/*
   *    Filename: cfag12864b-example.c
   *     Version: 0.1.0
   * Description: cfag12864b LCD userspace example program
   *     License: GPLv2
   *

   *      Author: Copyright (C) Miguel Ojeda Sandonis

   *        Date: 2006-10-31
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2 as
   *  published by the Free Software Foundation.
   *
   *  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, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  /*
   * ------------------------
   * start of cfag12864b code
   * ------------------------
   */
  
  #include <string.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/mman.h>
  
  #define CFAG12864B_WIDTH		(128)
  #define CFAG12864B_HEIGHT		(64)
  #define CFAG12864B_SIZE			(128 * 64 / 8)
  #define CFAG12864B_BPB			(8)
  #define CFAG12864B_ADDRESS(x, y)	((y) * CFAG12864B_WIDTH / \
  					CFAG12864B_BPB + (x) / CFAG12864B_BPB)
  #define CFAG12864B_BIT(n)		(((unsigned char) 1) << (n))
  
  #undef CFAG12864B_DOCHECK
  #ifdef CFAG12864B_DOCHECK
  	#define CFAG12864B_CHECK(x, y)		((x) < CFAG12864B_WIDTH && \
  						(y) < CFAG12864B_HEIGHT)
  #else
  	#define CFAG12864B_CHECK(x, y)		(1)
  #endif
  
  int cfag12864b_fd;
  unsigned char * cfag12864b_mem;
  unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
  
  /*
   * init a cfag12864b framebuffer device
   *
   * No error:       return = 0
   * Unable to open: return = -1
   * Unable to mmap: return = -2
   */

  static int cfag12864b_init(char *path)

  {
  	cfag12864b_fd = open(path, O_RDWR);
  	if (cfag12864b_fd == -1)
  		return -1;
  
  	cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
  		MAP_SHARED, cfag12864b_fd, 0);
  	if (cfag12864b_mem == MAP_FAILED) {
  		close(cfag12864b_fd);
  		return -2;
  	}
  
  	return 0;
  }
  
  /*
   * exit a cfag12864b framebuffer device
   */

  static void cfag12864b_exit(void)

  {
  	munmap(cfag12864b_mem, CFAG12864B_SIZE);
  	close(cfag12864b_fd);
  }
  
  /*
   * set (x, y) pixel
   */

  static void cfag12864b_set(unsigned char x, unsigned char y)

  {
  	if (CFAG12864B_CHECK(x, y))
  		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
  			CFAG12864B_BIT(x % CFAG12864B_BPB);
  }
  
  /*
   * unset (x, y) pixel
   */

  static void cfag12864b_unset(unsigned char x, unsigned char y)

  {
  	if (CFAG12864B_CHECK(x, y))
  		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
  			~CFAG12864B_BIT(x % CFAG12864B_BPB);
  }
  
  /*
   * is set (x, y) pixel?
   *
   * Pixel off: return = 0
   * Pixel on:  return = 1
   */

  static unsigned char cfag12864b_isset(unsigned char x, unsigned char y)

  {
  	if (CFAG12864B_CHECK(x, y))
  		if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
  			CFAG12864B_BIT(x % CFAG12864B_BPB))
  			return 1;
  
  	return 0;
  }
  
  /*
   * not (x, y) pixel
   */

  static void cfag12864b_not(unsigned char x, unsigned char y)

  {
  	if (cfag12864b_isset(x, y))
  		cfag12864b_unset(x, y);
  	else
  		cfag12864b_set(x, y);
  }
  
  /*
   * fill (set all pixels)
   */

  static void cfag12864b_fill(void)

  {
  	unsigned short i;
  
  	for (i = 0; i < CFAG12864B_SIZE; i++)
  		cfag12864b_buffer[i] = 0xFF;
  }
  
  /*
   * clear (unset all pixels)
   */

  static void cfag12864b_clear(void)

  {
  	unsigned short i;
  
  	for (i = 0; i < CFAG12864B_SIZE; i++)
  		cfag12864b_buffer[i] = 0;
  }
  
  /*
   * format a [128*64] matrix
   *
   * Pixel off: src[i] = 0
   * Pixel on:  src[i] > 0
   */

  static void cfag12864b_format(unsigned char * matrix)

  {
  	unsigned char i, j, n;
  
  	for (i = 0; i < CFAG12864B_HEIGHT; i++)
  	for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
  		cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
  			j] = 0;
  		for (n = 0; n < CFAG12864B_BPB; n++)
  			if (matrix[i * CFAG12864B_WIDTH +
  				j * CFAG12864B_BPB + n])
  				cfag12864b_buffer[i * CFAG12864B_WIDTH /
  					CFAG12864B_BPB + j] |=
  					CFAG12864B_BIT(n);
  	}
  }
  
  /*
   * blit buffer to lcd
   */

  static void cfag12864b_blit(void)

  {
  	memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
  }
  
  /*
   * ----------------------
   * end of cfag12864b code
   * ----------------------
   */
  
  #include <stdio.h>

  
  #define EXAMPLES	6

  static void example(unsigned char n)

  {
  	unsigned short i, j;
  	unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
  
  	if (n > EXAMPLES)
  		return;
  
  	printf("Example %i/%i - ", n, EXAMPLES);
  
  	switch (n) {
  	case 1:
  		printf("Draw points setting bits");
  		cfag12864b_clear();
  		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
  			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
  				cfag12864b_set(i, j);
  		break;
  
  	case 2:
  		printf("Clear the LCD");
  		cfag12864b_clear();
  		break;
  
  	case 3:
  		printf("Draw rows formatting a [128*64] matrix");
  		memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
  		for (i = 0; i < CFAG12864B_WIDTH; i++)
  			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
  				matrix[j * CFAG12864B_WIDTH + i] = 1;
  		cfag12864b_format(matrix);
  		break;
  
  	case 4:
  		printf("Fill the lcd");
  		cfag12864b_fill();
  		break;
  
  	case 5:
  		printf("Draw columns unsetting bits");
  		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
  			for (j = 0; j < CFAG12864B_HEIGHT; j++)
  				cfag12864b_unset(i, j);
  		break;
  
  	case 6:
  		printf("Do negative not-ing all bits");
  		for (i = 0; i < CFAG12864B_WIDTH; i++)
  			for (j = 0; j < CFAG12864B_HEIGHT; j ++)
  				cfag12864b_not(i, j);
  		break;
  	}
  
  	puts(" - [Press Enter]");
  }
  
  int main(int argc, char *argv[])
  {
  	unsigned char n;
  
  	if (argc != 2) {
  		printf(
  			"Sintax:  %s fbdev
  "
  			"Usually: /dev/fb0, /dev/fb1...
  ", argv[0]);
  		return -1;
  	}
  
  	if (cfag12864b_init(argv[1])) {
  		printf("Can't init %s fbdev
  ", argv[1]);
  		return -2;
  	}
  
  	for (n = 1; n <= EXAMPLES; n++) {
  		example(n);
  		cfag12864b_blit();
  		while (getchar() != '
  ');
  	}
  
  	cfag12864b_exit();
  
  	return 0;
  }