1 2 /* png.c - location for general purpose libpng functions 3 * 4 * Last changed in libpng 1.2.19 August 18, 2007 5 * For conditions of distribution and use, see copyright notice in png.h 6 * Copyright (c) 1998-2007 Glenn Randers-Pehrson 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 9 */ 10 11 #define PNG_INTERNAL 12 #define PNG_NO_EXTERN 13 #include "png.h" 14 15 /* Generate a compiler error if there is an old png.h in the search path. */ 16 typedef version_1_2_19 Your_png_h_is_not_version_1_2_19; 17 18 /* Version information for C files. This had better match the version 19 * string defined in png.h. */ 20 21 #ifdef PNG_USE_GLOBAL_ARRAYS 22 /* png_libpng_ver was changed to a function in version 1.0.5c */ 23 PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING; 24 25 #ifdef PNG_READ_SUPPORTED 26 27 /* png_sig was changed to a function in version 1.0.5c */ 28 /* Place to hold the signature string for a PNG file. */ 29 PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; 30 #endif /* PNG_READ_SUPPORTED */ 31 32 /* Invoke global declarations for constant strings for known chunk types */ 33 PNG_IHDR; 34 PNG_IDAT; 35 PNG_IEND; 36 PNG_PLTE; 37 PNG_bKGD; 38 PNG_cHRM; 39 PNG_gAMA; 40 PNG_hIST; 41 PNG_iCCP; 42 PNG_iTXt; 43 PNG_oFFs; 44 PNG_pCAL; 45 PNG_sCAL; 46 PNG_pHYs; 47 PNG_sBIT; 48 PNG_sPLT; 49 PNG_sRGB; 50 PNG_tEXt; 51 PNG_tIME; 52 PNG_tRNS; 53 PNG_zTXt; 54 55 #ifdef PNG_READ_SUPPORTED 56 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ 57 58 /* start of interlace block */ 59 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; 60 61 /* offset to next interlace block */ 62 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; 63 64 /* start of interlace block in the y direction */ 65 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; 66 67 /* offset to next interlace block in the y direction */ 68 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; 69 70 /* width of interlace block (used in assembler routines only) */ 71 #if defined(PNG_HAVE_MMX_COMBINE_ROW) || defined(PNG_OPTIMIZED_CODE_SUPPORTED) 72 PNG_CONST int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; 73 #endif 74 75 /* Height of interlace block. This is not currently used - if you need 76 * it, uncomment it here and in png.h 77 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; 78 */ 79 80 /* Mask to determine which pixels are valid in a pass */ 81 PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; 82 83 /* Mask to determine which pixels to overwrite while displaying */ 84 PNG_CONST int FARDATA png_pass_dsp_mask[] 85 = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; 86 87 #endif /* PNG_READ_SUPPORTED */ 88 #endif /* PNG_USE_GLOBAL_ARRAYS */ 89 90 /* Tells libpng that we have already handled the first "num_bytes" bytes 91 * of the PNG file signature. If the PNG data is embedded into another 92 * stream we can set num_bytes = 8 so that libpng will not attempt to read 93 * or write any of the magic bytes before it starts on the IHDR. 94 */ 95 96 #ifdef PNG_READ_SUPPORTED 97 void PNGAPI 98 png_set_sig_bytes(png_structp png_ptr, int num_bytes) 99 { 100 if(png_ptr == NULL) return; 101 png_debug(1, "in png_set_sig_bytes\n"); 102 if (num_bytes > 8) 103 png_error(png_ptr, "Too many bytes for PNG signature."); 104 105 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes); 106 } 107 108 /* Checks whether the supplied bytes match the PNG signature. We allow 109 * checking less than the full 8-byte signature so that those apps that 110 * already read the first few bytes of a file to determine the file type 111 * can simply check the remaining bytes for extra assurance. Returns 112 * an integer less than, equal to, or greater than zero if sig is found, 113 * respectively, to be less than, to match, or be greater than the correct 114 * PNG signature (this is the same behaviour as strcmp, memcmp, etc). 