般来说, 每种基本字体,都会有在其基础上变化字形的附加字体。比如,字体Arial, 就有其附加字体Arial Bold(粗体), ArialItalic(斜体), 及Arial BoldItalic(粗斜体)。一般你都可以找到或购买到相应的附加字体。
但有时为了应急,或对字体字形没有非常严格的要求。在这样的情况下,我们可以采用人工字形生成(Artificial font styles)。Artificial font styles是Acrobat的一个功能,它根据基本字形而模拟生成粗体,斜体及粗斜体。PDFlib支持这一功能,并遵守Acrobat对此功能的限制。目前此功能之局限于:
1.Acrobat标准字体, 就简体中文来说也就是PDFlib自带的STSong-Light,AdobeSongStd-Light-Acro,及STSongStd-Light-Acro三种简体中文字体。
2.PDFlib可以访问的.otf OpenType字体,并使用表1.1的编码(见《浅谈PDFlib中文输出(一)》), 且“embedding”参数设为假。
下面是一个相关的例子--C源程序(附上生成的pdf文件–PDFlib_cs5.pdf)。
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include"pdflib.h"
intmain(void)
{
PDF *p = NULL;
int Font_H = 0, Font_CS = 0, Left = 50, y =700;
constint INCRY = 25;
constchar TextUnicode[] = "\x80\x7B\x53\x4F\x2D\x4E\x87\x65";
constint TEXTLEN = 8;
if ((p =PDF_new()) == (PDF *) 0)
{
printf("Couldn't create PDFlib object (out of memory)!\n");
return(2);
}
PDF_TRY(p){
if(PDF_begin_document(p, "pdflib_cs5.pdf", 0, "") == -1)
{
printf("Error: %s\n", PDF_get_errmsg(p));
return(2);
}
PDF_set_info(p, "Creator", "pdflib_cs5.c");
PDF_set_info(p, "Author", "myi@pdflib.com");
PDF_set_info(p, "Title", "Usage of Artificial font styles");
PDF_begin_page_ext(p, a4_width, a4_height, "");
Font_H =PDF_load_font(p, "Helvetica-Bold", 0, "winansi", "");
PDF_setfont(p, Font_H, 24);
PDF_show_xy(p, "Artificial Font Styles", Left +100, y);
y -= 2 *INCRY;
PDF_setfont(p, Font_H, 14);
PDF_show_xy(p, "Normal", Left, y);
y -=INCRY;
Font_CS =PDF_load_font(p, "STSong-Light", 0, "UniGB-UCS2-H", "");
PDF_setfont(p, Font_CS, 14);
PDF_show_xy2(p, TextUnicode, TEXTLEN, Left, y);
y -= 2 *INCRY;
PDF_setfont(p, Font_H, 14);
PDF_show_xy(p, "Italic", Left, y);
y -=INCRY;
Font_CS =PDF_load_font(p, "STSong-Light", 0, "UniGB-UCS2-H", "fontstyleitalic");
PDF_setfont(p, Font_CS, 14);
PDF_show_xy2(p, TextUnicode, TEXTLEN, Left, y);
y -= 2 *INCRY;
PDF_setfont(p, Font_H, 14);
PDF_show_xy(p, "Bold", Left, y);
y -=INCRY;
Font_CS =PDF_load_font(p, "STSong-Light", 0, "UniGB-UCS2-H", "fontstylebold");
PDF_setfont(p, Font_CS, 14);
PDF_show_xy2(p, TextUnicode, TEXTLEN, Left, y);
y -= 2 *INCRY;
PDF_setfont(p, Font_H, 14);
PDF_show_xy(p, "Bold-italic", Left, y);
y -=INCRY;
Font_CS =PDF_load_font(p, "STSong-Light", 0, "UniGB-UCS2-H",
"fontstylebolditalic");
PDF_setfont(p, Font_CS, 14);
PDF_show_xy2(p, TextUnicode, TEXTLEN, Left, y);
PDF_end_page_ext(p, "");
PDF_end_document(p, "");
}
PDF_CATCH(p){
printf("PDFlib exception occurred in pdflib_cs5 sample:\n");
printf("[%d]%s: %s\n", PDF_get_errnum(p), PDF_get_apiname(p),
PDF_get_errmsg(p));
PDF_delete(p);
return(2);
}
PDF_delete(p);
return0;
}