png.c
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上传日期:2015-04-09
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- /* png.c - location for general purpose libpng functions
- *
- * Last changed in libpng 1.2.9 April 14, 2006
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2006 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.)
- */
- #define PNG_INTERNAL
- #define PNG_NO_EXTERN
- #include "png.h"
- /* Generate a compiler error if there is an old png.h in the search path. */
- typedef version_1_2_10 Your_png_h_is_not_version_1_2_10;
- /* Version information for C files. This had better match the version
- * string defined in png.h. */
- #ifdef PNG_USE_GLOBAL_ARRAYS
- /* png_libpng_ver was changed to a function in version 1.0.5c */
- const char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
- #ifdef PNG_READ_SUPPORTED
- /* png_sig was changed to a function in version 1.0.5c */
- /* Place to hold the signature string for a PNG file. */
- const png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
- #endif /* PNG_READ_SUPPORTED */
- /* Invoke global declarations for constant strings for known chunk types */
- PNG_IHDR;
- PNG_IDAT;
- PNG_IEND;
- PNG_PLTE;
- PNG_bKGD;
- PNG_cHRM;
- PNG_gAMA;
- PNG_hIST;
- PNG_iCCP;
- PNG_iTXt;
- PNG_oFFs;
- PNG_pCAL;
- PNG_sCAL;
- PNG_pHYs;
- PNG_sBIT;
- PNG_sPLT;
- PNG_sRGB;
- PNG_tEXt;
- PNG_tIME;
- PNG_tRNS;
- PNG_zTXt;
- #ifdef PNG_READ_SUPPORTED
- /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
- /* start of interlace block */
- const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
- /* offset to next interlace block */
- const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
- /* start of interlace block in the y direction */
- const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
- /* offset to next interlace block in the y direction */
- const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
- /* width of interlace block (used in assembler routines only) */
- #ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
- const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
- #endif
- /* Height of interlace block. This is not currently used - if you need
- * it, uncomment it here and in png.h
- const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
- */
- /* Mask to determine which pixels are valid in a pass */
- const int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
- /* Mask to determine which pixels to overwrite while displaying */
- const int FARDATA png_pass_dsp_mask[]
- = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
- #endif /* PNG_READ_SUPPORTED */
- #endif /* PNG_USE_GLOBAL_ARRAYS */
- /* Tells libpng that we have already handled the first "num_bytes" bytes
- * of the PNG file signature. If the PNG data is embedded into another
- * stream we can set num_bytes = 8 so that libpng will not attempt to read
- * or write any of the magic bytes before it starts on the IHDR.
- */
- #ifdef PNG_READ_SUPPORTED
- void PNGAPI
- png_set_sig_bytes(png_structp png_ptr, int num_bytes)
- {
- png_debug(1, "in png_set_sig_bytesn");
- if (num_bytes > 8)
- png_error(png_ptr, "Too many bytes for PNG signature.");
- png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
- }
- /* Checks whether the supplied bytes match the PNG signature. We allow
- * checking less than the full 8-byte signature so that those apps that
- * already read the first few bytes of a file to determine the file type
- * can simply check the remaining bytes for extra assurance. Returns
- * an integer less than, equal to, or greater than zero if sig is found,
- * respectively, to be less than, to match, or be greater than the correct
- * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
- */
- int PNGAPI
- png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
- {
- png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
- if (num_to_check > 8)
- num_to_check = 8;
- else if (num_to_check < 1)
- return (-1);
- if (start > 7)
- return (-1);
- if (start + num_to_check > 8)
- num_to_check = 8 - start;
- return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
- }
- #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
- /* (Obsolete) function to check signature bytes. It does not allow one
- * to check a partial signature. This function might be removed in the
- * future - use png_sig_cmp(). Returns true (nonzero) if the file is a PNG.
