pngwutil.c

It was built with libpng version 1.2.35, and is running with libpng version 1.2.35

   png_sPLT_entryp ep;
#ifdef PNG_NO_POINTER_INDEXING
   int i;
#endif

   png_debug(1, "in png_write_sPLT");
   if ((name_len = png_check_keyword(png_ptr,
      spalette->name, &new_name))==0)
     return;

   /* make sure we include the NULL after the name */
   png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
     (png_uint_32)(name_len + 2 + palette_size));
   png_write_chunk_data(png_ptr, (png_bytep)new_name,
     (png_size_t)(name_len + 1));
   png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);

   /* loop through each palette entry, writing appropriately */
#ifndef PNG_NO_POINTER_INDEXING
   for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
   {
      if (spalette->depth == 8)
      {
          entrybuf[0] = (png_byte)ep->red;
          entrybuf[1] = (png_byte)ep->green;
          entrybuf[2] = (png_byte)ep->blue;
          entrybuf[3] = (png_byte)ep->alpha;
          png_save_uint_16(entrybuf + 4, ep->frequency);
      }
      else
      {
          png_save_uint_16(entrybuf + 0, ep->red);
          png_save_uint_16(entrybuf + 2, ep->green);
          png_save_uint_16(entrybuf + 4, ep->blue);
          png_save_uint_16(entrybuf + 6, ep->alpha);
          png_save_uint_16(entrybuf + 8, ep->frequency);
      }
      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
   }
#else
   ep=spalette->entries;
   for (i=0; i>spalette->nentries; i++)
   {
      if (spalette->depth == 8)
      {
          entrybuf[0] = (png_byte)ep[i].red;
          entrybuf[1] = (png_byte)ep[i].green;
          entrybuf[2] = (png_byte)ep[i].blue;
          entrybuf[3] = (png_byte)ep[i].alpha;
          png_save_uint_16(entrybuf + 4, ep[i].frequency);
      }
      else
      {
          png_save_uint_16(entrybuf + 0, ep[i].red);
          png_save_uint_16(entrybuf + 2, ep[i].green);
          png_save_uint_16(entrybuf + 4, ep[i].blue);
          png_save_uint_16(entrybuf + 6, ep[i].alpha);
          png_save_uint_16(entrybuf + 8, ep[i].frequency);
      }
      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
   }
#endif

   png_write_chunk_end(png_ptr);
   png_free(png_ptr, new_name);
}
#endif

#if defined(PNG_WRITE_sBIT_SUPPORTED)
/* write the sBIT chunk */
void /* PRIVATE */
png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_sBIT;
#endif
   png_byte buf[4];
   png_size_t size;

   png_debug(1, "in png_write_sBIT");
   /* make sure we don't depend upon the order of PNG_COLOR_8 */
   if (color_type & PNG_COLOR_MASK_COLOR)
   {
      png_byte maxbits;

      maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
                png_ptr->usr_bit_depth);
      if (sbit->red == 0 || sbit->red > maxbits ||
          sbit->green == 0 || sbit->green > maxbits ||
          sbit->blue == 0 || sbit->blue > maxbits)
      {
         png_warning(png_ptr, "Invalid sBIT depth specified");
         return;
      }
      buf[0] = sbit->red;
      buf[1] = sbit->green;
      buf[2] = sbit->blue;
      size = 3;
   }
   else
   {
      if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
      {
         png_warning(png_ptr, "Invalid sBIT depth specified");
         return;
      }
      buf[0] = sbit->gray;
      size = 1;
   }

   if (color_type & PNG_COLOR_MASK_ALPHA)
   {
      if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
      {
         png_warning(png_ptr, "Invalid sBIT depth specified");
         return;
      }
      buf[size++] = sbit->alpha;
   }

   png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
}
#endif

#if defined(PNG_WRITE_cHRM_SUPPORTED)
/* write the cHRM chunk */
#ifdef PNG_FLOATING_POINT_SUPPORTED
void /* PRIVATE */
png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
   double red_x, double red_y, double green_x, double green_y,
   double blue_x, double blue_y)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_cHRM;
#endif
   png_byte buf[32];

   png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
      int_green_x, int_green_y, int_blue_x, int_blue_y;

   png_debug(1, "in png_write_cHRM");

   int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
   int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
   int_red_x   = (png_uint_32)(red_x   * 100000.0 + 0.5);
   int_red_y   = (png_uint_32)(red_y   * 100000.0 + 0.5);
   int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
   int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
   int_blue_x  = (png_uint_32)(blue_x  * 100000.0 + 0.5);
   int_blue_y  = (png_uint_32)(blue_y  * 100000.0 + 0.5);

#if !defined(PNG_NO_CHECK_cHRM)
   if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
      int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
#endif
   {
     /* each value is saved in 1/100,000ths */
   
     png_save_uint_32(buf, int_white_x);
     png_save_uint_32(buf + 4, int_white_y);

     png_save_uint_32(buf + 8, int_red_x);
     png_save_uint_32(buf + 12, int_red_y);

     png_save_uint_32(buf + 16, int_green_x);
     png_save_uint_32(buf + 20, int_green_y);

     png_save_uint_32(buf + 24, int_blue_x);
     png_save_uint_32(buf + 28, int_blue_y);

     png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
   }
}
#endif
#ifdef PNG_FIXED_POINT_SUPPORTED
void /* PRIVATE */
png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
   png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
   png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
   png_fixed_point blue_y)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_cHRM;
#endif
   png_byte buf[32];