115 */ 116 int PNGAPI 117 png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check) 118 { 119 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; 120 if (num_to_check > 8) 121 num_to_check = 8; 122 else if (num_to_check < 1) 123 return (-1); 124 125 if (start > 7) 126 return (-1); 127 128 if (start + num_to_check > 8) 129 num_to_check = 8 - start; 130 131 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check))); 132 } 133 134 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) 135 /* (Obsolete) function to check signature bytes. It does not allow one 136 * to check a partial signature. This function might be removed in the 137 * future - use png_sig_cmp(). Returns true (nonzero) if the file is PNG. 138 */ 139 int PNGAPI 140 png_check_sig(png_bytep sig, int num) 141 { 142 return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num)); 143 } 144 #endif 145 #endif /* PNG_READ_SUPPORTED */ 146 147 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) 148 /* Function to allocate memory for zlib and clear it to 0. */ 149 #ifdef PNG_1_0_X 150 voidpf PNGAPI 151 #else 152 voidpf /* private */ 153 #endif 154 png_zalloc(voidpf png_ptr, uInt items, uInt size) 155 { 156 png_voidp ptr; 157 png_structp p=(png_structp)png_ptr; 158 png_uint_32 save_flags=p->flags; 159 png_uint_32 num_bytes; 160 161 if(png_ptr == NULL) return (NULL); 162 if (items > PNG_UINT_32_MAX/size) 163 { 164 png_warning (p, "Potential overflow in png_zalloc()"); 165 return (NULL); 166 } 167 num_bytes = (png_uint_32)items * size; 168 169 p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK; 170 ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes); 171 p->flags=save_flags; 172 173 #if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO) 174 if (ptr == NULL) 175 return ((voidpf)ptr); 176 177 if (num_bytes > (png_uint_32)0x8000L) 178 { 179 png_memset(ptr, 0, (png_size_t)0x8000L); 180 png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0, 181 (png_size_t)(num_bytes - (png_uint_32)0x8000L)); 182 } 183 else 184 { 185 png_memset(ptr, 0, (png_size_t)num_bytes); 186 } 187 #endif 188 return ((voidpf)ptr); 189 } 190 191 /* function to free memory for zlib */ 192 #ifdef PNG_1_0_X 193 void PNGAPI 194 #else 195 void /* private */ 196 #endif 197 png_zfree(voidpf png_ptr, voidpf ptr) 198 { 199 png_free((png_structp)png_ptr, (png_voidp)ptr); 200 } 201 202 /* Reset the CRC variable to 32 bits of 1's. Care must be taken 203 * in case CRC is > 32 bits to leave the top bits 0. 204 */ 205 void /* PRIVATE */ 206 png_reset_crc(png_structp png_ptr) 207 { 208 png_ptr->crc = crc32(0, Z_NULL, 0); 209 } 210 211 /* Calculate the CRC over a section of data. We can only pass as 212 * much data to this routine as the largest single buffer size. We 213 * also check that this data will actually be used before going to the 214 * trouble of calculating it. 215 */ 216 void /* PRIVATE */ 217 png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) 218 { 219 int need_crc = 1; 220 221 if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ 222 { 223 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == 224 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) 225 need_crc = 0; 226 } 227 else /* critical */ 228 { 229 if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) 230 need_crc = 0; 231 } 232 233 if (need_crc) 234 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); 235 } 236 237 /* Allocate the memory for an info_struct for the application. We don't 238 * really need the png_ptr, but it could potentially be useful in the 239 * future. This should be used in favour of malloc(png_sizeof(png_info)) 240 * and png_info_init() so that applications that want to use a shared 241 * libpng don't have to be recompiled if