操作framebuffer填充位图的例子

一个操作FB填充位图的例子：

/****************/
/* Header Files */
/****************/

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <pthread.h>
#include <linux/fb.h>
#include "cnxtfb.h"

#pragma pack(1)
typedef struct{
    unsigned short  bfType;
    unsigned int    bfSize;
    unsigned short  bfReserved1;
    unsigned short  bfReserved2;
    unsigned int    bfOffBits;
    unsigned int    biSize;
    unsigned int    Width;
    unsigned int    Height;
    unsigned short  biPlanes;
    unsigned short  biBitCount;
    unsigned int    biCompression;
    unsigned int    biSizeImage;
    unsigned int    biXPelsPerMeter;
    unsigned int    biYPelsPerMeter;
    unsigned int    biClrUsed;
    unsigned int    biClrImportant;
}BMP_Header;
#pragma pack()
 
struct fb_var_screeninfo vinfo;
struct fb_fix_screeninfo finfo;
 
unsigned long screen_size;
unsigned long bmp_size;
unsigned char * lpScreenMem;//mmap to fb memory
unsigned char * lpPicMem;//memory for load pictrue
unsigned char * lpScreenMem_bak;//for ready the images and copy all size to lpScreenMem at once
 
BMP_Header bmp_header;
//#define DBG 1
/*************************************************
function:Draw one image to lpScreenMem_bak.
parameter:
 bitmap_file: The path of image which will be load.
 x_pos: The image's x position in srceen.
 y_pos: The image's y position in srceen.
*************************************************/
int DrawImage(char * bitmap_file,int x_pos,int y_pos)
{
 int i,j,k,l;
 unsigned char * pMem;//point to lpScreenMem_bak
 unsigned char * pMem1;//point to lpPicMem
 int draw_end_x = 0;
 int draw_end_y = 0;
 int bmp_end_x = 0;
 int bmp_end_y = 0;
 pMem = lpScreenMem_bak;
 pMem1 = lpPicMem;
   
 draw_end_y = (vinfo.yres - y_pos < bmp_header.Height)?(vinfo.yres):(bmp_header.Height + y_pos) ;
 bmp_end_y = (vinfo.yres - y_pos < bmp_header.Height)?(vinfo.yres - y_pos):bmp_header.Height;
 draw_end_x =  (vinfo.xres - x_pos)<bmp_header.Width?(vinfo.xres ):(bmp_header.Width + x_pos);
 bmp_end_x = (vinfo.xres - x_pos)<bmp_header.Width?(vinfo.xres - x_pos):bmp_header.Width;
 //printf("draw_end_x = %d, draw_end_y = %d\n",draw_end_x,draw_end_y);
 //printf("bmp_end_x = %d, bmp_end_y = %d\n",bmp_end_x,bmp_end_y);
 
 lpPicMem += bmp_header.bfOffBits;
 k = bmp_header.Height;
 for(i = y_pos;i<draw_end_y;i++)
 {
  pMem = lpScreenMem_bak + (vinfo.xres*i + x_pos)*(vinfo.bits_per_pixel / 8);
  pMem1 = lpPicMem +   bmp_header.Width*3*(k-1);
  j = 0;
  while(j<((draw_end_x < bmp_end_x)?draw_end_x:bmp_end_x))
   {
     *pMem = *pMem1;
     pMem++;
     pMem1++;
     *pMem = *pMem1;
     pMem++;
     pMem1++;
     *pMem = *pMem1;
     pMem++;
     pMem1++;
     *pMem = 0xff;
     pMem++;
     j++;
  }
  k--;
  if(k < (bmp_header.Height-bmp_end_y))
  {
   break;
  }
  
 }

 printf("DrawImage complete...\n");
 return 0;
}
 
int main(int argc, char ** argv)
{ 
 int x = 0;
 int y = 0;
 int fd = -1;
 int fb = -1;
 
