picture_explorer.c

在linux下利用framebuffer编写的图片浏览程序

#include<fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <linux/fb.h>
#include <sys/mman.h>
struct fb_var_screeninfo vinfo;
struct fb_fix_screeninfo finfo;
char *fbp = 0,*bitmapname="8.bmp",*bp="5.bmp",pixel;
int x = 0, y = 0,fb_color,x_axis,y_axis,fbfd = 0,xmin,xmax,ymin,ymax,color,i=0,j=0,screen_row=0,screen_column=0,interval=27,l=0,pixel_offset,BytesPerLine,bytes=0;
long int location = 0,screensize = 0;
void framebuffer(int,int,unsigned char fb_color);
void paint(int,int,unsigned char);
void clear_screen();
void show_string(int s_screen_row,int s_screen_column,int s_height,int s_interval,char string[100],unsigned char *s_after_convert_array);
void char_init();
void show_picture(int p_screen_row,int p_screen_column,int p_height,int p_width,unsigned char *p_after_convert_array);
unsigned char convert(unsigned char ch);
void bmp(int b_screen_row,int b_screen_column,char *file_name,int tag,char input_string[100]);
void page_one();
void page_two();
void page_three();
void main_page();
void print_head_info(FILE *fp);
FILE* judge_bmp(char *bmp_name);
long a,b,width,height,screensize;
void display_char(int d_screen_row,int d_screen_column,int d_height,int d_interval,int d_offset,unsigned char *d_after_convert_array);
FILE *fp_out;
unsigned rgbvalue;
struct node{
   char ch;
   int  offset;
}char_array[95];
struct tagbitmapfileheader
{ /* bmfh */
	short bftype;//位图文件类型，必须为"BM"
	long  bfsize;//位图文件大小，以字节为单位
	short bfreserved1;//位图文件保留字，必须为0
	short bfreserved2;//位图文件保留字，必须为0
	long  bfoffbits;//位图数据的起始位置，以相对于位图文件头的偏移量表示，以字节为单位
}bitmapfileheader;//该结构占据14个字节
struct tagbitmapinfoheader
{ /* bmih */
	long  bisize;//信息头文件的大小
	long  biwidth;//图象的宽，以像素为单位
	long  biheight;//图象的高，以像素为单位
	short biplanes;//目标设备的平面数不清，必须为0
	short bibitcount;//每个像素用几个比特，1，4，8，24
	long  bicompression;//图象是否被压缩，0，1
	long  bisizeimage;//位图的大小，以字节为单位 
	long  bixpelspermeter;//位图水平分辨率，每米像素数
	long  biypelspermeter;//位图垂直分辨率，每米像素数
	long  biclrused;//图象所用的颜色数
	long  biclrimportant;//位图显示过程中重要的颜色数
}bitmapinfoheader;//该结构占据40个字节
struct tagrgbquad
{ /* rgbq */
	unsigned char  rgbblue;//兰色的亮度(0-255)
	unsigned char  rgbgreen;//绿色的亮度(0-255)
	unsigned char  rgbred;//红色的亮度(0-255)
	unsigned char  rgbreserved;//保留，必须为0
}rgbquad[256];
///////////////////////////////////////////////////////////////////////////////////////////////////
int main()
{
	
        //page_one();
        //page_two();
        main_page();
        return 0;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
unsigned char convert(unsigned char ch)
{
  unsigned char m,n,p;
  unsigned char blue,green,red;
  unsigned char value1,value2,value,final_value;
  int w;
 /*每个像素的rgbquad值 */
 m=rgbquad[ch].rgbblue; 
 n=rgbquad[ch].rgbgreen;
 p=rgbquad[ch].rgbred;
/*格式之间的线性转换*/
 blue=m/64;//兰色
 green=n/32;//绿色
 red=p/32;//红色
 /*各个颜色的移位操作*/
 //兰色位于framebuffer格式的后两位,不用移位
 //绿色需要向左移3位
 //红色需要向左移5位
 value1=(green<<2);
 value2=(red<<5);
 /*将各个颜色值异或,得到framebuffer格式下的值*/
 value=value1^value2;
 value=value^blue;
 final_value=value%16;
 if(final_value==15)
    final_value=0;
 if(((m!=255)||(n!=255)||(p!=255))&&(final_value==0))
    final_value=final_value-6;
    
 return final_value;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
void print_head_info(FILE *fp)
{
	printf("The information of bitmapfileheader is:\n"
		"    bftype = %d;\n"
		"    bfsize = %d;\n"
		"    bfreserved1 = %d;\n"
		"    bfreserved2 = %d;\n"
		"    bfoffbits = %d;\n",
		bitmapfileheader.bftype,bitmapfileheader.bfsize,bitmapfileheader.bfreserved1,bitmapfileheader.bfreserved2,bitmapfileheader.bfoffbits );
if(
   fread(&bitmapinfoheader.bisize,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biwidth,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biheight,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biplanes,sizeof(short),1,fp)!=1||
   fread(&bitmapinfoheader.bibitcount,sizeof(short),1,fp)!=1||
   fread(&bitmapinfoheader.bicompression,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.bisizeimage,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.bixpelspermeter,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biypelspermeter,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biclrused,sizeof(long),1,fp)!=1||
   fread(&bitmapinfoheader.biclrimportant,sizeof(long),1,fp)!=1
  
)
{ 
	printf("fread error");
	exit(1);
}
printf("The information of bitmapinfoheader is:\n");

  printf("    biSize = %d;\n" 
         "    biWidth = %d;\n"
         "    biHeight = %d;\n"
         "    biPlanes =%d;\n"
         "    biBitCount =%d;\n"
         "    biCompression =%d;\n"
	 "    biSizeImage = %d;\n"
	 "    biXpelspermeter =%d;\n"
         "    biYpelspermeter =%d;\n"
         "    biClrUsed =%d;\n"
         "    biClrImportant =%d;\n",
          bitmapinfoheader.bisize,bitmapinfoheader.biwidth,bitmapinfoheader.biheight,bitmapinfoheader.biplanes,bitmapinfoheader.bibitcount,bitmapinfoheader.bicompression,bitmapinfoheader.bisizeimage,bitmapinfoheader.bixpelspermeter,bitmapinfoheader.biypelspermeter,bitmapinfoheader.biclrused,bitmapinfoheader.biclrimportant);
  a=bitmapinfoheader.biwidth;
  b=bitmapinfoheader.biheight;
  /*if((a>1024) || (b>768)) //800*600
  {
   printf("This map can't be showed.");
   exit(1);
  }*/     
if(fread(rgbquad,sizeof(rgbquad[0]),256,fp)!=256)
{
	printf("fread error");
	exit(1);
}
printf("offset of the file_descriptor is:%d.\n",ftell(fp));//location stream
}
///////////////////////////////////////////////////////////////////////////////////////////////////
FILE* judge_bmp(char *bmp_name)
{
        FILE *fp;
	if((fp=fopen(bmp_name, "r"))==NULL)
	{
		printf("fopen error");
		exit(1);
	}
	if(
		fread(&bitmapfileheader.bftype,sizeof(short),1 ,fp)!=1 ||
		fread(&bitmapfileheader.bfsize, sizeof(long), 1, fp) != 1 ||
		fread(&bitmapfileheader.bfreserved1,sizeof(short),1,fp)!=1||
		fread(&bitmapfileheader.bfreserved2,sizeof(short),1,fp)!=1||
		fread(&bitmapfileheader.bfoffbits,sizeof(long),1,fp)!=1
		)
	{
		printf("fread error");
		exit(1);
	}
	else if(bitmapfileheader.bftype==19778)
     printf("This is a .bmp file\nThe file name is %s\n",bmp_name);
	else exit(1);
        return fp;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
void framebuffer(int x_axis,int y_axis,unsigned char fb_color)
{

/* Open the file for reading and writing */
fbfd = open("/dev/fb0", O_RDWR);
if (!fbfd) {
printf("Error: cannot open framebuffer device.\n");
exit(1);
}
//printf("The framebuffer device was opened successfully.\n");

/* Get fixed screen information */
if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) {
printf("Error reading fixed information.\n");
exit(2);
}

/* Get variable screen information */
if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
printf("Error reading variable information.\n");
exit(3);
}

/* Figure out the size of the screen in bytes */
screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
/* Map the device to memory */
fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED,fbfd, 0);
if ((int)fbp == -1) { printf("Error: failed to map framebuffer device to memory.\n"); exit(4);
}
//printf("The framebuffer device was mapped to memory successfully.\n");

  paint(x_axis,y_axis,fb_color);


munmap(fbp, screensize);
close(fbfd);
}
void paint(int x,int y,unsigned char color)
{
  
/* Figure out where in memory to put the pixel */
location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) +(y+vinfo.yoffset) * finfo.line_length;