pngwio.c File Reference

#include "pngpriv.h"

Include dependency graph for pngwio.c:

Functions
void	png_write_data (png_structrp png_ptr, png_const_bytep data, png_size_t length)
void	png_default_write_data (png_structp png_ptr, png_bytep data, png_size_t length)
void	png_flush (png_structrp png_ptr)
void	png_default_flush (png_structp png_ptr)
void	png_set_write_fn (png_structrp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)

Function Documentation

void png_write_data	(	png_structrp	png_ptr,
		png_const_bytep	data,
		png_size_t	length
	)

{
   /* NOTE: write_data_fn must not change the buffer! */
   if (png_ptr->write_data_fn != NULL )
      (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
         length);

   else
      png_error(png_ptr, "Call to NULL write function");
}

void png_default_write_data	(	png_structp	png_ptr,
		png_bytep	data,
		png_size_t	length
	)

{
   png_size_t check;

   if (png_ptr == NULL)
      return;

   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));

   if (check != length)
      png_error(png_ptr, "Write Error");
}

void png_flush

(

png_structrp

png_ptr

)

{
   if (png_ptr->output_flush_fn != NULL)
      (*(png_ptr->output_flush_fn))(png_ptr);
}

void png_default_flush

(

png_structp

png_ptr

)

{
   png_FILE_p io_ptr;

   if (png_ptr == NULL)
      return;

   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
   fflush(io_ptr);
}

void png_set_write_fn	(	png_structrp	png_ptr,
		png_voidp	io_ptr,
		png_rw_ptr	write_data_fn,
		png_flush_ptr	output_flush_fn
	)

{
   if (png_ptr == NULL)
      return;

   png_ptr->io_ptr = io_ptr;

#ifdef PNG_STDIO_SUPPORTED
   if (write_data_fn != NULL)
      png_ptr->write_data_fn = write_data_fn;

   else
      png_ptr->write_data_fn = png_default_write_data;
#else
   png_ptr->write_data_fn = write_data_fn;
#endif

#ifdef PNG_WRITE_FLUSH_SUPPORTED
#  ifdef PNG_STDIO_SUPPORTED

   if (output_flush_fn != NULL)
      png_ptr->output_flush_fn = output_flush_fn;

   else
      png_ptr->output_flush_fn = png_default_flush;

#  else
   png_ptr->output_flush_fn = output_flush_fn;
#  endif
#else
   PNG_UNUSED(output_flush_fn)
#endif /* WRITE_FLUSH */

#ifdef PNG_READ_SUPPORTED
   /* It is an error to read while writing a png file */
   if (png_ptr->read_data_fn != NULL)
   {
      png_ptr->read_data_fn = NULL;

      png_warning(png_ptr,
          "Can't set both read_data_fn and write_data_fn in the"
          " same structure");
   }
#endif
}