png_info changes size. 242 */ 243 png_infop PNGAPI 244 png_create_info_struct(png_structp png_ptr) 245 { 246 png_infop info_ptr; 247 248 png_debug(1, "in png_create_info_struct\n"); 249 if(png_ptr == NULL) return (NULL); 250 #ifdef PNG_USER_MEM_SUPPORTED 251 info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO, 252 png_ptr->malloc_fn, png_ptr->mem_ptr); 253 #else 254 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); 255 #endif 256 if (info_ptr != NULL) 257 png_info_init_3(&info_ptr, png_sizeof(png_info)); 258 259 return (info_ptr); 260 } 261 262 /* This function frees the memory associated with a single info struct. 263 * Normally, one would use either png_destroy_read_struct() or 264 * png_destroy_write_struct() to free an info struct, but this may be 265 * useful for some applications. 266 */ 267 void PNGAPI 268 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) 269 { 270 png_infop info_ptr = NULL; 271 if(png_ptr == NULL) return; 272 273 png_debug(1, "in png_destroy_info_struct\n"); 274 if (info_ptr_ptr != NULL) 275 info_ptr = *info_ptr_ptr; 276 277 if (info_ptr != NULL) 278 { 279 png_info_destroy(png_ptr, info_ptr); 280 281 #ifdef PNG_USER_MEM_SUPPORTED 282 png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn, 283 png_ptr->mem_ptr); 284 #else 285 png_destroy_struct((png_voidp)info_ptr); 286 #endif 287 *info_ptr_ptr = NULL; 288 } 289 } 290 291 /* Initialize the info structure. This is now an internal function (0.89) 292 * and applications using it are urged to use png_create_info_struct() 293 * instead. 294 */ 295 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) 296 #undef png_info_init 297 void PNGAPI 298 png_info_init(png_infop info_ptr) 299 { 300 /* We only come here via pre-1.0.12-compiled applications */ 301 png_info_init_3(&info_ptr, 0); 302 } 303 #endif 304 305 void PNGAPI 306 png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size) 307 { 308 png_infop info_ptr = *ptr_ptr; 309 310 if(info_ptr == NULL) return; 311 312 png_debug(1, "in png_info_init_3\n"); 313 314 if(png_sizeof(png_info) > png_info_struct_size) 315 { 316 png_destroy_struct(info_ptr); 317 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); 318 *ptr_ptr = info_ptr; 319 } 320 321 /* set everything to 0 */ 322 png_memset(info_ptr, 0, png_sizeof (png_info)); 323 } 324 325 #ifdef PNG_FREE_ME_SUPPORTED 326 void PNGAPI 327 png_data_freer(png_structp png_ptr, png_infop info_ptr, 328 int freer, png_uint_32 mask) 329 { 330 png_debug(1, "in png_data_freer\n"); 331 if (png_ptr == NULL || info_ptr == NULL) 332 return; 333 if(freer == PNG_DESTROY_WILL_FREE_DATA) 334 info_ptr->free_me |= mask; 335 else if(freer == PNG_USER_WILL_FREE_DATA) 336 info_ptr->free_me &= ~mask; 337 else 338 png_warning(png_ptr, 339 "Unknown freer parameter in png_data_freer."); 340 } 341 #endif 342 343 void PNGAPI 344 png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask, 345 int num) 346 { 347 png_debug(1, "in png_free_data\n"); 348 if (png_ptr == NULL || info_ptr == NULL) 349 return; 350 351 #if defined(PNG_TEXT_SUPPORTED) 352 /* free text item num or (if num == -1) all text items */ 353 #ifdef PNG_FREE_ME_SUPPORTED 354 if ((mask & PNG_FREE_TEXT) & info_ptr->free_me) 355 #else 356 if (mask & PNG_FREE_TEXT) 357 #endif 358 { 359 if (num != -1) 360 { 361 if (info_ptr->text && info_ptr->text[num].key) 362 { 363 png_free(png_ptr, info_ptr->text[num].key); 364 info_ptr->text[num].key = NULL; 365 } 366 } 367 else 368 { 369 int i; 370 for (i = 0; i < info_ptr->num_text; i++) 371 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i); 372 png_free(png_ptr, info_ptr->text); 373 info_ptr->text = NULL; 374 info_ptr->num_text=0; 375 } 376 } 377 #endif 378 379 #if defined(PNG_tRNS_SUPPORTED) 380 /* free any tRNS entry */ 381 #ifdef PNG_FREE_ME_SUPPORTED 382 if ((mask & PNG_FREE_TRNS) & info_ptr->free_me) 383 #else 384 if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS)) 385 #endif 386 { 387 png_free(png_ptr, info_ptr->trans); 388 info_ptr->valid &= ~PNG_INFO_tRNS; 389 #ifndef PNG_FREE_ME_SUPPORTED 390 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS; 391 #endif 392 info_ptr->trans = NULL; 393 } 394 #endif 395 396 #if defined(PNG_sCAL_SUPPORTED) 397 /* free any sCAL entry */ 398 #ifdef PNG_FREE_ME_SUPPORTED 399 if ((mask & PNG_FREE_SCAL) & info_ptr->free_me) 400 #else 401 if (mask & PNG_FREE_SCAL) 402 #endif 403 { 404 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) 405 png_free(png_ptr, info_ptr->scal_s_width); 406 png_free(png_ptr, info_ptr->scal_s_height); 407 info_ptr->scal_s_width = NULL; 408 info_ptr->scal_s_height = NULL; 409 #endif 410 info_ptr->valid &= ~PNG_INFO_sCAL; 411 } 412 #endif 413 414 #if defined(PNG_pCAL_SUPPORTED) 415 /* free any pCAL entry */ 416 #ifdef PNG_FREE_ME_SUPPORTED 417 if ((mask & PNG_FREE_PCAL) & info_ptr->free_me) 418 #else 419 if (mask & PNG_FREE_PCAL) 420 #endif 421 { 422 png_free(png_ptr, info_ptr->pcal_purpose); 423 png_free(png_ptr, info_ptr->pcal_units); 424 info_ptr->pcal_purpose = NULL; 425 info_ptr->pcal_units = NULL; 426 if (info_ptr->pcal_params != NULL) 427 { 428 int i; 429 for (i = 0; i < (int)info_ptr->pcal_nparams; i++) 430 { 431 png_free(png_ptr, info_ptr->pcal_params[i]); 432 info_ptr->pcal_params[i]=NULL; 433 } 434 png_free(png_ptr, info_ptr->pcal_params); 435 info_ptr->pcal_params = NULL; 436 } 437 info_ptr->valid &= ~PNG_INFO_pCAL; 438 } 439 #endif 440 441 #if defined(PNG_iCCP_SUPPORTED) 442 /* free any iCCP entry */ 443 #ifdef PNG_FREE_ME_SUPPORTED 444 if ((mask & PNG_FREE_ICCP) & info_ptr->free_me) 445 #else 446 if (mask & PNG_FREE_ICCP) 447 #endif 448 { 449 png_free(png_ptr, info_ptr->iccp_name); 450 png_free(png_ptr, info_ptr->iccp_profile); 451 info_ptr->iccp_name = NULL; 452 info_ptr->iccp_profile = NULL; 453 info_ptr->valid &= ~PNG_INFO_iCCP; 454 } 455 #endif 456 457 #if defined(PNG_sPLT_SUPPORTED) 458 /* free a given sPLT entry, or (if num == -1) all sPLT entries */ 459 #ifdef PNG_FREE_ME_SUPPORTED 460 if ((mask & PNG_FREE_SPLT) & info_ptr->free_me) 461 #else 462 if (mask & PNG_FREE_SPLT) 463 #endif 464 { 465 if (num != -1) 466 { 467 if(info_ptr->splt_palettes) 468 { 469 png_free(png_ptr, info_ptr->splt_palettes[num].name); 470 png_free(png_ptr, info_ptr->splt_palettes[num].entries); 471 info_ptr->splt_palettes[num].name = NULL; 472 info_ptr->splt_palettes[num].entries = NULL; 473 } 474 } 475 else 476 { 477 if(info_ptr->splt_palettes_num) 478 { 479 int i; 480 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) 481 png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i); 482 483 png_free(png_ptr, info_ptr->splt_palettes); 484 info_ptr->splt_palettes = NULL; 485 info_ptr->splt_palettes_num = 0; 486 } 487 info_ptr->valid &= ~PNG_INFO_sPLT; 488 } 489 } 490 #endif 491 492 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) 493 if(png_ptr->unknown_chunk.data) 494 { 495 png_free(png_ptr, png_ptr->unknown_chunk.data); 496 png_ptr->unknown_chunk.data = NULL; 497 } 498 #ifdef PNG_FREE_ME_SUPPORTED 499 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me) 500 #else 501 if (mask & PNG_FREE_UNKN) 502 #endif 503 { 504 if (num != -1) 505 { 506 if(info_ptr->unknown_chunks) 507 { 508 png_free(png_ptr, info_ptr->unknown_chunks[num].data); 509 info_ptr->unknown_chunks[num].data = NULL; 510 } 511 } 512 else 513 { 514 int i; 515 516 if(info_ptr->unknown_chunks_num) 517 { 518 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++) 519 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i); 520 521 png_free(png_ptr, info_ptr->unknown_chunks); 522 info_ptr->unknown_chunks = NULL; 523 info_ptr->unknown_chunks_num = 0; 524 } 525 } 526 } 