这里我们用到了freetype。进入官网http://savannah.nongnu.org/download/freetype/ 中下载最新的版本2.7的源代码和文件。freetype-2.7.tar.gz freetype-doc-2.7.tar.gz

首先我们在使用官方提供的程序在pc上运行一下。需要安装zlib库。

在_freetype-doc-2.7.tar.gz文件中的docus目录下的tutorial有一个example.c的源文件。_

example.c：

/* example1.c */
/* */
/* This small program shows how to print a rotated string with the */
/* FreeType 2 library. */

#include
#include
#include

#include
#include FT_FREETYPE_H

#define WIDTH 80
#define HEIGHT 80

/* origin is the upper left corner */
unsigned char image[HEIGHT][WIDTH];

/* Replace this function with something useful. */

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 >= WIDTH || j >= HEIGHT )
continue;

  image\[j\]\[i\] |= bitmap->buffer\[q \* bitmap->width + p\];  
}  

}
}

void
show_image( void )
{
int i, j;

for ( i = 0; i < HEIGHT; i++ )
{
for ( j = 0; j < WIDTH; j++ )
putchar( image[i][j] == 0 ? ' '
: image[i][j] < 128 ? '+'
: '*' );
putchar( '\n' );
}
}

int
main( int argc,
char** argv )
{
FT_Library library;
FT_Face face;

FT_GlyphSlot slot;
FT_Matrix matrix; /* transformation matrix */
FT_Vector pen; /* untransformed origin */
FT_Error error;

char* filename;
char* text;

double angle;
int target_height;
int n, num_chars;

if ( argc != 3 )
{
fprintf ( stderr, "usage: %s font sample-text\n", argv[0] );
exit( 1 );
}

filename = argv[1]; /* first argument */
text = argv[2]; /* second argument */
num_chars = strlen( text );
angle = ( 0.0 / 360 ) * 3.14159 * 2; /* use 0 degrees 旋转 */
target_height = HEIGHT;

error = FT_Init_FreeType( &library ); /* initialize library */
/* error handling omitted */

error = FT_New_Face( library, filename, 0, &face );/* create face object */
/* error handling omitted */

/* use 50pt at 100dpi */
error = FT_Set_Char_Size( face, 50 * 64, 0,
30, 0 ); /* set character size */
/* error handling omitted */

slot = face->glyph;

/* 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 (40,0) relative to the upper left corner */
pen.x = 0 * 64;
pen.y = ( target_height - 40 ) * 64;

for ( n = 0; n < num_chars; n++ )
{
/* set transformation */
FT_Set_Transform( face, &matrix, &pen );

/\* load glyph image into the slot (erase previous one) \*/  
error = FT\_Load\_Char( face, text\[n\], FT\_LOAD\_RENDER );  
if ( error )  
  continue;                 /\* ignore errors \*/

/\* now, draw to our target surface (convert position) \*/  
draw\_bitmap( &slot->bitmap,  
             slot->bitmap\_left,  
             target\_height - slot->bitmap\_top );

/\* increment pen position \*/  
pen.x += slot->advance.x;  
pen.y += slot->advance.y;  

}

show_image();

FT_Done_Face ( face );
FT_Done_FreeType( library );

return 0;
}

/* EOF */

程序中把输出的字符打印在屏幕上，分辨率是640*480，从300,200 处开始显示.这里我为了便于查看就改为了80*80.从40，0处开始显示

编译：

gcc -o example1 example1.c -I /usr/local/include/freetype2/ -lfreetype -lm

运行程序即可。

arm：

首先配置：

./configure --host=arm-linux
make
make DESTDIR=$PWD/tmp install

将生成的文件拷贝到交叉编译器和开发板文件系统相应的位置。

编译文件：

arm-linux-gcc -o test main.c -lfreetype -lm

将test和字体文件拷贝到开发板中即可运行程序.

源代码：

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

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

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 lcd_put_ascii( int x, int y, unsigned char c )
{
unsigned char *dots = (unsigned char *)&fontdata_8x16[c*16];
int i,b;
unsigned char byte;

for( i=0; i< 16; i++ )  
{  
    byte = dots\[i\];  
    for( b=7;b>=0;b--)  
    {  
        if( byte & (1<<b))  
        {  
            lcd\_put\_pixel(x+7-b,y+i, 0xffffff );  
        }  
        else  
        {  
            lcd\_put\_pixel(x+7-b,y+i, 0x000000 );  
        }  
    }  
}

}

void lcd_put_chinese( int x, int y, unsigned char *c )
{
unsigned int area = c[0] - 0xa1;
unsigned int where = c[1] - 0xa1;
unsigned char *dots = hzkmem + (area*94+where)*32;
unsigned char byte;
int i,j,b;
for( i=0; i<16; i++ ) { for( j=0; j<2; j++ ) { byte = dots[i*2+j]; for( b=7; b>=0; b-- )
{
if( byte & (1<<b) )
lcd_put_pixel(x+j*8+7-b,y+i, 0xffffff );
else
lcd_put_pixel(x+j*8+7-b,y+i, 0x000000 );
}
}
}
}

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  \*/

double        angle;

wchar\_t \*chinese\_char = L"周zhou";

unsigned char str\[\]={0xd6,0xd0};  
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;  
}

hzk\_fd = open("HZK16",  O\_RDONLY );  
if( hzk\_fd<0 )  
{  
    printf("can't open hzk\\n");  
    return -1;  
}

if( fstat(hzk\_fd, &hzk\_stat))  
{  
    printf("can't get fstat\\n");  
    return -1;  
}

hzkmem = (unsigned char \*)mmap( NULL, hzk\_stat.st\_size,  PROT\_READ, MAP\_SHARED,hzk\_fd,0 );  
if( hzkmem == (unsigned char \*)-1 )  
{  
    printf("mmap hzk is failed\\n");  
    return -1;  
}

memset( fbmem, 0, screen\_size );

lcd\_put\_ascii(var.xres/2,var.yres/2,'A' );

printf("chinese code : %02x  %02x\\n", str\[0\],str\[1\]);  
lcd\_put\_chinese( var.xres/2 +8 ,var.yres/2, str );

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 (40,0) relative to the upper left corner  \*/  
pen.x = (var.xres/2+8+16) \* 64;  
pen.y = ( var.yres/2 - 16 ) \* 64;

/\* set transformation \*/  
FT\_Set\_Transform( face, &matrix, &pen );

/\* load glyph image into the slot (erase previous one) \*/  
error = FT\_Load\_Char( face, chinese\_char\[0\], FT\_LOAD\_RENDER );  
if(error)  
{  
    printf("FT\_load\_char error\\n");  
    return -1;  
}

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

return 0;

}

sds