/* pngread.c - read a PNG file
*
- * libpng 1.0.1
+ * libpng 1.2.7 - September 12, 2004
* 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
+ * Copyright (c) 1998-2004 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 contains routines that an application calls directly to
* read a PNG file or stream.
#include "png.h"
/* Create a PNG structure for reading, and allocate any memory needed. */
-png_structp
-png_create_read_struct(png_const_charp user_png_ver, voidp error_ptr,
+png_structp PNGAPI
+png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn)
{
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory needed. */
+png_structp PNGAPI
+png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
png_structp png_ptr;
+
+#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
jmp_buf jmpbuf;
#endif
+#endif
+
+ int i;
+
png_debug(1, "in png_create_read_struct\n");
- if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL)
- {
- return (png_structp)NULL;
- }
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+ (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
+#else
+ png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+#endif
+ if (png_ptr == NULL)
+ return (NULL);
+
+#if !defined(PNG_1_0_X)
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+ png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
+#endif
+#endif /* PNG_1_0_X */
+
+ /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
if (setjmp(jmpbuf))
#else
#endif
{
png_free(png_ptr, png_ptr->zbuf);
- png_destroy_struct(png_ptr);
- return (png_structp)NULL;
+ png_ptr->zbuf=NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr,
+ (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+ png_destroy_struct((png_voidp)png_ptr);
+#endif
+ return (NULL);
}
#ifdef USE_FAR_KEYWORD
- png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+ png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+#endif
+#endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
#endif
+
png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
- /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
- * we must recompile any applications that use any older library version.
- * For versions after libpng 1.0, we will be compatible, so we need
- * only check the first digit.
- */
- if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
- (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+ i=0;
+ do
{
- png_error(png_ptr,
- "Incompatible libpng version in application and library");
+ if(user_png_ver[i] != png_libpng_ver[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ } while (png_libpng_ver[i++]);
+
+ if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+ {
+ /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+ * we must recompile any applications that use any older library version.
+ * For versions after libpng 1.0, we will be compatible, so we need
+ * only check the first digit.
+ */
+ if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+ (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+ (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+ {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ char msg[80];
+ if (user_png_ver)
+ {
+ sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ sprintf(msg, "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+#endif
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "Incompatible libpng version in application and library");
+ }
}
/* initialize zbuf - compression buffer */
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_set_read_fn(png_ptr, NULL, NULL);
+ png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
+#ifdef PNG_SETJMP_SUPPORTED
+/* Applications that neglect to set up their own setjmp() and then encounter
+ a png_error() will longjmp here. Since the jmpbuf is then meaningless we
+ abort instead of returning. */
+#ifdef USE_FAR_KEYWORD
+ if (setjmp(jmpbuf))
+ PNG_ABORT();
+ png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+#else
+ if (setjmp(png_ptr->jmpbuf))
+ PNG_ABORT();
+#endif
+#endif
return (png_ptr);
}
/* Initialize PNG structure for reading, and allocate any memory needed.
