuclear@1 386 /* This converts from AG to GA */
nuclear@1 387 if (row_info->bit_depth == 8)
nuclear@1 388 {
nuclear@1 389 png_bytep sp, dp;
nuclear@1 390 png_uint_32 i;
nuclear@1 391 png_uint_32 row_width = row_info->width;
nuclear@1 392
nuclear@1 393 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 394 {
nuclear@1 395 png_byte save = *(sp++);
nuclear@1 396 *(dp++) = *(sp++);
nuclear@1 397 *(dp++) = save;
nuclear@1 398 }
nuclear@1 399 }
nuclear@1 400 /* This converts from AAGG to GGAA */
nuclear@1 401 else
nuclear@1 402 {
nuclear@1 403 png_bytep sp, dp;
nuclear@1 404 png_uint_32 i;
nuclear@1 405 png_uint_32 row_width = row_info->width;
nuclear@1 406
nuclear@1 407 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 408 {
nuclear@1 409 png_byte save[2];
nuclear@1 410 save[0] = *(sp++);
nuclear@1 411 save[1] = *(sp++);
nuclear@1 412 *(dp++) = *(sp++);
nuclear@1 413 *(dp++) = *(sp++);
nuclear@1 414 *(dp++) = save[0];
nuclear@1 415 *(dp++) = save[1];
nuclear@1 416 }
nuclear@1 417 }
nuclear@1 418 }
nuclear@1 419 }
nuclear@1 420 }
nuclear@1 421 #endif
nuclear@1 422
nuclear@1 423 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
nuclear@1 424 void /* PRIVATE */
nuclear@1 425 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
nuclear@1 426 {
nuclear@1 427 png_debug(1, "in png_do_write_invert_alpha\n");
nuclear@1 428 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1 429 if (row != NULL && row_info != NULL)
nuclear@1 430 #endif
nuclear@1 431 {
nuclear@1 432 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1 433 {
nuclear@1 434 /* This inverts the alpha channel in RGBA */
nuclear@1 435 if (row_info->bit_depth == 8)
nuclear@1 436 {
nuclear@1 437 png_bytep sp, dp;
nuclear@1 438 png_uint_32 i;
nuclear@1 439 png_uint_32 row_width = row_info->width;
nuclear@1 440 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 441 {
nuclear@1 442 /* does nothing
nuclear@1 443 *(dp++) = *(sp++);
nuclear@1 444 *(dp++) = *(sp++);
nuclear@1 445 *(dp++) = *(sp++);
nuclear@1 446 */
nuclear@1 447 sp+=3; dp = sp;
nuclear@1 448 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 449 }
nuclear@1 450 }
nuclear@1 451 /* This inverts the alpha channel in RRGGBBAA */
nuclear@1 452 else
nuclear@1 453 {
nuclear@1 454 png_bytep sp, dp;
nuclear@1 455 png_uint_32 i;
nuclear@1 456 png_uint_32 row_width = row_info->width;
nuclear@1 457
nuclear@1 458 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 459 {
nuclear@1 460 /* does nothing
nuclear@1 461 *(dp++) = *(sp++);
nuclear@1 462 *(dp++) = *(sp++);
nuclear@1 463 *(dp++) = *(sp++);
nuclear@1 464 *(dp++) = *(sp++);
nuclear@1 465 *(dp++) = *(sp++);
nuclear@1 466 *(dp++) = *(sp++);
nuclear@1 467 */
nuclear@1 468 sp+=6; dp = sp;
nuclear@1 469 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 470 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 471 }
nuclear@1 472 }
nuclear@1 473 }
nuclear@1 474 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@1 475 {
nuclear@1 476 /* This inverts the alpha channel in GA */
nuclear@1 477 if (row_info->bit_depth == 8)
nuclear@1 478 {
nuclear@1 479 png_bytep sp, dp;
nuclear@1 480 png_uint_32 i;
nuclear@1 481 png_uint_32 row_width = row_info->width;
nuclear@1 482
nuclear@1 483 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 484 {