- */
- int PNGAPI
- png_check_sig(png_bytep sig, int num)
- {
- return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
- }
- #endif
- #endif /* PNG_READ_SUPPORTED */
- #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
- /* Function to allocate memory for zlib and clear it to 0. */
- #ifdef PNG_1_0_X
- voidpf PNGAPI
- #else
- voidpf /* private */
- #endif
- png_zalloc(voidpf png_ptr, uInt items, uInt size)
- {
- png_voidp ptr;
- png_structp p=png_ptr;
- png_uint_32 save_flags=p->flags;
- png_uint_32 num_bytes;
- if (items > PNG_UINT_32_MAX/size)
- {
- png_warning (png_ptr, "Potential overflow in png_zalloc()");
- return (NULL);
- }
- num_bytes = (png_uint_32)items * size;
- p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
- ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
- p->flags=save_flags;
- #if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
- if (ptr == NULL)
- return ((voidpf)ptr);
- if (num_bytes > (png_uint_32)0x8000L)
- {
- png_memset(ptr, 0, (png_size_t)0x8000L);
- png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
- (png_size_t)(num_bytes - (png_uint_32)0x8000L));
- }
- else
- {
- png_memset(ptr, 0, (png_size_t)num_bytes);
- }
- #endif
- return ((voidpf)ptr);
- }
- /* function to free memory for zlib */
- #ifdef PNG_1_0_X
- void PNGAPI
- #else
- void /* private */
- #endif
- png_zfree(voidpf png_ptr, voidpf ptr)
- {
- png_free((png_structp)png_ptr, (png_voidp)ptr);
- }
- /* Reset the CRC variable to 32 bits of 1's. Care must be taken
- * in case CRC is > 32 bits to leave the top bits 0.
- */
- void /* PRIVATE */
- png_reset_crc(png_structp png_ptr)
- {
- png_ptr->crc = crc32(0, Z_NULL, 0);
- }
- /* Calculate the CRC over a section of data. We can only pass as
- * much data to this routine as the largest single buffer size. We
- * also check that this data will actually be used before going to the
- * trouble of calculating it.
- */
- void /* PRIVATE */
- png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
- {
- int need_crc = 1;
- if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
- {
- if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
- (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
- need_crc = 0;
- }
- else /* critical */
- {
- if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
- need_crc = 0;
- }
- if (need_crc)
- png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
- }
- /* Allocate the memory for an info_struct for the application. We don't
- * really need the png_ptr, but it could potentially be useful in the
- * future. This should be used in favour of malloc(png_sizeof(png_info))
- * and png_info_init() so that applications that want to use a shared
- * libpng don't have to be recompiled if png_info changes size.
- */
- png_infop PNGAPI
- png_create_info_struct(png_structp png_ptr)
- {
- png_infop info_ptr;
- png_debug(1, "in png_create_info_structn");
- if(png_ptr == NULL) return (NULL);
- #ifdef PNG_USER_MEM_SUPPORTED
- info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
- png_ptr->malloc_fn, png_ptr->mem_ptr);
- #else
- info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
- #endif
- if (info_ptr != NULL)
- png_info_init_3(&info_ptr, png_sizeof(png_info));
- return (info_ptr);
- }
- /* This function frees the memory associated with a single info struct.
- * Normally, one would use either png_destroy_read_struct() or
- * png_destroy_write_struct() to free an info struct, but this may be
- * useful for some applications.
- */
- void PNGAPI
- png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
- {
- png_infop info_ptr = NULL;
- png_debug(1, "in png_destroy_info_structn");
- if (info_ptr_ptr != NULL)
- info_ptr = *info_ptr_ptr;
- if (info_ptr != NULL)
- {
- png_info_destroy(png_ptr, info_ptr);
- #ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
- png_ptr->mem_ptr);
- #else
- png_destroy_struct((png_voidp)info_ptr);
- #endif
- *info_ptr_ptr = NULL;
- }
- }
- /* Initialize the info structure. This is now an internal function (0.89)
- * and applications using it are urged to use png_create_info_struct()
- * instead.
