X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/1f0299c17dc878540bf190c290392db241b425ad..c017416682938c39547836051c0fad74db45e8a0:/src/png/pngmem.c diff --git a/src/png/pngmem.c b/src/png/pngmem.c index b92fcc8ae0..bf5ff037da 100644 --- a/src/png/pngmem.c +++ b/src/png/pngmem.c @@ -1,67 +1,103 @@ /* pngmem.c - stub functions for memory allocation * - * libpng 1.0.1 - * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - * Copyright (c) 1996, 1997 Andreas Dilger - * Copyright (c) 1998, Glenn Randers-Pehrson - * March 15, 1998 + * Last changed in libpng 1.5.7 [December 15, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * - * This file provides a location for all memory allocation. Users which - * need special memory handling are expected to modify the code in this file - * to meet their needs. See the instructions at each function. + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all memory allocation. Users who + * need special memory handling are expected to supply replacement + * functions for png_malloc() and png_free(), and to use + * png_create_read_struct_2() and png_create_write_struct_2() to + * identify the replacement functions. */ -#define PNG_INTERNAL -#include "../png/png.h" +#include "pngpriv.h" -/* The following "hides" PNG_MALLOC and PNG_FREE thus allowing the pngtest - application to put a wrapper on top of them. */ -#ifdef PNGTEST_MEMORY_DEBUG -#define PNG_MALLOC png_debug_malloc -#define PNG_FREE png_debug_free -#else -#define PNG_MALLOC png_malloc -#define PNG_FREE png_free -#endif +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) /* Borland DOS special memory handler */ #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) -/* if you change this, be sure to change the one in png.h also */ +/* If you change this, be sure to change the one in png.h also */ /* Allocate memory for a png_struct. The malloc and memset can be replaced by a single call to calloc() if this is thought to improve performance. */ -png_voidp -png_create_struct(int type) +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct,(int type),PNG_ALLOCATED) +{ +# ifdef PNG_USER_MEM_SUPPORTED + return (png_create_struct_2(type, NULL, NULL)); +} + +/* Alternate version of png_create_struct, for use with user-defined malloc. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), + PNG_ALLOCATED) { +# endif /* PNG_USER_MEM_SUPPORTED */ png_size_t size; png_voidp struct_ptr; if (type == PNG_STRUCT_INFO) - size = sizeof(png_info); + size = png_sizeof(png_info); + else if (type == PNG_STRUCT_PNG) - size = sizeof(png_struct); + size = png_sizeof(png_struct); + else - return ((png_voidp)NULL); + return (png_get_copyright(NULL)); - if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) +# ifdef PNG_USER_MEM_SUPPORTED + if (malloc_fn != NULL) { - png_memset(struct_ptr, 0, size); + png_struct dummy_struct; + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size); } + else +# endif /* PNG_USER_MEM_SUPPORTED */ + struct_ptr = (png_voidp)farmalloc(size); + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); + return (struct_ptr); } - /* Free memory allocated by a png_create_struct() call */ -void +void /* PRIVATE */ png_destroy_struct(png_voidp struct_ptr) { +# ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2(struct_ptr, NULL, NULL); +} + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, + png_voidp mem_ptr) +{ +# endif if (struct_ptr != NULL) { +# ifdef PNG_USER_MEM_SUPPORTED + if (free_fn != NULL) + { + png_struct dummy_struct; + memset(&dummy_struct, 0, sizeof dummy_struct); + dummy_struct.mem_ptr=mem_ptr; + (*(free_fn))(&dummy_struct, struct_ptr); + return; + } + +# endif /* PNG_USER_MEM_SUPPORTED */ farfree (struct_ptr); - struct_ptr = NULL; } } @@ -72,7 +108,7 @@ png_destroy_struct(png_voidp struct_ptr) * have the ability to do that. * * Borland seems to have a problem in DOS mode for exactly 64K. - * It gives you a segment with an offset of 8 (perhaps to store it's + * It gives you a segment with an offset of 8 (perhaps to store its * memory stuff). zlib doesn't like this at all, so we have to * detect and deal with it. This code should not be needed in * Windows or OS/2 modes, and only in 16 bit mode. This code has @@ -84,31 +120,76 @@ png_destroy_struct(png_voidp struct_ptr) * result, we would be truncating potentially larger memory requests * (which should cause a fatal