文件浏览器及数码相框 -2.3.1freetype_pc

例子

#include <stdio.h>
#include <string.h>
#include <math.h>

#include <ft2build.h>
#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( '
' );
  }
}


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
", 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 */

    /* pixels = 50 /72 * 100 = 69 个像素点*/
#else
    FT_Set_Pixel_Sizes(face, 24, 0);
#endif
  /* 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 (0,40) 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;
}

1.编译free_type

配置  ./configure

编译   make

安装 sudo make install

gcc -o example1 example1.c

error: freetype/config/ftheader.h: No such file or directory
example1.c:12:10: error: #include expects "FILENAME" or <FILENAME>

指定头文件目录编译

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

报错缺库

example1.c:(.text+0x1ea): undefined reference to `FT_Init_FreeType'
example1.c:(.text+0x216): undefined reference to `FT_New_Face'
example1.c:(.text+0x236): undefined reference to `FT_Set_Pixel_Sizes'
example1.c:(.text+0x24d): undefined reference to `cos'
example1.c:(.text+0x285): undefined reference to `sin'
example1.c:(.text+0x2bd): undefined reference to `sin'
example1.c:(.text+0x2f5): undefined reference to `cos'
example1.c:(.text+0x360): undefined reference to `FT_Set_Transform'
example1.c:(.text+0x386): undefined reference to `FT_Load_Char'
example1.c:(.text+0x409): undefined reference to `FT_Done_Face'
example1.c:(.text+0x415): undefined reference to `FT_Done_FreeType'

example1.c:(.text+0x24d): undefined reference to `cos'
example1.c:(.text+0x285): undefined reference to `sin'
example1.c:(.text+0x2bd): undefined reference to `sin'
example1.c:(.text+0x2f5): undefined reference to `cos'

指定库编译freetype    gcc -o example1 example1.c  -I /usr/local/include/freetype2 –lfreetype

缺数学类定义

example1.c:(.text+0x24d): undefined reference to `cos'
example1.c:(.text+0x285): undefined reference to `sin'
example1.c:(.text+0x2bd): undefined reference to `sin'
example1.c:(.text+0x2f5): undefined reference to `cos'

加-lm为加数学类库意思   gcc -o example1 example1.c  -I /usr/local/include/freetype2 -lfreetype  -lm

执行exampe1  用宋体文件    显示abcfg 

./example1   ./simsun.ttc  abcfg

abcfg_thumb2

陈志朋uicode码为  48 96 D7 5F 67 0B

int chinese_str[] = {0x9648,0x5fd7,0x670b};

for ( n = 0; n < 4; n++ )
  {
    /* set transformation */
    FT_Set_Transform( face, &matrix, &pen );

    /* load glyph image into the slot (erase previous one) */
    error = FT_Load_Char( face, chinese_str[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;
  }

./example1   ./simsun.ttc   abc

_thumb7

无法直接使用“abc陈志朋a”

使用宽字符

添加头文件include<wchar.h>

#include <wchar.h>

  wchar_t * chinese_str = L"陈志朋~陈";
  unsigned int *p = (wchar_t *)chinese_str;

  int i = 0;

  printf("uicode: ");
  for( i = 0; i < wcslen(chinese_str); i++)
  {
    printf("0x%x " , p[i]);
  }

  printf(" ");
  return 0;
 

85:27: error: converting to execution character set: Invalid or incomplete multibyte or wide character

代码格式为asii应转化为uicode码

gcc -finput-charset=GBK -fexec-charset=UTF-8 -o example1 example1.c  -I /usr/local/include/freetype2 -lfreetype  -lm

结果

uicode:
0x9648 0x5fd7 0x670b 0x7e 0x9648

打印出位置大小参数

_thumb3

添加头文件#include FT_GLYPH_H   

FT_BBox bbox;
      FT_Glyph  glyph;
  
    // 将FT_GlyphSlot glyph转化为 FT_Glyph  glyph;
    error = FT_Get_Glyph( face->glyph, &glyph );
    if(error)
    {
        printf("FT_Get_Glyph error 
");
    }
    /*从glyph中获取bbox*/
    FT_Glyph_Get_CBox( glyph, FT_GLYPH_BBOX_TRUNCATE, &bbox );

//汉字uicode码
    printf("uicode: %x
", chinese_str[n]);
    //汉字位置原点
    printf("origin.x /64 = %d , origin.y /64 = %d ", pen.x/64, pen.y/64);    
    //最小最大X,Y
    printf("x_min = %d ,x_max = %d, y_min = %d, y_max = %d 
", bbox.xMin, bbox.xMax, bbox.yMin, bbox.yMax);
    //X,Y偏移值
    printf("slot.advance.x/64 = %d, slot.advance.y/64 = %d 
", slot->advance.x/64, slot->advance.y/64);

结果

uicode: 9648
origin.x /64 = 0 , origin.y /64 = 40 x_min = 2 ,x_max = 23, y_min = 37, y_max = 60
slot.advance.x/64 = 24, slot.advance.y/64 = 0
uicode: 5fd7
origin.x /64 = 24 , origin.y /64 = 40 x_min = 25 ,x_max = 47, y_min = 38, y_max = 60
slot.advance.x/64 = 24, slot.advance.y/64 = 0
uicode: 670b
origin.x /64 = 48 , origin.y /64 = 40 x_min = 48 ,x_max = 70, y_min = 37, y_max = 59
slot.advance.x/64 = 24, slot.advance.y/64 = 0
uicode: 7e
origin.x /64 = 72 , origin.y /64 = 40 x_min = 73 ,x_max = 84, y_min = 55, y_max = 60
slot.advance.x/64 = 12, slot.advance.y/64 = 0
uicode: 9648
origin.x /64 = 84 , origin.y /64 = 40 x_min = 86 ,x_max = 107, y_min = 37, y_max = 60
slot.advance.x/64 = 24, slot.advance.y/64 = 0

image_thumb4

3_thumb7

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原文地址：https://www.cnblogs.com/CZM-/p/5322434.html