Automation 4的核心文件 karaskel.lua 内置了许多函数，用来协助Automation 4 Lua方面的卡拉OK特效制作
它定义了几种新的数据结构，也拓展了Automation 4 本身定义的一些。
karaskel.lua 包含
`utils.lua` 和
`unicode.lua` 。所以你在使用karaskel.lua时不必再单独include这两项。
karaskel.lua 的用武之地主要是卡拉OK特效，它也可以被用来进行一些简单的文字样式调整。
摘要: meta, styles = karaskel.collect_head(subtitles, generate_furigana)
读取字幕文件来获取所有的头部信息和样式定义,也可以为假名生成新的样式。
subtitles 指的是Automation 4 Lua定义的字幕文件对象。generate_furigana 是在这种逻辑下进行的操作: 它会为没有对应 假名布局 的样式单独生成样式。生成的假名样式永远也不会覆盖存在的样式。使用 collect_head 一般情况下是你在处理函数中做的第一步。
返回的 meta 表包含着以下全部， Name: Value 对应到 [Script Info] 部分。它也包含 meta.res_x 和 meta.res_y ,它们对应到 PlayResX and PlayResY 。
返回的 styles 表包含着全部已定义的样式, 也包含着自动生成的假名样式, 样式结构在style表中占有单独的位置,如style.margin_v (又称 style.margin_t), 为了方便, styles 可以通过样式名称
(区分大小写,不可缺内容) 和数字来指定。 styles.n 是样式存储的编号, styles[1] 就是第一个被定义的样式。
摘要: karaskel.preproc_line(subtitles, meta, styles, line)
为单行字幕计算尺寸、位置和其它信息。这个函数按顺序调用 karaskel.preproc_line_text,
karaskel.preproc_line_size 和 karaskel.preproc_line_pos 。
这个函数不会返回值，但是在修饰 line 表的时候例外。详见下。
摘要: karaskel.preproc_line_text(meta, styles, line)
预处理单行的文本。 meta 和 styles 是由 [[karaskel.collect_head|karaskel.lua#karaskel.collect_head]] 返回的表。
这个函数不会返回值，但是在修饰 line 表的时候例外:
line.text_stripped - 返回除去特效标签和绘图代码的原文本line.duration - 返回行的持续时间(毫秒单位)line.kara 和 line.furi - 扩展版的 卡拉OK和假名标注表, 不含尺寸位置信息。这个函数不计算任何尺寸和位置信息。 (事实上它根本不使用 meta 或者 styles 之前获取到的尺寸位置信息)
摘要: karaskel.preproc_line_size(meta, styles, line)
为整行、所有的音节和假名标注计算尺寸，参照行样式信息。
这个函数不会返回值，但是在修饰 line 表的时候例外:
line.styleref - 参照样式表，返回当前被应用模板的行的样式表。line.furistyle - 参照样式表，返回当前被应用模板的行对应假名标注的样式表。如果没有匹配的样式名称这个区域就为 false (假)line.width, line.height, line.descent 和 line.extlead - 原文本的尺寸信息，由 `aegisub.text_extents`
返回。
这个函数也修饰 line.kara 和 line.furi 表, 增加尺寸信息。这一部分不涉及位置信息的计算。
如果 line 看起来没被 karaskel.preproc_line_text 处理过，那么这个步骤会自动完成。
摘要: karaskel.preproc_line_pos(meta, styles, line)
计算行、卡拉OK和假名标注的位置信息。
当没有可用的假名标注样式时，这个函数借助 karaskel.do_basic_layout, 当有可用的假名标注样式时借助 karaskel.do_furigana_layout 。假名布局算法可能改变行的计算宽度。
这个函数不会返回值，但是在修饰 line 表的时候例外:
line.margin_v - line.margin_t 的别名。line.eff_margin_l, line.eff_margin_r, line.eff_margin_t, line.eff_margin_b 和 line.eff_margin_v - 该行的有效边距值。如果某一行对应的值非零，则使用这些值，否则会使用样式管理器中定义的值。line.halign - 三种水平对齐方式 "left", "center" 或 "right"中的一种，是由 line.styleref.align派生出来的。line.valign - 三种竖直对齐方式 "top", "middle" 或 "bottom" 中的一种, 是由 line.styleref.align派生出来的。line.left - 行左边缘的X坐标，假设定义了对齐，有效边距，并且未检测到重叠。line.center - 行水平中点的X坐标，假设定义了对齐，有效边距，并且未检测到重叠。line.right - 行右边缘的X坐标，假设定义了对齐，有效边距，并且未检测到重叠。line.top - 行上边缘的Y坐标，假设定义了对齐，有效边距，并且未检测到重叠。line.middle - 行竖直中点的Y坐标，假设定义了对齐，有效边距，并且未检测到重叠。别名line.vcenter。