- This interface is depreciated in favour of the png_create_read_struct(),
+ This interface is deprecated in favour of the png_create_read_struct(),
and it will eventually disappear. */
-void
+#undef png_read_init
+void PNGAPI
png_read_init(png_structp png_ptr)
{
+ /* We only come here via pre-1.0.7-compiled applications */
+ png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
+}
+
+void PNGAPI
+png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
+ png_size_t png_struct_size, png_size_t png_info_size)
+{
+ /* We only come here via pre-1.0.12-compiled applications */
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ if(png_sizeof(png_struct) > png_struct_size ||
+ png_sizeof(png_info) > png_info_size)
+ {
+ char msg[80];
+ png_ptr->warning_fn=NULL;
+ if (user_png_ver)
+ {
+ sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
+ user_png_ver);
+ png_warning(png_ptr, msg);
+ }
+ sprintf(msg, "Application is running with png.c from libpng-%.20s",
+ png_libpng_ver);
+ png_warning(png_ptr, msg);
+ }
+#endif
+ if(png_sizeof(png_struct) > png_struct_size)
+ {
+ png_ptr->error_fn=NULL;
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "The png struct allocated by the application for reading is too small.");
+ }
+ if(png_sizeof(png_info) > png_info_size)
+ {
+ png_ptr->error_fn=NULL;
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags=0;
+#endif
+ png_error(png_ptr,
+ "The info struct allocated by application for reading is too small.");
+ }
+ png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
+}
+
+void PNGAPI
+png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
+ png_size_t png_struct_size)
+{
+#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp; /* to save current jump buffer */
+#endif
+
+ int i=0;
+
+ png_structp png_ptr=*ptr_ptr;
+
+ do
+ {
+ if(user_png_ver[i] != png_libpng_ver[i])
+ {
+#ifdef PNG_LEGACY_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+#else
+ png_ptr->warning_fn=NULL;
+ png_warning(png_ptr,
+ "Application uses deprecated png_read_init() and should be recompiled.");
+ break;
+#endif
+ }
+ } while (png_libpng_ver[i++]);
+
+ png_debug(1, "in png_read_init_3\n");
- png_debug(1, "in png_read_init\n");
+#ifdef PNG_SETJMP_SUPPORTED
/* save jump buffer and error functions */
- png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+#endif
+
+ if(png_sizeof(png_struct) > png_struct_size)
+ {
+ png_destroy_struct(png_ptr);
+ *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+ png_ptr = *ptr_ptr;
+ }
/* reset all variables to 0 */
- png_memset(png_ptr, 0, sizeof (png_struct));
+ png_memset(png_ptr, 0, png_sizeof (png_struct));
+#ifdef PNG_SETJMP_SUPPORTED
/* restore jump buffer */
- png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+#endif
+
+ /* added at libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
+ png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+#endif
/* initialize zbuf - compression buffer */
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_set_read_fn(png_ptr, NULL, NULL);
+ png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
}
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* Read the information before the actual image data. This has been
* changed in v0.90 to allow reading a file that already has the magic
* bytes read from the stream. You can tell libpng how many bytes have
- * been read from the beginning of the stream (up to the maxumum of 8)
+ * been read from the beginning of the stream (up to the maximum of 8)
* via png_set_sig_bytes(), and we will only check the remaining bytes
* here. The application can then have access to the signature bytes we
* read if it is determined that this isn't a valid PNG file.
*/
-void
+void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info\n");
- /* save jump buffer and error functions */
/* If we haven't checked all of the PNG signature bytes, do so now. */
if (png_ptr->sig_bytes < 8)
{
else
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
}
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
for(;;)
{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_IHDR;
+ PNG_IDAT;
+ PNG_IEND;
+ PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+ PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+ PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+ PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+ PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+ PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+ PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+ PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+ PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ PNG_sCAL;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ PNG_sPLT;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ PNG_sRGB;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+ PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+ PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+ PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+ PNG_zTXt;
+#endif
+#endif /* PNG_GLOBAL_ARRAYS */
png_byte chunk_length[4];
png_uint_32 length;
png_read_data(png_ptr, chunk_length, 4);
- length = png_get_uint_32(chunk_length);
+ length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
- png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
+ png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
+ length);
/* This should be a binary subdivision search or a hash for
* matching the chunk name rather than a linear search.
*/
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
- else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
- png_handle_PLTE(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+ {
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ png_handle_unknown(png_ptr, info_ptr, length);
+ if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+ break;
+ }
+ }
+#endif
+ else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ png_handle_PLTE(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+ png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
}
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
/* optional call to update the users info_ptr structure */
-void
+void PNGAPI
png_read_update_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_update_info\n");
- /* save jump buffer and error functions */
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
png_read_start_row(png_ptr);
+ else
+ png_warning(png_ptr,
+ "Ignoring extra png_read_update_info() call; row buffer not reallocated");
png_read_transform_info(png_ptr, info_ptr);
}
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* Initialize palette, background, etc, after transformations
* are set, but before any reading takes place. This allows
- * the user to obtail a gamma corrected palette, for example.
+ * the user to obtain a gamma-corrected palette, for example.
* If the user doesn't call this, we will do it ourselves.
