數碼相框——矢量字體原理（6）

來源：

http://liu1227787871.blog.163.com/blog/static/2053631972012628113620362/

前面我們的矢量字體顯示的例子是在pc上運行的，這一節裏面我們來編寫可以再lcd上顯示矢量字體的程序，例如顯示“hello 嵌入式”

2.3.3節_數碼相框_在LCD上顯示一個矢量字體

交叉編譯:
tar xjf freetype-2.4.10.tar.bz2
./configure --host=arm-linux
make
make DESTDIR=$PWD/tmp install

編譯出來的頭文件應該放入：
/usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include

編譯出來的庫文件應該放入：
/usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib

把tmp/usr/local/lib/*  複製到 /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib
sudo cp * /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib -d -rf
cp *so* /work/nfs_root/fs_mini_mdev_new/lib -d


把tmp/usr/local/include/*  複製到 /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include
cp * /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include -rf
cd /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include
mv freetype2/freetype .

//編譯
arm-linux-gcc -finput-charset=GBK -o example1 example1.c  -lfreetype -lm
arm-linux-gcc -finput-charset=GBK -o show_font show_font.c  -lfreetype -lm
arm-linux-gcc -finput-charset=GBK -o chinese_lcd chinese_lcd.c  -lfreetype -lm


//修改/ftheader.h的路徑
freetype/config/ftheader.h
freetype2/freetype/config/ftheader.h



//制定輸入字符charsert
arm-linux-gcc -finput-charset=GBK -fexec-charset=GBK -o show_font show_font.c -lfreetype -lm
arm-linux-gcc -finput-charset=GBK -o chinese_lcd chinese_lcd.c  -lfreetype -lm

一、搭建編譯環境

1、解壓：tar xvf freetype-2.4.10.tar.bz2

2、cd freetype-2.4.10

3、配置：./configure --host=arm-linux

4、編譯：make

5、安裝：make DESTDIR=$PWD/tmp install

編譯出來的頭文件應該放入：

/usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include

編譯出來的庫文件應該放入：

/usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib

6、cd tmp/usr/local

7、把tmp/usr/local/lib/*  複製到 /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib

 cp lib/* /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib -d -rf

8、把tmp/usr/local/include/*  複製到 /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include

cp include/* /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include -rf

cd /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/usr/include

mv freetype2/freetype .

9、將動態庫拷貝到根文件系統的lib目錄下

cp lib/*so* /home/share/jz2440/source/fs_mini_mdev_new/lib -d

10、編譯：arm-linux-gcc -finput-charset=GBK -o chinese_lcd chinese_lcd.c  -lfreetype -lm

執行文件，在開發板串口控制檯輸出根pc機一樣的漢字！

二：代碼修改（參考dot_Font.c 和Example1.c(Freetype)）
/*
*功能：在LCD上顯示Hello 嵌入式
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
//#include <sys/types.h>
//#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <linux/fb.h>
#include <string.h>
#include <math.h>
#include <wchar.h>
#include <ft2build.h>
#include FT_FREETYPE_H
 #include FT_GLYPH_H

int fd_fb = 0;
struct fb_var_screeninfo  fb_var;
struct fb_fix_screeninfo   fb_fix;
int screen_size = 0;
unsigned char* fb_mem;
int line_width;
int  pix_width;
void lcd_put_pixel(int x, int y, unsigned int color)
{
    unsigned char *pen_8 = (unsigned char*)(fb_mem+y*line_width+x*pix_width);
    unsigned short *pen_16;
    unsigned int *pen_32;
    pen_16 = (unsigned short*)pen_8;
    pen_32 = (unsigned int*)pen_8;
    unsigned char red,green,blue;
    switch(fb_var.bits_per_pixel)
    {
        case 8:
            *pen_8 = color;
            break;
        case 16:
            red = (color >>16)&0xff;
            green = (color>>8)&0xff;
            blue = (color>>0)&0xff;
            color = ((red>>3)<<11)|((green>>2)<<5)|((blue>>3)<<0);
            *pen_16 = color;
            break;
        case 32:
            *pen_32 = color;
            break;
        default:
            printf("Can' support  error\n");
            break;

    }
}


/* 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 >= fb_var.xres|| j >= fb_var.yres)
        continue;
    lcd_put_pixel(i,j, bitmap->buffer[q * bitmap->width + p]);
    }
  }
}


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;
    double        angle;
int           target_height;
int        n;
  wchar_t *chinese_str = L"hello 嵌入式";
 
    fd_fb = open("/dev/fb0",O_RDWR);
    if(fd_fb < 0)
    {
        printf("open /dev/fb0 failed\n");
        return -1;
    }
    
    if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &fb_var))
    {
        printf("get var information failed\n");
        return -1;
    }
    if (ioctl(fd_fb, FBIOGET_FSCREENINFO, &fb_fix))
    {
        printf("get fix information failed\n");
        return -1;
    }
    screen_size = fb_var.xres * fb_var.yres * fb_var.bits_per_pixel /8;
    line_width = fb_var.xres * fb_var.bits_per_pixel /8;
    pix_width = fb_var.bits_per_pixel /8;
    fb_mem =(unsigned char *)mmap(NULL , screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
    if(fb_mem == (unsigned char *)-1)
    {
        printf("fb_mem mmap failed\n ");
        return -1;
    }
    memset(fb_mem, 0, screen_size);
    /*Ôö¼ÓFreetype*/
    if(argc != 2)
    {
        printf("Useage: %s <font file>\n",argv[0]);
        return -1;
    }
    error = FT_Init_FreeType( &library );              /* initialize library */
    if(error)
    {
        printf("FT_Init_FreeType failed\n");
        return -1;
    }
     error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */
     if(error)
    {
        printf("FT_New_Face failed\n");
        return -1;
    }
    FT_Set_Pixel_Sizes(face, 24, 0);
      slot = face->glyph;
    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 (0,40) relative to the upper left corner  */
      pen.x = 0 * 64;
      pen.y = ( fb_var.yres- 50 ) * 64;
      for ( n = 0; n < wcslen(chinese_str); n++ )
      {
         FT_Set_Transform( face, &matrix, &pen );
          error = FT_Load_Char( face, chinese_str[n], FT_LOAD_RENDER );    
        if(error)
            continue;
         /* now, draw to our target surface (convert position) */
            draw_bitmap( &slot->bitmap,
                 slot->bitmap_left,
                 fb_var.yres- slot->bitmap_top );
            /* increment pen position */
        pen.x += slot->advance.x;
        pen.y += slot->advance.y;
    }
      FT_Done_Face    ( face );
      FT_Done_FreeType( library );

  return 0;
}