527 #endif 528 529 #if defined(PNG_hIST_SUPPORTED) 530 /* free any hIST entry */ 531 #ifdef PNG_FREE_ME_SUPPORTED 532 if ((mask & PNG_FREE_HIST) & info_ptr->free_me) 533 #else 534 if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST)) 535 #endif 536 { 537 png_free(png_ptr, info_ptr->hist); 538 info_ptr->hist = NULL; 539 info_ptr->valid &= ~PNG_INFO_hIST; 540 #ifndef PNG_FREE_ME_SUPPORTED 541 png_ptr->flags &= ~PNG_FLAG_FREE_HIST; 542 #endif 543 } 544 #endif 545 546 /* free any PLTE entry that was internally allocated */ 547 #ifdef PNG_FREE_ME_SUPPORTED 548 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me) 549 #else 550 if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE)) 551 #endif 552 { 553 png_zfree(png_ptr, info_ptr->palette); 554 info_ptr->palette = NULL; 555 info_ptr->valid &= ~PNG_INFO_PLTE; 556 #ifndef PNG_FREE_ME_SUPPORTED 557 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE; 558 #endif 559 info_ptr->num_palette = 0; 560 } 561 562 #if defined(PNG_INFO_IMAGE_SUPPORTED) 563 /* free any image bits attached to the info structure */ 564 #ifdef PNG_FREE_ME_SUPPORTED 565 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me) 566 #else 567 if (mask & PNG_FREE_ROWS) 568 #endif 569 { 570 if(info_ptr->row_pointers) 571 { 572 int row; 573 for (row = 0; row < (int)info_ptr->height; row++) 574 { 575 png_free(png_ptr, info_ptr->row_pointers[row]); 576 info_ptr->row_pointers[row]=NULL; 577 } 578 png_free(png_ptr, info_ptr->row_pointers); 579 info_ptr->row_pointers=NULL; 580 } 581 info_ptr->valid &= ~PNG_INFO_IDAT; 582 } 583 #endif 584 585 #ifdef PNG_FREE_ME_SUPPORTED 586 if(num == -1) 587 info_ptr->free_me &= ~mask; 588 else 589 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL); 590 #endif 591 } 592 593 /* This is an internal routine to free any memory that the info struct is 594 * pointing to before re-using it or freeing the struct itself. Recall 595 * that png_free() checks for NULL pointers for us. 596 */ 597 void /* PRIVATE */ 598 png_info_destroy(png_structp png_ptr, png_infop info_ptr) 599 { 600 png_debug(1, "in png_info_destroy\n"); 601 602 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); 603 604 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) 605 if (png_ptr->num_chunk_list) 606 { 607 png_free(png_ptr, png_ptr->chunk_list); 608 png_ptr->chunk_list=NULL; 609 png_ptr->num_chunk_list=0; 610 } 611 #endif 612 613 png_info_init_3(&info_ptr, png_sizeof(png_info)); 614 } 615 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ 616 617 /* This function returns a pointer to the io_ptr associated with the user 618 * functions. The application should free any memory associated with this 619 * pointer before png_write_destroy() or png_read_destroy() are called. 620 */ 621 png_voidp PNGAPI 622 png_get_io_ptr(png_structp png_ptr) 623 { 624 if(png_ptr == NULL) return (NULL); 625 return (png_ptr->io_ptr); 626 } 627 628 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) 629 #if !defined(PNG_NO_STDIO) 630 /* Initialize the default input/output functions for the PNG file. If you 631 * use your own read or write routines, you can call either png_set_read_fn() 632 * or png_set_write_fn() instead of png_init_io(). If you have defined 633 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't 634 * necessarily available. 635 */ 636 void PNGAPI 637 png_init_io(png_structp png_ptr, png_FILE_p fp) 638 { 639 png_debug(1, "in png_init_io\n"); 640 if(png_ptr == NULL) return; 641 png_ptr->io_ptr = (png_voidp)fp; 642 } 643 #endif 644 645 #if defined(PNG_TIME_RFC1123_SUPPORTED) 646 /* Convert the supplied time into an RFC 1123 string suitable for use in 647 * a "Creation Time" or other text-based time string. 