*/
-void
+void PNGAPI
png_start_read_image(png_structp png_ptr)
{
png_debug(1, "in png_start_read_image\n");
- /* save jump buffer and error functions */
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
png_read_start_row(png_ptr);
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
-void
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+void PNGAPI
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_IDAT;
+ const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+ const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+#endif
int ret;
- png_debug2(1, "in png_read_row (row %d, pass %d)\n",
+ png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
png_ptr->row_number, png_ptr->pass);
- /* save jump buffer and error functions */
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
png_read_start_row(png_ptr);
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
+#endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
+#endif
+ }
#if defined(PNG_READ_INTERLACING_SUPPORTED)
/* if interlaced and we do not need a new row, combine row and return */
switch (png_ptr->pass)
{
case 0:
- if (png_ptr->row_number & 7)
+ if (png_ptr->row_number & 0x07)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
}
break;
case 1:
- if ((png_ptr->row_number & 7) || png_ptr->width < 5)
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
}
break;
case 2:
- if ((png_ptr->row_number & 7) != 4)
+ if ((png_ptr->row_number & 0x07) != 4)
{
if (dsp_row != NULL && (png_ptr->row_number & 4))
png_combine_row(png_ptr, dsp_row,
png_crc_finish(png_ptr, 0);
png_read_data(png_ptr, chunk_length, 4);
- png_ptr->idat_size = png_get_uint_32(chunk_length);
+ png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
png_ptr->row_info.channels = png_ptr->channels;
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
- {
- png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
- (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
- }
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+ if(png_ptr->row_buf[0])
png_read_filter_row(png_ptr, &(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
(int)(png_ptr->row_buf[0]));
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
png_ptr->rowbytes + 1);
+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ }
+#endif
if (png_ptr->transformations)
png_do_read_transformations(png_ptr);
(png_ptr->transformations & PNG_INTERLACE))
{
if (png_ptr->pass < 6)
+/* old interface (pre-1.0.9):
png_do_read_interlace(&(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+ */
+ png_do_read_interlace(png_ptr);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
if (png_ptr->read_row_fn != NULL)
(*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* Read one or more rows of image data. If the image is interlaced,
* and png_set_interlace_handling() has been called, the rows need to
* contain the contents of the rows from the previous pass. If the
- * image has alpha or transparency, and png_handle_alpha() has been
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
* called, the rows contents must be initialized to the contents of the
* screen.
- *
+ *
* "row" holds the actual image, and pixels are placed in it
* as they arrive. If the image is displayed after each pass, it will
* appear to "sparkle" in. "display_row" can be used to display a
* also, but you may. If the image is not interlaced, or if you have
* not called png_set_interlace_handling(), the display_row buffer will
* be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.7
*/
-void
+void PNGAPI
png_read_rows(png_structp png_ptr, png_bytepp row,
png_bytepp display_row, png_uint_32 num_rows)
{
png_bytepp dp;
png_debug(1, "in png_read_rows\n");
- /* save jump buffer and error functions */
rp = row;
dp = display_row;
- for (i = 0; i < num_rows; i++)
- {
- png_bytep rptr;
- png_bytep dptr;
+ if (rp != NULL && dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp++;
+ png_bytep dptr = *dp++;
- if (rp != NULL)
- rptr = *rp;
- else
- rptr = NULL;
- if (dp != NULL)
- dptr = *dp;
- else
- dptr = NULL;
- png_read_row(png_ptr, rptr, dptr);
- if (row != NULL)
+ png_read_row(png_ptr, rptr, dptr);
+ }
+ else if(rp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp;
+ png_read_row(png_ptr, rptr, png_bytep_NULL);
rp++;
- if (display_row != NULL)
+ }
+ else if(dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep dptr = *dp;
+ png_read_row(png_ptr, png_bytep_NULL, dptr);
dp++;
- }
+ }
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* Read the entire image. If the image has an alpha channel or a tRNS
- * chunk, and you have called png_handle_alpha(), you will need to
+ * chunk, and you have called png_handle_alpha()[*], you will need to
* initialize the image to the current image that PNG will be overlaying.