- */
- #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
- #undef png_info_init
- void PNGAPI
- png_info_init(png_infop info_ptr)
- {
- /* We only come here via pre-1.0.12-compiled applications */
- png_info_init_3(&info_ptr, 0);
- }
- #endif
- void PNGAPI
- png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
- {
- png_infop info_ptr = *ptr_ptr;
- png_debug(1, "in png_info_init_3n");
- if(png_sizeof(png_info) > png_info_struct_size)
- {
- png_destroy_struct(info_ptr);
- info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
- *ptr_ptr = info_ptr;
- }
- /* set everything to 0 */
- png_memset(info_ptr, 0, png_sizeof (png_info));
- }
- #ifdef PNG_FREE_ME_SUPPORTED
- void PNGAPI
- png_data_freer(png_structp png_ptr, png_infop info_ptr,
- int freer, png_uint_32 mask)
- {
- png_debug(1, "in png_data_freern");
- if (png_ptr == NULL || info_ptr == NULL)
- return;
- if(freer == PNG_DESTROY_WILL_FREE_DATA)
- info_ptr->free_me |= mask;
- else if(freer == PNG_USER_WILL_FREE_DATA)
- info_ptr->free_me &= ~mask;
- else
- png_warning(png_ptr,
- "Unknown freer parameter in png_data_freer.");
- }
- #endif
- void PNGAPI
- png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
- int num)
- {
- png_debug(1, "in png_free_datan");
- if (png_ptr == NULL || info_ptr == NULL)
- return;
- #if defined(PNG_TEXT_SUPPORTED)
- /* free text item num or (if num == -1) all text items */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_TEXT)
- #endif
- {
- if (num != -1)
- {
- if (info_ptr->text && info_ptr->text[num].key)
- {
- png_free(png_ptr, info_ptr->text[num].key);
- info_ptr->text[num].key = NULL;
- }
- }
- else
- {
- int i;
- for (i = 0; i < info_ptr->num_text; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
- png_free(png_ptr, info_ptr->text);
- info_ptr->text = NULL;
- info_ptr->num_text=0;
- }
- }
- #endif
- #if defined(PNG_tRNS_SUPPORTED)
- /* free any tRNS entry */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
- #else
- if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
- #endif
- {
- png_free(png_ptr, info_ptr->trans);
- info_ptr->valid &= ~PNG_INFO_tRNS;
- #ifndef PNG_FREE_ME_SUPPORTED
- png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
- #endif
- info_ptr->trans = NULL;
- }
- #endif
- #if defined(PNG_sCAL_SUPPORTED)
- /* free any sCAL entry */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_SCAL)
- #endif
- {
- #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
- png_free(png_ptr, info_ptr->scal_s_width);
- png_free(png_ptr, info_ptr->scal_s_height);
- info_ptr->scal_s_width = NULL;
- info_ptr->scal_s_height = NULL;
- #endif
- info_ptr->valid &= ~PNG_INFO_sCAL;
- }
- #endif
- #if defined(PNG_pCAL_SUPPORTED)
- /* free any pCAL entry */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_PCAL)
- #endif
- {
- png_free(png_ptr, info_ptr->pcal_purpose);
- png_free(png_ptr, info_ptr->pcal_units);
- info_ptr->pcal_purpose = NULL;
- info_ptr->pcal_units = NULL;
- if (info_ptr->pcal_params != NULL)
- {
- int i;
- for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
- {
- png_free(png_ptr, info_ptr->pcal_params[i]);
- info_ptr->pcal_params[i]=NULL;
- }
- png_free(png_ptr, info_ptr->pcal_params);
- info_ptr->pcal_params = NULL;
- }
- info_ptr->valid &= ~PNG_INFO_pCAL;
- }
- #endif
- #if defined(PNG_iCCP_SUPPORTED)