648 */ 649 png_charp PNGAPI 650 png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime) 651 { 652 static PNG_CONST char short_months[12][4] = 653 {"Jan", "Feb", "Mar", "Apr", "May", "Jun", 654 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; 655 656 if(png_ptr == NULL) return (NULL); 657 if (png_ptr->time_buffer == NULL) 658 { 659 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29* 660 png_sizeof(char))); 661 } 662 663 #if defined(_WIN32_WCE) 664 { 665 wchar_t time_buf[29]; 666 wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"), 667 ptime->day % 32, short_months[(ptime->month - 1) % 12], 668 ptime->year, ptime->hour % 24, ptime->minute % 60, 669 ptime->second % 61); 670 WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29, 671 NULL, NULL); 672 } 673 #else 674 #ifdef USE_FAR_KEYWORD 675 { 676 char near_time_buf[29]; 677 png_snprintf6(near_time_buf,29,"%d %s %d %02d:%02d:%02d +0000", 678 ptime->day % 32, short_months[(ptime->month - 1) % 12], 679 ptime->year, ptime->hour % 24, ptime->minute % 60, 680 ptime->second % 61); 681 png_memcpy(png_ptr->time_buffer, near_time_buf, 682 29*png_sizeof(char)); 683 } 684 #else 685 png_snprintf6(png_ptr->time_buffer,29,"%d %s %d %02d:%02d:%02d +0000", 686 ptime->day % 32, short_months[(ptime->month - 1) % 12], 687 ptime->year, ptime->hour % 24, ptime->minute % 60, 688 ptime->second % 61); 689 #endif 690 #endif /* _WIN32_WCE */ 691 return ((png_charp)png_ptr->time_buffer); 692 } 693 #endif /* PNG_TIME_RFC1123_SUPPORTED */ 694 695 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ 696 697 png_charp PNGAPI 698 png_get_copyright(png_structp png_ptr) 699 { 700 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */ 701 return ((png_charp) "\n libpng version 1.2.19 - August 18, 2007\n\ 702 Copyright (c) 1998-2007 Glenn Randers-Pehrson\n\ 703 Copyright (c) 1996-1997 Andreas Dilger\n\ 704 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n"); 705 } 706 707 /* The following return the library version as a short string in the 708 * format 1.0.0 through 99.99.99zz. To get the version of *.h files 709 * used with your application, print out PNG_LIBPNG_VER_STRING, which 710 * is defined in png.h. 711 * Note: now there is no difference between png_get_libpng_ver() and 712 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, 713 * it is guaranteed that png.c uses the correct version of png.h. 714 */ 715 png_charp PNGAPI 716 png_get_libpng_ver(png_structp png_ptr) 717 { 718 /* Version of *.c files used when building libpng */ 719 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */ 720 return ((png_charp) PNG_LIBPNG_VER_STRING); 721 } 722 723 png_charp PNGAPI 724 png_get_header_ver(png_structp png_ptr) 725 { 726 /* Version of *.h files used when building libpng */ 727 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */ 728 return ((png_charp) PNG_LIBPNG_VER_STRING); 729 } 730 731 png_charp PNGAPI 732 png_get_header_version(png_structp png_ptr) 733 { 734 /* Returns longer string containing both version and date */ 735 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */ 736 return ((png_charp) PNG_HEADER_VERSION_STRING 737 #ifdef PNG_READ_SUPPORTED 738 # ifdef PNG_USE_PNGGCCRD 739 # ifdef __x86_64__ 740 # ifdef __PIC__ 741 " (PNGGCRD x86_64, PIC)\n" 742 # else 743 # ifdef PNG_THREAD_UNSAFE_OK 744 " (PNGGCRD x86_64, Thread unsafe)\n" 745 # else 746 " (PNGGCRD x86_64, Thread safe)\n" 747 # endif 748 # endif 749 # else 750 # ifdef PNG_THREAD_UNSAFE_OK 751 " (PNGGCRD, Thread unsafe)\n" 752 # else 753 " (PNGGCRD, Thread safe)\n" 754 # endif 755 # endif 756 # else 757 # ifdef PNG_USE_PNGVCRD 758 # ifdef __x86_64__ 759 " (x86_64 PNGVCRD)\n" 760 # else 761 " (PNGVCRD)\n" 762 # endif 763 # else 764 # ifdef __x86_64__ 765 # ifdef PNG_OPTIMIZED_CODE_SUPPORTED 766 " (x86_64 OPTIMIZED)\n" 767 # else 768 " (x86_64 NOT OPTIMIZED)\n" 769 # endif 770 # else 771 # ifdef PNG_OPTIMIZED_CODE_SUPPORTED 