* We set the num_rows again here, in case it was incorrectly set in
* png_read_start_row() by a call to png_read_update_info() or
* prior to either of these functions like it should have been. You can
* only call this function once. If you desire to have an image for
* each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.7
*/
-void
+void PNGAPI
png_read_image(png_structp png_ptr, png_bytepp image)
{
- png_uint_32 i;
+ png_uint_32 i,image_height;
int pass, j;
png_bytepp rp;
png_debug(1, "in png_read_image\n");
- /* save jump buffer and error functions */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
pass = png_set_interlace_handling(png_ptr);
+#else
+ if (png_ptr->interlaced)
+ png_error(png_ptr,
+ "Cannot read interlaced image -- interlace handler disabled.");
+ pass = 1;
+#endif
+
- png_ptr->num_rows = png_ptr->height; /* Make sure this is set correctly */
+ image_height=png_ptr->height;
+ png_ptr->num_rows = image_height; /* Make sure this is set correctly */
for (j = 0; j < pass; j++)
{
rp = image;
- for (i = 0; i < png_ptr->height; i++)
+ for (i = 0; i < image_height; i++)
{
- png_read_row(png_ptr, *rp, NULL);
+ png_read_row(png_ptr, *rp, png_bytep_NULL);
rp++;
}
}
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
/* Read the end of the PNG file. Will not read past the end of the
* file, will verify the end is accurate, and will read any comments
* or time information at the end of the file, if info is not NULL.
*/
-void
+void PNGAPI
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
png_byte chunk_length[4];
png_uint_32 length;
png_debug(1, "in png_read_end\n");
- /* save jump buffer and error functions */
png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
do
{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_IHDR;
+ PNG_IDAT;
+ PNG_IEND;
+ PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+ PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+ PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+ PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+ PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+ PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+ PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+ PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+ PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ PNG_sCAL;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ PNG_sPLT;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ PNG_sRGB;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+ PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+ PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+ PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+ PNG_zTXt;
+#endif
+#endif /* PNG_GLOBAL_ARRAYS */
+
png_read_data(png_ptr, chunk_length, 4);
- length = png_get_uint_32(chunk_length);
+ length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
+ else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+ png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+ {
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
+ png_error(png_ptr, "Too many IDAT's found");
+ }
+ else
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_handle_unknown(png_ptr, info_ptr, length);
+ if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
/* Zero length IDATs are legal after the last IDAT has been
*/
if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
png_error(png_ptr, "Too many IDAT's found");
- else
- png_crc_finish(png_ptr, 0);
+ png_crc_finish(png_ptr, length);
}
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_handle_PLTE(png_ptr, info_ptr, length);
- else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
- png_handle_IEND(png_ptr, info_ptr, length);
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
png_handle_bKGD(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+ png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+ png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+ png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+ png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
} while (!(png_ptr->mode & PNG_HAVE_IEND));
}
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
/* free all memory used by the read */
-void
+void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
png_infopp end_info_ptr_ptr)
{
png_structp png_ptr = NULL;
png_infop info_ptr = NULL, end_info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn;
+ png_voidp mem_ptr;
+#endif
png_debug(1, "in png_destroy_read_struct\n");