- /* free any iCCP entry */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_ICCP)
- #endif
- {
- png_free(png_ptr, info_ptr->iccp_name);
- png_free(png_ptr, info_ptr->iccp_profile);
- info_ptr->iccp_name = NULL;
- info_ptr->iccp_profile = NULL;
- info_ptr->valid &= ~PNG_INFO_iCCP;
- }
- #endif
- #if defined(PNG_sPLT_SUPPORTED)
- /* free a given sPLT entry, or (if num == -1) all sPLT entries */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_SPLT)
- #endif
- {
- if (num != -1)
- {
- if(info_ptr->splt_palettes)
- {
- png_free(png_ptr, info_ptr->splt_palettes[num].name);
- png_free(png_ptr, info_ptr->splt_palettes[num].entries);
- info_ptr->splt_palettes[num].name = NULL;
- info_ptr->splt_palettes[num].entries = NULL;
- }
- }
- else
- {
- if(info_ptr->splt_palettes_num)
- {
- int i;
- for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
- png_free(png_ptr, info_ptr->splt_palettes);
- info_ptr->splt_palettes = NULL;
- info_ptr->splt_palettes_num = 0;
- }
- info_ptr->valid &= ~PNG_INFO_sPLT;
- }
- }
- #endif
- #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_UNKN)
- #endif
- {
- if (num != -1)
- {
- if(info_ptr->unknown_chunks)
- {
- png_free(png_ptr, info_ptr->unknown_chunks[num].data);
- info_ptr->unknown_chunks[num].data = NULL;
- }
- }
- else
- {
- int i;
- if(info_ptr->unknown_chunks_num)
- {
- for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
- png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
- png_free(png_ptr, info_ptr->unknown_chunks);
- info_ptr->unknown_chunks = NULL;
- info_ptr->unknown_chunks_num = 0;
- }
- }
- }
- #endif
- #if defined(PNG_hIST_SUPPORTED)
- /* free any hIST entry */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
- #else
- if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
- #endif
- {
- png_free(png_ptr, info_ptr->hist);
- info_ptr->hist = NULL;
- info_ptr->valid &= ~PNG_INFO_hIST;
- #ifndef PNG_FREE_ME_SUPPORTED
- png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
- #endif
- }
- #endif
- /* free any PLTE entry that was internally allocated */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
- #else
- if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
- #endif
- {
- png_zfree(png_ptr, info_ptr->palette);
- info_ptr->palette = NULL;
- info_ptr->valid &= ~PNG_INFO_PLTE;
- #ifndef PNG_FREE_ME_SUPPORTED
- png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
- #endif
- info_ptr->num_palette = 0;
- }
- #if defined(PNG_INFO_IMAGE_SUPPORTED)
- /* free any image bits attached to the info structure */
- #ifdef PNG_FREE_ME_SUPPORTED
- if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
- #else
- if (mask & PNG_FREE_ROWS)
- #endif
- {
- if(info_ptr->row_pointers)
- {
- int row;
- for (row = 0; row < (int)info_ptr->height; row++)
- {
- png_free(png_ptr, info_ptr->row_pointers[row]);
- info_ptr->row_pointers[row]=NULL;
- }
- png_free(png_ptr, info_ptr->row_pointers);
- info_ptr->row_pointers=NULL;
- }
- info_ptr->valid &= ~PNG_INFO_IDAT;
- }
- #endif
- #ifdef PNG_FREE_ME_SUPPORTED
- if(num == -1)
- info_ptr->free_me &= ~mask;
- else
- info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
- #endif
- }
- /* This is an internal routine to free any memory that the info struct is
- * pointing to before re-using it or freeing the struct itself. Recall
- * that png_free() checks for NULL pointers for us.
