/**
 * crt-calibrator – Calibration utility for CRT monitors
 * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "framebuffer.h"

#include <unistd.h>
#include <stdio.h>


/**
 * The psuedodevice pathname pattern used to access a framebuffer
 */
#ifndef FB_DEVICE_PATTERN
# define FB_DEVICE_PATTERN  "/dev/fb%lu"
#endif


/**
 * Figure out how many framebuffers there are on the system
 * 
 * @return  The number of framebuffers on the system
 */
size_t fb_count(void)
{
  char buf[sizeof(FB_DEVICE_PATTERN) / sizeof(char) + 3 * sizeof(size_t)];
  size_t count = 0;
  
  for (;; count++)
    {
      sprintf(buf, FB_DEVICE_PATTERN, count);
      if (access(buf, F_OK) < 0)
	return count;
    }
}