error) and introducing major problems. */ -png_voidp -PNG_MALLOC(png_structp png_ptr, png_uint_32 size) +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = (png_malloc(png_ptr, size)); + + if (ret != NULL) + png_memset(ret,0,(png_size_t)size); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret; + if (png_ptr == NULL || size == 0) - return ((png_voidp)NULL); + return (NULL); + +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->malloc_fn != NULL) + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); + + else + ret = (png_malloc_default(png_ptr, size)); + + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of memory"); -#ifdef PNG_MAX_MALLOC_64K + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || size == 0) + return (NULL); + +# ifdef PNG_MAX_MALLOC_64K if (size > (png_uint_32)65536L) - png_error(png_ptr, "Cannot Allocate > 64K"); -#endif + { + png_warning(png_ptr, "Cannot Allocate > 64K"); + ret = NULL; + } - if (size == (png_uint_32)65536L) + else +# endif + + if (size != (size_t)size) + ret = NULL; + + else if (size == (png_uint_32)65536L) { if (png_ptr->offset_table == NULL) { - /* try to see if we need to do any of this fancy stuff */ + /* Try to see if we need to do any of this fancy stuff */ ret = farmalloc(size); if (ret == NULL || ((png_size_t)ret & 0xffff)) { int num_blocks; png_uint_32 total_size; png_bytep table; - int i; + int i, mem_level, window_bits; png_byte huge * hptr; + int window_bits if (ret != NULL) { @@ -116,11 +197,23 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size) ret = NULL; } - num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); - if (num_blocks < 1) + window_bits = + png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ? + png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits; + + if (window_bits > 14) + num_blocks = (int)(1 << (window_bits - 14)); + + else num_blocks = 1; - if (png_ptr->zlib_mem_level >= 7) - num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); + + mem_level = + png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ? + png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level; + + if (mem_level >= 7) + num_blocks += (int)(1 << (mem_level - 7)); + else num_blocks++; @@ -130,33 +223,57 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size) if (table == NULL) { - png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */ +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */ + + else + png_warning(png_ptr, "Out Of Memory"); +# endif + return (NULL); } if ((png_size_t)table & 0xfff0) { - png_error(png_ptr, "Farmalloc didn't return normalized pointer"); +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, + "Farmalloc didn't return normalized pointer"); + + else + png_warning(png_ptr, + "Farmalloc didn't return normalized pointer"); +# endif + return (NULL); } png_ptr->offset_table = table; png_ptr->offset_table_ptr = farmalloc(num_blocks * - sizeof (png_bytep)); + png_sizeof(png_bytep)); if (png_ptr->offset_table_ptr == NULL) { - png_error(png_ptr, "Out Of memory."); +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */ + + else + png_warning(png_ptr, "Out Of memory"); +# endif + return (NULL); } hptr = (png_byte huge *)table; if ((png_size_t)hptr & 0xf) { hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L); - hptr += 16L; + hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */ } + for (i = 0; i < num_blocks; i++) { png_ptr->offset_table_ptr[i] = (png_bytep)hptr; - hptr += (png_uint_32)65536L; + hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */ } png_ptr->offset_table_number = num_blocks; @@ -166,30 +283,66 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size) } if (png_ptr->offset_table_count >= png_ptr->offset_table_number) - png_error(png_ptr, "Out of Memory."); + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */ + + else + png_warning(png_ptr, "Out of Memory"); +# endif + return (NULL); + } ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; } + else ret = farmalloc(size); +# ifndef PNG_USER_MEM_SUPPORTED if (ret == NULL) { - png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */ + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */ + + else + png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */ } +# endif return (ret); } -/* free a pointer allocated by PNG_MALLOC(). In the default - configuration, png_ptr is not used, but is passed in