#include <stdio.h>
#include <malloc.h>
#include "png.h"
#include "cartographer.h"

void savePng( FILE * fp, unsigned __int16 raster_index)
{
    unsigned __int8 trans[]={_transparent_color};
    png_infop info_ptr;
    png_structp png_ptr;
    png_ptr = png_create_write_struct
    (PNG_LIBPNG_VER_STRING, 
    NULL, NULL, NULL);
    if (!png_ptr)
       return ;
    info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr)
    {
       png_destroy_write_struct(&png_ptr,
         (png_infopp)NULL);
       return;
    }
    if (setjmp(png_jmpbuf(png_ptr))) 
    {
        png_destroy_write_struct(&png_ptr, &info_ptr);
        return;
    }
    png_init_io(png_ptr, fp);

    /* set the zlib compression level */
    png_set_compression_level(png_ptr,
        Z_NO_COMPRESSION);

    /*set information chunk*/
    png_set_IHDR(png_ptr, info_ptr, _width, _height,
       _bit_depth, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
       PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);

    png_set_packing(png_ptr);

    png_set_PLTE(png_ptr, info_ptr, _palette,
       _palette_count);

    png_set_tRNS(png_ptr, info_ptr, trans, 1,
       NULL);

    png_write_info(png_ptr, info_ptr);//<------it stops here

    png_set_flush(png_ptr, _height);
	
    png_write_image(png_ptr, _rasters+raster_index);

    png_write_end(png_ptr, info_ptr);

    png_destroy_write_struct(&png_ptr, &info_ptr);
}