pngdriver/graph_close.c

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/*!
   \file lib/pngdriver/graph_close.c
 
   \brief GRASS png display driver - close graphics processing
 
   (C) 2003-2014 by Glynn Clements and the GRASS Development Team
 
   This program is free software under the GNU General Public License
   (>=v2). Read the file COPYING that comes with GRASS for details.
 
   \author Per Henrik Johansen (original contributor)
   \author Glynn Clements
 */
 
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/mman.h>
#endif
 
#include <grass/gis.h>
#include "pngdriver.h"
 
static void unmap_file(void)
{
    size_t size =
        HEADER_SIZE + (size_t)png.width * png.height * sizeof(unsigned int);
    void *ptr = (char *)png.grid - HEADER_SIZE;
 
    if (!png.mapped)
        return;
 
#ifdef _WIN32
    UnmapViewOfFile(ptr);
    CloseHandle(png.handle);
#else
    munmap(ptr, size);
#endif
 
    png.mapped = 0;
}
 
/*!
   \brief Close down the graphics processing. This gets called only at driver
   termination time.
 */
void PNG_Graph_close(void)
{
    write_image();
 
    if (png.mapped)
        unmap_file();
    else
        G_free(png.grid);
}