TrueType 1.0 字体规范详解

5星 · 超过95%的资源需积分: 9 128 浏览量更新于2024-07-31 收藏 5.72MB PDF 举报

"TrueType 1.0 字体文件(修订版1.66)" TrueType 1.0 字体文件是Microsoft公布的一种字体格式标准，它在1995年8月的修订版1.66中进行了更新。TrueType字体是一种向量字体技术，这意味着字体由数学曲线描述，无论放大到何种程度都能保持清晰。这种技术使得TrueType字体在各种屏幕和打印环境中都具有优秀的可读性和质量。 TrueType 1.0 的核心特性包括： 1. **可缩放性**：由于基于数学曲线，TrueType字体可以轻松地缩放至任何大小，无论是小到电子设备的显示屏，还是大到大幅面印刷。 2. **平滑渲染**：在低分辨率的屏幕上，TrueType字体支持抗锯齿技术，使得字体边缘平滑，提高视觉效果。 3. **跨平台兼容**：TrueType字体不仅适用于Windows操作系统，也与Apple的Mac OS及其他支持TrueType格式的操作系统兼容。 4. **字库结构**：TrueType字体由一系列字形（glyphs）组成，每个字形代表一个字符或符号。字体文件中包含了每个字形的轮廓信息，以及关于如何组合这些字形形成连字（ligatures）和复合字符的信息。 5. **字形索引**：TrueType字体使用字形索引来快速定位和绘制特定字符，提高了效率。 6. **嵌入式字体**：TrueType允许字体被嵌入到文档中，如PDF文件，这样即使目标系统没有安装相应的字体，也能正确显示文档内容。 7. **版权保护**：文档中提到，TrueType字体软件的复制和使用受到许可协议或非披露协议的限制，违法复制可能会触犯法律。部分手册内容由Apple Computer, Inc.持有版权。 8. **美国政府限制**：对于美国政府的使用，TrueType字体和相关文档受到DFARS 252.227条款下的限制，即在特定条件下才能进行使用、复制或披露。 TrueType 1.0 字体文件规范的修订版1.66可能包含了一些改进和修正，比如错误修复、性能优化或者增加了对新字符集的支持。不过，具体的更改内容需要查阅完整的规格文档来了解。随着技术的发展，后续的TrueType版本（如TrueType Open、TrueTypeGX等）引入了更多的复杂特性和扩展功能，如OpenType特性，以满足更高级的排版和设计需求。

TrueType Fundamentals

The origin of the em square need not have any consistent relationship to the

glyph outlines. In practice, however, applications depend upon the existence

of some convention for the placement of glyphs for a given font. For Roman

fonts, which are intended to be laid out horizontally, a y-coordinate value of 0

typically is assumed to correspond to the baseline of the font. No particular

meaning is assigned to an x-coordinate of 0 but manufacturers may improve

the performance of applications by choosing a standard meaning for the

x-origin.

For example, you might place a glyph so that its aesthetic center is at the

x-coordinate value of 0. That is, a set of glyphs so designed when placed in a

column such that their x-coordinate values of 0 are coincident will appear to

be nicely centered. This option would be used for Kanji or any fonts that are

typeset vertically. Another alternative is to place each glyph so that its

leftmost extreme outline point has an x-value equal to the left-side-bearing of

the glyph. Fonts created in this way may allow some applications to print

more quickly to PostScript printers.

Figure 1-5 Two possible choices for the glyph origin in a Roman font. In

the first case (left) the left side bearing is x-zero. In the second

(right), the aesthetic center of the character is x-zero

Page 10 Revision 1.66

File Name: ttch01.doc

TrueType Fundamentals

Revision 1.66 Page 13

File Name: ttch01.doc

Scaling a glyph

This section describes how glyph outlines are scaled from the master size

stored in the font file to the size requested by an application.

Device space

Whatever the resolution of the em square used to define a glyph outline,

before that glyph can be displayed it must be scaled to reflect the size,

transformation and the characteristics of the output device on which it is to be

displayed. The scaled outline must describe the character outline in units that

reflect an absolute rather than relative system of measurement. In this case the

points that make up a glyph outline are described in terms of pixels.

Intuitively, pixels are the actual output bits that will appear on screen or

printer. To allow for greater precision in managing outlines, TrueType

describes pixel coordinates to the nearest sixty-fourth of a pixel.

Converting FUnits to pixels

Values in the em square are converted to values in the pixel coordinate system

by multiplying them by a scale. This scale is:

pointSize *

resolution

72 points per inch * units_per_em

where pointSize is the size at which the glyph is to be displayed, and

resolution is the resolution of the output device. The 72 in the denominator

reflects the number of points per inch.

For example, assume that a glyph feature is 550 FUnits in length on a 72 dpi

screen at 18 point. There are 2048 units per em. The following calculation

reveals that the feature is 4.83 pixels long.

550 *

18 * 72

72 * 2048

= 4.83

Display device characteristics

The resolution of any particular display device is specified by the number of

dots or pixels per inch (dpi) that are displayed. For example, a VGA under

OS/2 and Windows is treated as a 96 dpi device, and most laser printers have

a resolution of 300 dpi. Some devices, such as an EGA, have different

resolution in the horizontal and vertical directions (i.e. non-square pixels); in

the case of the EGA this resolution is 96 x 72. In such cases, horizontal dots

per inch must be distinguished from vertical dots per inch.

剩余381页未读，继续阅读

jglin2003

粉丝: 1
资源: 5

TrueType 1.0 字体规范详解

ttfspec2.zip Windows字体文件（.TTF）格式详解

TrueType Specification

TrueType Font Specification

Google Android TrueType Font

TrueType Font Subset Source Code

TrueType Font Server for X11-开源

Google Android TrueType Font - Droid Sans Mono

Arame-Font-Files:Arame字体文件

gohufont-ttf:TrueType 格式的 GohuFont（来自 font.gohu.org）

fontnamefromfile_src.zip_TTF_font name _opentype_truetype

最新资源