帧缓存显示bmp图片（转载）
在Framebuffer下编程显示BMP图象
标签： Framebuffer BMP 2006-11-10 17:02
今天看别人的代码，知道可以使控制台进入图形模式，这样SHELL程序的显示就不会影响BMP图像的显示了。于是，COPY过来，放入自己先前的那个程序，再整个800x600的BMP图，试试全屏显示的效果！爽^0^爽
/*
showbmp.c
allenyao 2006/11/10
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
typedef struct
{
char cfType[2]; /* 文件类型, 必须为 "BM" (0x4D42) */
char cfSize[4]; /* 文件的大小(字节) */
char cfReserved[4]; /* 保留, 必须为 0 */
char cfoffBits[4]; /* 位图阵列相对于文件头的偏移量(字节) */
} BITMAPFILEHEADER; /* 文件头结构 */
typedef struct
{
char ciSize[4]; /* size of BITMAPINFOHEADER */
char ciWidth[4]; /* 位图宽度(像素) */
char ciHeight[4]; /* 位图高度(像素) */
char ciPlanes[2]; /* 目标设备的位平面数, 必须置为1 */
char ciBitCount[2]; /* 每个像素的位数, 1,4,8或24 */
char ciCompress[4]; /* 位图阵列的压缩方法,0=不压缩 */
char ciSizeImage[4]; /* 图像大小(字节) */
char ciXPelsPerMeter[4];/* 目标设备水平每米像素个数 */
char ciYPelsPerMeter[4];/* 目标设备垂直每米像素个数 */
char ciClrUsed[4]; /* 位图实际使用的颜色表的颜色数 */
char ciClrImportant[4]; /* 重要颜色索引的个数 */
} BITMAPINFOHEADER; /* 位图信息头结构 */
typedef struct
{
char rgbBlue;
char rgbGreen;
char rgbRed;
char rgbReserved;
} RGBQUAD;
BITMAPFILEHEADER FileHead;
BITMAPINFOHEADER InfoHead;
RGBQUAD rgbquad;
char *fbp = 0;
int xres = 0;
int yres = 0;
int bits_per_pixel = 0;
int tty;
int tty_mode_was;
int set_tty_graphics( void );
int set_tty_text( void );
int show_bmp ( char *bmpfile );
long chartolong( char * string, int length );
/******************************************************************************
*
******************************************************************************/
int main( int argc, char *argv[] )
{
int fbfd = 0;
struct fb_var_screeninfo vinfo;
struct fb_fix_screeninfo finfo;
long int screensize = 0;
// Open the file for reading and writing
fbfd = open("/dev/fb0", O_RDWR);
if (!fbfd)
{
printf("Error: cannot open framebuffer device./n");
exit(1);
}
// 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);
}
printf("%dx%d, %dbpp/n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel );
xres = vinfo.xres;
yres = vinfo.yres;
bits_per_pixel = vinfo.bits_per_pixel;
// 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);
}
if (set_tty_graphics())
{
show_bmp( argv[1] );
}
sleep( 10 );
set_tty_text();
munmap(fbp, screensize);
close(fbfd);
return 0;
}
/******************************************************************************
*
******************************************************************************/
int show_bmp( char *bmpfile )
{
FILE *fp;
int rc;
int ciBitCount, ciWidth, ciHeight;
int line_x, line_y;
long int location = 0, BytesPerLine = 0;
char tmp[1024*10];
/* 打开位图文件 */
fp = fopen( bmpfile, "rb" );
if (fp == NULL)
{
return( -1 );
}
/* 读取位图文件头 */
rc = fread( &FileHead, 1, sizeof(BITMAPFILEHEADER), fp );
if ( rc != sizeof( BITMAPFILEHEADER ) )
{
fclose( fp );
return( -2 );
}
/* 判断位图的类型 */
if (memcmp(FileHead.cfType, "BM", 2) != 0)
{
fclose( fp );
return( -3 );
}
/* 读取位图信息头 */
rc = fread( (char *)&InfoHead, 1, sizeof(BITMAPINFOHEADER), fp );
if ( rc != sizeof(BITMAPINFOHEADER) )
{
fclose( fp );
return( -4 );
}
ciWidth = (int) chartolong( InfoHead.ciWidth, 4 );
ciHeight = (int) chartolong( InfoHead.ciHeight, 4 );
ciBitCount = (int) chartolong( InfoHead.ciBitCount, 4 );
line_x = line_y = 0;
/*
while( !feof( fp ) )
{
rc = fread( (char *)&rgbquad, 1, sizeof(RGBQUAD), fp );
if ( rc != sizeof(RGBQUAD) )
{
break;
}
location = line_x * bits_per_pixel / 8 + (ciHeight - line_y - 1) * xres * bits_per_pixel / 8;
*(fbp + location) = rgbquad.rgbBlue;
*(fbp + location + 1) = rgbquad.rgbGreen;
*(fbp + location + 2) = rgbquad.rgbRed;
*(fbp + location + 3) = rgbquad.rgbReserved;
line_x++;
if ( line_x == ( ciWidth - 1 ) )
{
line_x = 0;
line_y++;
}
}
*/
BytesPerLine = (ciWidth * ciBitCount + 31) / 32 * 4;
while( !feof( fp ) )
{
rc = fread( tmp, 1, BytesPerLine, fp );
if ( rc != BytesPerLine )
{
break;
}
location = (ciHeight - line_y - 1) * xres * bits_per_pixel / 8;
memcpy( (fbp + location) , tmp, BytesPerLine );
line_y++;
}
fclose( fp );
return( 0 );
}
/******************************************************************************
*
******************************************************************************/
long chartolong( char * string, int length )
{
long number;
if (length <= 4)
{
memset( &number, 0x00, sizeof(long) );
memcpy( &number, string, length );
}
return( number );
}
/******************************************************************************
*
******************************************************************************/
int set_tty_graphics( void )
{
int ret = 1;
if(0 > (tty = open("/dev/tty0", O_RDWR)))
{
printf( "ERROR: /dev/tty0 open failed/n" );
ret = 0;
}
else if(0 > ioctl(tty, KDGETMODE, &tty_mode_was))
{
printf( "ERROR: /dev/tty0 get mode failed/n");
close(tty);
ret = 0;
}
else if((KD_GRAPHICS != tty_mode_was)
&& (0 > ioctl(tty, KDSETMODE, KD_GRAPHICS)))
{
printf( "ERROR: /dev/tty0 set graphics failed/n");
close(tty);
ret = 0;
}
else
{
printf("tty mode was ");
switch(tty_mode_was)
{
case KD_TEXT : printf("KD_TEXT" ); break;
case KD_GRAPHICS : printf("KD_GRAPHICS" ); break;
default : printf("IMPOSSIBLE!" ); break;
}
printf("/n");
printf("tty mode set to KD_GRAPHICS/n");
fflush(stdout);
close(tty);
}
return( ret );
}
/******************************************************************************
*
******************************************************************************/
int set_tty_text( void )
{
int ret = 1;
if(0 > (tty = open("/dev/tty0", O_RDWR)))
{
printf( "ERROR: /dev/tty0 open failed/n" );
ret = 0;
}
else if(0 > ioctl(tty, KDSETMODE, tty_mode_was))
{
printf( "ERROR: /dev/tty0 reset mode failed/n");
close(tty);
ret = 0;
}
else
{
printf("tty mode set to ");
switch(tty_mode_was)
{
case KD_TEXT : printf("KD_TEXT" ); break;
case KD_GRAPHICS : printf("KD_GRAPHICS" ); break;
default : printf("IMPOSSIBLE!" ); break;
}
printf("/n");
fflush(stdout);
close(tty);
}
return( ret );
}