case it - is needed. If ptr is NULL, return without taking any action. */ -void -PNG_FREE(png_structp png_ptr, png_voidp ptr) +/* Free a pointer allocated by png_malloc(). In the default + * configuration, png_ptr is not used, but is passed in case it + * is needed. If ptr is NULL, return without taking any action. + */ +void PNGAPI +png_free(png_structp png_ptr, png_voidp ptr) { if (png_ptr == NULL || ptr == NULL) return; +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + { + (*(png_ptr->free_fn))(png_ptr, ptr); + return; + } + + else + png_free_default(png_ptr, ptr); +} + +void PNGAPI +png_free_default(png_structp png_ptr, png_voidp ptr) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || ptr == NULL) + return; + if (png_ptr->offset_table != NULL) { int i; @@ -213,148 +366,302 @@ PNG_FREE(png_structp png_ptr, png_voidp ptr) } if (ptr != NULL) - { farfree(ptr); - ptr = NULL; - } } #else /* Not the Borland DOS special memory handler */ /* Allocate memory for a png_struct or a png_info. The malloc and memset can be replaced by a single call to calloc() if this is thought - to improve performance noticably.*/ -png_voidp -png_create_struct(int type) + to improve performance noticably. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct,(int type),PNG_ALLOCATED) +{ +# ifdef PNG_USER_MEM_SUPPORTED + return (png_create_struct_2(type, NULL, NULL)); +} + +/* Allocate memory for a png_struct or a png_info. The malloc and + memset can be replaced by a single call to calloc() if this is thought + to improve performance noticably. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), + PNG_ALLOCATED) { +# endif /* PNG_USER_MEM_SUPPORTED */ png_size_t size; png_voidp struct_ptr; if (type == PNG_STRUCT_INFO) - size = sizeof(png_info); + size = png_sizeof(png_info); + else if (type == PNG_STRUCT_PNG) - size = sizeof(png_struct); + size = png_sizeof(png_struct); + else - return ((png_voidp)NULL); - -#if defined(__TURBOC__) && !defined(__FLAT__) - if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) -#else -# if defined(_MSC_VER) && defined(MAXSEG_64K) - if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL) -# else - if ((struct_ptr = (png_voidp)malloc(size)) != NULL) -# endif -#endif + return (NULL); + +# ifdef PNG_USER_MEM_SUPPORTED + if (malloc_fn != NULL) { - png_memset(struct_ptr, 0, size); + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(png_ptr, size); + + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); + + return (struct_ptr); } +# endif /* PNG_USER_MEM_SUPPORTED */ + +# if defined(__TURBOC__) && !defined(__FLAT__) + struct_ptr = (png_voidp)farmalloc(size); +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + struct_ptr = (png_voidp)halloc(size, 1); +# else + struct_ptr = (png_voidp)malloc(size); +# endif +# endif + + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); return (struct_ptr); } /* Free memory allocated by a png_create_struct() call */ -void +void /* PRIVATE */ png_destroy_struct(png_voidp struct_ptr) { +# ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2(struct_ptr, NULL, NULL); +} + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, + png_voidp mem_ptr) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ if (struct_ptr != NULL) { -#if defined(__TURBOC__) && !defined(__FLAT__) +# ifdef PNG_USER_MEM_SUPPORTED + if (free_fn != NULL) + { + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + (*(free_fn))(png_ptr, struct_ptr); + return; + } +# endif /* PNG_USER_MEM_SUPPORTED */ +# if defined(__TURBOC__) && !defined(__FLAT__) farfree(struct_ptr); -#else -# if defined(_MSC_VER) && defined(MAXSEG_64K) + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) hfree(struct_ptr); -# else + +# else free(struct_ptr); -# endif -#endif + +# endif +# endif } } - /* Allocate memory. For reasonable files, size should never exceed - 64K. However, zlib may allocate more then 64K if you don't tell - it not to. See zconf.h and png.h for more information. zlib does - need to allocate exactly 64K, so whatever you call here must - have the ability to do that. */ + * 64K. However, zlib may allocate more then 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + */ + +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = (png_malloc(png_ptr, size)); + + if (ret != NULL) + png_memset(ret,0,(png_size_t)size); -png_voidp -PNG_MALLOC(png_structp png_ptr, png_uint_32 size) + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret; +# ifdef PNG_USER_MEM_SUPPORTED if (png_ptr == NULL || size == 0) - return ((png_voidp)NULL); + return (NULL); -#ifdef PNG_MAX_MALLOC_64K - if (size > (png_uint_32)65536L) - png_error(png_ptr, "Cannot Allocate > 64K"); -#endif - -#if defined(__TURBOC__) && !defined(__FLAT__) - ret = farmalloc(size); -#else -# if defined(_MSC_VER) && defined(MAXSEG_64K) - ret = halloc(size, 1); -# else - ret = malloc((size_t)size); -# endif -#endif + if (png_ptr->malloc_fn != NULL) + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); - if (ret == NULL) + else + ret = (png_malloc_default(png_ptr, size)); + + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || size == 0) + return (NULL); + +# ifdef PNG_MAX_MALLOC_64K + if (size > (png_uint_32)65536L) { - png_error(png_ptr, "Out of Memory"); +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Cannot Allocate > 64K"); + + else +# endif + return NULL; } +# endif + + /* Check for overflow */ +# if defined(__TURBOC__) && !defined(__FLAT__) + + if (size != (unsigned long)size) + ret = NULL; + + else + ret = farmalloc(size); + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + if (size != (unsigned long)size) + ret = NULL; + + else + ret = halloc(size, 1); + +# else + if (size != (size_t)size) + ret = NULL; + + else + ret = malloc((size_t)size); +# endif +# endif + +# ifndef PNG_USER_MEM_SUPPORTED + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); +# endif return (ret); } -/* Free a pointer allocated by PNG_MALLOC(). In the default - configuration, png_ptr is not used, but is passed in case it - is needed. If ptr is NULL, return without taking any action. */ -void -PNG_FREE(png_structp png_ptr, png_voidp ptr) +/* Free a pointer allocated by png_malloc(). If ptr is NULL, return + * without taking any action. + */ +void PNGAPI +png_free(png_structp png_ptr, png_voidp ptr) { if (png_ptr == NULL || ptr == NULL) return; -#if defined(__TURBOC__) && !defined(__FLAT__) +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + { + (*(png_ptr->free_fn))(png_ptr, ptr); + return; + } + + else + png_free_default(png_ptr, ptr); +} + +void PNGAPI +png_free_default(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +# endif /* PNG_USER_MEM_SUPPORTED */ + +# if defined(__TURBOC__) && !defined(__FLAT__) farfree(ptr); -#else -# if defined(_MSC_VER) && defined(MAXSEG_64K) + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) hfree(ptr); -# else + +# else free(ptr); -# endif -#endif -} +# endif +# endif +} #endif /* Not Borland DOS special memory handler */ -png_voidp -png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2, - png_uint_32 length) +/* This function was added at libpng version 1.2.3. The png_malloc_warn() + * function will set up png_malloc() to issue a png_warning and return NULL + * instead of issuing a png_error, if it fails to allocate the requested + * memory. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { - png_size_t size; - - size = (png_size_t)length; - if ((png_uint_32)size != length) - png_error(png_ptr,"Overflow in png_memcpy_check."); - - return(png_memcpy (s1, s2, size)); + png_voidp ptr; + png_uint_32 save_flags; + if (png_ptr == NULL) + return (NULL); + + save_flags = png_ptr->flags; + png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK; + ptr = (png_voidp)png_malloc((png_structp)png_ptr, size); + png_ptr->flags=save_flags; + return(ptr); } -png_voidp -png_memset_check (png_structp png_ptr, png_voidp s1, int value, - png_uint_32 length) -{ - png_size_t size; - size = (png_size_t)length; - if ((png_uint_32)size != length) - png_error(png_ptr,"Overflow in png_memset_check."); +#ifdef PNG_USER_MEM_SUPPORTED +/* This function is called when the application wants to use another method + * of allocating and freeing memory. + */ +void PNGAPI +png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr + malloc_fn, png_free_ptr free_fn) +{ + if (png_ptr != NULL) + { + png_ptr->mem_ptr = mem_ptr; + png_ptr->malloc_fn = malloc_fn; + png_ptr->free_fn = free_fn; + } +} - return (png_memset (s1, value, size)); +/* This function returns a pointer to the mem_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_mem_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + return ((png_voidp)png_ptr->mem_ptr); } +#endif /* PNG_USER_MEM_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */