/********************************************************************************
 *      Copyright:  (C) 2023 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  fbtest.c
 *    Description:  This program used to:
 *                  1, Show framebuffer device information
 *                  2, Show RGB color on LCD full screen
 *                  3, Show BMP file on LCD;
 *
 *        Version:  1.0.0(08/19/23)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "08/19/23 12:56:31"
 *                 
 ********************************************************************************/

#include <stdio.h>  
#include <stdlib.h>  
#include <stdint.h>  
#include <string.h>
#include <errno.h>
#include <unistd.h>  
#include <fcntl.h>  
#include <getopt.h>
#include <libgen.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <linux/fb.h>  
#include <sys/mman.h>  

#define PROG_VERSION      "1.0.0"

enum
{
    CMD_SHOW_INFO, /* show LCD info  */
    CMD_SHOW_RGB,  /* show RGB color */
    CMD_SHOW_BMP,  /* show BMP file  */
};

typedef struct fb_ctx_s 
{
    int                       fd;       /* framebuffer file descriptor */
    char                      dev[64];  /* framebuffer device name */
    long                      fb_size;  /* framebuffer size */
    int                       pix_size; /* lcd screen pix size  */
    struct fb_var_screeninfo  vinfo;    /* framebuffer var information */
    char                     *fbp;      /* framebuffer mmap() address */
} fb_ctx_t; 


int fb_init(fb_ctx_t *fb_ctx);
int fb_term(fb_ctx_t *fb_ctx);
int show_rgb(fb_ctx_t *fb_ctx, int times);
int show_bmp(fb_ctx_t *fb_ctx, char *bmp_file);

static void program_usage(char *progname)
{
    printf("Usage: %s [OPTION]...\n", progname);
    printf(" %s is a program to show RGB color or BMP file on LCD screen\n", progname);

    printf("\nMandatory arguments to long options are mandatory for short options too:\n");
    printf(" -d[device  ]  Specify framebuffer device, such as: /dev/fb0\n");
    printf(" -c[color   ]  Display RGB corlor on LCD screen for some times, such as: -c 3\n");
    printf(" -b[bmp     ]  Display BMP file, such as: -b bg.bmp\n");
    printf(" -h[help    ]  Display this help information\n");
    printf(" -v[version ]  Display the program version\n");

    printf("\n%s version %s\n", progname, PROG_VERSION);
    return;
}

int main (int argc, char **argv)
{  
    fb_ctx_t                  fb_ctx;
    char                     *progname=NULL;
    char                     *bmp_file=NULL;
    char                     *fb_dev="/dev/fb0";
    int                       cmd = CMD_SHOW_INFO;
    int                       opt, times;

    struct option long_options[] = { 
        {"device", required_argument, NULL, 'd'},
        {"color", required_argument, NULL, 'c'},
        {"bmp", required_argument, NULL, 'b'},
        {"version", no_argument, NULL, 'v'},
        {"help", no_argument, NULL, 'h'},
        {NULL, 0, NULL, 0}
    };

    progname = (char *)basename(argv[0]);

    /* Parser the command line parameters */
    while ((opt = getopt_long(argc, argv, "d:c:b:vh", long_options, NULL)) != -1)
    {
        switch (opt)
        {
            case 'd': /* Set framebuffer device */
                 fb_dev = optarg;
                break;

            case 'b': /* Set BMP file */
                bmp_file = optarg;
                cmd = CMD_SHOW_BMP;
                break;

            case 'c': /* Show RGB color */
                times = atoi(optarg);
                cmd = CMD_SHOW_RGB;
                break;

            case 'v':  /* Get software version */
                printf("%s version %s\n", progname, PROG_VERSION);
                return 0;

            case 'h':  /* Get help information */
                program_usage(progname);
                return 0;

            default:
                break;
        }

    }

    memset(&fb_ctx, 0, sizeof(fb_ctx));
    strncpy(fb_ctx.dev, fb_dev, sizeof(fb_ctx.dev));

    if( fb_init(&fb_ctx) < 0 )
    {
        printf("ERROR: Initial framebuffer device '%s' failure.\n", fb_ctx.dev);
        return 1;
    }