 if(argc == 1)
 {
  printf("you must specify [FILE] options\n");
  printf("Try `fb_splash--help' or `fb_splash --usage' for more information.\n");
  return -1;
 }
 else if(argc == 2)
 {
  if(access(argv[1], 0) != 0)
  {
   if((strcmp(argv[1],"--help") == 0)||(strcmp(argv[1],"--usage") == 0))
   {
    printf("Usage: fb_splash [FILE] [POS_X] [POS_Y]\n");
    printf("\t[FILE]\t24bit RGB format bmp file supported only\n");
    printf("\t[POS_X]\tx offset you want draw\n");
    printf("\t[POS_Y]\ty offset you want draw\n");
    return -1;
   }
   else
   {
    printf("BMP file %s not exit!\n",argv[1]);
    return -1;
   }
  }
  else
  {
   x = 0;
   y = 0;
  }
 }
 else if(argc == 4)
 {
  if(access(argv[1], 0) != 0)
  {
   printf("bmp file %s not exit!\n",argv[1]);
   return -1;
  }
  x = atoi(argv[2]);
  y = atoi(argv[3]);
 }
 else
 {
  //printf("Usage: fb_splash [FILE] [POS_X] [POS_Y]\n");
  printf("Try `fb_splash --help' or `fb_splash --usage' for more information.\n");
  return -1;
 }
 
 fb = open("/dev/fb0", O_RDWR);
 if (fb < 0)
 {
   fprintf(stderr, "open /dev/fb0 error!\n");
     return -1;
 }
 if (ioctl(fb, FBIOGET_VSCREENINFO, &vinfo))
 {
     fprintf(stderr, "error get var screeninfo!\n");
     close(fb);
     return -1;
 }
 //printf("%dx%d %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);
 screen_size = vinfo.xres * vinfo.yres * (vinfo.bits_per_pixel / 8);
 //printf("screen_size = 0x%x , %d bytes\n",screen_size,screen_size);
 if((y >= vinfo.yres)||(x >= vinfo.xres))
 {
  printf("can't show bmp file out of screen!\n");
  close(fb);
  return -1;
 }
 lpScreenMem_bak = (unsigned char *) malloc(screen_size);
 if(lpScreenMem_bak != NULL)
 {
  printf("lpScreenMem_bak = %p\n",lpScreenMem_bak);
 }
 lpScreenMem = (unsigned char *)mmap(0, screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fb, 0);
 
 if (lpScreenMem == -1)
 {
   printf("mmap error\n");
   return -1;
 }
 
 //use lpScreenMem_bak to parse bmp file header
 fd = open(argv[1], O_RDONLY);
 if (fd < 0)
 {
  printf("Error opening %s\n", argv[1]);
   return -1;
 }
 
 int count = read(fd, lpScreenMem_bak, sizeof(BMP_Header));
 if(count <=0)
 {
  printf("Read bmp header of  %s error\n", argv[1]);
  return -1;
 }
 
 memcpy(&bmp_header,lpScreenMem_bak,(sizeof(BMP_Header)));
 bmp_size = bmp_header.bfSize;
 //printf("bmp file's height is %d,width is %d\n",bmp_header.Height,bmp_header.Width);
 
 lpPicMem = (unsigned char *) malloc(bmp_size);
 if(lpPicMem != NULL)
 {
  if(lseek(fd,0,SEEK_SET ) != 0)
  {
   printf("Read bmp file of  %s error\n", argv[1]);
   return -1;
  }
  count = read(fd, lpPicMem, bmp_size);
  if(count <=0)
  {
   printf("Read bmp file of  %s error\n", argv[1]);
   return -1;
  }  
 }
 //clear buffer
 memset(lpScreenMem_bak,0,screen_size);
 
 if (ioctl(fb, FBIO_STOPDISPLAY, NULL) < 0)
 {
  printf("ioctl PHSTBOSD_IOCTL_DISPLAY_OSD failed");
     close(fb);
   fb=-1;
   return -1;
 }
 //printf("show %s at %d,%d\n",argv[1],x,y);
 DrawImage(argv[1],x,y);
 memcpy(lpScreenMem,lpScreenMem_bak,screen_size);
 
 if (ioctl(fb, FBIO_STARTDISPLAY, NULL) < 0)
 {
  printf("ioctl PHSTBOSD_IOCTL_DISPLAY_OSD failed");
     close(fb);
   fb=-1;
   return -1;
 }
 
 if (ioctl(fb, FBIO_SCALE_SD_OSD, NULL) < 0)
 {
  printf("ioctl PHSTBOSD_IOCTL_DISPLAY_OSD failed");
     close(fb);
   fb=-1;
   return -1;
 }
 free(lpPicMem);
 free(lpScreenMem_bak);
 close(fb);
 close(fd);
 fb=-1;
 return 0;
}