summaryrefslogtreecommitdiffstats
path: root/libpng/png.c
diff options
context:
space:
mode:
Diffstat (limited to 'libpng/png.c')
-rw-r--r--libpng/png.c777
1 files changed, 777 insertions, 0 deletions
diff --git a/libpng/png.c b/libpng/png.c
new file mode 100644
index 0000000..72bd00e
--- /dev/null
+++ b/libpng/png.c
@@ -0,0 +1,777 @@
+
+/* png.c - location for general purpose libpng functions
+ *
+ * libpng version 1.2.1 - December 12, 2001
+ * Copyright (c) 1998-2001 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_1 Your_png_h_is_not_version_1_2_1;
+
+/* 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] = "1.2.1";
+
+/* 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};
+
+/* 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;
+
+/* 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
+
+/* 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.
+ */
+
+void PNGAPI
+png_set_sig_bytes(png_structp png_ptr, int num_bytes)
+{
+ png_debug(1, "in png_set_sig_bytes\n");
+ 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 (0);
+
+ if (start > 7)
+ return (0);
+
+ if (start + num_to_check > 8)
+ num_to_check = 8 - start;
+
+ return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+/* (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));
+}
+
+/* Function to allocate memory for zlib and clear it to 0. */
+voidpf /* PRIVATE */
+png_zalloc(voidpf png_ptr, uInt items, uInt size)
+{
+ png_uint_32 num_bytes = (png_uint_32)items * size;
+ png_voidp ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
+
+#ifndef PNG_NO_ZALLOC_ZERO
+ 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 */
+void /* PRIVATE */
+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(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_struct\n");
+ 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, 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_struct\n");
+ 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.
+ */
+#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);
+}
+
+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_3\n");
+
+ if(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, 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_freer\n");
+ 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_data\n");
+ 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;
+ 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;
+}
+#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;
+ 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_destroy\n");
+
+ 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, sizeof(png_info));
+}
+
+/* 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_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_io\n");
+ 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*
+ 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*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)"\211\120\116\107\015\012\032\012");
+}
+#endif
+
+png_charp PNGAPI
+png_get_copyright(png_structp png_ptr)
+{
+ if (png_ptr != NULL || png_ptr == NULL) /* silence compiler warning */
+ return ((png_charp) "\n libpng version 1.2.1 - December 12, 2001\n\
+ Copyright (c) 1998-2001 Glenn Randers-Pehrson\n\
+ Copyright (c) 1996, 1997 Andreas Dilger\n\
+ 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.
+ */
+
+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) "1.2.1");
+ return((png_charp) "1.2.1");
+}
+
+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_LIBPNG_VER_STRING);
+}
+
+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) PNG_HEADER_VERSION_STRING);
+}
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int /* PRIVATE */
+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));
+}
+
+/* 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) 10201L);
+}
+
+
+#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()) {
+ 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