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( '\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 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
, 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





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
, 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





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

printf("\n");
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





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 \n");
}
/*从glyph中获取bbox*/
FT_Glyph_Get_CBox( glyph, FT_GLYPH_BBOX_TRUNCATE, &bbox );

//汉字uicode码
printf("uicode: %x\n", chinese_str
);
//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 \n", bbox.xMin, bbox.xMax, bbox.yMin, bbox.yMax);
//X,Y偏移值
printf("slot.advance.x/64 = %d, slot.advance.y/64 = %d \n", 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