freetype的简单使用
安装完毕以后我们先做个简单的实例程序看看效果
1.首先先下载字体
链接：
提取码：rohm
2.编写程序
编译测试文件example.c
/*编译命令*/ -I指定库文件所在位置-L指定动态库位置gcc example.c -o example -I /usr/local/freetype/include/freetype2 -L/usr/local/freetype/lib -lfreetype example.c 程序
/* 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 <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 */
#elseFT_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;
}/* EOF */
运行测试程序 ./example ./simsun.ttc fbg (预先将simsun.ttc字体文件拷贝到当前目录)结果如下：
freetype的简单使用
安装完毕以后我们先做个简单的实例程序看看效果
1.首先先下载字体
链接：
提取码：rohm
2.编写程序
编译测试文件example.c
/*编译命令*/ -I指定库文件所在位置-L指定动态库位置gcc example.c -o example -I /usr/local/freetype/include/freetype2 -L/usr/local/freetype/lib -lfreetype example.c 程序
/* 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 <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 */
#elseFT_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;
}/* EOF */
运行测试程序 ./example ./simsun.ttc fbg (预先将simsun.ttc字体文件拷贝到当前目录)结果如下：