cfag12864b-example.c

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/*
 *    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\n"
            "Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
        return -1;
    }

    if (cfag12864b_init(argv[1])) {
        printf("Can't init %s fbdev\n", argv[1]);
        return -2;
    }

    for (n = 1; n <= EXAMPLES; n++) {
        example(n);
        cfag12864b_blit();
        while (getchar() != '\n');
    }

    cfag12864b_exit();

    return 0;
}