772 " (OPTIMIZED)\n" 773 # else 774 " (NOT OPTIMIZED)\n" 775 # endif 776 # endif 777 # endif 778 # endif 779 #else 780 " (NO READ SUPPORT)\n" 781 #endif 782 ); 783 } 784 785 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) 786 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 787 int PNGAPI 788 png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name) 789 { 790 /* check chunk_name and return "keep" value if it's on the list, else 0 */ 791 int i; 792 png_bytep p; 793 if(png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0) 794 return 0; 795 p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5; 796 for (i = png_ptr->num_chunk_list; i; i--, p-=5) 797 if (!png_memcmp(chunk_name, p, 4)) 798 return ((int)*(p+4)); 799 return 0; 800 } 801 #endif 802 803 /* This function, added to libpng-1.0.6g, is untested. */ 804 int PNGAPI 805 png_reset_zstream(png_structp png_ptr) 806 { 807 if (png_ptr == NULL) return Z_STREAM_ERROR; 808 return (inflateReset(&png_ptr->zstream)); 809 } 810 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ 811 812 /* This function was added to libpng-1.0.7 */ 813 png_uint_32 PNGAPI 814 png_access_version_number(void) 815 { 816 /* Version of *.c files used when building libpng */ 817 return((png_uint_32) PNG_LIBPNG_VER); 818 } 819 820 821 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) 822 #if !defined(PNG_1_0_X) 823 #if defined(PNG_MMX_CODE_SUPPORTED) 824 /* this INTERNAL function was added to libpng 1.2.0 */ 825 void /* PRIVATE */ 826 png_init_mmx_flags (png_structp png_ptr) 827 { 828 if(png_ptr == NULL) return; 829 png_ptr->mmx_rowbytes_threshold = 0; 830 png_ptr->mmx_bitdepth_threshold = 0; 831 832 # if (defined(PNG_USE_PNGVCRD) || defined(PNG_USE_PNGGCCRD)) 833 834 png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_COMPILED; 835 836 if (png_mmx_support() > 0) { 837 png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 838 # ifdef PNG_HAVE_MMX_COMBINE_ROW 839 | PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 840 # endif 841 # ifdef PNG_HAVE_MMX_READ_INTERLACE 842 | PNG_ASM_FLAG_MMX_READ_INTERLACE 843 # endif 844 # ifndef PNG_HAVE_MMX_READ_FILTER_ROW 845 ; 846 # else 847 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB 848 | PNG_ASM_FLAG_MMX_READ_FILTER_UP 849 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG 850 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ; 851 852 png_ptr->mmx_rowbytes_threshold = PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT; 853 png_ptr->mmx_bitdepth_threshold = PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT; 854 # endif 855 } else { 856 png_ptr->asm_flags &= ~( PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 857 | PNG_MMX_READ_FLAGS 858 | PNG_MMX_WRITE_FLAGS ); 859 } 860 861 # else /* !(PNGVCRD || PNGGCCRD) */ 862 863 /* clear all MMX flags; no support is compiled in */ 864 png_ptr->asm_flags &= ~( PNG_MMX_FLAGS ); 865 866 # endif /* ?(PNGVCRD || PNGGCCRD) */ 867 } 868 869 #endif /* !(PNG_MMX_CODE_SUPPORTED) */ 870 871 /* this function was added to libpng 1.2.0 */ 872 #if !defined(PNG_USE_PNGGCCRD) && \ 873 !(defined(PNG_MMX_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD)) 874 int PNGAPI 875 png_mmx_support(void) 876 { 877 return -1; 878 } 879 #endif 880 #endif /* PNG_1_0_X */ 881 #endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */ 882 883 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) 884 #ifdef PNG_SIZE_T 885 /* Added at libpng version 1.2.6 */ 886 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size)); 887 png_size_t PNGAPI 888 png_convert_size(size_t size) 889 { 890 if (size > (png_size_t)-1) 891 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */ 892 return ((png_size_t)size); 893 } 894 #endif /* PNG_SIZE_T */ 895 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ 896