nuclear@1 485 *(dp++) = *(sp++);
nuclear@1 486 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 487 }
nuclear@1 488 }
nuclear@1 489 /* This inverts the alpha channel in GGAA */
nuclear@1 490 else
nuclear@1 491 {
nuclear@1 492 png_bytep sp, dp;
nuclear@1 493 png_uint_32 i;
nuclear@1 494 png_uint_32 row_width = row_info->width;
nuclear@1 495
nuclear@1 496 for (i = 0, sp = dp = row; i < row_width; i++)
nuclear@1 497 {
nuclear@1 498 /* does nothing
nuclear@1 499 *(dp++) = *(sp++);
nuclear@1 500 *(dp++) = *(sp++);
nuclear@1 501 */
nuclear@1 502 sp+=2; dp = sp;
nuclear@1 503 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 504 *(dp++) = (png_byte)(255 - *(sp++));
nuclear@1 505 }
nuclear@1 506 }
nuclear@1 507 }
nuclear@1 508 }
nuclear@1 509 }
nuclear@1 510 #endif
nuclear@1 511
nuclear@1 512 #if defined(PNG_MNG_FEATURES_SUPPORTED)
nuclear@1 513 /* undoes intrapixel differencing */
nuclear@1 514 void /* PRIVATE */
nuclear@1 515 png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
nuclear@1 516 {
nuclear@1 517 png_debug(1, "in png_do_write_intrapixel\n");
nuclear@1 518 if (
nuclear@1 519 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1 520 row != NULL && row_info != NULL &&
nuclear@1 521 #endif
nuclear@1 522 (row_info->color_type & PNG_COLOR_MASK_COLOR))
nuclear@1 523 {
nuclear@1 524 int bytes_per_pixel;
nuclear@1 525 png_uint_32 row_width = row_info->width;
nuclear@1 526 if (row_info->bit_depth == 8)
nuclear@1 527 {
nuclear@1 528 png_bytep rp;
nuclear@1 529 png_uint_32 i;
nuclear@1 530
nuclear@1 531 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1 532 bytes_per_pixel = 3;
nuclear@1 533 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1 534 bytes_per_pixel = 4;
nuclear@1 535 else
nuclear@1 536 return;
nuclear@1 537
nuclear@1 538 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
nuclear@1 539 {
nuclear@1 540 *(rp) = (png_byte)((*rp - *(rp+1))&0xff);
nuclear@1 541 *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff);
nuclear@1 542 }
nuclear@1 543 }
nuclear@1 544 else if (row_info->bit_depth == 16)
nuclear@1 545 {
nuclear@1 546 png_bytep rp;
nuclear@1 547 png_uint_32 i;
nuclear@1 548
nuclear@1 549 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1 550 bytes_per_pixel = 6;
nuclear@1 551 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1 552 bytes_per_pixel = 8;
nuclear@1 553 else
nuclear@1 554 return;
nuclear@1 555
nuclear@1 556 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
nuclear@1 557 {
nuclear@1 558 png_uint_32 s0 = (*(rp ) << 8) | *(rp+1);
nuclear@1 559 png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3);
nuclear@1 560 png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5);
nuclear@1 561 png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
nuclear@1 562 png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
nuclear@1 563 *(rp ) = (png_byte)((red >> 8) & 0xff);
nuclear@1 564 *(rp+1) = (png_byte)(red & 0xff);
nuclear@1 565 *(rp+4) = (png_byte)((blue >> 8) & 0xff);
nuclear@1 566 *(rp+5) = (png_byte)(blue & 0xff);
nuclear@1 567 }
nuclear@1 568 }
nuclear@1 569 }
nuclear@1 570 }
nuclear@1 571 #endif /* PNG_MNG_FEATURES_SUPPORTED */
nuclear@1 572 #endif /* PNG_WRITE_SUPPORTED */