显示文字这里我用了freetype库。

以左上角显示两行文字：

#include
#include
#include
#include
#include
#include
#include
#include
#include

#include "show_font.h"
#include
#include FT_FREETYPE_H
#include

unsigned char *hzkmem;
unsigned char *fbmem;
unsigned int line_width;
unsigned int pixel_width;

struct fb_var_screeninfo var;

void lcd_put_pixel( int x, int y, unsigned int color )
{
unsigned char *pen_8 = fbmem +y*line_width + x*pixel_width;
unsigned short *pen_16;
unsigned short *pen_32;
unsigned char red,green,blue;

pen\_16 = (unsigned short \*)pen\_8;  
pen\_32 = (unsigned short \*)pen\_8;

switch( pixel\_width\*8 )  
{  
case 8:  
    \*pen\_8 = color;  
    break;

case 16:  
    /\* 565 \*/  
    red = (color>>16) & 0xff;  
    green = (color>>8) & 0xff;  
    blue = (color>>0) & 0xff;  
    color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3));  
    \*pen\_16 = color;  
    break;

case 32:  
    \*pen\_32 = color;  
    break;  
default:  
    printf("can't support %ddpp\\n",pixel\_width\*8 );  
    break;  
}  

}

void draw_bitmap( FT_Bitmap* bitmap,
FT_Int x,
FT_Int y)
{
FT_Int i, j, p, q;
FT_Int x_max = x + bitmap->width;
FT_Int y_max = y + bitmap->rows;

for ( i = x, p = 0; i < x_max; i++, p++ ) { for ( j = y, q = 0; j < y_max; j++, q++ ) { if ( i < 0 || j < 0 || i >= var.xres || j >= var.yres )
continue;

  //image\[j\]\[i\] |= bitmap->buffer\[q \* bitmap->width + p\];  
  lcd\_put\_pixel(i,j,bitmap->buffer\[q \* bitmap->width + p\]);  
}  

}
}

int main( int argc, char **argv )
{
int hzk_fd;
int fd_fb;
struct fb_fix_screeninfo fix;

int screen\_size;

FT\_Library    library;  
FT\_Error      error;  
FT\_Face       face;  
FT\_Matrix     matrix;                 /\* transformation matrix \*/  
FT\_Vector     pen;                    /\* untransformed origin  \*/  
FT\_BBox       bbox;  
FT\_Glyph      glyph;

int i;

double        angle;

wchar\_t \*chinese\_char = L"周zhou";  
wchar\_t \*chinese\_char2 = L"嵌入式Linux";

int line\_box\_ymin=800;  
int line\_box\_ymax=0;

struct stat hzk\_stat;

fd\_fb = open("/dev/fb0",  O\_RDWR );  
if( fd\_fb<0 )  
{  
    perror("oepn failed");  
    return -1;  
}

if( ioctl( fd\_fb,  FBIOGET\_VSCREENINFO, &var ) )  
{  
    printf("can't get var\\n");  
    return -1;  
}

if( ioctl( fd\_fb,  FBIOGET\_FSCREENINFO, &fix ) )  
{  
    printf("can't get fix\\n");  
    return -1;  
}  
line\_width = var.xres \* var.bits\_per\_pixel / 8;  
pixel\_width = var.bits\_per\_pixel / 8;

screen\_size = var.xres \* var.yres \* var.bits\_per\_pixel / 8;  
fbmem = (unsigned char \*)mmap( NULL, screen\_size,  PROT\_READ | PROT\_WRITE, MAP\_SHARED,fd\_fb,0 );  
if( fbmem == (unsigned char \*)-1 )  
{  
    printf("mmap is failed\\n");  
    return -1;  
}

memset( fbmem, 0, screen\_size );

if( argc != 2 )  
{  
    printf("Usage: %s  <font\_file>\\n", argv\[0\]);  
    return -1;  
}

error = FT\_Init\_FreeType( &library );              /\* initialize library \*/  
/\* error handling omitted \*/

error = FT\_New\_Face( library, argv\[1\], 0, &face ); /\* create face object \*/

/\* use 50pt at 100dpi \*/  
error = FT\_Set\_Pixel\_Sizes( face, 30, 0 );                /\* set character size \*/

angle         = ( 0.0 / 360 ) \* 3.14159 \* 2;      /\* use 25 degrees     \*/  
 /\* set up matrix \*/  
matrix.xx = (FT\_Fixed)( cos( angle ) \* 0x10000L );  
matrix.xy = (FT\_Fixed)(-sin( angle ) \* 0x10000L );  
matrix.yx = (FT\_Fixed)( sin( angle ) \* 0x10000L );  
matrix.yy = (FT\_Fixed)( cos( angle ) \* 0x10000L );

/\* the pen position in 26.6 cartesian space coordinates; \*/  
/\* start at (0,24) relative to the upper left corner  \*/  
pen.x = (0) \* 64;  
pen.y = ( var.yres - 24 ) \* 64;  
for( i=0; i<wcslen(chinese\_char); i++ )  
{  
    /\* set transformation \*/  
    FT\_Set\_Transform( face, &matrix, &pen );

    /\* load glyph image into the slot (erase previous one) \*/  
    error = FT\_Load\_Char( face, chinese\_char\[i\], FT\_LOAD\_RENDER );  
    if(error)  
    {  
        printf("FT\_load\_char error\\n");  
        return -1;  
    }

    error = FT\_Get\_Glyph(face->glyph, &glyph );  
    if(error)  
    {  
        printf("FT\_Get\_Glyph error\\n");  
        return -1;  
    }

    FT\_Glyph\_Get\_CBox(glyph, FT\_GLYPH\_BBOX\_TRUNCATE, &bbox);  
    if( line\_box\_ymin > bbox.yMin )  
        line\_box\_ymin = bbox.yMin;  
    if( line\_box\_ymax < bbox.yMax )  
        line\_box\_ymax = bbox.yMax;

    draw\_bitmap( &face->glyph->bitmap,  
                 face->glyph->bitmap\_left,  
                 var.yres - face->glyph->bitmap\_top );

    /\* increment pen position \*/  
    pen.x += face->glyph->advance.x;  
    pen.y += face->glyph->advance.y;  
}

/\* the pen position in 26.6 cartesian space coordinates; \*/  
/\* start at (0,24) relative to the upper left corner  \*/  
pen.x = (0) \* 64;  
pen.y = ( var.yres-( line\_box\_ymax-line\_box\_ymin+24) ) \* 64;  
for( i=0; i<wcslen(chinese\_char2); i++ )  
{  
    /\* set transformation \*/  
    FT\_Set\_Transform( face, &matrix, &pen );

    /\* load glyph image into the slot (erase previous one) \*/  
    error = FT\_Load\_Char( face, chinese\_char2\[i\], FT\_LOAD\_RENDER );  
    if(error)  
    {  
        printf("FT\_load\_char error\\n");  
        return -1;  
    }

    error = FT\_Get\_Glyph(face->glyph, &glyph );  
    if(error)  
    {  
        printf("FT\_Get\_Glyph error\\n");  
        return -1;  
    }

    FT\_Glyph\_Get\_CBox(glyph, FT\_GLYPH\_BBOX\_TRUNCATE, &bbox);  
    if( line\_box\_ymin > bbox.yMin )  
        line\_box\_ymin = bbox.yMin;  
    if( line\_box\_ymax < bbox.yMax )  
        line\_box\_ymax = bbox.yMax;

    draw\_bitmap( &face->glyph->bitmap,  
                 face->glyph->bitmap\_left,  
                 var.yres - face->glyph->bitmap\_top );

    /\* increment pen position \*/  
    pen.x += face->glyph->advance.x;  
    pen.y += face->glyph->advance.y;  
}

return 0;

}

在屏幕的中间左右上下对称显示：

#include
#include
#include
#include
#include
#include
#include
#include
#include

#include "show_font.h"
#include
#include FT_FREETYPE_H
#include

typedef struct TGlyph_
{
FT_UInt index; /* glyph index */
FT_Vector pos; /* glyph origin on the baseline */
FT_Glyph image; /* glyph image */

} TGlyph, *PGlyph;

