报告题目：汉字异体字管理与字型云服务（IVS Processing and Font Cloud Sevice）
This chapter defines some important typographical concepts relevant to the text system. Many of the terms representing these concepts are reflected in text system APIs. If you’re familiar with typography, you can skip this chapter.
本章定义了与公事系统有关的一部分重大的排版概念。 这一个概念的大队人马术语都反映在文书系统API中。 假令你驾驭制版，可以跳过本章。
报 告 人：吴健研商员（中科院软件所）
Characters and Glyphs(字符和字形卡塔尔(قطر
A character is the smallest unit of written language that carries meaning. Characters can correspond to a particular sound in the spoken form of the language, as do the letters of the roman alphabet; they can represent entire words, such as Chinese ideographs; or they can represent independent concepts, such as mathematical symbols. In every case, however, a character is an abstract concept.
四个字符是有自然意义的书面语言的一丝一毫单位。 字符能够指某种语言的失声，如拉丁字母;它能够象征任何词，如中华夏族民共和国酌量文字; 大概它也能够表示独立的定义，譬如数学符号。 无论在何种处境下，字符都以二个浮泛的定义。
Although characters must be represented in a display area by a recognizable shape, they are not identical to that shape. That is, a character can be drawn in various forms and remain the same character. For example, an “uppercase A” character can be drawn with a different size or a different stroke thickness, it can lean or be vertical, and it can have certain optional variations in form, such as serifs. Any one of these various concrete forms of a character is called a glyph. Figure 2-1 shows different glyphs that all represent the character “uppercase A.”
固然如此字符必得通过可识别的形象在突显区域爱慕味，但它们的形制各异。 也等于说，能够以各个情势来绘制同一个字符。 比方，能够利用不一致尺寸或不相同路程厚度绘制“大写A”字符，它能够偏斜或垂直，何况能够在样式上有着有些可选的变体，举例衬线。 字符的那个种种现实格局中的任何五个叫作字形。 图2-1来得了具备代表字符“大写A”的不等字形。
Figure 2-1 Glyphs of the character A
Characters and glyphs do not have a one-to-one correspondence. In some cases a character may be represented by multiple glyphs, such as an “é” which may be an “e” glyph combined with an acute accent glyph “´”. In other cases, a single glyph may represent multiple characters, as in the case of a ligature, or joined letter. Figure 2-2 shows individual characters and the single-glyph ligature often used when they are adjacent.
Figure 2-2 Ligatures
A ligature is an example of a contextual form in which the glyph used to represent a character changes depending on the characters next to it. Other contextual forms include alternate glyphs for characters beginning or ending a word.
Computers store characters as numbers mapped by encoding tables to their corresponding characters. The encoding scheme native to iOS and OS X conforms to the Unicode standard. Unicode provides a standard methodology for assigning a unique number for every character in every modern written language in the world, independent of the platform, program, and programming language being used. This universal standard solves a longstanding problem of different computer systems using hundreds of conflicting encoding schemes. It also provides information specifying how to handle bidirectional text and contextual forms; how to form words and break lines; how to sort text in different languages; and how to format numbers, dates, times, and other elements appropriate to different languages.
电脑将字符存款和储蓄为编码表来映射字符到其对应的数字。 iOS和OS X原生的编码方案相符Unicode标准。 Unicode提供了一种标准措施，用于为世界上每一个今世书写语言中的每一个字符分配唯一的号码，而与所利用的平台，程序和编程语言非亲非故。那些通用标准解决了运用数百种冲突编码方案的不等Computer种类的短时间存在的难题。它还提供了点名如哪个地方理双向文本和上下文方式的新闻;怎样演进单词和断字;如何对差别语言的文本举行排序？以至怎么着格式化切合分化语言的数字，日期，时间和别的因素。
Glyphs are also represented by numeric codes called glyph codes. The glyphs used to depict characters are selected by the layout manager during composition and layout processing. The layout manager determines which glyphs to use and where to place them in the display, or view. The layout manager caches the glyph codes in use and provides methods to convert between characters and glyphs and between characters and view coordinates.
金沙澳门手机版网址 ，报告时间：二〇一七年3月19日 中午14:15
Typefaces(Font-Family卡塔尔(قطر and Fonts(字种类列和字体卡塔尔(قطر
A typeface is a set of visually related shapes for some or all of the characters in a written language. For example, Times is a typeface, designed by Stanley Morrison in 1931 for The Times newspaper of London. All of the letter forms in Times are related in appearance, having consistent proportions between stems (vertical strokes) and counters (rounded shapes in letter bodies) and other elements. When laid out in blocks of text, the shapes in a typeface work together to enhance readability.
A typestyle, or simply style, is a distinguishing visual characteristic of a typeface. For example, roman typestyle is characterized by upright letters having serifs and stems thicker than horizontal lines. In italic typestyle, the letters slant to the right and are rounded, similar to cursive or handwritten letter shapes. A typeface usually has several associated typestyles.
A font is a series of glyphs depicting the characters in a consistent size, typeface, and typestyle. A font is intended for use in a specific display environment. Fonts contain glyphs for all the contextual forms, such as ligatures, as well as the normal character forms.
A font family is a group of fonts that share a typeface but differ in typestyle. So, for example, Times is the name of a font family (as well as the name of its typeface). Times roman and Times Italic are the names of two individual fonts belonging to the Times family. Figure 2-3 shows several of the fonts in the Times font family.
字系列列是一组分享字体但字体分裂的字体。所以，举例，Times是一个字种类列的称呼（以致它的书体名称）。Times roman和Times Italic是“Times family”字类别列中多个例外的书体。图2-3展现了Times字连串列中的二种字体。
Figure 2-3 Fonts in the Times font family
Styles, also called traits, include variations such as bold, italic, condensed, expanded, narrow, small caps, poster fonts, and fixed pitch. The text system includes objects called font descriptors, which provide font-matching capability, so that you can partially describe a font by creating a font descriptor with, for example, just a family name or weight, and you can then find all the fonts on the system that match the given trait.
Text layout is the process of arranging glyphs on a display device, in an area called a text view, which represents an area similar to a page in traditional typesetting. The order in which glyphs are laid out relative to each other is called text direction. In English and other languages derived from Latin, glyphs are placed side by side to form words that are separated by spaces. Words are laid out in lines beginning at the top left of the text view proceeding from left to right until the text reaches the right side of the view. Text then begins a new line at the left side of the view under the beginning of the previous line, and layout proceeds in the same manner to the bottom of the text view.
文件布局是在展现设备上排列字形的经过，此人展览示设备和金钱观制版中的页面相似， 被誉为TextView。 字形相对于页面包车型客车布阵各种称为文本方向。 以塞尔维亚语和其余语言派生自拉丁语，字形并列排在一条线放置产生由空格分开的单词。 单词以从左到右的文书视图的左上角开端，直到文本视图的下手。 然后，文本在上一行最初处的视图右边开首一行，布局以平等的不二等秘书籍开展到文本视图的底层。
In other languages, glyph layout can be quite different. For example, some languages lay out glyphs from right to left or vertically instead of horizontally. It is common, especially in technical writing, to mix languages with differing text direction, such as English and Hebrew, in the same line. Some writing systems even alternate layout direction in every other line (an arrangement called boustrophedonic writing). Some languages do not group glyphs into words separated by spaces. Moreover, some apps call for arbitrary arrangements of glyphs; for example, in a graphic design context, a layout may require glyphs to be arranged on a nonlinear path.
To create lines from a string of glyphs, the layout engine must perform line breaking by finding a point at which to end one line and begin the next. In the text system, you can specify line breaking at either word or glyph boundaries. In roman text, a word broken between glyphs requires insertion of a hyphen glyph at the breakpoint.
要从字符串成立行，布局引擎必需透过找到甘休一行并初阶下贰个行的点来施行换行。 在文件系统中，您能够在任三个字或字形边界上点名换行符。 在埃及开罗文件中，字形之间的字词须要在断点处插入连字符号。
The layout manager lays out glyphs along an invisible line called the baseline. In roman text, the baseline is horizontal, and the bottom edge of most of the glyphs rest on it. Some glyphs extend below the baseline, including those for characters like “g” that have descenders, or “tails,” and large rounded characters like “O” that must extend slightly below the baseline to compensate for optical effects. Other writing systems place glyphs below or centered on the baseline. Every glyph includes an origin point that the layout manager uses to align it properly with the baseline.
结构微机沿着一条名字为基线的不可以预知线排列字形。 在亚特兰洲大学文件中，基线是程度的，大多数字形的底层注重于它。 一些字形延伸到基线以下，包蕴持有裁减字符的“g”或“尾”等字符，以至像“O”那样的大圆角字符必得微微低于基线，以补充光学效果。 别的书写系统将字形放在基线的灯利口酒绿或居中。 每个字形包含构造微型机用于将其科学与标准对齐的原点。
Glyph designers provide a set of measurements with a font, called metrics, which describe the spacing around each glyph in the font. The layout manager uses these metrics to determining glyph placement. In horizontal text, the glyph has a metric called the advance width, which measures the distance along the baseline to the origin point of the next glyph. Typically there is some space between the origin point and the left side of the glyph, which is called the left-side bearing. There may also be space between the right side of the glyph and the point described by the advance width, which is called the right-side bearing. The vertical dimension of the glyph is provided by two metrics called the ascent and the descent. The ascent is the distance from the origin (on the baseline) to the top of the tallest glyphs in the font. The descent, which is the distance below the baseline to the bottom of the font’s deepest descender. The rectangle enclosing the visible parts of the glyph is called the bounding rectangle or bounding box. Figure 2-4 illustrates these metrics.
Figure 2-4 Glyph metrics
By default, in horizontal text, typesetters place glyphs side-by-side using the advance width, resulting in a standard interglyph space. However, in some combinations, text is made more readable by kerning, which is shrinking or stretching the space between two glyphs. A very common example of kerning occurs between an uppercase W and uppercase A, as shown in Figure 2-5. Type designers include kerning information in the metrics for a font. The text system provides methods to turn kerning off, use the default settings provided with the font, or tighten or loosen the kerning throughout a selection of text.
私下认可情形下，在等级次序文本中，制版器使用前进宽度并撂下置字形，被称作规范的间距空间。 不过，在好几组合中，通过字距调节使文本变得愈加易读，字距缩短或缩短七个字形之间的空间。 字母间距的一个很宽泛的例子是在大写字母W和大写字母A之间时有发生，如图2-5所示。 类型设计员包蕴字体目标中的字距新闻。 文本系统提供关闭字距的章程，使用字体提供的暗许设置，或在整个文件选取中紧紧或松手字距。
Figure 2-5 Kerning字距
Type systems usually measure font metrics in units called points, which measure exactly 72 per inch in most computer typesetting systems. Adding the distance of the ascent and the descent of a font provides the font’s point size.
Space added during typesetting between lines of type is called leading, after the slugs of lead used for that purpose in traditional metal-type page layout. The total amount of ascent plus descent plus leading provides a font’s line height. (Leading is sometimes also called linegap. It is often specified as a ratio of a font’s point size over the line height at which a block of text is set, such as 14/16.5.)
在制版之间加多的上空类型称为指点，在价值观金属类页面构造中用于此指标的铅笔。上涨加下落加指导的总数提供字体的行高。 （辅导临时也称为线间隙，平时被钦命为字体的点大小与安装文本块的行中度的百分比，举个例子14 / 16.5）。
Although the preceding typographic concepts of type design may be somewhat esoteric, most people who have created documents on a computer or typewriter are familiar with the elements of text layout on a page. For example, the margins are the areas of white space between the edges of the page and the text area where the layout engine places glyphs. Alignment describes the way text lines are placed relative to the margins. For example, horizontal text can be aligned right, left, or centered, as shown in Figure 2-6.
Figure 2-6 Alignment of text relative to margins
Lines of text can also be justified; for horizontal text the lines are aligned on both right and left margin by varying interword and interglyph spacing, as shown in Figure 2-7. The system performs alignment and justification, if requested, after the text stream has been broken into lines and hyphens added and other glyph substitutions made.
Figure 2-7 Justified text
主 持 人：王振宇教授