line.bottom - 行下边缘的Y坐标，假设定义了对齐，有效边距，并且未检测到重叠。line.x 和 line.y - 行的X 和 Y 坐标，适合与 \pos 配合使用，保持行的原位置。此外, line.kara 和 line.furi 表是被布局函数调用，然后加上位置信息。
详见这部分 data structures 。
如果没有找到任何行的尺寸信息, karaskel.preproc_line_size 会被调用, 它可能会转而调用 karaskel.preproc_line_text。
这个函数不是被直接调用的，它更像是一个 karaskel.preproc_line_pos 的辅助函数。
它为 line.kara 表运行一个简单的布局算法，简单地计算一行中各个音节的位置。位置信息被添加到各个音节。
line.furi 表在这个函数中不被处理。
这个函数也不是被直接调用的，它更像是一个 karaskel.preproc_line_pos 的辅助函数。
它为运行一个高级的布局算法，来把卡拉OK音节和假名标注整齐地排布，还能防止重叠。对这部分使用的算法感兴趣的人可以读读源码。
这个函数为 line.kara 和 line.furi 表添加位置信息。它也有可能改变 line.width ，因为行宽度可能受假名标注影响而变化。
卡拉OK框架是指帮助你构筑卡拉OK特效的一套框架。你可以在一些自定义函数中使用它，来解决特定的特效问题，框架中的内容会多次被调用。你具体需要写什么样的函数也取决于卡拉OK框架。
主函数: karaskel.use_fx_library_furi(use_furigana, add_macro)
调用 karaskel.use_fx_library_furi 函数为当前脚本安装 特效库 框架。script_name 和
script_description 全局变量用来命名导出滤镜。
如果 use_furigana 为真, 则会生成专门的标注假名样式。
如果 add_macro 为真, 则会在导出滤镜处添加宏。
使用特效库功能的前提是在每一打好K值行的特效栏填写了你希望应用的特效类型（名称）。 如果你想在一个文件里应用多种卡拉OK效果，这是一个很好的选择。
当特效库函数被调用,它会首先为每个对话行调用 "fx_特效" 。举个例子, 如果某个对话行的特效栏填写的是 "jump", 则名为 fx_jump 的函数将会被调用。对于特效栏为空的对话行, 函数 fx_none 将会被调用。
如果指明的 fx 函数并不存在，那么原始的行将会被保留。否则，原始行是否存在取决于 fx 函数在返回部分的写法。返回真值则意味着保留原始行，否则将会把原始行设置为注释行。
fx 函数用法: keep = fx_effect(subtitles, meta, styles, line, fxdata)
fxdata 指的是特效栏中声明特效类型后紧跟的特效名称。 fx 函数的所有输出都是 subtitles 被处理后添加到字幕文件中的行。
简化的主函数: karaskel.use_fx_library(add_macro)
与 _furi 变种相同，除了 use_furigana 被去除；它被假定为false。
Main function: karaskel.use_classic_adv(use_furigana, add_macro)
Call the karaskel.use_classic_adv function to install the Classic
Advanced skeleton for this script file. The script_name and
script_description globals are used to name the export filter produced.
If use_furigana is true, furigana styles are created and added as needed,
and furigana processing is enabled. If add_macro is true, a macro is
registered in addition to the export filter.
This skeleton is created in the image of the Automation 3 karaskel-adv
skeleton, but it is not compatible with it. (You cannot use a
karaskel-adv script with Classic Advanced without rewriting parts of your
script.) The basic premise is that the do_syllable function is called
once for each syllable. Optionally, you can have a function called for each
line, using the do_line function.
Classic Advanced uses a slightly different model than the usual Automation
4 Lua one. Here all subtitle lines are collected first before any further
processing is done. They also have line.prev and line.next fields
added, to allow linked list style access. To add lines to the output, you
must still add lines to the subs object though. Before processing starts,
all original lines are deleted from the subs object.