#define MAX_GLYPHS 100

unsigned char *hzkmem;
unsigned char *fbmem;
unsigned int line_width;
unsigned int pixel_width;

struct fb_var_screeninfo var;

void lcd_put_pixel( int x, int y, unsigned int color )
{
unsigned char *pen_8 = fbmem +y*line_width + x*pixel_width;
unsigned short *pen_16;
unsigned short *pen_32;
unsigned char red,green,blue;

pen\_16 = (unsigned short \*)pen\_8;  
pen\_32 = (unsigned short \*)pen\_8;

switch( pixel\_width\*8 )  
{  
case 8:  
    \*pen\_8 = color;  
    break;

case 16:  
    /\* 565 \*/  
    red = (color>>16) & 0xff;  
    green = (color>>8) & 0xff;  
    blue = (color>>0) & 0xff;  
    color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3));  
    \*pen\_16 = color;  
    break;

case 32:  
    \*pen\_32 = color;  
    break;  
default:  
    printf("can't support %ddpp\\n",pixel\_width\*8 );  
    break;  
}  

}

void draw_bitmap( FT_Bitmap* bitmap,
FT_Int x,
FT_Int y)
{
FT_Int i, j, p, q;
FT_Int x_max = x + bitmap->width;
FT_Int y_max = y + bitmap->rows;

for ( i = x, p = 0; i < x_max; i++, p++ ) { for ( j = y, q = 0; j < y_max; j++, q++ ) { if ( i < 0 || j < 0 || i >= var.xres || j >= var.yres )
continue;

  //image\[j\]\[i\] |= bitmap->buffer\[q \* bitmap->width + p\];  
  lcd\_put\_pixel(i,j,bitmap->buffer\[q \* bitmap->width + p\]);  
}  

}
}

int Get_Glyphs_From_Wstr( FT_Face face, wchar_t* wstr, TGlyph glyphs[] )
{
int n;
PGlyph glyph = glyphs;
int pen_x=0;
int pen_y=0;
int error;

for( n=0; n<wcslen( wstr ); n++ )  
{  
     glyph->index = FT\_Get\_Char\_Index( face, wstr\[n\] );  
    /\* store current pen position \*/  
    glyph->pos.x = pen\_x;  
    glyph->pos.y = pen\_y;

    error = FT\_Load\_Glyph( face, glyph->index, FT\_LOAD\_DEFAULT );  
    if ( error )  
        continue;

    error = FT\_Get\_Glyph( face->glyph, &glyph->image );  
    if ( error )  
        continue;

      /\* translate the glyph image now \*/  
    FT\_Glyph\_Transform( glyph->image, 0, &glyph->pos );

    pen\_x   += face->glyph->advance.x ;

    /\* increment number of glyphs \*/  
    glyph++;  
}  
 /\* count number of glyphs loaded \*/  

return (glyph - glyphs);
}

void compute_string_bbox( TGlyph glyphs[],FT_UInt num_glyphs,FT_BBox *abbox )
{
FT_BBox bbox;
int n;

bbox.xMin = bbox.yMin =  32000;  
bbox.xMax = bbox.yMax = -32000;  
for ( n = 0; n < num\_glyphs; n++ )  
{  
    FT\_BBox  glyph\_bbox;  
    FT\_Glyph\_Get\_CBox( glyphs\[n\].image, FT\_GLYPH\_BBOX\_TRUNCATE,  
                     &glyph\_bbox );

  if (glyph\_bbox.xMin < bbox.xMin)  
    bbox.xMin = glyph\_bbox.xMin;

  if (glyph\_bbox.yMin < bbox.yMin)  
    bbox.yMin = glyph\_bbox.yMin;

  if (glyph\_bbox.xMax > bbox.xMax)  
    bbox.xMax = glyph\_bbox.xMax;

  if (glyph\_bbox.yMax > bbox.yMax)  
    bbox.yMax = glyph\_bbox.yMax;  
}

\*abbox = bbox;

}

void Draw_Glyphs( TGlyph glyphs[],FT_UInt num_glyphs,FT_Vector pen )
{
int n;
int error;

for( n=0; n<num\_glyphs; n++ )  
{  
    FT\_Glyph\_Transform( glyphs\[n\].image, 0, &pen );  
    /\* convert glyph image to bitmap (destroy the glyph copy!) \*/  
    error = FT\_Glyph\_To\_Bitmap( &glyphs\[n\].image, FT\_RENDER\_MODE\_NORMAL,  
          0,                  /\* no additional translation \*/  
          1 );                /\* destroy copy in "image"   \*/

     if ( !error )  
    {  
      FT\_BitmapGlyph  bit = (FT\_BitmapGlyph)glyphs\[n\].image;

      draw\_bitmap( &bit->bitmap,  
                      bit->left,  
                      var.yres - bit->top );

      FT\_Done\_Glyph( glyphs\[n\].image );  
    }  
}  

}

int main( int argc, char **argv )
{
int hzk_fd;
int fd_fb;
struct fb_fix_screeninfo fix;

int screen\_size;

FT\_Library    library;  
FT\_Error      error;  
FT\_Face       face;  
FT\_Matrix     matrix;                 /\* transformation matrix \*/  
FT\_Vector     pen;                    /\* untransformed origin  \*/  
FT\_BBox       bbox;

TGlyph        glyphs\[MAX\_GLYPHS\];  /\* glyphs table \*/  
PGlyph        glyph;               /\* current glyph in table \*/  
FT\_UInt       num\_glyphs;

int i;

double        angle;

wchar\_t \*chinese\_char = L"周zhou";  
wchar\_t \*chinese\_char2 = L"嵌入式Linux";

int line\_box\_ymin=800;  
int line\_box\_ymax=0;

int line\_box\_width;  
int line\_box\_hight;

struct stat hzk\_stat;

fd\_fb = open("/dev/fb0",  O\_RDWR );  
if( fd\_fb<0 )  
{  
    perror("oepn failed");  
    return -1;  
}

if( ioctl( fd\_fb,  FBIOGET\_VSCREENINFO, &var ) )  
{  
    printf("can't get var\\n");  
    return -1;  
}

if( ioctl( fd\_fb,  FBIOGET\_FSCREENINFO, &fix ) )  
{  
    printf("can't get fix\\n");  
    return -1;  
}  
line\_width = var.xres \* var.bits\_per\_pixel / 8;  
pixel\_width = var.bits\_per\_pixel / 8;

screen\_size = var.xres \* var.yres \* var.bits\_per\_pixel / 8;  
fbmem = (unsigned char \*)mmap( NULL, screen\_size,  PROT\_READ | PROT\_WRITE, MAP\_SHARED,fd\_fb,0 );  
if( fbmem == (unsigned char \*)-1 )  
{  
    printf("mmap is failed\\n");  
    return -1;  
}

memset( fbmem, 0, screen\_size );

if( argc != 2 )  
{  
    printf("Usage: %s  <font\_file>\\n", argv\[0\]);  
    return -1;  
}

error = FT\_Init\_FreeType( &library );              /\* initialize library \*/  
/\* error handling omitted \*/

error = FT\_New\_Face( library, argv\[1\], 0, &face ); /\* create face object \*/

/\* use 50pt at 100dpi \*/  
error = FT\_Set\_Pixel\_Sizes( face, 24, 0 );                /\* set character size \*/

num\_glyphs = Get\_Glyphs\_From\_Wstr( face, chinese\_char, glyphs);  
compute\_string\_bbox( glyphs, num\_glyphs, &bbox );  
line\_box\_width = bbox.xMax - bbox.xMin;  
line\_box\_hight = bbox.yMax - bbox.yMin;  
pen.x = (var.xres - line\_box\_width)/2\*64;  
pen.y = (var.yres - line\_box\_hight)/2\*64;  
Draw\_Glyphs( glyphs, num\_glyphs, pen );

num\_glyphs = Get\_Glyphs\_From\_Wstr( face, chinese\_char2, glyphs);  
compute\_string\_bbox( glyphs, num\_glyphs, &bbox );  
line\_box\_width = bbox.xMax - bbox.xMin;  
line\_box\_hight = bbox.yMax - bbox.yMin;  
pen.x = (var.xres - line\_box\_width)/2\*64;  
pen.y = pen.y-24\*64;  
Draw\_Glyphs( glyphs, num\_glyphs, pen );

return 0;

}

sd