- /* save jump buffer and error functions */
if (png_ptr_ptr != NULL)
png_ptr = *png_ptr_ptr;
if (end_info_ptr_ptr != NULL)
end_info_ptr = *end_info_ptr_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+ mem_ptr = png_ptr->mem_ptr;
+#endif
+
png_read_destroy(png_ptr, info_ptr, end_info_ptr);
if (info_ptr != NULL)
{
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
- png_free(png_ptr, info_ptr->text);
+#if defined(PNG_TEXT_SUPPORTED)
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
#endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
png_destroy_struct((png_voidp)info_ptr);
- *info_ptr_ptr = (png_infop)NULL;
+#endif
+ *info_ptr_ptr = NULL;
}
if (end_info_ptr != NULL)
{
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
- png_free(png_ptr, end_info_ptr->text);
+#if defined(PNG_READ_TEXT_SUPPORTED)
+ png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
#endif
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
png_destroy_struct((png_voidp)end_info_ptr);
- *end_info_ptr_ptr = (png_infop)NULL;
+#endif
+ *end_info_ptr_ptr = NULL;
}
if (png_ptr != NULL)
{
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+ (png_voidp)mem_ptr);
+#else
png_destroy_struct((png_voidp)png_ptr);
- *png_ptr_ptr = (png_structp)NULL;
+#endif
+ *png_ptr_ptr = NULL;
}
}
/* free all memory used by the read (old method) */
-void
+void /* PRIVATE */
png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
{
+#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp;
+#endif
png_error_ptr error_fn;
png_error_ptr warning_fn;
png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_free_ptr free_fn;
+#endif
png_debug(1, "in png_read_destroy\n");
- /* save jump buffer and error functions */
if (info_ptr != NULL)
png_info_destroy(png_ptr, info_ptr);
png_info_destroy(png_ptr, end_info_ptr);
png_free(png_ptr, png_ptr->zbuf);
- png_free(png_ptr, png_ptr->row_buf);
+ png_free(png_ptr, png_ptr->big_row_buf);
png_free(png_ptr, png_ptr->prev_row);
#if defined(PNG_READ_DITHER_SUPPORTED)
png_free(png_ptr, png_ptr->palette_lookup);
png_free(png_ptr, png_ptr->gamma_from_1);
png_free(png_ptr, png_ptr->gamma_to_1);
#endif
- if (png_ptr->flags & PNG_FLAG_FREE_PALETTE)
+#ifdef PNG_FREE_ME_SUPPORTED
+ if (png_ptr->free_me & PNG_FREE_PLTE)
+ png_zfree(png_ptr, png_ptr->palette);
+ png_ptr->free_me &= ~PNG_FREE_PLTE;
+#else
+ if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
png_zfree(png_ptr, png_ptr->palette);
- if (png_ptr->flags & PNG_FLAG_FREE_TRANS)
+ png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
+#endif
+#if defined(PNG_tRNS_SUPPORTED) || \
+ defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_FREE_ME_SUPPORTED
+ if (png_ptr->free_me & PNG_FREE_TRNS)
+ png_free(png_ptr, png_ptr->trans);
+ png_ptr->free_me &= ~PNG_FREE_TRNS;
+#else
+ if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
png_free(png_ptr, png_ptr->trans);
+ png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
+#endif
+#endif
#if defined(PNG_READ_hIST_SUPPORTED)
+#ifdef PNG_FREE_ME_SUPPORTED
+ if (png_ptr->free_me & PNG_FREE_HIST)
+ png_free(png_ptr, png_ptr->hist);
+ png_ptr->free_me &= ~PNG_FREE_HIST;
+#else
if (png_ptr->flags & PNG_FLAG_FREE_HIST)
png_free(png_ptr, png_ptr->hist);
+ png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
+#endif
#endif
#if defined(PNG_READ_GAMMA_SUPPORTED)
if (png_ptr->gamma_16_table != NULL)
{
int i;
- for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_table[i]);
}
+ png_free(png_ptr, png_ptr->gamma_16_table);
}
-#endif
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- png_free(png_ptr, png_ptr->gamma_16_table);
if (png_ptr->gamma_16_from_1 != NULL)
{
int i;
- for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
}
- }
png_free(png_ptr, png_ptr->gamma_16_from_1);
+ }
if (png_ptr->gamma_16_to_1 != NULL)
{
int i;
- for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++)
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
}
- }
png_free(png_ptr, png_ptr->gamma_16_to_1);
+ }
+#endif
+#endif
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+ png_free(png_ptr, png_ptr->time_buffer);
#endif
inflateEnd(&png_ptr->zstream);
png_free(png_ptr, png_ptr->save_buffer);
#endif
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+#ifdef PNG_TEXT_SUPPORTED
+ png_free(png_ptr, png_ptr->current_text);
+#endif /* PNG_TEXT_SUPPORTED */
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+
/* Save the important info out of the png_struct, in case it is
* being used again.