Signature of syllable function: do_syllable(subs, meta, styles, lines, line, syl)
The syllable function must be named do_syllable. If furigana processing
is enabled, you can also define a function called do_furigana with the
same signature, to process furigana syllables. Furigana still follows the
Automation 4 model here.
Signature of line function: do_line(subs, meta, styles, lines, line, default_do_line)
Defining a line function is optional, and is often not required. The line
function must be named do_line if it exists. The default_do_line
parameter is the function that would be called if do_line didn't exist.
You can call it to run the default line processing along with your own
processing.
karaskel.lua defines and extends several data structures. Some of the
changes are already listed above under the individual functions.
The styles array is produced by the karaskel.collect_head function and
should be passed to most other karaskel.lua functions. It contains a list
of all styles in the subtitle file, and can be accessed in two ways.
styles.n is a number telling the number of styles in the array.
styles[1] is the first defined style and styles[styles.n] is the last
defined style.
The styles array can also be indexed by style names, such that
styles[style.name] == style. The names are not mangled and the indexing
is case sensitive.
Be aware that modifying the styles will never update the subtitles file,
and conversely updating the styles in the subtitle file will not
automatically be reflected in styles either.
This is a slight extension of the basic style class subtitle line structure.
One field is added:
style.margin_v is a convenience alias for style.margin_t.Full list of fields:
style.class == "style"style.raw - The raw line text.style.section == "[V4+ Styles]"style.name - Name of the style.style.fontname - Name of the font face used by the style.style.fontsize - Font size for the style.style.color1, style.color2, style.color3 and style.color4 - The
four colours used by the style, in regular order. Use
[[extract_color|Automation/Lua/Modules/#extractcolor]] and family to
manipulate these.style.bold - true/false to specify bold/non-bold font face. Can
also be a number to specify font weight, but this is not well supported
and should be avoided.style.italic - Boolean, whether an italic/oblique version of the font
face is used or not.style.underline and style.strikeout - Boolean, whether to apply these
two decorations to the text.style.scale_x and style.scale_y - Scaling in X and Y direction, 100
is neutral.style.spacing - Additional spacing in pixels between individual
characters in text.style.angle - Z axis rotation for the text.style.borderstyle - 1 (one) for regular outlined text, 3 for opaque
box behind subtitles.style.outline - Width of the extended outline around the text.style.shadow - Distance to the shadow behind the text.style.align - Numpad-style alignment for the text on screen.style.margin_l, style.margin_r, style.margin_t and style.margin_b
style.margin_v is an alias for top margin.style.encoding - Windows font encoding ID for the style.style.relative_to - Currently unsupported.style.vertical - Unsupported, tentative AS5 feature.A large number of new fields have been added to the dialogue line class.
Basic fields:
line.class == "dialogue", also for comment linesline.raw - The raw line text.line.section - Usually "[Events]".line.comment - Boolean, true if the line is a Comment line rather than
Dialogue.line.layer - Layer of the line.line.start_time, line.end_time - Start and end times of the line in
milliseconds.line.style - Name of the style used for the line.line.actor - Actor field for the line.line.margin_l, line.margin_r, line.margin_t and line.margin_b -
Margin overrides for the line, a zero value means use margin from style.line.effect - Effect field of the line.line.userdata - Unused.line.text - Dialogue text.Basic added fields, by karaskel.preproc_line_text:
line.text_stripped - Line text with all override tags and vector
drawings removed.line.duration - Duration of the line in millisecondsline.kara and line.furi - Array tables of extended karaoke and
furigana tables, respectively. They do not contain sizing and positioning
data from the beginning.Added fields for sizing, by karaskel.preproc_line_size:
line.styleref - A reference to the Style table representing this line's
selected style.line.furistyle - A reference to the Style table representing this
line's furigana layout style. If there is no style with the right name,
this field is false instead.line.width, line.height, line.descent and line.extlead - Sizing
information for the stripped line text, as returned by
aegisub.text_extents. line.width may also be modified by
karaskel.preproc_line_pos.Added fields for positioning, by karaskel.preproc_line_pos:
line.margin_v - A convenience alias for line.margin_t.line.eff_margin_l, line.eff_margin_r, line.eff_margin_t,
line.eff_margin_b and line.eff_margin_v - 有效 margin values for
the line. If the corresponding margin override for the line is non-zero,
that value is used, otherwise the value defined in the style is used.line.halign - One of "left", "center" or "right", the horizontal
alignment of the line, derived from line.styleref.align.line.valign - One of "top", "middle" or "bottom", the vertical
alignment of the line, derived from line.styleref.align.line.left - The left edge X coordinate for the line, assuming its given
alignment, 有效 margins and no collision detection.line.center - The line centre X coordinate, assuming its given
alignment, 有效 margins and no collision detection.line.right - The right edge X coordinate for the line, assuming its
given alignment, 有效 margins and no collision detection.line.top - The top edge Y coordinate for the line, assuming its given
alignment, 有效 margins and no collision detection.line.middle - The line vertical centre Y coordinate, assuming its given
alignment, 有效 margins and no collision detection line.vcenter is
an alias for this.line.bottom - The bottom edge Y coordinate for the line, assuming its
given alignment, 有效 margins and no collision detection.line.x and line.y - X and Y coordinates for the line, suitable for
using in a \pos override tag to get the line's original position.Added fields for linked list access, only available when using the Classic Advanced skeleton:
line.prev, line.next - Access the dialogue line before and after this
one. These might be nil on the first/last dialogue lines. Blank lines,
style lines, header lines etc. are not included in this linked list.Tables for regular karaoke syllables and furigana parts are identical in
(almost) every aspect, and can usually be processed by the same code
without problems. There are a few points to take note of which are marked.
Everywhere it says syl here, you can replace that with furi unless
otherwise noted.
Basic fields, defined by aegisub.parse_karaoke_data:
syl.duration - syllable duration in milliseconds (divide by 10 to get a
number suitable for \k tags.)syl.start_time, syl.end_time - Start and end time of the syllable in
milliseconds, relative to the start time of the line.syl.tag - The name of the tag defining this syllable, without
backslash. It will usually be one of k, K, kf or ko. Note that
kt is not handled. Furigana parts have the same tag as the original
syllable defining them.syl.text - Text including tags of the syllable. Same as stripped text
for furigana.syl.text_stripped - Text of the syllable with all tags removed. For
main syllables, this also has furigana and multi-highlight parts removed.
This is the text you will usually want to use.Additions by karaskel.preproc_line_text:
syl.kdur - Syllable duration in centiseconds, suitable for use in \k
tags.syl.line - Back reference to the line table containing this syllable.syl.inline_fx - Name of the _inline-fx_ for this
syllable.syl.i - Index number of this syllable.syl.prespace, syl.postspace - Space characaters at the start/end of
the syllable. Always blank for furigana. These are spaces included in
syl.text_stripped. You will usually never need this.syl.text_spacestripped - Syllable text stripped for tags and trimmed of
spaces at the start and end. This, syl.prespace and syl.postspace
together can produce the same as syl.text_stripped. You will usually
never need this.syl.isfuri - true if the table is a furigana table, false if it is
not. If you use a single function to process both regular and furigana
syllables, you can use this to do differentiated processing still.syl.highlights - Array table of multi-highlight data for the syllable.
For furigana, there is always exactly one highlight defined. See below
for format of highlight tables.Additions by karaskel.preproc_line_size:
syl.style - Reference to the style used to calculate sizing for this
syllable. This will be the main line style for regular syllables and the
furigana style for furigana. You should always set the style of the
generated lines to this one.syl.width, syl.height - Width and height of syl.text_spacestripped,
as returned by aegisub.text_extents.syl.prespacewidth, syl.postspacewidth - Width of syl.prespace and
syl.postspace respectively. You will usually not need these. Always
zero for furigana.Additions by karaskel.preproc_line_pos:
syl.left, syl.center, syl.right - Respectively left, center and
right aligned positions of the syllable/furigana, for use with different
alignments. The positions are relative to the left edge of the line,
meaning you will need to add a value for line positioning to use these
values to position syllables on screen. There is no guarantee that
syl.right for one syllable is equal to syl.left for the next
syllable.line.left + syl.center
Calculates the default X position of a syllable, suitable for use with
\an2, \an5 or \an8 alignment.
A highlight table defines one highlight of a multi-highlight timed syllable.
Highlight tables are entirely defined by karaskel.preproc_line_text, and
contain the following fields:
hl.start_time, hl.end_time - Start and end time of the highlight, in
milliseconds, relative to the start of the line.hl.duration - Duration of the highlight in milliseconds.