    switch( cmd )
    {
        case CMD_SHOW_RGB:
            show_rgb(&fb_ctx, times);
            break;

        case CMD_SHOW_BMP:
            show_bmp(&fb_ctx, bmp_file);
            break;

        default:
            break;
    }

    fb_term(&fb_ctx);

    return 0;
}


int fb_get_var_screeninfo(int fd, struct fb_var_screeninfo *vinfo)
{
    if( fd<0 || !vinfo )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }
 
    if(ioctl(fd, FBIOGET_VSCREENINFO, vinfo))
    {
        printf("ERROR: ioctl() get variable info failure: %s\n", strerror(errno));  
        return -2;
    }  

    printf("LCD information : %dx%d, bpp:%d rgba:%d/%d,%d/%d,%d/%d,%d/%d\n", vinfo->xres, vinfo->yres, vinfo->bits_per_pixel,
            vinfo->red.length, vinfo->red.offset, vinfo->green.length, vinfo->green.offset, 
			vinfo->blue.length,vinfo->blue.offset, vinfo->transp.length, vinfo->transp.offset);

    return 0;
}

int fb_init(fb_ctx_t *fb_ctx)
{
    struct fb_var_screeninfo    *vinfo;

    if( !fb_ctx || !strlen(fb_ctx->dev) )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }

    if( (fb_ctx->fd=open(fb_ctx->dev, O_RDWR)) < 0 )
    {
        printf("ERROR: Open framebuffer device '%s' failure: %s\n", fb_ctx->dev, strerror(errno));  
        return -2;
    } 

    fb_get_var_screeninfo(fb_ctx->fd, &fb_ctx->vinfo);

    vinfo = &fb_ctx->vinfo;
    fb_ctx->fb_size = vinfo->xres * vinfo->yres * vinfo->bits_per_pixel / 8;  
    fb_ctx->pix_size = vinfo->xres * vinfo->yres;

    fb_ctx->fbp =(char *)mmap(0, fb_ctx->fb_size, PROT_READ | PROT_WRITE, MAP_SHARED, fb_ctx->fd ,0);  
    if ( !fb_ctx->fbp )  
    {    
        printf ("ERROR: Framebuffer mmap() failure: %s\n", strerror(errno));  
        return -2;
    }

    vinfo->xoffset = 0;
    vinfo->yoffset = 0;

    return 0;
}

int fb_term(fb_ctx_t *fb_ctx)
{
    if( !fb_ctx )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }

    munmap(fb_ctx->fbp, fb_ctx->fb_size);
    close (fb_ctx->fd);
 
    return 0;
}

int show_rgb_screen(fb_ctx_t *fb_ctx)
{
    struct fb_var_screeninfo    *vinfo;
    char                        *fb_addr;
    int                          interval = 1;
    int                          i, color;
    int                          bpp_bytes;

    if( !fb_ctx )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }

    vinfo = &fb_ctx->vinfo;
    bpp_bytes = vinfo->bits_per_pixel / 8;

    printf("show full screen on red\n");
    color = (1<<vinfo->red.length-1) << vinfo->red.offset;
    fb_addr = fb_ctx->fbp;
    for(i=0; i<fb_ctx->pix_size; i++)
    {
        memcpy(fb_addr, &color, bpp_bytes);
        fb_addr += bpp_bytes;
    }
    sleep(interval);

    printf("show full screen on green\n");
    color = (1<<vinfo->green.length-1) << vinfo->green.offset;
    fb_addr = fb_ctx->fbp;
    for(i=0; i<fb_ctx->pix_size; i++)
    {
        memcpy(fb_addr, &color, bpp_bytes);
        fb_addr += bpp_bytes;
    }
    sleep(interval);

    printf("show full screen on blue\n");
    color = (1<<vinfo->blue.length-1) << vinfo->blue.offset;
    fb_addr = fb_ctx->fbp;
    for(i=0; i<fb_ctx->pix_size; i++)
    {
        memcpy(fb_addr, &color, bpp_bytes);
        fb_addr += bpp_bytes;
    }
    sleep(interval);

    return 0;
}

int show_rgb(fb_ctx_t *fb_ctx, int times)
{
    int       i;

    if( !fb_ctx )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }

    for(i=0; i<times; i++)
    {
        show_rgb_screen(fb_ctx);
    }

    return 0;
}


/* BMP format: https://blog.csdn.net/weixin_39756273/article/details/110585675  */
typedef struct bmp_file_head_s 
{
    uint8_t  bfType[2];        /* BMP file type: "BM" */
    int32_t bfSize;           /* BMP file size */
    int32_t bfReserved;       /* reserved */
    int32_t bfoffBits;        /* image data offset */
}__attribute__((packed)) bmp_file_head_t; 


typedef struct bmp_bitmap_info_s 
{
    int32_t biSize;           /* this struture size */
    int32_t biWidth;          /* image width in pix */
    int32_t biHeight;         /* image height in pix */
    uint16_t biPlanes;         /* display planes, always be 1 */
    uint16_t biBitCount;       /* bpp: 1,4,8,16,24,32 */
    int32_t biCompress;       /* compress type */
    int32_t biSizeImage;      /* image size in byte */
    int32_t biXPelsPerMeter;  /* x-res in pix/m */
    int32_t biYPelsPerMeter;  /* y-res in pix/m */
    int32_t biClrUsed;
    int32_t biClrImportant;
}__attribute__((packed)) bmp_bitmap_info_t; 

/*
 * BMP image file format:
 * +----------------+------------------+--------------------+---------------+
 * | File Head(14B) | Bitmap Info(40B) | color palette(OPT) |  bitmap data  |
 * +----------------+------------------+--------------------+---------------+
 */
int show_bmp(fb_ctx_t *fb_ctx, char *bmp_file)
{
    struct fb_var_screeninfo    *vinfo;
    char                        *fb_addr;
    bmp_file_head_t            *file_head;
    bmp_bitmap_info_t          *bitmap_info;
    struct stat                 statbuf;
    char                       *f_addr;
    char                       *d_addr;
    char                       *p_addr;
    int                         fd;
    int                         bpp_bytes;
    int                         i, j;
	int                         width, height;

    if( !fb_ctx || !bmp_file )
    {
        printf("ERROR: Invalid input arguments\n");
        return -1;
    }

    if( (fd=open(bmp_file, O_RDONLY)) < 0 )
    {
        printf("ERROR: Open file '%s' failure: %s\n", bmp_file, strerror(errno));
        return -2;
    }

    fstat(fd, &statbuf);
    f_addr =(char *)mmap(0, statbuf.st_size, PROT_READ, MAP_SHARED, fd ,0);  
    if ( !f_addr )   
    {    
        printf ("ERROR: BMP file mmap() failure: %s\n", strerror(errno));  
        return -2; 
    }   

    /* BMP file header */
    file_head = (bmp_file_head_t *)f_addr;
    if( memcmp(file_head->bfType, "BM", 2) != 0)  
    {
        printf("ERROR: It's not a BMP file\n");
        return -3;
    }

    /* BMP bitmap information header */
    bitmap_info = (bmp_bitmap_info_t *)(f_addr+sizeof(bmp_file_head_t));

    /* BMP bitmap data */
    d_addr = f_addr + file_head->bfoffBits;

    vinfo = &fb_ctx->vinfo;
    fb_addr = fb_ctx->fbp;
    bpp_bytes = vinfo->bits_per_pixel / 8;

    width = bitmap_info->biWidth>vinfo->xres ? vinfo->xres : bitmap_info->biWidth;
    height = bitmap_info->biHeight>vinfo->yres ? vinfo->yres : bitmap_info->biHeight;

    printf("BMP file '%s': %dx%d and display %dx%d\n", bmp_file, bitmap_info->biWidth, bitmap_info->biHeight, width, height);

	/* if biHeight is positive, the bitmap is a bottom-up DIB */
	for(i=0; i<height; i++)
	{
		p_addr=d_addr+(height-1-i)*bitmap_info->biWidth*bpp_bytes;
		memcpy(fb_addr, p_addr, bpp_bytes*width);
		fb_addr += bpp_bytes * vinfo->xres;
	}

    munmap(f_addr, statbuf.st_size);
    close (fd);

    return 0;
}