*/
- png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+#endif
error_fn = png_ptr->error_fn;
warning_fn = png_ptr->warning_fn;
error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ free_fn = png_ptr->free_fn;
+#endif
- png_memset(png_ptr, 0, sizeof (png_struct));
+ png_memset(png_ptr, 0, png_sizeof (png_struct));
png_ptr->error_fn = error_fn;
png_ptr->warning_fn = warning_fn;
png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_ptr->free_fn = free_fn;
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+#endif
- png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
}
-void
+void PNGAPI
png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
{
png_ptr->read_row_fn = read_row_fn;
}
+
+
+#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void PNGAPI
+png_read_png(png_structp png_ptr, png_infop info_ptr,
+ int transforms,
+ voidp params)
+{
+ int row;
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+ /* invert the alpha channel from opacity to transparency
+ */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+ png_set_invert_alpha(png_ptr);
+#endif
+
+ /* png_read_info() gives us all of the information from the
+ * PNG file before the first IDAT (image data chunk).
+ */
+ png_read_info(png_ptr, info_ptr);
+ if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+ png_error(png_ptr,"Image is too high to process with png_read_png()");
+
+ /* -------------- image transformations start here ------------------- */
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+ /* tell libpng to strip 16 bit/color files down to 8 bits per color
+ */
+ if (transforms & PNG_TRANSFORM_STRIP_16)
+ png_set_strip_16(png_ptr);
+#endif
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+ /* Strip alpha bytes from the input data without combining with
+ * the background (not recommended).
+ */
+ if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
+ png_set_strip_alpha(png_ptr);
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
+ /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+ * byte into separate bytes (useful for paletted and grayscale images).
+ */
+ if (transforms & PNG_TRANSFORM_PACKING)
+ png_set_packing(png_ptr);
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ /* Change the order of packed pixels to least significant bit first
+ * (not useful if you are using png_set_packing).
+ */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+ png_set_packswap(png_ptr);
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ /* Expand paletted colors into true RGB triplets
+ * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+ * Expand paletted or RGB images with transparency to full alpha
+ * channels so the data will be available as RGBA quartets.
+ */
+ if (transforms & PNG_TRANSFORM_EXPAND)
+ if ((png_ptr->bit_depth < 8) ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
+ (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
+ png_set_expand(png_ptr);
+#endif
+
+ /* We don't handle background color or gamma transformation or dithering.
+ */
+
+#if defined(PNG_READ_INVERT_SUPPORTED)
+ /* invert monochrome files to have 0 as white and 1 as black
+ */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+ png_set_invert_mono(png_ptr);
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+ /* If you want to shift the pixel values from the range [0,255] or
+ * [0,65535] to the original [0,7] or [0,31], or whatever range the
+ * colors were originally in:
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT)
+ && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+ {
+ png_color_8p sig_bit;
+
+ png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+ png_set_shift(png_ptr, sig_bit);
+ }
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED)
+ /* flip the RGB pixels to BGR (or RGBA to BGRA)
+ */
+ if (transforms & PNG_TRANSFORM_BGR)
+ png_set_bgr(png_ptr);
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+ /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
+ */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+ png_set_swap_alpha(png_ptr);
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED)
+ /* swap bytes of 16 bit files to least significant byte first
+ */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+ png_set_swap(png_ptr);
+#endif
+
+ /* We don't handle adding filler bytes */
+
+ /* Optional call to gamma correct and add the background to the palette
+ * and update info structure. REQUIRED if you are expecting libpng to
+ * update the palette for you (i.e., you selected such a transform above).
+ */
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* -------------- image transformations end here ------------------- */
+
+#ifdef PNG_FREE_ME_SUPPORTED
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+#endif
+ if(info_ptr->row_pointers == NULL)
+ {
+ info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
+ info_ptr->height * png_sizeof(png_bytep));
+#ifdef PNG_FREE_ME_SUPPORTED
+ info_ptr->free_me |= PNG_FREE_ROWS;
+#endif
+ for (row = 0; row < (int)info_ptr->height; row++)
+ {
+ info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr));
+ }
+ }
+
+ png_read_image(png_ptr, info_ptr->row_pointers);
+ info_ptr->valid |= PNG_INFO_IDAT;
+
+ /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ png_read_end(png_ptr, info_ptr);
+
+ if(transforms == 0 || params == NULL)
+ /* quiet compiler warnings */ return;
+
+}
+#endif
+#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */