nuclear@2: 
nuclear@2: /* pngrutil.c - utilities to read a PNG file
nuclear@2:  *
nuclear@2:  * Last changed in libpng 1.2.33 [October 31, 2008]
nuclear@2:  * For conditions of distribution and use, see copyright notice in png.h
nuclear@2:  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
nuclear@2:  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
nuclear@2:  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
nuclear@2:  *
nuclear@2:  * This file contains routines that are only called from within
nuclear@2:  * libpng itself during the course of reading an image.
nuclear@2:  */
nuclear@2: 
nuclear@2: #define PNG_INTERNAL
nuclear@2: #include "png.h"
nuclear@2: #if defined(PNG_READ_SUPPORTED)
nuclear@2: 
nuclear@2: #if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
nuclear@2: #  define WIN32_WCE_OLD
nuclear@2: #endif
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2: #  if defined(WIN32_WCE_OLD)
nuclear@2: /* strtod() function is not supported on WindowsCE */
nuclear@2: __inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **endptr)
nuclear@2: {
nuclear@2:    double result = 0;
nuclear@2:    int len;
nuclear@2:    wchar_t *str, *end;
nuclear@2: 
nuclear@2:    len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
nuclear@2:    str = (wchar_t *)png_malloc(png_ptr, len * png_sizeof(wchar_t));
nuclear@2:    if ( NULL != str )
nuclear@2:    {
nuclear@2:       MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
nuclear@2:       result = wcstod(str, &end);
nuclear@2:       len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
nuclear@2:       *endptr = (char *)nptr + (png_strlen(nptr) - len + 1);
nuclear@2:       png_free(png_ptr, str);
nuclear@2:    }
nuclear@2:    return result;
nuclear@2: }
nuclear@2: #  else
nuclear@2: #    define png_strtod(p,a,b) strtod(a,b)
nuclear@2: #  endif
nuclear@2: #endif
nuclear@2: 
nuclear@2: png_uint_32 PNGAPI
nuclear@2: png_get_uint_31(png_structp png_ptr, png_bytep buf)
nuclear@2: {
nuclear@2: #ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
nuclear@2:    png_uint_32 i = png_get_uint_32(buf);
nuclear@2: #else
nuclear@2:    /* Avoid an extra function call by inlining the result. */
nuclear@2:    png_uint_32 i = ((png_uint_32)(*buf) << 24) +
nuclear@2:       ((png_uint_32)(*(buf + 1)) << 16) +
nuclear@2:       ((png_uint_32)(*(buf + 2)) << 8) +
nuclear@2:       (png_uint_32)(*(buf + 3));
nuclear@2: #endif
nuclear@2:    if (i > PNG_UINT_31_MAX)
nuclear@2:      png_error(png_ptr, "PNG unsigned integer out of range.");
nuclear@2:    return (i);
nuclear@2: }
nuclear@2: #ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
nuclear@2: /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
nuclear@2: png_uint_32 PNGAPI
nuclear@2: png_get_uint_32(png_bytep buf)
nuclear@2: {
nuclear@2:    png_uint_32 i = ((png_uint_32)(*buf) << 24) +
nuclear@2:       ((png_uint_32)(*(buf + 1)) << 16) +
nuclear@2:       ((png_uint_32)(*(buf + 2)) << 8) +
nuclear@2:       (png_uint_32)(*(buf + 3));
nuclear@2: 
nuclear@2:    return (i);
nuclear@2: }
nuclear@2: 
nuclear@2: /* Grab a signed 32-bit integer from a buffer in big-endian format.  The
nuclear@2:  * data is stored in the PNG file in two's complement format, and it is
nuclear@2:  * assumed that the machine format for signed integers is the same. */
nuclear@2: png_int_32 PNGAPI
nuclear@2: png_get_int_32(png_bytep buf)
nuclear@2: {
nuclear@2:    png_int_32 i = ((png_int_32)(*buf) << 24) +
nuclear@2:       ((png_int_32)(*(buf + 1)) << 16) +
nuclear@2:       ((png_int_32)(*(buf + 2)) << 8) +
nuclear@2:       (png_int_32)(*(buf + 3));
nuclear@2: 
nuclear@2:    return (i);
nuclear@2: }
nuclear@2: 
nuclear@2: /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
nuclear@2: png_uint_16 PNGAPI
nuclear@2: png_get_uint_16(png_bytep buf)
nuclear@2: {
nuclear@2:    png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
nuclear@2:       (png_uint_16)(*(buf + 1)));
nuclear@2: 
nuclear@2:    return (i);
nuclear@2: }
nuclear@2: #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
nuclear@2: 
nuclear@2: /* Read the chunk header (length + type name).
nuclear@2:  * Put the type name into png_ptr->chunk_name, and return the length.
nuclear@2:  */
nuclear@2: png_uint_32 /* PRIVATE */
nuclear@2: png_read_chunk_header(png_structp png_ptr)
nuclear@2: {
nuclear@2:    png_byte buf[8];
nuclear@2:    png_uint_32 length;
nuclear@2: 
nuclear@2:    /* read the length and the chunk name */
nuclear@2:    png_read_data(png_ptr, buf, 8);
nuclear@2:    length = png_get_uint_31(png_ptr, buf);
nuclear@2: 
nuclear@2:    /* put the chunk name into png_ptr->chunk_name */
nuclear@2:    png_memcpy(png_ptr->chunk_name, buf + 4, 4);
nuclear@2: 
nuclear@2:    png_debug2(0, "Reading %s chunk, length = %lu\n",
nuclear@2:       png_ptr->chunk_name, length);
nuclear@2: 
nuclear@2:    /* reset the crc and run it over the chunk name */
nuclear@2:    png_reset_crc(png_ptr);
nuclear@2:    png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
nuclear@2: 
nuclear@2:    /* check to see if chunk name is valid */
nuclear@2:    png_check_chunk_name(png_ptr, png_ptr->chunk_name);
nuclear@2: 
nuclear@2:    return length;
nuclear@2: }
nuclear@2: 
nuclear@2: /* Read data, and (optionally) run it through the CRC. */
nuclear@2: void /* PRIVATE */
nuclear@2: png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
nuclear@2: {
nuclear@2:    if (png_ptr == NULL) return;
nuclear@2:    png_read_data(png_ptr, buf, length);
nuclear@2:    png_calculate_crc(png_ptr, buf, length);
nuclear@2: }
nuclear@2: 
nuclear@2: /* Optionally skip data and then check the CRC.  Depending on whether we
nuclear@2:    are reading a ancillary or critical chunk, and how the program has set
nuclear@2:    things up, we may calculate the CRC on the data and print a message.
nuclear@2:    Returns '1' if there was a CRC error, '0' otherwise. */
nuclear@2: int /* PRIVATE */
nuclear@2: png_crc_finish(png_structp png_ptr, png_uint_32 skip)
nuclear@2: {
nuclear@2:    png_size_t i;
nuclear@2:    png_size_t istop = png_ptr->zbuf_size;
nuclear@2: 
nuclear@2:    for (i = (png_size_t)skip; i > istop; i -= istop)
nuclear@2:    {
nuclear@2:       png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
nuclear@2:    }
nuclear@2:    if (i)
nuclear@2:    {
nuclear@2:       png_crc_read(png_ptr, png_ptr->zbuf, i);
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_crc_error(png_ptr))
nuclear@2:    {
nuclear@2:       if (((png_ptr->chunk_name[0] & 0x20) &&                /* Ancillary */
nuclear@2:            !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
nuclear@2:           (!(png_ptr->chunk_name[0] & 0x20) &&             /* Critical  */
nuclear@2:           (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
nuclear@2:       {
nuclear@2:          png_chunk_warning(png_ptr, "CRC error");
nuclear@2:       }
nuclear@2:       else
nuclear@2:       {
nuclear@2:          png_chunk_error(png_ptr, "CRC error");
nuclear@2:       }
nuclear@2:       return (1);
nuclear@2:    }
nuclear@2: 
nuclear@2:    return (0);
nuclear@2: }
nuclear@2: 
nuclear@2: /* Compare the CRC stored in the PNG file with that calculated by libpng from
nuclear@2:    the data it has read thus far. */
nuclear@2: int /* PRIVATE */
nuclear@2: png_crc_error(png_structp png_ptr)
nuclear@2: {
nuclear@2:    png_byte crc_bytes[4];
nuclear@2:    png_uint_32 crc;
nuclear@2:    int need_crc = 1;
nuclear@2: 
nuclear@2:    if (png_ptr->chunk_name[0] & 0x20)                     /* ancillary */
nuclear@2:    {
nuclear@2:       if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
nuclear@2:           (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
nuclear@2:          need_crc = 0;
nuclear@2:    }
nuclear@2:    else                                                    /* critical */
nuclear@2:    {
nuclear@2:       if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
nuclear@2:          need_crc = 0;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_read_data(png_ptr, crc_bytes, 4);
nuclear@2: 
nuclear@2:    if (need_crc)
nuclear@2:    {
nuclear@2:       crc = png_get_uint_32(crc_bytes);
nuclear@2:       return ((int)(crc != png_ptr->crc));
nuclear@2:    }
nuclear@2:    else
nuclear@2:       return (0);
nuclear@2: }
nuclear@2: 
nuclear@2: #if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
nuclear@2:     defined(PNG_READ_iCCP_SUPPORTED)
nuclear@2: /*
nuclear@2:  * Decompress trailing data in a chunk.  The assumption is that chunkdata
nuclear@2:  * points at an allocated area holding the contents of a chunk with a
nuclear@2:  * trailing compressed part.  What we get back is an allocated area
nuclear@2:  * holding the original prefix part and an uncompressed version of the
nuclear@2:  * trailing part (the malloc area passed in is freed).
nuclear@2:  */
nuclear@2: void /* PRIVATE */
nuclear@2: png_decompress_chunk(png_structp png_ptr, int comp_type,
nuclear@2:                               png_size_t chunklength,
nuclear@2:                               png_size_t prefix_size, png_size_t *newlength)
nuclear@2: {
nuclear@2:    static PNG_CONST char msg[] = "Error decoding compressed text";
nuclear@2:    png_charp text;
nuclear@2:    png_size_t text_size;
nuclear@2: 
nuclear@2:    if (comp_type == PNG_COMPRESSION_TYPE_BASE)
nuclear@2:    {
nuclear@2:       int ret = Z_OK;
nuclear@2:       png_ptr->zstream.next_in = (png_bytep)(png_ptr->chunkdata + prefix_size);
nuclear@2:       png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
nuclear@2:       png_ptr->zstream.next_out = png_ptr->zbuf;
nuclear@2:       png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
nuclear@2: 
nuclear@2:       text_size = 0;
nuclear@2:       text = NULL;
nuclear@2: 
nuclear@2:       while (png_ptr->zstream.avail_in)
nuclear@2:       {
nuclear@2:          ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
nuclear@2:          if (ret != Z_OK && ret != Z_STREAM_END)
nuclear@2:          {
nuclear@2:             if (png_ptr->zstream.msg != NULL)
nuclear@2:                png_warning(png_ptr, png_ptr->zstream.msg);
nuclear@2:             else
nuclear@2:                png_warning(png_ptr, msg);
nuclear@2:             inflateReset(&png_ptr->zstream);
nuclear@2:             png_ptr->zstream.avail_in = 0;
nuclear@2: 
nuclear@2:             if (text ==  NULL)
nuclear@2:             {
nuclear@2:                text_size = prefix_size + png_sizeof(msg) + 1;
nuclear@2:                text = (png_charp)png_malloc_warn(png_ptr, text_size);
nuclear@2:                if (text ==  NULL)
nuclear@2:                  {
nuclear@2:                     png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:                     png_ptr->chunkdata = NULL;
nuclear@2:                     png_error(png_ptr, "Not enough memory to decompress chunk");
nuclear@2:                  }
nuclear@2:                png_memcpy(text, png_ptr->chunkdata, prefix_size);
nuclear@2:             }
nuclear@2: 
nuclear@2:             text[text_size - 1] = 0x00;
nuclear@2: 
nuclear@2:             /* Copy what we can of the error message into the text chunk */
nuclear@2:             text_size = (png_size_t)(chunklength -
nuclear@2:               (text - png_ptr->chunkdata) - 1);
nuclear@2:             if (text_size > png_sizeof(msg))
nuclear@2:                text_size = png_sizeof(msg);
nuclear@2:             png_memcpy(text + prefix_size, msg, text_size);
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
nuclear@2:          {
nuclear@2:             if (text == NULL)
nuclear@2:             {
nuclear@2:                text_size = prefix_size +
nuclear@2:                    png_ptr->zbuf_size - png_ptr->zstream.avail_out;
nuclear@2:                text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
nuclear@2:                if (text ==  NULL)
nuclear@2:                {
nuclear@2:                   png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:                   png_ptr->chunkdata = NULL;
nuclear@2:                   png_error(png_ptr,
nuclear@2:                     "Not enough memory to decompress chunk.");
nuclear@2:                }
nuclear@2:                png_memcpy(text + prefix_size, png_ptr->zbuf,
nuclear@2:                     text_size - prefix_size);
nuclear@2:                png_memcpy(text, png_ptr->chunkdata, prefix_size);
nuclear@2:                *(text + text_size) = 0x00;
nuclear@2:             }
nuclear@2:             else
nuclear@2:             {
nuclear@2:                png_charp tmp;
nuclear@2: 
nuclear@2:                tmp = text;
nuclear@2:                text = (png_charp)png_malloc_warn(png_ptr,
nuclear@2:                   (png_uint_32)(text_size +
nuclear@2:                   png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
nuclear@2:                if (text == NULL)
nuclear@2:                {
nuclear@2:                   png_free(png_ptr, tmp);
nuclear@2:                   png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:                   png_ptr->chunkdata = NULL;
nuclear@2:                   png_error(png_ptr,
nuclear@2:                     "Not enough memory to decompress chunk..");
nuclear@2:                }
nuclear@2:                png_memcpy(text, tmp, text_size);
nuclear@2:                png_free(png_ptr, tmp);
nuclear@2:                png_memcpy(text + text_size, png_ptr->zbuf,
nuclear@2:                   (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
nuclear@2:                text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
nuclear@2:                *(text + text_size) = 0x00;
nuclear@2:             }
nuclear@2:             if (ret == Z_STREAM_END)
nuclear@2:                break;
nuclear@2:             else
nuclear@2:             {
nuclear@2:                png_ptr->zstream.next_out = png_ptr->zbuf;
nuclear@2:                png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
nuclear@2:             }
nuclear@2:          }
nuclear@2:       }
nuclear@2:       if (ret != Z_STREAM_END)
nuclear@2:       {
nuclear@2: #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
nuclear@2:          char umsg[52];
nuclear@2: 
nuclear@2:          if (ret == Z_BUF_ERROR)
nuclear@2:             png_snprintf(umsg, 52,
nuclear@2:                 "Buffer error in compressed datastream in %s chunk",
nuclear@2:                 png_ptr->chunk_name);
nuclear@2:          else if (ret == Z_DATA_ERROR)
nuclear@2:             png_snprintf(umsg, 52,
nuclear@2:                 "Data error in compressed datastream in %s chunk",
nuclear@2:                 png_ptr->chunk_name);
nuclear@2:          else
nuclear@2:             png_snprintf(umsg, 52,
nuclear@2:                 "Incomplete compressed datastream in %s chunk",
nuclear@2:                 png_ptr->chunk_name);
nuclear@2:          png_warning(png_ptr, umsg);
nuclear@2: #else
nuclear@2:          png_warning(png_ptr,
nuclear@2:             "Incomplete compressed datastream in chunk other than IDAT");
nuclear@2: #endif
nuclear@2:          text_size = prefix_size;
nuclear@2:          if (text ==  NULL)
nuclear@2:          {
nuclear@2:             text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
nuclear@2:             if (text == NULL)
nuclear@2:               {
nuclear@2:                 png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:                 png_ptr->chunkdata = NULL;
nuclear@2:                 png_error(png_ptr, "Not enough memory for text.");
nuclear@2:               }
nuclear@2:             png_memcpy(text, png_ptr->chunkdata, prefix_size);
nuclear@2:          }
nuclear@2:          *(text + text_size) = 0x00;
nuclear@2:       }
nuclear@2: 
nuclear@2:       inflateReset(&png_ptr->zstream);
nuclear@2:       png_ptr->zstream.avail_in = 0;
nuclear@2: 
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = text;
nuclear@2:       *newlength=text_size;
nuclear@2:    }
nuclear@2:    else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
nuclear@2:    {
nuclear@2: #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
nuclear@2:       char umsg[50];
nuclear@2: 
nuclear@2:       png_snprintf(umsg, 50, "Unknown zTXt compression type %d", comp_type);
nuclear@2:       png_warning(png_ptr, umsg);
nuclear@2: #else
nuclear@2:       png_warning(png_ptr, "Unknown zTXt compression type");
nuclear@2: #endif
nuclear@2: 
nuclear@2:       *(png_ptr->chunkdata + prefix_size) = 0x00;
nuclear@2:       *newlength = prefix_size;
nuclear@2:    }
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: /* read and check the IDHR chunk */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte buf[13];
nuclear@2:    png_uint_32 width, height;
nuclear@2:    int bit_depth, color_type, compression_type, filter_type;
nuclear@2:    int interlace_type;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_IHDR\n");
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IHDR)
nuclear@2:       png_error(png_ptr, "Out of place IHDR");
nuclear@2: 
nuclear@2:    /* check the length */
nuclear@2:    if (length != 13)
nuclear@2:       png_error(png_ptr, "Invalid IHDR chunk");
nuclear@2: 
nuclear@2:    png_ptr->mode |= PNG_HAVE_IHDR;
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 13);
nuclear@2:    png_crc_finish(png_ptr, 0);
nuclear@2: 
nuclear@2:    width = png_get_uint_31(png_ptr, buf);
nuclear@2:    height = png_get_uint_31(png_ptr, buf + 4);
nuclear@2:    bit_depth = buf[8];
nuclear@2:    color_type = buf[9];
nuclear@2:    compression_type = buf[10];
nuclear@2:    filter_type = buf[11];
nuclear@2:    interlace_type = buf[12];
nuclear@2: 
nuclear@2:    /* set internal variables */
nuclear@2:    png_ptr->width = width;
nuclear@2:    png_ptr->height = height;
nuclear@2:    png_ptr->bit_depth = (png_byte)bit_depth;
nuclear@2:    png_ptr->interlaced = (png_byte)interlace_type;
nuclear@2:    png_ptr->color_type = (png_byte)color_type;
nuclear@2: #if defined(PNG_MNG_FEATURES_SUPPORTED)
nuclear@2:    png_ptr->filter_type = (png_byte)filter_type;
nuclear@2: #endif
nuclear@2:    png_ptr->compression_type = (png_byte)compression_type;
nuclear@2: 
nuclear@2:    /* find number of channels */
nuclear@2:    switch (png_ptr->color_type)
nuclear@2:    {
nuclear@2:       case PNG_COLOR_TYPE_GRAY:
nuclear@2:       case PNG_COLOR_TYPE_PALETTE:
nuclear@2:          png_ptr->channels = 1;
nuclear@2:          break;
nuclear@2:       case PNG_COLOR_TYPE_RGB:
nuclear@2:          png_ptr->channels = 3;
nuclear@2:          break;
nuclear@2:       case PNG_COLOR_TYPE_GRAY_ALPHA:
nuclear@2:          png_ptr->channels = 2;
nuclear@2:          break;
nuclear@2:       case PNG_COLOR_TYPE_RGB_ALPHA:
nuclear@2:          png_ptr->channels = 4;
nuclear@2:          break;
nuclear@2:    }
nuclear@2: 
nuclear@2:    /* set up other useful info */
nuclear@2:    png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
nuclear@2:    png_ptr->channels);
nuclear@2:    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
nuclear@2:    png_debug1(3, "bit_depth = %d\n", png_ptr->bit_depth);
nuclear@2:    png_debug1(3, "channels = %d\n", png_ptr->channels);
nuclear@2:    png_debug1(3, "rowbytes = %lu\n", png_ptr->rowbytes);
nuclear@2:    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
nuclear@2:       color_type, interlace_type, compression_type, filter_type);
nuclear@2: }
nuclear@2: 
nuclear@2: /* read and check the palette */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_color palette[PNG_MAX_PALETTE_LENGTH];
nuclear@2:    int num, i;
nuclear@2: #ifndef PNG_NO_POINTER_INDEXING
nuclear@2:    png_colorp pal_ptr;
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_PLTE\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before PLTE");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid PLTE after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:       png_error(png_ptr, "Duplicate PLTE chunk");
nuclear@2: 
nuclear@2:    png_ptr->mode |= PNG_HAVE_PLTE;
nuclear@2: 
nuclear@2:    if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr,
nuclear@2:         "Ignoring PLTE chunk in grayscale PNG");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: #if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
nuclear@2:    if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
nuclear@2:    {
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
nuclear@2:    {
nuclear@2:       if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Invalid palette chunk");
nuclear@2:          png_crc_finish(png_ptr, length);
nuclear@2:          return;
nuclear@2:       }
nuclear@2:       else
nuclear@2:       {
nuclear@2:          png_error(png_ptr, "Invalid palette chunk");
nuclear@2:       }
nuclear@2:    }
nuclear@2: 
nuclear@2:    num = (int)length / 3;
nuclear@2: 
nuclear@2: #ifndef PNG_NO_POINTER_INDEXING
nuclear@2:    for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
nuclear@2:    {
nuclear@2:       png_byte buf[3];
nuclear@2: 
nuclear@2:       png_crc_read(png_ptr, buf, 3);
nuclear@2:       pal_ptr->red = buf[0];
nuclear@2:       pal_ptr->green = buf[1];
nuclear@2:       pal_ptr->blue = buf[2];
nuclear@2:    }
nuclear@2: #else
nuclear@2:    for (i = 0; i < num; i++)
nuclear@2:    {
nuclear@2:       png_byte buf[3];
nuclear@2: 
nuclear@2:       png_crc_read(png_ptr, buf, 3);
nuclear@2:       /* don't depend upon png_color being any order */
nuclear@2:       palette[i].red = buf[0];
nuclear@2:       palette[i].green = buf[1];
nuclear@2:       palette[i].blue = buf[2];
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
nuclear@2:       whatever the normal CRC configuration tells us.  However, if we
nuclear@2:       have an RGB image, the PLTE can be considered ancillary, so
nuclear@2:       we will act as though it is. */
nuclear@2: #if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2: #endif
nuclear@2:    {
nuclear@2:       png_crc_finish(png_ptr, 0);
nuclear@2:    }
nuclear@2: #if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
nuclear@2:    else if (png_crc_error(png_ptr))  /* Only if we have a CRC error */
nuclear@2:    {
nuclear@2:       /* If we don't want to use the data from an ancillary chunk,
nuclear@2:          we have two options: an error abort, or a warning and we
nuclear@2:          ignore the data in this chunk (which should be OK, since
nuclear@2:          it's considered ancillary for a RGB or RGBA image). */
nuclear@2:       if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
nuclear@2:       {
nuclear@2:          if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
nuclear@2:          {
nuclear@2:             png_chunk_error(png_ptr, "CRC error");
nuclear@2:          }
nuclear@2:          else
nuclear@2:          {
nuclear@2:             png_chunk_warning(png_ptr, "CRC error");
nuclear@2:             return;
nuclear@2:          }
nuclear@2:       }
nuclear@2:       /* Otherwise, we (optionally) emit a warning and use the chunk. */
nuclear@2:       else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
nuclear@2:       {
nuclear@2:          png_chunk_warning(png_ptr, "CRC error");
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_set_PLTE(png_ptr, info_ptr, palette, num);
nuclear@2: 
nuclear@2: #if defined(PNG_READ_tRNS_SUPPORTED)
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:    {
nuclear@2:       if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
nuclear@2:       {
nuclear@2:          if (png_ptr->num_trans > (png_uint_16)num)
nuclear@2:          {
nuclear@2:             png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
nuclear@2:             png_ptr->num_trans = (png_uint_16)num;
nuclear@2:          }
nuclear@2:          if (info_ptr->num_trans > (png_uint_16)num)
nuclear@2:          {
nuclear@2:             png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
nuclear@2:             info_ptr->num_trans = (png_uint_16)num;
nuclear@2:          }
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2: }
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_debug(1, "in png_handle_IEND\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
nuclear@2:    {
nuclear@2:       png_error(png_ptr, "No image in file");
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
nuclear@2: 
nuclear@2:    if (length != 0)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect IEND chunk length");
nuclear@2:    }
nuclear@2:    png_crc_finish(png_ptr, length);
nuclear@2: 
nuclear@2:    info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
nuclear@2: }
nuclear@2: 
nuclear@2: #if defined(PNG_READ_gAMA_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_fixed_point igamma;
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    float file_gamma;
nuclear@2: #endif
nuclear@2:    png_byte buf[4];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_gAMA\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before gAMA");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid gAMA after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:       /* Should be an error, but we can cope with it */
nuclear@2:       png_warning(png_ptr, "Out of place gAMA chunk");
nuclear@2: 
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
nuclear@2: #if defined(PNG_READ_sRGB_SUPPORTED)
nuclear@2:       && !(info_ptr->valid & PNG_INFO_sRGB)
nuclear@2: #endif
nuclear@2:       )
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate gAMA chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (length != 4)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect gAMA chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 4);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    igamma = (png_fixed_point)png_get_uint_32(buf);
nuclear@2:    /* check for zero gamma */
nuclear@2:    if (igamma == 0)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr,
nuclear@2:            "Ignoring gAMA chunk with gamma=0");
nuclear@2:          return;
nuclear@2:       }
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sRGB_SUPPORTED)
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
nuclear@2:       if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
nuclear@2:       {
nuclear@2:          png_warning(png_ptr,
nuclear@2:            "Ignoring incorrect gAMA value when sRGB is also present");
nuclear@2: #ifndef PNG_NO_CONSOLE_IO
nuclear@2:          fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma);
nuclear@2: #endif
nuclear@2:          return;
nuclear@2:       }
nuclear@2: #endif /* PNG_READ_sRGB_SUPPORTED */
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    file_gamma = (float)igamma / (float)100000.0;
nuclear@2: #  ifdef PNG_READ_GAMMA_SUPPORTED
nuclear@2:      png_ptr->gamma = file_gamma;
nuclear@2: #  endif
nuclear@2:      png_set_gAMA(png_ptr, info_ptr, file_gamma);
nuclear@2: #endif
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
nuclear@2: #endif
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sBIT_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_size_t truelen;
nuclear@2:    png_byte buf[4];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_sBIT\n");
nuclear@2: 
nuclear@2:    buf[0] = buf[1] = buf[2] = buf[3] = 0;
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before sBIT");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid sBIT after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:    {
nuclear@2:       /* Should be an error, but we can cope with it */
nuclear@2:       png_warning(png_ptr, "Out of place sBIT chunk");
nuclear@2:    }
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate sBIT chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:       truelen = 3;
nuclear@2:    else
nuclear@2:       truelen = (png_size_t)png_ptr->channels;
nuclear@2: 
nuclear@2:    if (length != truelen || length > 4)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect sBIT chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, truelen);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
nuclear@2:    {
nuclear@2:       png_ptr->sig_bit.red = buf[0];
nuclear@2:       png_ptr->sig_bit.green = buf[1];
nuclear@2:       png_ptr->sig_bit.blue = buf[2];
nuclear@2:       png_ptr->sig_bit.alpha = buf[3];
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:       png_ptr->sig_bit.gray = buf[0];
nuclear@2:       png_ptr->sig_bit.red = buf[0];
nuclear@2:       png_ptr->sig_bit.green = buf[0];
nuclear@2:       png_ptr->sig_bit.blue = buf[0];
nuclear@2:       png_ptr->sig_bit.alpha = buf[1];
nuclear@2:    }
nuclear@2:    png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_cHRM_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte buf[32];
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
nuclear@2: #endif
nuclear@2:    png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
nuclear@2:       int_y_green, int_x_blue, int_y_blue;
nuclear@2: 
nuclear@2:    png_uint_32 uint_x, uint_y;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_cHRM\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before cHRM");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid cHRM after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:       /* Should be an error, but we can cope with it */
nuclear@2:       png_warning(png_ptr, "Missing PLTE before cHRM");
nuclear@2: 
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
nuclear@2: #if defined(PNG_READ_sRGB_SUPPORTED)
nuclear@2:       && !(info_ptr->valid & PNG_INFO_sRGB)
nuclear@2: #endif
nuclear@2:       )
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate cHRM chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (length != 32)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect cHRM chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 32);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    uint_x = png_get_uint_32(buf);
nuclear@2:    uint_y = png_get_uint_32(buf + 4);
nuclear@2:    if (uint_x > 80000L || uint_y > 80000L ||
nuclear@2:       uint_x + uint_y > 100000L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid cHRM white point");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    int_x_white = (png_fixed_point)uint_x;
nuclear@2:    int_y_white = (png_fixed_point)uint_y;
nuclear@2: 
nuclear@2:    uint_x = png_get_uint_32(buf + 8);
nuclear@2:    uint_y = png_get_uint_32(buf + 12);
nuclear@2:    if (uint_x + uint_y > 100000L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid cHRM red point");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    int_x_red = (png_fixed_point)uint_x;
nuclear@2:    int_y_red = (png_fixed_point)uint_y;
nuclear@2: 
nuclear@2:    uint_x = png_get_uint_32(buf + 16);
nuclear@2:    uint_y = png_get_uint_32(buf + 20);
nuclear@2:    if (uint_x + uint_y > 100000L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid cHRM green point");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    int_x_green = (png_fixed_point)uint_x;
nuclear@2:    int_y_green = (png_fixed_point)uint_y;
nuclear@2: 
nuclear@2:    uint_x = png_get_uint_32(buf + 24);
nuclear@2:    uint_y = png_get_uint_32(buf + 28);
nuclear@2:    if (uint_x + uint_y > 100000L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid cHRM blue point");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    int_x_blue = (png_fixed_point)uint_x;
nuclear@2:    int_y_blue = (png_fixed_point)uint_y;
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    white_x = (float)int_x_white / (float)100000.0;
nuclear@2:    white_y = (float)int_y_white / (float)100000.0;
nuclear@2:    red_x   = (float)int_x_red   / (float)100000.0;
nuclear@2:    red_y   = (float)int_y_red   / (float)100000.0;
nuclear@2:    green_x = (float)int_x_green / (float)100000.0;
nuclear@2:    green_y = (float)int_y_green / (float)100000.0;
nuclear@2:    blue_x  = (float)int_x_blue  / (float)100000.0;
nuclear@2:    blue_y  = (float)int_y_blue  / (float)100000.0;
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sRGB_SUPPORTED)
nuclear@2:    if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
nuclear@2:       {
nuclear@2:       if (PNG_OUT_OF_RANGE(int_x_white, 31270,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_y_white, 32900,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_x_red,   64000L, 1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_y_red,   33000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_x_green, 30000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_x_blue,  15000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(int_y_blue,   6000,  1000))
nuclear@2:          {
nuclear@2:             png_warning(png_ptr,
nuclear@2:               "Ignoring incorrect cHRM value when sRGB is also present");
nuclear@2: #ifndef PNG_NO_CONSOLE_IO
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:             fprintf(stderr, "wx=%f, wy=%f, rx=%f, ry=%f\n",
nuclear@2:                white_x, white_y, red_x, red_y);
nuclear@2:             fprintf(stderr, "gx=%f, gy=%f, bx=%f, by=%f\n",
nuclear@2:                green_x, green_y, blue_x, blue_y);
nuclear@2: #else
nuclear@2:             fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
nuclear@2:                int_x_white, int_y_white, int_x_red, int_y_red);
nuclear@2:             fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
nuclear@2:                int_x_green, int_y_green, int_x_blue, int_y_blue);
nuclear@2: #endif
nuclear@2: #endif /* PNG_NO_CONSOLE_IO */
nuclear@2:          }
nuclear@2:          return;
nuclear@2:       }
nuclear@2: #endif /* PNG_READ_sRGB_SUPPORTED */
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    png_set_cHRM(png_ptr, info_ptr,
nuclear@2:       white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
nuclear@2: #endif
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    png_set_cHRM_fixed(png_ptr, info_ptr,
nuclear@2:       int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
nuclear@2:       int_y_green, int_x_blue, int_y_blue);
nuclear@2: #endif
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sRGB_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    int intent;
nuclear@2:    png_byte buf[1];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_sRGB\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before sRGB");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid sRGB after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:       /* Should be an error, but we can cope with it */
nuclear@2:       png_warning(png_ptr, "Out of place sRGB chunk");
nuclear@2: 
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate sRGB chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (length != 1)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect sRGB chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 1);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    intent = buf[0];
nuclear@2:    /* check for bad intent */
nuclear@2:    if (intent >= PNG_sRGB_INTENT_LAST)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Unknown sRGB intent");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2: #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
nuclear@2:    {
nuclear@2:    png_fixed_point igamma;
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:       igamma=info_ptr->int_gamma;
nuclear@2: #else
nuclear@2: #  ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:       igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
nuclear@2: #  endif
nuclear@2: #endif
nuclear@2:       if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
nuclear@2:       {
nuclear@2:          png_warning(png_ptr,
nuclear@2:            "Ignoring incorrect gAMA value when sRGB is also present");
nuclear@2: #ifndef PNG_NO_CONSOLE_IO
nuclear@2: #  ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:          fprintf(stderr, "incorrect gamma=(%d/100000)\n",
nuclear@2:             (int)png_ptr->int_gamma);
nuclear@2: #  else
nuclear@2: #    ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:          fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
nuclear@2: #    endif
nuclear@2: #  endif
nuclear@2: #endif
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif /* PNG_READ_gAMA_SUPPORTED */
nuclear@2: 
nuclear@2: #ifdef PNG_READ_cHRM_SUPPORTED
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
nuclear@2:       if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_x_red,   64000L, 1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_y_red,   33000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_x_blue,  15000,  1000) ||
nuclear@2:           PNG_OUT_OF_RANGE(info_ptr->int_y_blue,   6000,  1000))
nuclear@2:          {
nuclear@2:             png_warning(png_ptr,
nuclear@2:               "Ignoring incorrect cHRM value when sRGB is also present");
nuclear@2:          }
nuclear@2: #endif /* PNG_FIXED_POINT_SUPPORTED */
nuclear@2: #endif /* PNG_READ_cHRM_SUPPORTED */
nuclear@2: 
nuclear@2:    png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
nuclear@2: }
nuclear@2: #endif /* PNG_READ_sRGB_SUPPORTED */
nuclear@2: 
nuclear@2: #if defined(PNG_READ_iCCP_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: /* Note: this does not properly handle chunks that are > 64K under DOS */
nuclear@2: {
nuclear@2:    png_byte compression_type;
nuclear@2:    png_bytep pC;
nuclear@2:    png_charp profile;
nuclear@2:    png_uint_32 skip = 0;
nuclear@2:    png_uint_32 profile_size, profile_length;
nuclear@2:    png_size_t slength, prefix_length, data_length;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_iCCP\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before iCCP");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid iCCP after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_PLTE)
nuclear@2:       /* Should be an error, but we can cope with it */
nuclear@2:       png_warning(png_ptr, "Out of place iCCP chunk");
nuclear@2: 
nuclear@2:    if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate iCCP chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    if (length > (png_uint_32)65535L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "iCCP chunk too large to fit in memory");
nuclear@2:       skip = length - (png_uint_32)65535L;
nuclear@2:       length = (png_uint_32)65535L;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, skip))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00;
nuclear@2: 
nuclear@2:    for (profile = png_ptr->chunkdata; *profile; profile++)
nuclear@2:       /* empty loop to find end of name */ ;
nuclear@2: 
nuclear@2:    ++profile;
nuclear@2: 
nuclear@2:    /* there should be at least one zero (the compression type byte)
nuclear@2:       following the separator, and we should be on it  */
nuclear@2:    if ( profile >= png_ptr->chunkdata + slength - 1)
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       png_warning(png_ptr, "Malformed iCCP chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    /* compression_type should always be zero */
nuclear@2:    compression_type = *profile++;
nuclear@2:    if (compression_type)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
nuclear@2:       compression_type = 0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
nuclear@2:                                  wrote nonzero) */
nuclear@2:    }
nuclear@2: 
nuclear@2:    prefix_length = profile - png_ptr->chunkdata;
nuclear@2:    png_decompress_chunk(png_ptr, compression_type,
nuclear@2:      slength, prefix_length, &data_length);
nuclear@2: 
nuclear@2:    profile_length = data_length - prefix_length;
nuclear@2: 
nuclear@2:    if ( prefix_length > data_length || profile_length < 4)
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       png_warning(png_ptr, "Profile size field missing from iCCP chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    /* Check the profile_size recorded in the first 32 bits of the ICC profile */
nuclear@2:    pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
nuclear@2:    profile_size = ((*(pC    ))<<24) |
nuclear@2:                   ((*(pC + 1))<<16) |
nuclear@2:                   ((*(pC + 2))<< 8) |
nuclear@2:                   ((*(pC + 3))    );
nuclear@2: 
nuclear@2:    if (profile_size < profile_length)
nuclear@2:       profile_length = profile_size;
nuclear@2: 
nuclear@2:    if (profile_size > profile_length)
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       png_warning(png_ptr, "Ignoring truncated iCCP profile.");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
nuclear@2:      compression_type, png_ptr->chunkdata + prefix_length, profile_length);
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2: }
nuclear@2: #endif /* PNG_READ_iCCP_SUPPORTED */
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sPLT_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: /* Note: this does not properly handle chunks that are > 64K under DOS */
nuclear@2: {
nuclear@2:    png_bytep entry_start;
nuclear@2:    png_sPLT_t new_palette;
nuclear@2: #ifdef PNG_NO_POINTER_INDEXING
nuclear@2:    png_sPLT_entryp pp;
nuclear@2: #endif
nuclear@2:    int data_length, entry_size, i;
nuclear@2:    png_uint_32 skip = 0;
nuclear@2:    png_size_t slength;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_sPLT\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before sPLT");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid sPLT after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    if (length > (png_uint_32)65535L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "sPLT chunk too large to fit in memory");
nuclear@2:       skip = length - (png_uint_32)65535L;
nuclear@2:       length = (png_uint_32)65535L;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, skip))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00;
nuclear@2: 
nuclear@2:    for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; entry_start++)
nuclear@2:       /* empty loop to find end of name */ ;
nuclear@2:    ++entry_start;
nuclear@2: 
nuclear@2:    /* a sample depth should follow the separator, and we should be on it  */
nuclear@2:    if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       png_warning(png_ptr, "malformed sPLT chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    new_palette.depth = *entry_start++;
nuclear@2:    entry_size = (new_palette.depth == 8 ? 6 : 10);
nuclear@2:    data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));
nuclear@2: 
nuclear@2:    /* integrity-check the data length */
nuclear@2:    if (data_length % entry_size)
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       png_warning(png_ptr, "sPLT chunk has bad length");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    new_palette.nentries = (png_int_32) ( data_length / entry_size);
nuclear@2:    if ((png_uint_32) new_palette.nentries >
nuclear@2:        (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
nuclear@2:    {
nuclear@2:        png_warning(png_ptr, "sPLT chunk too long");
nuclear@2:        return;
nuclear@2:    }
nuclear@2:    new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
nuclear@2:        png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
nuclear@2:    if (new_palette.entries == NULL)
nuclear@2:    {
nuclear@2:        png_warning(png_ptr, "sPLT chunk requires too much memory");
nuclear@2:        return;
nuclear@2:    }
nuclear@2: 
nuclear@2: #ifndef PNG_NO_POINTER_INDEXING
nuclear@2:    for (i = 0; i < new_palette.nentries; i++)
nuclear@2:    {
nuclear@2:       png_sPLT_entryp pp = new_palette.entries + i;
nuclear@2: 
nuclear@2:       if (new_palette.depth == 8)
nuclear@2:       {
nuclear@2:           pp->red = *entry_start++;
nuclear@2:           pp->green = *entry_start++;
nuclear@2:           pp->blue = *entry_start++;
nuclear@2:           pp->alpha = *entry_start++;
nuclear@2:       }
nuclear@2:       else
nuclear@2:       {
nuclear@2:           pp->red   = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp->green = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:       }
nuclear@2:       pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:    }
nuclear@2: #else
nuclear@2:    pp = new_palette.entries;
nuclear@2:    for (i = 0; i < new_palette.nentries; i++)
nuclear@2:    {
nuclear@2: 
nuclear@2:       if (new_palette.depth == 8)
nuclear@2:       {
nuclear@2:           pp[i].red   = *entry_start++;
nuclear@2:           pp[i].green = *entry_start++;
nuclear@2:           pp[i].blue  = *entry_start++;
nuclear@2:           pp[i].alpha = *entry_start++;
nuclear@2:       }
nuclear@2:       else
nuclear@2:       {
nuclear@2:           pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:           pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:       }
nuclear@2:       pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    /* discard all chunk data except the name and stash that */
nuclear@2:    new_palette.name = png_ptr->chunkdata;
nuclear@2: 
nuclear@2:    png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2:    png_free(png_ptr, new_palette.entries);
nuclear@2: }
nuclear@2: #endif /* PNG_READ_sPLT_SUPPORTED */
nuclear@2: 
nuclear@2: #if defined(PNG_READ_tRNS_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_tRNS\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before tRNS");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid tRNS after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate tRNS chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@2:    {
nuclear@2:       png_byte buf[2];
nuclear@2: 
nuclear@2:       if (length != 2)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Incorrect tRNS chunk length");
nuclear@2:          png_crc_finish(png_ptr, length);
nuclear@2:          return;
nuclear@2:       }
nuclear@2: 
nuclear@2:       png_crc_read(png_ptr, buf, 2);
nuclear@2:       png_ptr->num_trans = 1;
nuclear@2:       png_ptr->trans_values.gray = png_get_uint_16(buf);
nuclear@2:    }
nuclear@2:    else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
nuclear@2:    {
nuclear@2:       png_byte buf[6];
nuclear@2: 
nuclear@2:       if (length != 6)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Incorrect tRNS chunk length");
nuclear@2:          png_crc_finish(png_ptr, length);
nuclear@2:          return;
nuclear@2:       }
nuclear@2:       png_crc_read(png_ptr, buf, (png_size_t)length);
nuclear@2:       png_ptr->num_trans = 1;
nuclear@2:       png_ptr->trans_values.red = png_get_uint_16(buf);
nuclear@2:       png_ptr->trans_values.green = png_get_uint_16(buf + 2);
nuclear@2:       png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
nuclear@2:    }
nuclear@2:    else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:    {
nuclear@2:       if (!(png_ptr->mode & PNG_HAVE_PLTE))
nuclear@2:       {
nuclear@2:          /* Should be an error, but we can cope with it. */
nuclear@2:          png_warning(png_ptr, "Missing PLTE before tRNS");
nuclear@2:       }
nuclear@2:       if (length > (png_uint_32)png_ptr->num_palette ||
nuclear@2:           length > PNG_MAX_PALETTE_LENGTH)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Incorrect tRNS chunk length");
nuclear@2:          png_crc_finish(png_ptr, length);
nuclear@2:          return;
nuclear@2:       }
nuclear@2:       if (length == 0)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Zero length tRNS chunk");
nuclear@2:          png_crc_finish(png_ptr, length);
nuclear@2:          return;
nuclear@2:       }
nuclear@2:       png_crc_read(png_ptr, readbuf, (png_size_t)length);
nuclear@2:       png_ptr->num_trans = (png_uint_16)length;
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:    {
nuclear@2:       png_ptr->num_trans = 0;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
nuclear@2:       &(png_ptr->trans_values));
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_bKGD_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_size_t truelen;
nuclear@2:    png_byte buf[6];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_bKGD\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before bKGD");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid bKGD after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
nuclear@2:             !(png_ptr->mode & PNG_HAVE_PLTE))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Missing PLTE before bKGD");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate bKGD chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:       truelen = 1;
nuclear@2:    else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
nuclear@2:       truelen = 6;
nuclear@2:    else
nuclear@2:       truelen = 2;
nuclear@2: 
nuclear@2:    if (length != truelen)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect bKGD chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, truelen);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    /* We convert the index value into RGB components so that we can allow
nuclear@2:     * arbitrary RGB values for background when we have transparency, and
nuclear@2:     * so it is easy to determine the RGB values of the background color
nuclear@2:     * from the info_ptr struct. */
nuclear@2:    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:    {
nuclear@2:       png_ptr->background.index = buf[0];
nuclear@2:       if (info_ptr && info_ptr->num_palette)
nuclear@2:       {
nuclear@2:           if (buf[0] > info_ptr->num_palette)
nuclear@2:           {
nuclear@2:              png_warning(png_ptr, "Incorrect bKGD chunk index value");
nuclear@2:              return;
nuclear@2:           }
nuclear@2:           png_ptr->background.red =
nuclear@2:              (png_uint_16)png_ptr->palette[buf[0]].red;
nuclear@2:           png_ptr->background.green =
nuclear@2:              (png_uint_16)png_ptr->palette[buf[0]].green;
nuclear@2:           png_ptr->background.blue =
nuclear@2:              (png_uint_16)png_ptr->palette[buf[0]].blue;
nuclear@2:       }
nuclear@2:    }
nuclear@2:    else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
nuclear@2:    {
nuclear@2:       png_ptr->background.red =
nuclear@2:       png_ptr->background.green =
nuclear@2:       png_ptr->background.blue =
nuclear@2:       png_ptr->background.gray = png_get_uint_16(buf);
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:       png_ptr->background.red = png_get_uint_16(buf);
nuclear@2:       png_ptr->background.green = png_get_uint_16(buf + 2);
nuclear@2:       png_ptr->background.blue = png_get_uint_16(buf + 4);
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_hIST_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    unsigned int num, i;
nuclear@2:    png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_hIST\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before hIST");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid hIST after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (!(png_ptr->mode & PNG_HAVE_PLTE))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Missing PLTE before hIST");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate hIST chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    num = length / 2 ;
nuclear@2:    if (num != (unsigned int) png_ptr->num_palette || num >
nuclear@2:       (unsigned int) PNG_MAX_PALETTE_LENGTH)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect hIST chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    for (i = 0; i < num; i++)
nuclear@2:    {
nuclear@2:       png_byte buf[2];
nuclear@2: 
nuclear@2:       png_crc_read(png_ptr, buf, 2);
nuclear@2:       readbuf[i] = png_get_uint_16(buf);
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    png_set_hIST(png_ptr, info_ptr, readbuf);
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_pHYs_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte buf[9];
nuclear@2:    png_uint_32 res_x, res_y;
nuclear@2:    int unit_type;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_pHYs\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before pHYs");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid pHYs after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate pHYs chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (length != 9)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect pHYs chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 9);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    res_x = png_get_uint_32(buf);
nuclear@2:    res_y = png_get_uint_32(buf + 4);
nuclear@2:    unit_type = buf[8];
nuclear@2:    png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_oFFs_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte buf[9];
nuclear@2:    png_int_32 offset_x, offset_y;
nuclear@2:    int unit_type;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_oFFs\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before oFFs");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid oFFs after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate oFFs chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (length != 9)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect oFFs chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 9);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    offset_x = png_get_int_32(buf);
nuclear@2:    offset_y = png_get_int_32(buf + 4);
nuclear@2:    unit_type = buf[8];
nuclear@2:    png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_pCAL_SUPPORTED)
nuclear@2: /* read the pCAL chunk (described in the PNG Extensions document) */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_int_32 X0, X1;
nuclear@2:    png_byte type, nparams;
nuclear@2:    png_charp buf, units, endptr;
nuclear@2:    png_charpp params;
nuclear@2:    png_size_t slength;
nuclear@2:    int i;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_pCAL\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before pCAL");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid pCAL after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate pCAL chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n",
nuclear@2:       length + 1);
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
nuclear@2:    if (png_ptr->chunkdata == NULL)
nuclear@2:      {
nuclear@2:        png_warning(png_ptr, "No memory for pCAL purpose.");
nuclear@2:        return;
nuclear@2:      }
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
nuclear@2: 
nuclear@2:    png_debug(3, "Finding end of pCAL purpose string\n");
nuclear@2:    for (buf = png_ptr->chunkdata; *buf; buf++)
nuclear@2:       /* empty loop */ ;
nuclear@2: 
nuclear@2:    endptr = png_ptr->chunkdata + slength;
nuclear@2: 
nuclear@2:    /* We need to have at least 12 bytes after the purpose string
nuclear@2:       in order to get the parameter information. */
nuclear@2:    if (endptr <= buf + 12)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid pCAL data");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
nuclear@2:    X0 = png_get_int_32((png_bytep)buf+1);
nuclear@2:    X1 = png_get_int_32((png_bytep)buf+5);
nuclear@2:    type = buf[9];
nuclear@2:    nparams = buf[10];
nuclear@2:    units = buf + 11;
nuclear@2: 
nuclear@2:    png_debug(3, "Checking pCAL equation type and number of parameters\n");
nuclear@2:    /* Check that we have the right number of parameters for known
nuclear@2:       equation types. */
nuclear@2:    if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
nuclear@2:        (type == PNG_EQUATION_BASE_E && nparams != 3) ||
nuclear@2:        (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
nuclear@2:        (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid pCAL parameters for equation type");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (type >= PNG_EQUATION_LAST)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
nuclear@2:    }
nuclear@2: 
nuclear@2:    for (buf = units; *buf; buf++)
nuclear@2:       /* Empty loop to move past the units string. */ ;
nuclear@2: 
nuclear@2:    png_debug(3, "Allocating pCAL parameters array\n");
nuclear@2:    params = (png_charpp)png_malloc_warn(png_ptr,
nuclear@2:       (png_uint_32)(nparams * png_sizeof(png_charp))) ;
nuclear@2:    if (params == NULL)
nuclear@2:      {
nuclear@2:        png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:        png_ptr->chunkdata = NULL;
nuclear@2:        png_warning(png_ptr, "No memory for pCAL params.");
nuclear@2:        return;
nuclear@2:      }
nuclear@2: 
nuclear@2:    /* Get pointers to the start of each parameter string. */
nuclear@2:    for (i = 0; i < (int)nparams; i++)
nuclear@2:    {
nuclear@2:       buf++; /* Skip the null string terminator from previous parameter. */
nuclear@2: 
nuclear@2:       png_debug1(3, "Reading pCAL parameter %d\n", i);
nuclear@2:       for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++)
nuclear@2:          /* Empty loop to move past each parameter string */ ;
nuclear@2: 
nuclear@2:       /* Make sure we haven't run out of data yet */
nuclear@2:       if (buf > endptr)
nuclear@2:       {
nuclear@2:          png_warning(png_ptr, "Invalid pCAL data");
nuclear@2:          png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:          png_ptr->chunkdata = NULL;
nuclear@2:          png_free(png_ptr, params);
nuclear@2:          return;
nuclear@2:       }
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
nuclear@2:       units, params);
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2:    png_free(png_ptr, params);
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_sCAL_SUPPORTED)
nuclear@2: /* read the sCAL chunk */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_charp ep;
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    double width, height;
nuclear@2:    png_charp vp;
nuclear@2: #else
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    png_charp swidth, sheight;
nuclear@2: #endif
nuclear@2: #endif
nuclear@2:    png_size_t slength;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_sCAL\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before sCAL");
nuclear@2:    else if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid sCAL after IDAT");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate sCAL chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n",
nuclear@2:       length + 1);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
nuclear@2:    if (png_ptr->chunkdata == NULL)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Out of memory while processing sCAL chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
nuclear@2: 
nuclear@2:    ep = png_ptr->chunkdata + 1;        /* skip unit byte */
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    width = png_strtod(png_ptr, ep, &vp);
nuclear@2:    if (*vp)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "malformed width string in sCAL chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: #else
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
nuclear@2:    if (swidth == NULL)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
nuclear@2: #endif
nuclear@2: #endif
nuclear@2: 
nuclear@2:    for (ep = png_ptr->chunkdata; *ep; ep++)
nuclear@2:       /* empty loop */ ;
nuclear@2:    ep++;
nuclear@2: 
nuclear@2:    if (png_ptr->chunkdata + slength < ep)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Truncated sCAL chunk");
nuclear@2: #if defined(PNG_FIXED_POINT_SUPPORTED) && \
nuclear@2:     !defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@2:       png_free(png_ptr, swidth);
nuclear@2: #endif
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    height = png_strtod(png_ptr, ep, &vp);
nuclear@2:    if (*vp)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "malformed height string in sCAL chunk");
nuclear@2:       return;
nuclear@2:    }
nuclear@2: #else
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
nuclear@2:    if (sheight == NULL)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
nuclear@2: #endif
nuclear@2: #endif
nuclear@2: 
nuclear@2:    if (png_ptr->chunkdata + slength < ep
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:       || width <= 0. || height <= 0.
nuclear@2: #endif
nuclear@2:       )
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Invalid sCAL data");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2: #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@2:       png_free(png_ptr, swidth);
nuclear@2:       png_free(png_ptr, sheight);
nuclear@2: #endif
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2: 
nuclear@2: #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@2:    png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height);
nuclear@2: #else
nuclear@2: #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@2:    png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight);
nuclear@2: #endif
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2: #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@2:    png_free(png_ptr, swidth);
nuclear@2:    png_free(png_ptr, sheight);
nuclear@2: #endif
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_tIME_SUPPORTED)
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_byte buf[7];
nuclear@2:    png_time mod_time;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_tIME\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Out of place tIME chunk");
nuclear@2:    else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Duplicate tIME chunk");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:       png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2: 
nuclear@2:    if (length != 7)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Incorrect tIME chunk length");
nuclear@2:       png_crc_finish(png_ptr, length);
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_crc_read(png_ptr, buf, 7);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:       return;
nuclear@2: 
nuclear@2:    mod_time.second = buf[6];
nuclear@2:    mod_time.minute = buf[5];
nuclear@2:    mod_time.hour = buf[4];
nuclear@2:    mod_time.day = buf[3];
nuclear@2:    mod_time.month = buf[2];
nuclear@2:    mod_time.year = png_get_uint_16(buf);
nuclear@2: 
nuclear@2:    png_set_tIME(png_ptr, info_ptr, &mod_time);
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_tEXt_SUPPORTED)
nuclear@2: /* Note: this does not properly handle chunks that are > 64K under DOS */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_textp text_ptr;
nuclear@2:    png_charp key;
nuclear@2:    png_charp text;
nuclear@2:    png_uint_32 skip = 0;
nuclear@2:    png_size_t slength;
nuclear@2:    int ret;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_tEXt\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before tEXt");
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:       png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    if (length > (png_uint_32)65535L)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "tEXt chunk too large to fit in memory");
nuclear@2:       skip = length - (png_uint_32)65535L;
nuclear@2:       length = (png_uint_32)65535L;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
nuclear@2:    if (png_ptr->chunkdata == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "No memory to process text chunk.");
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2: 
nuclear@2:    if (png_crc_finish(png_ptr, skip))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    key = png_ptr->chunkdata;
nuclear@2:    key[slength] = 0x00;
nuclear@2: 
nuclear@2:    for (text = key; *text; text++)
nuclear@2:       /* empty loop to find end of key */ ;
nuclear@2: 
nuclear@2:    if (text != key + slength)
nuclear@2:       text++;
nuclear@2: 
nuclear@2:    text_ptr = (png_textp)png_malloc_warn(png_ptr,
nuclear@2:       (png_uint_32)png_sizeof(png_text));
nuclear@2:    if (text_ptr == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "Not enough memory to process text chunk.");
nuclear@2:      png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:      png_ptr->chunkdata = NULL;
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
nuclear@2:    text_ptr->key = key;
nuclear@2: #ifdef PNG_iTXt_SUPPORTED
nuclear@2:    text_ptr->lang = NULL;
nuclear@2:    text_ptr->lang_key = NULL;
nuclear@2:    text_ptr->itxt_length = 0;
nuclear@2: #endif
nuclear@2:    text_ptr->text = text;
nuclear@2:    text_ptr->text_length = png_strlen(text);
nuclear@2: 
nuclear@2:    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2:    png_free(png_ptr, text_ptr);
nuclear@2:    if (ret)
nuclear@2:      png_warning(png_ptr, "Insufficient memory to process text chunk.");
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_zTXt_SUPPORTED)
nuclear@2: /* note: this does not correctly handle chunks that are > 64K under DOS */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_textp text_ptr;
nuclear@2:    png_charp text;
nuclear@2:    int comp_type;
nuclear@2:    int ret;
nuclear@2:    png_size_t slength, prefix_len, data_len;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_zTXt\n");
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before zTXt");
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:       png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    /* We will no doubt have problems with chunks even half this size, but
nuclear@2:       there is no hard and fast rule to tell us where to stop. */
nuclear@2:    if (length > (png_uint_32)65535L)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "zTXt chunk too large to fit in memory");
nuclear@2:      png_crc_finish(png_ptr, length);
nuclear@2:      return;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
nuclear@2:    if (png_ptr->chunkdata == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "Out of memory processing zTXt chunk.");
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00;
nuclear@2: 
nuclear@2:    for (text = png_ptr->chunkdata; *text; text++)
nuclear@2:       /* empty loop */ ;
nuclear@2: 
nuclear@2:    /* zTXt must have some text after the chunkdataword */
nuclear@2:    if (text >= png_ptr->chunkdata + slength - 2)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Truncated zTXt chunk");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:        comp_type = *(++text);
nuclear@2:        if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
nuclear@2:        {
nuclear@2:           png_warning(png_ptr, "Unknown compression type in zTXt chunk");
nuclear@2:           comp_type = PNG_TEXT_COMPRESSION_zTXt;
nuclear@2:        }
nuclear@2:        text++;        /* skip the compression_method byte */
nuclear@2:    }
nuclear@2:    prefix_len = text - png_ptr->chunkdata;
nuclear@2: 
nuclear@2:    png_decompress_chunk(png_ptr, comp_type,
nuclear@2:      (png_size_t)length, prefix_len, &data_len);
nuclear@2: 
nuclear@2:    text_ptr = (png_textp)png_malloc_warn(png_ptr,
nuclear@2:       (png_uint_32)png_sizeof(png_text));
nuclear@2:    if (text_ptr == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "Not enough memory to process zTXt chunk.");
nuclear@2:      png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:      png_ptr->chunkdata = NULL;
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    text_ptr->compression = comp_type;
nuclear@2:    text_ptr->key = png_ptr->chunkdata;
nuclear@2: #ifdef PNG_iTXt_SUPPORTED
nuclear@2:    text_ptr->lang = NULL;
nuclear@2:    text_ptr->lang_key = NULL;
nuclear@2:    text_ptr->itxt_length = 0;
nuclear@2: #endif
nuclear@2:    text_ptr->text = png_ptr->chunkdata + prefix_len;
nuclear@2:    text_ptr->text_length = data_len;
nuclear@2: 
nuclear@2:    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
nuclear@2: 
nuclear@2:    png_free(png_ptr, text_ptr);
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2:    if (ret)
nuclear@2:      png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_iTXt_SUPPORTED)
nuclear@2: /* note: this does not correctly handle chunks that are > 64K under DOS */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_textp text_ptr;
nuclear@2:    png_charp key, lang, text, lang_key;
nuclear@2:    int comp_flag;
nuclear@2:    int comp_type = 0;
nuclear@2:    int ret;
nuclear@2:    png_size_t slength, prefix_len, data_len;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_iTXt\n");
nuclear@2: 
nuclear@2:    if (!(png_ptr->mode & PNG_HAVE_IHDR))
nuclear@2:       png_error(png_ptr, "Missing IHDR before iTXt");
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:       png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    /* We will no doubt have problems with chunks even half this size, but
nuclear@2:       there is no hard and fast rule to tell us where to stop. */
nuclear@2:    if (length > (png_uint_32)65535L)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "iTXt chunk too large to fit in memory");
nuclear@2:      png_crc_finish(png_ptr, length);
nuclear@2:      return;
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
nuclear@2:    if (png_ptr->chunkdata == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "No memory to process iTXt chunk.");
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    slength = (png_size_t)length;
nuclear@2:    png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
nuclear@2:    if (png_crc_finish(png_ptr, 0))
nuclear@2:    {
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_ptr->chunkdata[slength] = 0x00;
nuclear@2: 
nuclear@2:    for (lang = png_ptr->chunkdata; *lang; lang++)
nuclear@2:       /* empty loop */ ;
nuclear@2:    lang++;        /* skip NUL separator */
nuclear@2: 
nuclear@2:    /* iTXt must have a language tag (possibly empty), two compression bytes,
nuclear@2:       translated keyword (possibly empty), and possibly some text after the
nuclear@2:       keyword */
nuclear@2: 
nuclear@2:    if (lang >= png_ptr->chunkdata + slength - 3)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Truncated iTXt chunk");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:        comp_flag = *lang++;
nuclear@2:        comp_type = *lang++;
nuclear@2:    }
nuclear@2: 
nuclear@2:    for (lang_key = lang; *lang_key; lang_key++)
nuclear@2:       /* empty loop */ ;
nuclear@2:    lang_key++;        /* skip NUL separator */
nuclear@2: 
nuclear@2:    if (lang_key >= png_ptr->chunkdata + slength)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Truncated iTXt chunk");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    for (text = lang_key; *text; text++)
nuclear@2:       /* empty loop */ ;
nuclear@2:    text++;        /* skip NUL separator */
nuclear@2:    if (text >= png_ptr->chunkdata + slength)
nuclear@2:    {
nuclear@2:       png_warning(png_ptr, "Malformed iTXt chunk");
nuclear@2:       png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:       png_ptr->chunkdata = NULL;
nuclear@2:       return;
nuclear@2:    }
nuclear@2: 
nuclear@2:    prefix_len = text - png_ptr->chunkdata;
nuclear@2: 
nuclear@2:    key=png_ptr->chunkdata;
nuclear@2:    if (comp_flag)
nuclear@2:        png_decompress_chunk(png_ptr, comp_type,
nuclear@2:          (size_t)length, prefix_len, &data_len);
nuclear@2:    else
nuclear@2:        data_len = png_strlen(png_ptr->chunkdata + prefix_len);
nuclear@2:    text_ptr = (png_textp)png_malloc_warn(png_ptr,
nuclear@2:       (png_uint_32)png_sizeof(png_text));
nuclear@2:    if (text_ptr == NULL)
nuclear@2:    {
nuclear@2:      png_warning(png_ptr, "Not enough memory to process iTXt chunk.");
nuclear@2:      png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:      png_ptr->chunkdata = NULL;
nuclear@2:      return;
nuclear@2:    }
nuclear@2:    text_ptr->compression = (int)comp_flag + 1;
nuclear@2:    text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
nuclear@2:    text_ptr->lang = png_ptr->chunkdata + (lang - key);
nuclear@2:    text_ptr->itxt_length = data_len;
nuclear@2:    text_ptr->text_length = 0;
nuclear@2:    text_ptr->key = png_ptr->chunkdata;
nuclear@2:    text_ptr->text = png_ptr->chunkdata + prefix_len;
nuclear@2: 
nuclear@2:    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
nuclear@2: 
nuclear@2:    png_free(png_ptr, text_ptr);
nuclear@2:    png_free(png_ptr, png_ptr->chunkdata);
nuclear@2:    png_ptr->chunkdata = NULL;
nuclear@2:    if (ret)
nuclear@2:      png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
nuclear@2: }
nuclear@2: #endif
nuclear@2: 
nuclear@2: /* This function is called when we haven't found a handler for a
nuclear@2:    chunk.  If there isn't a problem with the chunk itself (ie bad
nuclear@2:    chunk name, CRC, or a critical chunk), the chunk is silently ignored
nuclear@2:    -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
nuclear@2:    case it will be saved away to be written out later. */
nuclear@2: void /* PRIVATE */
nuclear@2: png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
nuclear@2: {
nuclear@2:    png_uint_32 skip = 0;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_handle_unknown\n");
nuclear@2: 
nuclear@2:    if (png_ptr->mode & PNG_HAVE_IDAT)
nuclear@2:    {
nuclear@2: #ifdef PNG_USE_LOCAL_ARRAYS
nuclear@2:       PNG_CONST PNG_IDAT;
nuclear@2: #endif
nuclear@2:       if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))  /* not an IDAT */
nuclear@2:          png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (!(png_ptr->chunk_name[0] & 0x20))
nuclear@2:    {
nuclear@2: #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
nuclear@2:       if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
nuclear@2:            PNG_HANDLE_CHUNK_ALWAYS
nuclear@2: #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
nuclear@2:            && png_ptr->read_user_chunk_fn == NULL
nuclear@2: #endif
nuclear@2:         )
nuclear@2: #endif
nuclear@2:           png_chunk_error(png_ptr, "unknown critical chunk");
nuclear@2:    }
nuclear@2: 
nuclear@2: #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
nuclear@2:    if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) ||
nuclear@2:        (png_ptr->read_user_chunk_fn != NULL))
nuclear@2:    {
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:        if (length > (png_uint_32)65535L)
nuclear@2:        {
nuclear@2:            png_warning(png_ptr, "unknown chunk too large to fit in memory");
nuclear@2:            skip = length - (png_uint_32)65535L;
nuclear@2:            length = (png_uint_32)65535L;
nuclear@2:        }
nuclear@2: #endif
nuclear@2:        png_memcpy((png_charp)png_ptr->unknown_chunk.name,
nuclear@2:                   (png_charp)png_ptr->chunk_name, 
nuclear@2:                   png_sizeof(png_ptr->unknown_chunk.name));
nuclear@2:        png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] = '\0';
nuclear@2:        png_ptr->unknown_chunk.size = (png_size_t)length;
nuclear@2:        if (length == 0)
nuclear@2:          png_ptr->unknown_chunk.data = NULL;
nuclear@2:        else
nuclear@2:        {
nuclear@2:          png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
nuclear@2:          png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
nuclear@2:        }
nuclear@2: #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
nuclear@2:        if (png_ptr->read_user_chunk_fn != NULL)
nuclear@2:        {
nuclear@2:           /* callback to user unknown chunk handler */
nuclear@2:           int ret;
nuclear@2:           ret = (*(png_ptr->read_user_chunk_fn))
nuclear@2:             (png_ptr, &png_ptr->unknown_chunk);
nuclear@2:           if (ret < 0)
nuclear@2:              png_chunk_error(png_ptr, "error in user chunk");
nuclear@2:           if (ret == 0)
nuclear@2:           {
nuclear@2:              if (!(png_ptr->chunk_name[0] & 0x20))
nuclear@2:                 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
nuclear@2:                      PNG_HANDLE_CHUNK_ALWAYS)
nuclear@2:                    png_chunk_error(png_ptr, "unknown critical chunk");
nuclear@2:              png_set_unknown_chunks(png_ptr, info_ptr,
nuclear@2:                &png_ptr->unknown_chunk, 1);
nuclear@2:           }
nuclear@2:        }
nuclear@2:        else
nuclear@2: #endif
nuclear@2:        png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
nuclear@2:        png_free(png_ptr, png_ptr->unknown_chunk.data);
nuclear@2:        png_ptr->unknown_chunk.data = NULL;
nuclear@2:    }
nuclear@2:    else
nuclear@2: #endif
nuclear@2:       skip = length;
nuclear@2: 
nuclear@2:    png_crc_finish(png_ptr, skip);
nuclear@2: 
nuclear@2: #if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
nuclear@2:    info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
nuclear@2: #endif
nuclear@2: }
nuclear@2: 
nuclear@2: /* This function is called to verify that a chunk name is valid.
nuclear@2:    This function can't have the "critical chunk check" incorporated
nuclear@2:    into it, since in the future we will need to be able to call user
nuclear@2:    functions to handle unknown critical chunks after we check that
nuclear@2:    the chunk name itself is valid. */
nuclear@2: 
nuclear@2: #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
nuclear@2: {
nuclear@2:    png_debug(1, "in png_check_chunk_name\n");
nuclear@2:    if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
nuclear@2:        isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
nuclear@2:    {
nuclear@2:       png_chunk_error(png_ptr, "invalid chunk type");
nuclear@2:    }
nuclear@2: }
nuclear@2: 
nuclear@2: /* Combines the row recently read in with the existing pixels in the
nuclear@2:    row.  This routine takes care of alpha and transparency if requested.
nuclear@2:    This routine also handles the two methods of progressive display
nuclear@2:    of interlaced images, depending on the mask value.
nuclear@2:    The mask value describes which pixels are to be combined with
nuclear@2:    the row.  The pattern always repeats every 8 pixels, so just 8
nuclear@2:    bits are needed.  A one indicates the pixel is to be combined,
nuclear@2:    a zero indicates the pixel is to be skipped.  This is in addition
nuclear@2:    to any alpha or transparency value associated with the pixel.  If
nuclear@2:    you want all pixels to be combined, pass 0xff (255) in mask.  */
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_combine_row(png_structp png_ptr, png_bytep row, int mask)
nuclear@2: {
nuclear@2:    png_debug(1, "in png_combine_row\n");
nuclear@2:    if (mask == 0xff)
nuclear@2:    {
nuclear@2:       png_memcpy(row, png_ptr->row_buf + 1,
nuclear@2:          PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
nuclear@2:    }
nuclear@2:    else
nuclear@2:    {
nuclear@2:       switch (png_ptr->row_info.pixel_depth)
nuclear@2:       {
nuclear@2:          case 1:
nuclear@2:          {
nuclear@2:             png_bytep sp = png_ptr->row_buf + 1;
nuclear@2:             png_bytep dp = row;
nuclear@2:             int s_inc, s_start, s_end;
nuclear@2:             int m = 0x80;
nuclear@2:             int shift;
nuclear@2:             png_uint_32 i;
nuclear@2:             png_uint_32 row_width = png_ptr->width;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (png_ptr->transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                 s_start = 0;
nuclear@2:                 s_end = 7;
nuclear@2:                 s_inc = 1;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                 s_start = 7;
nuclear@2:                 s_end = 0;
nuclear@2:                 s_inc = -1;
nuclear@2:             }
nuclear@2: 
nuclear@2:             shift = s_start;
nuclear@2: 
nuclear@2:             for (i = 0; i < row_width; i++)
nuclear@2:             {
nuclear@2:                if (m & mask)
nuclear@2:                {
nuclear@2:                   int value;
nuclear@2: 
nuclear@2:                   value = (*sp >> shift) & 0x01;
nuclear@2:                   *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(value << shift);
nuclear@2:                }
nuclear@2: 
nuclear@2:                if (shift == s_end)
nuclear@2:                {
nuclear@2:                   shift = s_start;
nuclear@2:                   sp++;
nuclear@2:                   dp++;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   shift += s_inc;
nuclear@2: 
nuclear@2:                if (m == 1)
nuclear@2:                   m = 0x80;
nuclear@2:                else
nuclear@2:                   m >>= 1;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          case 2:
nuclear@2:          {
nuclear@2:             png_bytep sp = png_ptr->row_buf + 1;
nuclear@2:             png_bytep dp = row;
nuclear@2:             int s_start, s_end, s_inc;
nuclear@2:             int m = 0x80;
nuclear@2:             int shift;
nuclear@2:             png_uint_32 i;
nuclear@2:             png_uint_32 row_width = png_ptr->width;
nuclear@2:             int value;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (png_ptr->transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                s_start = 0;
nuclear@2:                s_end = 6;
nuclear@2:                s_inc = 2;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                s_start = 6;
nuclear@2:                s_end = 0;
nuclear@2:                s_inc = -2;
nuclear@2:             }
nuclear@2: 
nuclear@2:             shift = s_start;
nuclear@2: 
nuclear@2:             for (i = 0; i < row_width; i++)
nuclear@2:             {
nuclear@2:                if (m & mask)
nuclear@2:                {
nuclear@2:                   value = (*sp >> shift) & 0x03;
nuclear@2:                   *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(value << shift);
nuclear@2:                }
nuclear@2: 
nuclear@2:                if (shift == s_end)
nuclear@2:                {
nuclear@2:                   shift = s_start;
nuclear@2:                   sp++;
nuclear@2:                   dp++;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   shift += s_inc;
nuclear@2:                if (m == 1)
nuclear@2:                   m = 0x80;
nuclear@2:                else
nuclear@2:                   m >>= 1;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          case 4:
nuclear@2:          {
nuclear@2:             png_bytep sp = png_ptr->row_buf + 1;
nuclear@2:             png_bytep dp = row;
nuclear@2:             int s_start, s_end, s_inc;
nuclear@2:             int m = 0x80;
nuclear@2:             int shift;
nuclear@2:             png_uint_32 i;
nuclear@2:             png_uint_32 row_width = png_ptr->width;
nuclear@2:             int value;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (png_ptr->transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                s_start = 0;
nuclear@2:                s_end = 4;
nuclear@2:                s_inc = 4;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                s_start = 4;
nuclear@2:                s_end = 0;
nuclear@2:                s_inc = -4;
nuclear@2:             }
nuclear@2:             shift = s_start;
nuclear@2: 
nuclear@2:             for (i = 0; i < row_width; i++)
nuclear@2:             {
nuclear@2:                if (m & mask)
nuclear@2:                {
nuclear@2:                   value = (*sp >> shift) & 0xf;
nuclear@2:                   *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(value << shift);
nuclear@2:                }
nuclear@2: 
nuclear@2:                if (shift == s_end)
nuclear@2:                {
nuclear@2:                   shift = s_start;
nuclear@2:                   sp++;
nuclear@2:                   dp++;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   shift += s_inc;
nuclear@2:                if (m == 1)
nuclear@2:                   m = 0x80;
nuclear@2:                else
nuclear@2:                   m >>= 1;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          default:
nuclear@2:          {
nuclear@2:             png_bytep sp = png_ptr->row_buf + 1;
nuclear@2:             png_bytep dp = row;
nuclear@2:             png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
nuclear@2:             png_uint_32 i;
nuclear@2:             png_uint_32 row_width = png_ptr->width;
nuclear@2:             png_byte m = 0x80;
nuclear@2: 
nuclear@2: 
nuclear@2:             for (i = 0; i < row_width; i++)
nuclear@2:             {
nuclear@2:                if (m & mask)
nuclear@2:                {
nuclear@2:                   png_memcpy(dp, sp, pixel_bytes);
nuclear@2:                }
nuclear@2: 
nuclear@2:                sp += pixel_bytes;
nuclear@2:                dp += pixel_bytes;
nuclear@2: 
nuclear@2:                if (m == 1)
nuclear@2:                   m = 0x80;
nuclear@2:                else
nuclear@2:                   m >>= 1;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:       }
nuclear@2:    }
nuclear@2: }
nuclear@2: 
nuclear@2: #ifdef PNG_READ_INTERLACING_SUPPORTED
nuclear@2: /* OLD pre-1.0.9 interface:
nuclear@2: void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
nuclear@2:    png_uint_32 transformations)
nuclear@2:  */
nuclear@2: void /* PRIVATE */
nuclear@2: png_do_read_interlace(png_structp png_ptr)
nuclear@2: {
nuclear@2:    png_row_infop row_info = &(png_ptr->row_info);
nuclear@2:    png_bytep row = png_ptr->row_buf + 1;
nuclear@2:    int pass = png_ptr->pass;
nuclear@2:    png_uint_32 transformations = png_ptr->transformations;
nuclear@2: #ifdef PNG_USE_LOCAL_ARRAYS
nuclear@2:    /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
nuclear@2:    /* offset to next interlace block */
nuclear@2:    PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_debug(1, "in png_do_read_interlace\n");
nuclear@2:    if (row != NULL && row_info != NULL)
nuclear@2:    {
nuclear@2:       png_uint_32 final_width;
nuclear@2: 
nuclear@2:       final_width = row_info->width * png_pass_inc[pass];
nuclear@2: 
nuclear@2:       switch (row_info->pixel_depth)
nuclear@2:       {
nuclear@2:          case 1:
nuclear@2:          {
nuclear@2:             png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
nuclear@2:             png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
nuclear@2:             int sshift, dshift;
nuclear@2:             int s_start, s_end, s_inc;
nuclear@2:             int jstop = png_pass_inc[pass];
nuclear@2:             png_byte v;
nuclear@2:             png_uint_32 i;
nuclear@2:             int j;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                 sshift = (int)((row_info->width + 7) & 0x07);
nuclear@2:                 dshift = (int)((final_width + 7) & 0x07);
nuclear@2:                 s_start = 7;
nuclear@2:                 s_end = 0;
nuclear@2:                 s_inc = -1;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                 sshift = 7 - (int)((row_info->width + 7) & 0x07);
nuclear@2:                 dshift = 7 - (int)((final_width + 7) & 0x07);
nuclear@2:                 s_start = 0;
nuclear@2:                 s_end = 7;
nuclear@2:                 s_inc = 1;
nuclear@2:             }
nuclear@2: 
nuclear@2:             for (i = 0; i < row_info->width; i++)
nuclear@2:             {
nuclear@2:                v = (png_byte)((*sp >> sshift) & 0x01);
nuclear@2:                for (j = 0; j < jstop; j++)
nuclear@2:                {
nuclear@2:                   *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(v << dshift);
nuclear@2:                   if (dshift == s_end)
nuclear@2:                   {
nuclear@2:                      dshift = s_start;
nuclear@2:                      dp--;
nuclear@2:                   }
nuclear@2:                   else
nuclear@2:                      dshift += s_inc;
nuclear@2:                }
nuclear@2:                if (sshift == s_end)
nuclear@2:                {
nuclear@2:                   sshift = s_start;
nuclear@2:                   sp--;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   sshift += s_inc;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          case 2:
nuclear@2:          {
nuclear@2:             png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
nuclear@2:             png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
nuclear@2:             int sshift, dshift;
nuclear@2:             int s_start, s_end, s_inc;
nuclear@2:             int jstop = png_pass_inc[pass];
nuclear@2:             png_uint_32 i;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                sshift = (int)(((row_info->width + 3) & 0x03) << 1);
nuclear@2:                dshift = (int)(((final_width + 3) & 0x03) << 1);
nuclear@2:                s_start = 6;
nuclear@2:                s_end = 0;
nuclear@2:                s_inc = -2;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
nuclear@2:                dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
nuclear@2:                s_start = 0;
nuclear@2:                s_end = 6;
nuclear@2:                s_inc = 2;
nuclear@2:             }
nuclear@2: 
nuclear@2:             for (i = 0; i < row_info->width; i++)
nuclear@2:             {
nuclear@2:                png_byte v;
nuclear@2:                int j;
nuclear@2: 
nuclear@2:                v = (png_byte)((*sp >> sshift) & 0x03);
nuclear@2:                for (j = 0; j < jstop; j++)
nuclear@2:                {
nuclear@2:                   *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(v << dshift);
nuclear@2:                   if (dshift == s_end)
nuclear@2:                   {
nuclear@2:                      dshift = s_start;
nuclear@2:                      dp--;
nuclear@2:                   }
nuclear@2:                   else
nuclear@2:                      dshift += s_inc;
nuclear@2:                }
nuclear@2:                if (sshift == s_end)
nuclear@2:                {
nuclear@2:                   sshift = s_start;
nuclear@2:                   sp--;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   sshift += s_inc;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          case 4:
nuclear@2:          {
nuclear@2:             png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
nuclear@2:             png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
nuclear@2:             int sshift, dshift;
nuclear@2:             int s_start, s_end, s_inc;
nuclear@2:             png_uint_32 i;
nuclear@2:             int jstop = png_pass_inc[pass];
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:             if (transformations & PNG_PACKSWAP)
nuclear@2:             {
nuclear@2:                sshift = (int)(((row_info->width + 1) & 0x01) << 2);
nuclear@2:                dshift = (int)(((final_width + 1) & 0x01) << 2);
nuclear@2:                s_start = 4;
nuclear@2:                s_end = 0;
nuclear@2:                s_inc = -4;
nuclear@2:             }
nuclear@2:             else
nuclear@2: #endif
nuclear@2:             {
nuclear@2:                sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
nuclear@2:                dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
nuclear@2:                s_start = 0;
nuclear@2:                s_end = 4;
nuclear@2:                s_inc = 4;
nuclear@2:             }
nuclear@2: 
nuclear@2:             for (i = 0; i < row_info->width; i++)
nuclear@2:             {
nuclear@2:                png_byte v = (png_byte)((*sp >> sshift) & 0xf);
nuclear@2:                int j;
nuclear@2: 
nuclear@2:                for (j = 0; j < jstop; j++)
nuclear@2:                {
nuclear@2:                   *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
nuclear@2:                   *dp |= (png_byte)(v << dshift);
nuclear@2:                   if (dshift == s_end)
nuclear@2:                   {
nuclear@2:                      dshift = s_start;
nuclear@2:                      dp--;
nuclear@2:                   }
nuclear@2:                   else
nuclear@2:                      dshift += s_inc;
nuclear@2:                }
nuclear@2:                if (sshift == s_end)
nuclear@2:                {
nuclear@2:                   sshift = s_start;
nuclear@2:                   sp--;
nuclear@2:                }
nuclear@2:                else
nuclear@2:                   sshift += s_inc;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          default:
nuclear@2:          {
nuclear@2:             png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
nuclear@2:             png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
nuclear@2:             png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
nuclear@2: 
nuclear@2:             int jstop = png_pass_inc[pass];
nuclear@2:             png_uint_32 i;
nuclear@2: 
nuclear@2:             for (i = 0; i < row_info->width; i++)
nuclear@2:             {
nuclear@2:                png_byte v[8];
nuclear@2:                int j;
nuclear@2: 
nuclear@2:                png_memcpy(v, sp, pixel_bytes);
nuclear@2:                for (j = 0; j < jstop; j++)
nuclear@2:                {
nuclear@2:                   png_memcpy(dp, v, pixel_bytes);
nuclear@2:                   dp -= pixel_bytes;
nuclear@2:                }
nuclear@2:                sp -= pixel_bytes;
nuclear@2:             }
nuclear@2:             break;
nuclear@2:          }
nuclear@2:       }
nuclear@2:       row_info->width = final_width;
nuclear@2:       row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
nuclear@2:    }
nuclear@2: #if !defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@2:    transformations = transformations; /* silence compiler warning */
nuclear@2: #endif
nuclear@2: }
nuclear@2: #endif /* PNG_READ_INTERLACING_SUPPORTED */
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
nuclear@2:    png_bytep prev_row, int filter)
nuclear@2: {
nuclear@2:    png_debug(1, "in png_read_filter_row\n");
nuclear@2:    png_debug2(2, "row = %lu, filter = %d\n", png_ptr->row_number, filter);
nuclear@2:    switch (filter)
nuclear@2:    {
nuclear@2:       case PNG_FILTER_VALUE_NONE:
nuclear@2:          break;
nuclear@2:       case PNG_FILTER_VALUE_SUB:
nuclear@2:       {
nuclear@2:          png_uint_32 i;
nuclear@2:          png_uint_32 istop = row_info->rowbytes;
nuclear@2:          png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
nuclear@2:          png_bytep rp = row + bpp;
nuclear@2:          png_bytep lp = row;
nuclear@2: 
nuclear@2:          for (i = bpp; i < istop; i++)
nuclear@2:          {
nuclear@2:             *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2:          break;
nuclear@2:       }
nuclear@2:       case PNG_FILTER_VALUE_UP:
nuclear@2:       {
nuclear@2:          png_uint_32 i;
nuclear@2:          png_uint_32 istop = row_info->rowbytes;
nuclear@2:          png_bytep rp = row;
nuclear@2:          png_bytep pp = prev_row;
nuclear@2: 
nuclear@2:          for (i = 0; i < istop; i++)
nuclear@2:          {
nuclear@2:             *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2:          break;
nuclear@2:       }
nuclear@2:       case PNG_FILTER_VALUE_AVG:
nuclear@2:       {
nuclear@2:          png_uint_32 i;
nuclear@2:          png_bytep rp = row;
nuclear@2:          png_bytep pp = prev_row;
nuclear@2:          png_bytep lp = row;
nuclear@2:          png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
nuclear@2:          png_uint_32 istop = row_info->rowbytes - bpp;
nuclear@2: 
nuclear@2:          for (i = 0; i < bpp; i++)
nuclear@2:          {
nuclear@2:             *rp = (png_byte)(((int)(*rp) +
nuclear@2:                ((int)(*pp++) / 2 )) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2: 
nuclear@2:          for (i = 0; i < istop; i++)
nuclear@2:          {
nuclear@2:             *rp = (png_byte)(((int)(*rp) +
nuclear@2:                (int)(*pp++ + *lp++) / 2 ) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2:          break;
nuclear@2:       }
nuclear@2:       case PNG_FILTER_VALUE_PAETH:
nuclear@2:       {
nuclear@2:          png_uint_32 i;
nuclear@2:          png_bytep rp = row;
nuclear@2:          png_bytep pp = prev_row;
nuclear@2:          png_bytep lp = row;
nuclear@2:          png_bytep cp = prev_row;
nuclear@2:          png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
nuclear@2:          png_uint_32 istop=row_info->rowbytes - bpp;
nuclear@2: 
nuclear@2:          for (i = 0; i < bpp; i++)
nuclear@2:          {
nuclear@2:             *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2: 
nuclear@2:          for (i = 0; i < istop; i++)   /* use leftover rp,pp */
nuclear@2:          {
nuclear@2:             int a, b, c, pa, pb, pc, p;
nuclear@2: 
nuclear@2:             a = *lp++;
nuclear@2:             b = *pp++;
nuclear@2:             c = *cp++;
nuclear@2: 
nuclear@2:             p = b - c;
nuclear@2:             pc = a - c;
nuclear@2: 
nuclear@2: #ifdef PNG_USE_ABS
nuclear@2:             pa = abs(p);
nuclear@2:             pb = abs(pc);
nuclear@2:             pc = abs(p + pc);
nuclear@2: #else
nuclear@2:             pa = p < 0 ? -p : p;
nuclear@2:             pb = pc < 0 ? -pc : pc;
nuclear@2:             pc = (p + pc) < 0 ? -(p + pc) : p + pc;
nuclear@2: #endif
nuclear@2: 
nuclear@2:             /*
nuclear@2:                if (pa <= pb && pa <= pc)
nuclear@2:                   p = a;
nuclear@2:                else if (pb <= pc)
nuclear@2:                   p = b;
nuclear@2:                else
nuclear@2:                   p = c;
nuclear@2:              */
nuclear@2: 
nuclear@2:             p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
nuclear@2: 
nuclear@2:             *rp = (png_byte)(((int)(*rp) + p) & 0xff);
nuclear@2:             rp++;
nuclear@2:          }
nuclear@2:          break;
nuclear@2:       }
nuclear@2:       default:
nuclear@2:          png_warning(png_ptr, "Ignoring bad adaptive filter type");
nuclear@2:          *row = 0;
nuclear@2:          break;
nuclear@2:    }
nuclear@2: }
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_read_finish_row(png_structp png_ptr)
nuclear@2: {
nuclear@2: #ifdef PNG_USE_LOCAL_ARRAYS
nuclear@2: #ifdef PNG_READ_INTERLACING_SUPPORTED
nuclear@2:    /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
nuclear@2: 
nuclear@2:    /* start of interlace block */
nuclear@2:    PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
nuclear@2: 
nuclear@2:    /* offset to next interlace block */
nuclear@2:    PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
nuclear@2: 
nuclear@2:    /* start of interlace block in the y direction */
nuclear@2:    PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
nuclear@2: 
nuclear@2:    /* offset to next interlace block in the y direction */
nuclear@2:    PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
nuclear@2: #endif /* PNG_READ_INTERLACING_SUPPORTED */
nuclear@2: #endif
nuclear@2: 
nuclear@2:    png_debug(1, "in png_read_finish_row\n");
nuclear@2:    png_ptr->row_number++;
nuclear@2:    if (png_ptr->row_number < png_ptr->num_rows)
nuclear@2:       return;
nuclear@2: 
nuclear@2: #ifdef PNG_READ_INTERLACING_SUPPORTED
nuclear@2:    if (png_ptr->interlaced)
nuclear@2:    {
nuclear@2:       png_ptr->row_number = 0;
nuclear@2:       png_memset_check(png_ptr, png_ptr->prev_row, 0,
nuclear@2:          png_ptr->rowbytes + 1);
nuclear@2:       do
nuclear@2:       {
nuclear@2:          png_ptr->pass++;
nuclear@2:          if (png_ptr->pass >= 7)
nuclear@2:             break;
nuclear@2:          png_ptr->iwidth = (png_ptr->width +
nuclear@2:             png_pass_inc[png_ptr->pass] - 1 -
nuclear@2:             png_pass_start[png_ptr->pass]) /
nuclear@2:             png_pass_inc[png_ptr->pass];
nuclear@2: 
nuclear@2:          png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
nuclear@2:             png_ptr->iwidth) + 1;
nuclear@2: 
nuclear@2:          if (!(png_ptr->transformations & PNG_INTERLACE))
nuclear@2:          {
nuclear@2:             png_ptr->num_rows = (png_ptr->height +
nuclear@2:                png_pass_yinc[png_ptr->pass] - 1 -
nuclear@2:                png_pass_ystart[png_ptr->pass]) /
nuclear@2:                png_pass_yinc[png_ptr->pass];
nuclear@2:             if (!(png_ptr->num_rows))
nuclear@2:                continue;
nuclear@2:          }
nuclear@2:          else  /* if (png_ptr->transformations & PNG_INTERLACE) */
nuclear@2:             break;
nuclear@2:       } while (png_ptr->iwidth == 0);
nuclear@2: 
nuclear@2:       if (png_ptr->pass < 7)
nuclear@2:          return;
nuclear@2:    }
nuclear@2: #endif /* PNG_READ_INTERLACING_SUPPORTED */
nuclear@2: 
nuclear@2:    if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
nuclear@2:    {
nuclear@2: #ifdef PNG_USE_LOCAL_ARRAYS
nuclear@2:       PNG_CONST PNG_IDAT;
nuclear@2: #endif
nuclear@2:       char extra;
nuclear@2:       int ret;
nuclear@2: 
nuclear@2:       png_ptr->zstream.next_out = (Byte *)&extra;
nuclear@2:       png_ptr->zstream.avail_out = (uInt)1;
nuclear@2:       for (;;)
nuclear@2:       {
nuclear@2:          if (!(png_ptr->zstream.avail_in))
nuclear@2:          {
nuclear@2:             while (!png_ptr->idat_size)
nuclear@2:             {
nuclear@2:                png_byte chunk_length[4];
nuclear@2: 
nuclear@2:                png_crc_finish(png_ptr, 0);
nuclear@2: 
nuclear@2:                png_read_data(png_ptr, chunk_length, 4);
nuclear@2:                png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
nuclear@2:                png_reset_crc(png_ptr);
nuclear@2:                png_crc_read(png_ptr, png_ptr->chunk_name, 4);
nuclear@2:                if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
nuclear@2:                   png_error(png_ptr, "Not enough image data");
nuclear@2: 
nuclear@2:             }
nuclear@2:             png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
nuclear@2:             png_ptr->zstream.next_in = png_ptr->zbuf;
nuclear@2:             if (png_ptr->zbuf_size > png_ptr->idat_size)
nuclear@2:                png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
nuclear@2:             png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
nuclear@2:             png_ptr->idat_size -= png_ptr->zstream.avail_in;
nuclear@2:          }
nuclear@2:          ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
nuclear@2:          if (ret == Z_STREAM_END)
nuclear@2:          {
nuclear@2:             if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
nuclear@2:                png_ptr->idat_size)
nuclear@2:                png_warning(png_ptr, "Extra compressed data");
nuclear@2:             png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2:             png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
nuclear@2:             break;
nuclear@2:          }
nuclear@2:          if (ret != Z_OK)
nuclear@2:             png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
nuclear@2:                       "Decompression Error");
nuclear@2: 
nuclear@2:          if (!(png_ptr->zstream.avail_out))
nuclear@2:          {
nuclear@2:             png_warning(png_ptr, "Extra compressed data.");
nuclear@2:             png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2:             png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
nuclear@2:             break;
nuclear@2:          }
nuclear@2: 
nuclear@2:       }
nuclear@2:       png_ptr->zstream.avail_out = 0;
nuclear@2:    }
nuclear@2: 
nuclear@2:    if (png_ptr->idat_size || png_ptr->zstream.avail_in)
nuclear@2:       png_warning(png_ptr, "Extra compression data");
nuclear@2: 
nuclear@2:    inflateReset(&png_ptr->zstream);
nuclear@2: 
nuclear@2:    png_ptr->mode |= PNG_AFTER_IDAT;
nuclear@2: }
nuclear@2: 
nuclear@2: void /* PRIVATE */
nuclear@2: png_read_start_row(png_structp png_ptr)
nuclear@2: {
nuclear@2: #ifdef PNG_USE_LOCAL_ARRAYS
nuclear@2: #ifdef PNG_READ_INTERLACING_SUPPORTED
nuclear@2:    /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
nuclear@2: 
nuclear@2:    /* start of interlace block */
nuclear@2:    PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
nuclear@2: 
nuclear@2:    /* offset to next interlace block */
nuclear@2:    PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
nuclear@2: 
nuclear@2:    /* start of interlace block in the y direction */
nuclear@2:    PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
nuclear@2: 
nuclear@2:    /* offset to next interlace block in the y direction */
nuclear@2:    PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
nuclear@2: #endif
nuclear@2: #endif
nuclear@2: 
nuclear@2:    int max_pixel_depth;
nuclear@2:    png_size_t row_bytes;
nuclear@2: 
nuclear@2:    png_debug(1, "in png_read_start_row\n");
nuclear@2:    png_ptr->zstream.avail_in = 0;
nuclear@2:    png_init_read_transformations(png_ptr);
nuclear@2: #ifdef PNG_READ_INTERLACING_SUPPORTED
nuclear@2:    if (png_ptr->interlaced)
nuclear@2:    {
nuclear@2:       if (!(png_ptr->transformations & PNG_INTERLACE))
nuclear@2:          png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
nuclear@2:             png_pass_ystart[0]) / png_pass_yinc[0];
nuclear@2:       else
nuclear@2:          png_ptr->num_rows = png_ptr->height;
nuclear@2: 
nuclear@2:       png_ptr->iwidth = (png_ptr->width +
nuclear@2:          png_pass_inc[png_ptr->pass] - 1 -
nuclear@2:          png_pass_start[png_ptr->pass]) /
nuclear@2:          png_pass_inc[png_ptr->pass];
nuclear@2: 
nuclear@2:          png_ptr->irowbytes =
nuclear@2:             PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1;
nuclear@2:    }
nuclear@2:    else
nuclear@2: #endif /* PNG_READ_INTERLACING_SUPPORTED */
nuclear@2:    {
nuclear@2:       png_ptr->num_rows = png_ptr->height;
nuclear@2:       png_ptr->iwidth = png_ptr->width;
nuclear@2:       png_ptr->irowbytes = png_ptr->rowbytes + 1;
nuclear@2:    }
nuclear@2:    max_pixel_depth = png_ptr->pixel_depth;
nuclear@2: 
nuclear@2: #if defined(PNG_READ_PACK_SUPPORTED)
nuclear@2:    if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
nuclear@2:       max_pixel_depth = 8;
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@2:    if (png_ptr->transformations & PNG_EXPAND)
nuclear@2:    {
nuclear@2:       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:       {
nuclear@2:          if (png_ptr->num_trans)
nuclear@2:             max_pixel_depth = 32;
nuclear@2:          else
nuclear@2:             max_pixel_depth = 24;
nuclear@2:       }
nuclear@2:       else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@2:       {
nuclear@2:          if (max_pixel_depth < 8)
nuclear@2:             max_pixel_depth = 8;
nuclear@2:          if (png_ptr->num_trans)
nuclear@2:             max_pixel_depth *= 2;
nuclear@2:       }
nuclear@2:       else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
nuclear@2:       {
nuclear@2:          if (png_ptr->num_trans)
nuclear@2:          {
nuclear@2:             max_pixel_depth *= 4;
nuclear@2:             max_pixel_depth /= 3;
nuclear@2:          }
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_FILLER_SUPPORTED)
nuclear@2:    if (png_ptr->transformations & (PNG_FILLER))
nuclear@2:    {
nuclear@2:       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@2:          max_pixel_depth = 32;
nuclear@2:       else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@2:       {
nuclear@2:          if (max_pixel_depth <= 8)
nuclear@2:             max_pixel_depth = 16;
nuclear@2:          else
nuclear@2:             max_pixel_depth = 32;
nuclear@2:       }
nuclear@2:       else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
nuclear@2:       {
nuclear@2:          if (max_pixel_depth <= 32)
nuclear@2:             max_pixel_depth = 32;
nuclear@2:          else
nuclear@2:             max_pixel_depth = 64;
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@2:    if (png_ptr->transformations & PNG_GRAY_TO_RGB)
nuclear@2:    {
nuclear@2:       if (
nuclear@2: #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@2:         (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
nuclear@2: #endif
nuclear@2: #if defined(PNG_READ_FILLER_SUPPORTED)
nuclear@2:         (png_ptr->transformations & (PNG_FILLER)) ||
nuclear@2: #endif
nuclear@2:         png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@2:       {
nuclear@2:          if (max_pixel_depth <= 16)
nuclear@2:             max_pixel_depth = 32;
nuclear@2:          else
nuclear@2:             max_pixel_depth = 64;
nuclear@2:       }
nuclear@2:       else
nuclear@2:       {
nuclear@2:          if (max_pixel_depth <= 8)
nuclear@2:            {
nuclear@2:              if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@2:                max_pixel_depth = 32;
nuclear@2:              else
nuclear@2:                max_pixel_depth = 24;
nuclear@2:            }
nuclear@2:          else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@2:             max_pixel_depth = 64;
nuclear@2:          else
nuclear@2:             max_pixel_depth = 48;
nuclear@2:       }
nuclear@2:    }
nuclear@2: #endif
nuclear@2: 
nuclear@2: #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
nuclear@2: defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
nuclear@2:    if (png_ptr->transformations & PNG_USER_TRANSFORM)
nuclear@2:      {
nuclear@2:        int user_pixel_depth = png_ptr->user_transform_depth*
nuclear@2:          png_ptr->user_transform_channels;
nuclear@2:        if (user_pixel_depth > max_pixel_depth)
nuclear@2:          max_pixel_depth=user_pixel_depth;
nuclear@2:      }
nuclear@2: #endif
nuclear@2: 
nuclear@2:    /* align the width on the next larger 8 pixels.  Mainly used
nuclear@2:       for interlacing */
nuclear@2:    row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
nuclear@2:    /* calculate the maximum bytes needed, adding a byte and a pixel
nuclear@2:       for safety's sake */
nuclear@2:    row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
nuclear@2:       1 + ((max_pixel_depth + 7) >> 3);
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    if (row_bytes > (png_uint_32)65536L)
nuclear@2:       png_error(png_ptr, "This image requires a row greater than 64KB");
nuclear@2: #endif
nuclear@2: 
nuclear@2:    if (row_bytes + 64 > png_ptr->old_big_row_buf_size)
nuclear@2:    {
nuclear@2:      png_free(png_ptr, png_ptr->big_row_buf);
nuclear@2:      png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64);
nuclear@2:      png_ptr->row_buf = png_ptr->big_row_buf+32;
nuclear@2:      png_ptr->old_big_row_buf_size = row_bytes+64;
nuclear@2:    }
nuclear@2: 
nuclear@2: #ifdef PNG_MAX_MALLOC_64K
nuclear@2:    if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
nuclear@2:       png_error(png_ptr, "This image requires a row greater than 64KB");
nuclear@2: #endif
nuclear@2:    if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
nuclear@2:       png_error(png_ptr, "Row has too many bytes to allocate in memory.");
nuclear@2: 
nuclear@2:    if (png_ptr->rowbytes+1 > png_ptr->old_prev_row_size)
nuclear@2:    {
nuclear@2:      png_free(png_ptr, png_ptr->prev_row);
nuclear@2:      png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
nuclear@2:         png_ptr->rowbytes + 1));
nuclear@2:      png_ptr->old_prev_row_size = png_ptr->rowbytes+1;
nuclear@2:    }
nuclear@2: 
nuclear@2:    png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
nuclear@2: 
nuclear@2:    png_debug1(3, "width = %lu,\n", png_ptr->width);
nuclear@2:    png_debug1(3, "height = %lu,\n", png_ptr->height);
nuclear@2:    png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth);
nuclear@2:    png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows);
nuclear@2:    png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes);
nuclear@2:    png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes);
nuclear@2: 
nuclear@2:    png_ptr->flags |= PNG_FLAG_ROW_INIT;
nuclear@2: }
nuclear@2: #endif /* PNG_READ_SUPPORTED */