数码相框——矢量字体原理（4）

一 在PC平台上，通过使用FreeType库，打印出宽字符信息

代码如下：

/* example1.c                                                      */

/*                                                                 */

/* This small program shows how to print a rotated string with the */

/* FreeType 2 library.                                             */

#include <stdio.h>

#include <string.h>

#include <math.h>

#include <wchar.h>

#include <ft2build.h>

#include <string.h>

#include FT_FREETYPE_H

 #include FT_GLYPH_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;

//printf("x =%d,y =%d\n",x,y);

  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++ )

  {

  printf("%d",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;

 FT_BBox  bbox;

   FT_Glyph  glyph;

 

  char*         filename;

  char*         text;

  double        angle;

  int           target_height;

  int           n, num_chars;

 

//unsigned int str[]= {0x8D75,0x521B,0x007A};

wchar_t *chinese_str = L“嵌入式abc";

unsigned int *p = (wchar_t *)chinese_str;

int i;

printf("Unicode:\n");

for(i=0;i<wcslen(chinese_str);i++)

{

    printf("0x%x\n",p[i]);

}

printf("\n");

  if ( argc != 2 )

  {

    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 25 degrees     */

  target_height = HEIGHT;

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

  /* error handling omitted */

  error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */

  /* error handling omitted */

#if 0

  /* use 50pt at 100dpi */

  error = FT_Set_Char_Size( face, 50 * 64, 0,

                            100, 0 );                /* set character size */

  /* error handling omitted */

#else

    FT_Set_Pixel_Sizes(face, 24, 0);

#endif

  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 (0,40) relative to the upper left corner  */

  pen.x = 0 * 64;

  pen.y = ( target_height - 40 ) * 64;

  for ( n = 0; n < wcslen(chinese_str); n++ )

  {

    /* set transformation */

    FT_Set_Transform( face, &matrix, &pen );  

    /* load glyph image into the slot (erase previous one) */

    error = FT_Load_Char( face, p
, FT_LOAD_RENDER );

    if ( error )

      continue;                 /* ignore errors */

    

   error = FT_Get_Glyph( face->glyph, &glyph );

   if(error)

   {

    printf("FT_Get_Glyph error\n");

   }

    FT_Glyph_Get_CBox( glyph, FT_GLYPH_BBOX_TRUNCATE, &bbox );

    

    /* now, draw to our target surface (convert position) */

    draw_bitmap( &slot->bitmap,

                 slot->bitmap_left,

                 target_height - slot->bitmap_top );

    printf("Unicode:0x%x\n",chinese_str
);

    printf("origin.x/64 = %d, origin.y/64 = %d\n",pen.x/64,pen.y/64);

    printf("lcd_x = %d,lcd_y = %d ,xMin = %d, xMax = %d,yMin = %d, yMax = %d\n ",slot->bitmap_left,target_height - slot->bitmap_top,bbox.xMin,bbox.xMax,bbox.yMin,bbox.yMax);

    printf("slot->advance.x/64 = %d",slot->advance.x/64);

    printf("slot->advance.y/64 = %d\n",slot->advance.y/64);

    /* 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 */