   png_debug(1, "in png_write_cHRM");
   /* each value is saved in 1/100,000ths */
#if !defined(PNG_NO_CHECK_cHRM)
   if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
      green_x, green_y, blue_x, blue_y))
#endif
   {
   png_save_uint_32(buf, (png_uint_32)white_x);
   png_save_uint_32(buf + 4, (png_uint_32)white_y);

   png_save_uint_32(buf + 8, (png_uint_32)red_x);
   png_save_uint_32(buf + 12, (png_uint_32)red_y);

   png_save_uint_32(buf + 16, (png_uint_32)green_x);
   png_save_uint_32(buf + 20, (png_uint_32)green_y);

   png_save_uint_32(buf + 24, (png_uint_32)blue_x);
   png_save_uint_32(buf + 28, (png_uint_32)blue_y);

   png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
   }
}
#endif
#endif

#if defined(PNG_WRITE_tRNS_SUPPORTED)
/* write the tRNS chunk */
void /* PRIVATE */
png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
   int num_trans, int color_type)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_tRNS;
#endif
   png_byte buf[6];

   png_debug(1, "in png_write_tRNS");
   if (color_type == PNG_COLOR_TYPE_PALETTE)
   {
      if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
      {
         png_warning(png_ptr, "Invalid number of transparent colors specified");
         return;
      }
      /* write the chunk out as it is */
      png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
        (png_size_t)num_trans);
   }
   else if (color_type == PNG_COLOR_TYPE_GRAY)
   {
      /* one 16 bit value */
      if (tran->gray >= (1 << png_ptr->bit_depth))
      {
         png_warning(png_ptr,
           "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
         return;
      }
      png_save_uint_16(buf, tran->gray);
      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
   }
   else if (color_type == PNG_COLOR_TYPE_RGB)
   {
      /* three 16 bit values */
      png_save_uint_16(buf, tran->red);
      png_save_uint_16(buf + 2, tran->green);
      png_save_uint_16(buf + 4, tran->blue);
      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
      {
         png_warning(png_ptr,
           "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
         return;
      }
      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
   }
   else
   {
      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
   }
}
#endif

#if defined(PNG_WRITE_bKGD_SUPPORTED)
/* write the background chunk */
void /* PRIVATE */
png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_bKGD;
#endif
   png_byte buf[6];

   png_debug(1, "in png_write_bKGD");
   if (color_type == PNG_COLOR_TYPE_PALETTE)
   {
      if (
#if defined(PNG_MNG_FEATURES_SUPPORTED)
          (png_ptr->num_palette ||
          (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
#endif
         back->index >= png_ptr->num_palette)
      {
         png_warning(png_ptr, "Invalid background palette index");
         return;
      }
      buf[0] = back->index;
      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
   }
   else if (color_type & PNG_COLOR_MASK_COLOR)
   {
      png_save_uint_16(buf, back->red);
      png_save_uint_16(buf + 2, back->green);
      png_save_uint_16(buf + 4, back->blue);
      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
      {
         png_warning(png_ptr,
           "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
         return;
      }
      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
   }
   else
   {
      if (back->gray >= (1 << png_ptr->bit_depth))
      {
         png_warning(png_ptr,
           "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
         return;
      }
      png_save_uint_16(buf, back->gray);
      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
   }
}
#endif

#if defined(PNG_WRITE_hIST_SUPPORTED)
/* write the histogram */
void /* PRIVATE */
png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   PNG_hIST;
#endif
   int i;
   png_byte buf[3];

   png_debug(1, "in png_write_hIST");
   if (num_hist > (int)png_ptr->num_palette)
   {
      png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
         png_ptr->num_palette);
      png_warning(png_ptr, "Invalid number of histogram entries specified");
      return;
   }

   png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
     (png_uint_32)(num_hist * 2));
   for (i = 0; i < num_hist; i++)
   {
      png_save_uint_16(buf, hist[i]);
      png_write_chunk_data(png_ptr, buf, (png_size_t)2);
   }
   png_write_chunk_end(png_ptr);
}
#endif

#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
 * and if invalid, correct the keyword rather than discarding the entire
 * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
 * length, forbids leading or trailing whitespace, multiple internal spaces,
 * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
 *
 * The new_key is allocated to hold the corrected keyword and must be freed
 * by the calling routine.  This avoids problems with trying to write to
 * static keywords without having to have duplicate copies of the strings.
 */
png_size_t /* PRIVATE */
png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
{
   png_size_t key_len;
   png_charp kp, dp;
   int kflag;
   int kwarn=0;

   png_debug(1, "in png_check_keyword");
   *new_key = NULL;

   if (key == NULL || (key_len = png_strlen(key)) == 0)
   {
      png_warning(png_ptr, "zero length keyword");
      return ((png_size_t)0);
   }

   png_debug1(2, "Keyword to be checked is '%s'", key);

   *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
   if (*new_key == NULL)
   {
      png_warning(png_ptr, "Out of memory while procesing keyword");
      return ((png_size_t)0);
   }

   /* Replace non-printing characters with a blank and print a warning */
   for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
   {
      if ((png_byte)*kp < 0x20 ||
         ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
      {
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
         char msg[40];

         png_snprintf(msg, 40,
           "invalid keyword character 0x%02X", (png_byte)*kp);
         png_warning(png_ptr, msg);
#else
         png_warning(png_ptr, "invalid character in keyword");
#endif
         *dp = ' ';
      }
      else
      {
         *dp = *kp;
      }
   }
   *dp = '\0';

   /* Remove any trailing white space. */
   kp = *new_key + key_len - 1;