- */
- void /* PRIVATE */
- png_info_destroy(png_structp png_ptr, png_infop info_ptr)
- {
- png_debug(1, "in png_info_destroyn");
- png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
- #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
- if (png_ptr->num_chunk_list)
- {
- png_free(png_ptr, png_ptr->chunk_list);
- png_ptr->chunk_list=NULL;
- png_ptr->num_chunk_list=0;
- }
- #endif
- png_info_init_3(&info_ptr, png_sizeof(png_info));
- }
- #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
- /* This function returns a pointer to the io_ptr associated with the user
- * functions. The application should free any memory associated with this
- * pointer before png_write_destroy() or png_read_destroy() are called.
- */
- png_voidp PNGAPI
- png_get_io_ptr(png_structp png_ptr)
- {
- return (png_ptr->io_ptr);
- }
- #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
- #if !defined(PNG_NO_STDIO)
- /* Initialize the default input/output functions for the PNG file. If you
- * use your own read or write routines, you can call either png_set_read_fn()
- * or png_set_write_fn() instead of png_init_io(). If you have defined
- * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
- * necessarily available.
- */
- void PNGAPI
- png_init_io(png_structp png_ptr, png_FILE_p fp)
- {
- png_debug(1, "in png_init_ion");
- png_ptr->io_ptr = (png_voidp)fp;
- }
- #endif
- #if defined(PNG_TIME_RFC1123_SUPPORTED)
- /* Convert the supplied time into an RFC 1123 string suitable for use in
- * a "Creation Time" or other text-based time string.
- */
- png_charp PNGAPI
- png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
- {
- static PNG_CONST char short_months[12][4] =
- {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
- "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
- if (png_ptr->time_buffer == NULL)
- {
- png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
- png_sizeof(char)));
- }
- #if defined(_WIN32_WCE)
- {
- wchar_t time_buf[29];
- wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
- ptime->day % 32, short_months[(ptime->month - 1) % 12],
- ptime->year, ptime->hour % 24, ptime->minute % 60,
- ptime->second % 61);
- WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
- NULL, NULL);
- }
- #else
- #ifdef USE_FAR_KEYWORD
- {
- char near_time_buf[29];
- sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
- ptime->day % 32, short_months[(ptime->month - 1) % 12],
- ptime->year, ptime->hour % 24, ptime->minute % 60,
- ptime->second % 61);
- png_memcpy(png_ptr->time_buffer, near_time_buf,
- 29*png_sizeof(char));
- }
- #else
- sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
- ptime->day % 32, short_months[(ptime->month - 1) % 12],
- ptime->year, ptime->hour % 24, ptime->minute % 60,
- ptime->second % 61);
- #endif
- #endif /* _WIN32_WCE */
- return ((png_charp)png_ptr->time_buffer);
- }
- #endif /* PNG_TIME_RFC1123_SUPPORTED */
- #if 0
- /* Signature string for a PNG file. */
- png_bytep PNGAPI
- png_sig_bytes(void)
- {
- return ((png_bytep)"211120116107 15 12 32 12");
- }
- #endif
- #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
- png_charp PNGAPI
- png_get_copyright(png_structp png_ptr)
- {
- if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
- return ((png_charp) "n libpng version 1.2.10 - April 23, 2006n
- Copyright (c) 1998-2006 Glenn Randers-Pehrsonn
- Copyright (c) 1996-1997 Andreas Dilgern
- Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.n");
- return ((png_charp) "");
- }
- /* The following return the library version as a short string in the
- * format 1.0.0 through 99.99.99zz. To get the version of *.h files
- * used with your application, print out PNG_LIBPNG_VER_STRING, which
- * is defined in png.h.
- * Note: now there is no difference between png_get_libpng_ver() and
- * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
- * it is guaranteed that png.c uses the correct version of png.h.
- */
- png_charp PNGAPI
- png_get_libpng_ver(png_structp png_ptr)
- {
- /* Version of *.c files used when building libpng */
- if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
- return ((png_charp) PNG_LIBPNG_VER_STRING);
- return ((png_charp) "");
- }
- png_charp PNGAPI
- png_get_header_ver(png_structp png_ptr)
- {
- /* Version of *.h files used when building libpng */
- if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
- return ((png_charp) PNG_LIBPNG_VER_STRING);
- return ((png_charp) "");
- }
- png_charp PNGAPI
- png_get_header_version(png_structp png_ptr)
- {
- /* Returns longer string containing both version and date */
- if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
- return ((png_charp) PNG_HEADER_VERSION_STRING);
- return ((png_charp) "");
- }
- #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
- #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
- int PNGAPI
- png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
- {
- /* check chunk_name and return "keep" value if it's on the list, else 0 */
- int i;
- png_bytep p;
- if((png_ptr == NULL && chunk_name == NULL) || png_ptr->num_chunk_list<=0)
- return 0;
- p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
- for (i = png_ptr->num_chunk_list; i; i--, p-=5)
- if (!png_memcmp(chunk_name, p, 4))
- return ((int)*(p+4));
- return 0;
- }
- #endif
- /* This function, added to libpng-1.0.6g, is untested. */
- int PNGAPI
- png_reset_zstream(png_structp png_ptr)
- {
- return (inflateReset(&png_ptr->zstream));
- }
- #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
- /* This function was added to libpng-1.0.7 */
- png_uint_32 PNGAPI
- png_access_version_number(void)
- {
- /* Version of *.c files used when building libpng */
- return((png_uint_32) PNG_LIBPNG_VER);
- }
- #if defined(PNG_READ_SUPPORTED)
- #if !defined(PNG_1_0_X)
- #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
- /* GRR: could add this: && defined(PNG_MMX_CODE_SUPPORTED) */
- /* this INTERNAL function was added to libpng 1.2.0 */
- void /* PRIVATE */
- png_init_mmx_flags (png_structp png_ptr)
- {
- png_ptr->mmx_rowbytes_threshold = 0;
- png_ptr->mmx_bitdepth_threshold = 0;
- # if (defined(PNG_USE_PNGVCRD) || defined(PNG_USE_PNGGCCRD))
- png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_COMPILED;
- if (png_mmx_support() > 0) {
- png_ptr->asm_flags |= PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
- # ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
- | PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
- # endif
- # ifdef PNG_HAVE_ASSEMBLER_READ_INTERLACE
- | PNG_ASM_FLAG_MMX_READ_INTERLACE
- # endif
- # ifndef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
- ;
- # else
- | PNG_ASM_FLAG_MMX_READ_FILTER_SUB
- | PNG_ASM_FLAG_MMX_READ_FILTER_UP
- | PNG_ASM_FLAG_MMX_READ_FILTER_AVG
- | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
- png_ptr->mmx_rowbytes_threshold = PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT;
- png_ptr->mmx_bitdepth_threshold = PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT;
- # endif
- } else {
- png_ptr->asm_flags &= ~( PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
- | PNG_MMX_READ_FLAGS
- | PNG_MMX_WRITE_FLAGS );
- }
- # else /* !((PNGVCRD || PNGGCCRD) && PNG_ASSEMBLER_CODE_SUPPORTED)) */
- /* clear all MMX flags; no support is compiled in */
- png_ptr->asm_flags &= ~( PNG_MMX_FLAGS );
- # endif /* ?(PNGVCRD || PNGGCCRD) */
- }
- #endif /* !(PNG_ASSEMBLER_CODE_SUPPORTED) */
- /* this function was added to libpng 1.2.0 */
- #if !defined(PNG_USE_PNGGCCRD) &&
- !(defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD))
- int PNGAPI
- png_mmx_support(void)
- {
- return -1;
- }
- #endif
- #endif /* PNG_1_0_X */
- #endif /* PNG_READ_SUPPORTED */
- #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
- #ifdef PNG_SIZE_T
- /* Added at libpng version 1.2.6 */
- PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
- png_size_t PNGAPI
- png_convert_size(size_t size)
- {
- if (size > (png_size_t)-1)
- PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
- return ((png_size_t)size);
- }
- #endif /* PNG_SIZE_T */
- #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */