/* pngwrite.c - general routines to write a PNG file

 *

 * libpng 1.2.5 - October 3, 2002

 * For conditions of distribution and use, see copyright notice in png.h

 * Copyright (c) 1998-2002 Glenn Randers-Pehrson

 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)

 */

/* get internal access to png.h */

#define PNG_INTERNAL

#include "png.h"

#ifdef PNG_WRITE_SUPPORTED

/* Writes all the PNG information.  This is the suggested way to use the

 * library.  If you have a new chunk to add, make a function to write it,

 * and put it in the correct location here.  If you want the chunk written

 * after the image data, put it in png_write_end().  I strongly encourage

 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing

 * the chunk, as that will keep the code from breaking if you want to just

 * write a plain PNG file.  If you have long comments, I suggest writing

 * them in png_write_end(), and compressing them.

 */

void PNGAPI

png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)

{

   png_debug(1, "in png_write_info_before_PLTE\n");

   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))

   {

   png_write_sig(png_ptr); /* write PNG signature */

#if defined(PNG_MNG_FEATURES_SUPPORTED)

   if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))

   {

      png_warning(png_ptr,"MNG features are not allowed in a PNG datastream\n");

      png_ptr->mng_features_permitted=0;

   }

#endif

   /* write IHDR information. */

   png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,

      info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,

      info_ptr->filter_type,

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)

      info_ptr->interlace_type);

#else

      0);

#endif

   /* the rest of these check to see if the valid field has the appropriate

      flag set, and if it does, writes the chunk. */

#if defined(PNG_WRITE_gAMA_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_gAMA)

   {

#  ifdef PNG_FLOATING_POINT_SUPPORTED

      png_write_gAMA(png_ptr, info_ptr->gamma);

#else

#ifdef PNG_FIXED_POINT_SUPPORTED

      png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);

#  endif

#endif

   }

#endif

#if defined(PNG_WRITE_sRGB_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_sRGB)

      png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);

#endif

#if defined(PNG_WRITE_iCCP_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_iCCP)

      png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,

                     info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);

#endif

#if defined(PNG_WRITE_sBIT_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_sBIT)

      png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);

#endif

#if defined(PNG_WRITE_cHRM_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_cHRM)

   {

#ifdef PNG_FLOATING_POINT_SUPPORTED

      png_write_cHRM(png_ptr,

         info_ptr->x_white, info_ptr->y_white,

         info_ptr->x_red, info_ptr->y_red,

         info_ptr->x_green, info_ptr->y_green,

         info_ptr->x_blue, info_ptr->y_blue);

#else

#  ifdef PNG_FIXED_POINT_SUPPORTED

      png_write_cHRM_fixed(png_ptr,

         info_ptr->int_x_white, info_ptr->int_y_white,

         info_ptr->int_x_red, info_ptr->int_y_red,

         info_ptr->int_x_green, info_ptr->int_y_green,

         info_ptr->int_x_blue, info_ptr->int_y_blue);

#  endif

#endif

   }

#endif

#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)

   if (info_ptr->unknown_chunks_num)

   {

       png_unknown_chunk *up;

       png_debug(5, "writing extra chunks\n");

       for (up = info_ptr->unknown_chunks;

            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;

            up++)

       {

         int keep=png_handle_as_unknown(png_ptr, up->name);

         if (keep != HANDLE_CHUNK_NEVER &&

            up->location && (!(up->location & PNG_HAVE_PLTE)) &&

            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||

            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))

         {

            png_write_chunk(png_ptr, up->name, up->data, up->size);

         }

       }

   }

#endif

      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;

   }

}

void PNGAPI

png_write_info(png_structp png_ptr, png_infop info_ptr)

{

#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)

   int i;

#endif

   png_debug(1, "in png_write_info\n");

   png_write_info_before_PLTE(png_ptr, info_ptr);

   if (info_ptr->valid & PNG_INFO_PLTE)

      png_write_PLTE(png_ptr, info_ptr->palette,

         (png_uint_32)info_ptr->num_palette);

   else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)

      png_error(png_ptr, "Valid palette required for paletted images\n");

#if defined(PNG_WRITE_tRNS_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_tRNS)

      {

#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)

         /* invert the alpha channel (in tRNS) */

         if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&

            info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)

         {

            int j;

            for (j=0; j<(int)info_ptr->num_trans; j++)

               info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);

         }

#endif

      png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),

         info_ptr->num_trans, info_ptr->color_type);

      }

#endif

#if defined(PNG_WRITE_bKGD_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_bKGD)

      png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);

#endif

#if defined(PNG_WRITE_hIST_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_hIST)

      png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);

#endif

#if defined(PNG_WRITE_oFFs_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_oFFs)

      png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,

         info_ptr->offset_unit_type);

#endif

#if defined(PNG_WRITE_pCAL_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_pCAL)

      png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,

         info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,

         info_ptr->pcal_units, info_ptr->pcal_params);

#endif

#if defined(PNG_WRITE_sCAL_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_sCAL)

#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)

      png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,

          info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);

#else

#ifdef PNG_FIXED_POINT_SUPPORTED

      png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,

          info_ptr->scal_s_width, info_ptr->scal_s_height);

#else

      png_warning(png_ptr,

          "png_write_sCAL not supported; sCAL chunk not written.\n");

#endif

#endif

#endif

#if defined(PNG_WRITE_pHYs_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_pHYs)

      png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,

         info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);

#endif

#if defined(PNG_WRITE_tIME_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_tIME)

   {

      png_write_tIME(png_ptr, &(info_ptr->mod_time));

      png_ptr->mode |= PNG_WROTE_tIME;

   }

#endif

#if defined(PNG_WRITE_sPLT_SUPPORTED)

   if (info_ptr->valid & PNG_INFO_sPLT)

     for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)

       png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);

#endif

#if defined(PNG_WRITE_TEXT_SUPPORTED)

   /* Check to see if we need to write text chunks */

   for (i = 0; i < info_ptr->num_text; i++)

   {

      png_debug2(2, "Writing header text chunk %d, type %d\n", i,

         info_ptr->text[i].compression);

      /* an internationalized chunk? */

      if (info_ptr->text[i].compression > 0)

      {

#if defined(PNG_WRITE_iTXt_SUPPORTED)

          /* write international chunk */

          png_write_iTXt(png_ptr,

                         info_ptr->text[i].compression,

                         info_ptr->text[i].key,

                         info_ptr->text[i].lang,

                         info_ptr->text[i].lang_key,

                         info_ptr->text[i].text);

#else

          png_warning(png_ptr, "Unable to write international text\n");

#endif

          /* Mark this chunk as written */

          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;

      }

      /* If we want a compressed text chunk */

      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)

      {

#if defined(PNG_WRITE_zTXt_SUPPORTED)

         /* write compressed chunk */

         png_write_zTXt(png_ptr, info_ptr->text[i].key,

            info_ptr->text[i].text, 0,

            info_ptr->text[i].compression);

#else

         png_warning(png_ptr, "Unable to write compressed text\n");

#endif

         /* Mark this chunk as written */

         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;

      }

      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)

      {

#if defined(PNG_WRITE_tEXt_SUPPORTED)

         /* write uncompressed chunk */

         png_write_tEXt(png_ptr, info_ptr->text[i].key,

                         info_ptr->text[i].text,

                         0);

#else

         png_warning(png_ptr, "Unable to write uncompressed text\n");

#endif

         /* Mark this chunk as written */

         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;

      }

   }

#endif

#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)

   if (info_ptr->unknown_chunks_num)

   {

       png_unknown_chunk *up;

       png_debug(5, "writing extra chunks\n");

       for (up = info_ptr->unknown_chunks;

            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;

            up++)

       {

         int keep=png_handle_as_unknown(png_ptr, up->name);

         if (keep != HANDLE_CHUNK_NEVER &&

            up->location && (up->location & PNG_HAVE_PLTE) &&

            !(up->location & PNG_HAVE_IDAT) &&

            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||

            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))

         {

            png_write_chunk(png_ptr, up->name, up->data, up->size);

         }

       }

   }

#endif

}

/* Writes the end of the PNG file.  If you don't want to write comments or

 * time information, you can pass NULL for info.  If you already wrote these

 * in png_write_info(), do not write them again here.  If you have long

 * comments, I suggest writing them here, and compressing them.

 */

void PNGAPI

png_write_end(png_structp png_ptr, png_infop info_ptr)

{

   png_debug(1, "in png_write_end\n");

   if (!(png_ptr->mode & PNG_HAVE_IDAT))

      png_error(png_ptr, "No IDATs written into file");

   /* see if user wants us to write information chunks */

   if (info_ptr != NULL)

   {

#if defined(PNG_WRITE_TEXT_SUPPORTED)

      int i; /* local index variable */

#endif

#if defined(PNG_WRITE_tIME_SUPPORTED)

      /* check to see if user has supplied a time chunk */

      if ((info_ptr->valid & PNG_INFO_tIME) &&

         !(png_ptr->mode & PNG_WROTE_tIME))

         png_write_tIME(png_ptr, &(info_ptr->mod_time));

#endif

#if defined(PNG_WRITE_TEXT_SUPPORTED)

      /* loop through comment chunks */

      for (i = 0; i < info_ptr->num_text; i++)

      {

         png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,

            info_ptr->text[i].compression);

         /* an internationalized chunk? */

         if (info_ptr->text[i].compression > 0)

         {

#if defined(PNG_WRITE_iTXt_SUPPORTED)

             /* write international chunk */

             png_write_iTXt(png_ptr,

                         info_ptr->text[i].compression,

                         info_ptr->text[i].key,

                         info_ptr->text[i].lang,

                         info_ptr->text[i].lang_key,

                         info_ptr->text[i].text);

#else

             png_warning(png_ptr, "Unable to write international text\n");

#endif

             /* Mark this chunk as written */

             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;

         }

         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)

         {

#if defined(PNG_WRITE_zTXt_SUPPORTED)

            /* write compressed chunk */

            png_write_zTXt(png_ptr, info_ptr->text[i].key,

               info_ptr->text[i].text, 0,

               info_ptr->text[i].compression);

#else

            png_warning(png_ptr, "Unable to write compressed text\n");

#endif

            /* Mark this chunk as written */

            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;

         }

         else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)

         {

#if defined(PNG_WRITE_tEXt_SUPPORTED)

            /* write uncompressed chunk */

            png_write_tEXt(png_ptr, info_ptr->text[i].key,

               info_ptr->text[i].text, 0);

#else

            png_warning(png_ptr, "Unable to write uncompressed text\n");

#endif

            /* Mark this chunk as written */

            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;

         }

      }

#endif

#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)

   if (info_ptr->unknown_chunks_num)

   {

       png_unknown_chunk *up;

       png_debug(5, "writing extra chunks\n");

       for (up = info_ptr->unknown_chunks;

            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;

            up++)

       {

         int keep=png_handle_as_unknown(png_ptr, up->name);

         if (keep != HANDLE_CHUNK_NEVER &&

            up->location && (up->location & PNG_AFTER_IDAT) &&

            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||

            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))

         {

            png_write_chunk(png_ptr, up->name, up->data, up->size);

         }

       }

   }

#endif

   }

   png_ptr->mode |= PNG_AFTER_IDAT;

   /* write end of PNG file */

   png_write_IEND(png_ptr);

#if 0

/* This flush, added in libpng-1.0.8,  causes some applications to crash

   because they do not set png_ptr->output_flush_fn */

   png_flush(png_ptr);

#endif

}

#if defined(PNG_WRITE_tIME_SUPPORTED)

#if !defined(_WIN32_WCE)

/* "time.h" functions are not supported on WindowsCE */

void PNGAPI

png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)

{

   png_debug(1, "in png_convert_from_struct_tm\n");

   ptime->year = (png_uint_16)(1900 + ttime->tm_year);

   ptime->month = (png_byte)(ttime->tm_mon + 1);

   ptime->day = (png_byte)ttime->tm_mday;

   ptime->hour = (png_byte)ttime->tm_hour;

   ptime->minute = (png_byte)ttime->tm_min;

   ptime->second = (png_byte)ttime->tm_sec;

}

void PNGAPI

png_convert_from_time_t(png_timep ptime, time_t ttime)

{

   struct tm *tbuf;

   png_debug(1, "in png_convert_from_time_t\n");

   tbuf = gmtime(&ttime);

   png_convert_from_struct_tm(ptime, tbuf);

}

#endif

#endif

/* Initialize png_ptr structure, and allocate any memory needed */

png_structp PNGAPI

png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,

   png_error_ptr error_fn, png_error_ptr warn_fn)

{

#ifdef PNG_USER_MEM_SUPPORTED

   return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,

      warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));

}

/* Alternate initialize png_ptr structure, and allocate any memory needed */

png_structp PNGAPI

png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,

   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,

   png_malloc_ptr malloc_fn, png_free_ptr free_fn)

{

#endif /* PNG_USER_MEM_SUPPORTED */

   png_structp png_ptr;

#ifdef PNG_SETJMP_SUPPORTED

#ifdef USE_FAR_KEYWORD

   jmp_buf jmpbuf;

#endif

#endif

   int i;

   png_debug(1, "in png_create_write_struct\n");

#ifdef PNG_USER_MEM_SUPPORTED

   png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,

      (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);

#else

   png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);

#endif /* PNG_USER_MEM_SUPPORTED */

   if (png_ptr == NULL)

      return (NULL);

#if !defined(PNG_1_0_X)

#ifdef PNG_ASSEMBLER_CODE_SUPPORTED

   png_init_mmx_flags(png_ptr);   /* 1.2.0 addition */

#endif

#endif /* PNG_1_0_X */

#ifdef PNG_SETJMP_SUPPORTED

#ifdef USE_FAR_KEYWORD

   if (setjmp(jmpbuf))

#else

   if (setjmp(png_ptr->jmpbuf))

#endif

   {

      png_free(png_ptr, png_ptr->zbuf);

      png_ptr->zbuf=NULL;

      png_destroy_struct(png_ptr);

      return (NULL);

   }

#ifdef USE_FAR_KEYWORD

   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));

#endif

#endif

#ifdef PNG_USER_MEM_SUPPORTED

   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);

#endif /* PNG_USER_MEM_SUPPORTED */

   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);

   i=0;

   do

   {

     if(user_png_ver[i] != png_libpng_ver[i])

        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;

   } while (png_libpng_ver[i++]);

   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)

   {

     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so

      * we must recompile any applications that use any older library version.

      * For versions after libpng 1.0, we will be compatible, so we need

      * only check the first digit.

      */

     if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||

         (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||

         (user_png_ver[0] == '0' && user_png_ver[2] < '9'))

     {

#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)

        char msg[80];

        if (user_png_ver)

        {

          sprintf(msg, "Application was compiled with png.h from libpng-%.20s",

             user_png_ver);

          png_warning(png_ptr, msg);

        }

        sprintf(msg, "Application  is  running with png.c from libpng-%.20s",

           png_libpng_ver);

        png_warning(png_ptr, msg);

#endif

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

        png_ptr->flags=0;

#endif

        png_error(png_ptr,

           "Incompatible libpng version in application and library");

     }

   }

   /* initialize zbuf - compression buffer */

   png_ptr->zbuf_size = PNG_ZBUF_SIZE;

   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,

      (png_uint_32)png_ptr->zbuf_size);

   png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,

      png_flush_ptr_NULL);

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)

   png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,

      1, png_doublep_NULL, png_doublep_NULL);

#endif

#ifdef PNG_SETJMP_SUPPORTED

/* Applications that neglect to set up their own setjmp() and then encounter

   a png_error() will longjmp here.  Since the jmpbuf is then meaningless we

   abort instead of returning. */

#ifdef USE_FAR_KEYWORD

   if (setjmp(jmpbuf))

      PNG_ABORT();

   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));

#else

   if (setjmp(png_ptr->jmpbuf))

      PNG_ABORT();

#endif

#endif

   return (png_ptr);

}

/* Initialize png_ptr structure, and allocate any memory needed */

#undef png_write_init

void PNGAPI

png_write_init(png_structp png_ptr)

{

   /* We only come here via pre-1.0.7-compiled applications */

   png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);

}

void PNGAPI

png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,

   png_size_t png_struct_size, png_size_t png_info_size)

{

   /* We only come here via pre-1.0.12-compiled applications */

#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)

   if(sizeof(png_struct) > png_struct_size || sizeof(png_info) > png_info_size)

   {

      char msg[80];

      png_ptr->warning_fn=NULL;

      if (user_png_ver)

      {

        sprintf(msg, "Application was compiled with png.h from libpng-%.20s",

           user_png_ver);

        png_warning(png_ptr, msg);

      }

      sprintf(msg, "Application  is  running with png.c from libpng-%.20s",

         png_libpng_ver);

      png_warning(png_ptr, msg);

   }

#endif

   if(sizeof(png_struct) > png_struct_size)

     {

       png_ptr->error_fn=NULL;

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

       png_ptr->flags=0;

#endif

       png_error(png_ptr,

       "The png struct allocated by the application for writing is too small.");

     }

   if(sizeof(png_info) > png_info_size)

     {

       png_ptr->error_fn=NULL;

#ifdef PNG_ERROR_NUMBERS_SUPPORTED

       png_ptr->flags=0;

#endif

       png_error(png_ptr,

       "The info struct allocated by the application for writing is too small.");

     }

   png_write_init_3(&png_ptr, user_png_ver, png_struct_size);

}

void PNGAPI

png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,

   png_size_t png_struct_size)

{

   png_structp png_ptr=*ptr_ptr;

#ifdef PNG_SETJMP_SUPPORTED

   jmp_buf tmp_jmp; /* to save current jump buffer */

#endif

   int i = 0;

   do

   {

     if (user_png_ver[i] != png_libpng_ver[i])

     {

#ifdef PNG_LEGACY_SUPPORTED

       png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;

#else

       png_ptr->warning_fn=NULL;

       png_warning(png_ptr,

     "Application uses deprecated png_write_init() and should be recompiled.");

       break;

#endif

     }

   } while (png_libpng_ver[i++]);

   png_debug(1, "in png_write_init_3\n");

#ifdef PNG_SETJMP_SUPPORTED

   /* save jump buffer and error functions */

   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));

#endif

   if (sizeof(png_struct) > png_struct_size)

     {

       png_destroy_struct(png_ptr);

       png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);

       *ptr_ptr = png_ptr;

     }

   /* reset all variables to 0 */

   png_memset(png_ptr, 0, sizeof (png_struct));

#if !defined(PNG_1_0_X)

#ifdef PNG_ASSEMBLER_CODE_SUPPORTED

   png_init_mmx_flags(png_ptr);   /* 1.2.0 addition */

#endif

#endif /* PNG_1_0_X */

#ifdef PNG_SETJMP_SUPPORTED

   /* restore jump buffer */

   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));

#endif

   png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,

      png_flush_ptr_NULL);

   /* initialize zbuf - compression buffer */

   png_ptr->zbuf_size = PNG_ZBUF_SIZE;

   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,

      (png_uint_32)png_ptr->zbuf_size);

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)

   png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,

      1, png_doublep_NULL, png_doublep_NULL);

#endif

}

/* Write a few rows of image data.  If the image is interlaced,

 * either you will have to write the 7 sub images, or, if you

 * have called png_set_interlace_handling(), you will have to

 * "write" the image seven times.

 */

void PNGAPI

png_write_rows(png_structp png_ptr, png_bytepp row,

   png_uint_32 num_rows)

{

   png_uint_32 i; /* row counter */

   png_bytepp rp; /* row pointer */

   png_debug(1, "in png_write_rows\n");

   /* loop through the rows */

   for (i = 0, rp = row; i < num_rows; i++, rp++)

   {

      png_write_row(png_ptr, *rp);

   }

}

/* Write the image.  You only need to call this function once, even

 * if you are writing an interlaced image.

 */

void PNGAPI

png_write_image(png_structp png_ptr, png_bytepp image)

{

   png_uint_32 i; /* row index */

   int pass, num_pass; /* pass variables */

   png_bytepp rp; /* points to current row */

   png_debug(1, "in png_write_image\n");

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)

   /* intialize interlace handling.  If image is not interlaced,

      this will set pass to 1 */

   num_pass = png_set_interlace_handling(png_ptr);

#else

   num_pass = 1;

#endif

   /* loop through passes */

   for (pass = 0; pass < num_pass; pass++)

   {

      /* loop through image */

      for (i = 0, rp = image; i < png_ptr->height; i++, rp++)

      {

         png_write_row(png_ptr, *rp);

      }

   }

}

/* called by user to write a row of image data */

void PNGAPI

png_write_row(png_structp png_ptr, png_bytep row)

{

   png_debug2(1, "in png_write_row (row %ld, pass %d)\n",

      png_ptr->row_number, png_ptr->pass);

   /* initialize transformations and other stuff if first time */

   if (png_ptr->row_number == 0 && png_ptr->pass == 0)

   {

   /* make sure we wrote the header info */

   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))

      png_error(png_ptr,

         "png_write_info was never called before png_write_row.");

   /* check for transforms that have been set but were defined out */

#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)

   if (png_ptr->transformations & PNG_INVERT_MONO)

      png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)

   if (png_ptr->transformations & PNG_FILLER)

      png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)

   if (png_ptr->transformations & PNG_PACKSWAP)

      png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)

   if (png_ptr->transformations & PNG_PACK)

      png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)

   if (png_ptr->transformations & PNG_SHIFT)

      png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)

   if (png_ptr->transformations & PNG_BGR)

      png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");

#endif

#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)

   if (png_ptr->transformations & PNG_SWAP_BYTES)

      png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");

#endif

      png_write_start_row(png_ptr);

   }

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)

   /* if interlaced and not interested in row, return */

   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))

   {

      switch (png_ptr->pass)

      {

         case 0:

            if (png_ptr->row_number & 0x07)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 1:

            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 2:

            if ((png_ptr->row_number & 0x07) != 4)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 3:

            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 4:

            if ((png_ptr->row_number & 0x03) != 2)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 5:

            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

         case 6:

            if (!(png_ptr->row_number & 0x01))

            {

               png_write_finish_row(png_ptr);

               return;

            }

            break;

      }

   }

#endif

   /* set up row info for transformations */

   png_ptr->row_info.color_type = png_ptr->color_type;

   png_ptr->row_info.width = png_ptr->usr_width;

   png_ptr->row_info.channels = png_ptr->usr_channels;

   png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;

   png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *

      png_ptr->row_info.channels);

   png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *

      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);

   png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);

   png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);

   png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);

   png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);

   png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);

   png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);

   /* Copy user's row into buffer, leaving room for filter byte. */

   png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,

      png_ptr->row_info.rowbytes);

#if defined(PNG_WRITE_INTERLACING_SUPPORTED)

   /* handle interlacing */

   if (png_ptr->interlaced && png_ptr->pass < 6 &&

      (png_ptr->transformations & PNG_INTERLACE))

   {

      png_do_write_interlace(&(png_ptr->row_info),

         png_ptr->row_buf + 1, png_ptr->pass);

      /* this should always get caught above, but still ... */

      if (!(png_ptr->row_info.width))

      {

         png_write_finish_row(png_ptr);

         return;

      }

   }

#endif

   /* handle other transformations */

   if (png_ptr->transformations)

      png_do_write_transformations(png_ptr);

#if defined(PNG_MNG_FEATURES_SUPPORTED)

   /* Write filter_method 64 (intrapixel differencing) only if

    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and

    * 2. Libpng did not write a PNG signature (this filter_method is only

    *    used in PNG datastreams that are embedded in MNG datastreams) and

    * 3. The application called png_permit_mng_features with a mask that

    *    included PNG_FLAG_MNG_FILTER_64 and

    * 4. The filter_method is 64 and

    * 5. The color_type is RGB or RGBA

    */

   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&

      (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))

   {

      /* Intrapixel differencing */

      png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);

   }