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diff --git a/doc/context/sources/general/manuals/followingup/followingup-directions.tex b/doc/context/sources/general/manuals/followingup/followingup-directions.tex new file mode 100644 index 000000000..244baff90 --- /dev/null +++ b/doc/context/sources/general/manuals/followingup/followingup-directions.tex @@ -0,0 +1,778 @@ +% language=us + +\startcomponent followingup-directions + +\environment followingup-style + +\startchapter[title={Directions}] + +\startsection[title={Introduction}] + +In \LUATEX\ the directional model taken from \OMEGA\ has been upgraded a bit. For +instance in addition to the \type {\*dir} commands we have \type {\*direction} +commands that take a number instead of a keyword. This is a bit more efficient and +consistent as using these keywords was kind of un|-|\TEX. Internally direction +related nodes (text directions) are not whatsits but first class nodes. We also +use a subtype that indicates the push or pop state. + +The \LUATEX\ directional model provides four directions which is a subset of the +many that \OMEGA\ provided, indicated by three letters, like \type {TRT} and +\type {LTT}. In the beginning we had them all fixed\footnote {This was doen by +Hartmut by rigorously checking all possible combinations} and thereby implemented +but being in doubt about their usefulness we dropped most of them, just four were +kept. However, in practice only right|-|to|-|left makes sense. Going from top to +bottom in Japanese or Mongolian can also involve glyph rotation, which actually +is not implemented in the engine at all. Spacing and inter|-|character breaks +have to be implemented and in the end one has to combine the results into a +page body. So, in practice you end up with juggling node list and macro magic in +the page builder. The \type {LTL} (number~2) and \type {RTT} (number~3) +directions are not used for serious work. Therefore, in \LUAMETATEX\ the model +has been adapted. In the end, it was not entirely clear anyway what the three +letters were indicating in each direction property (page, body, par, text, math) +as most had no real meaning. + +As a side note: if you leave the (not really working well) vertical directions +out of the picture, directional typesetting is not that hard to deal with and has +hardly any consequences for the code. This is because horizontal dimensions are +not affected by direction, only the final ship out is: when a run (wrapped in an +hbox) goes the other way, the backend effectively has to skip the width and then +with each component goes back. Not much more is involved. This means that a +bidirectional engine is rather simple. The complications are more in the way a +macro package deals with it, in relation to the input as well as the layout. The +backend has to do the real work. \footnote {Of course when one hooks in \LUA\ +code taking care of direction can be needed!} + +\stopsection + +\startsection[title=Two directions] + +We now have only two directions left: the default left|-|to|-|right (l2r) and +right|-|to|-|left (r2l). They work the same as before and in the backend we can +get rid of the fuzzy parallel and rotation (which actually was just stacking +nodes) heuristics. + +Reducing the lot to two directions simplifies some code in the engine. This is +because when calculating dimensions a change in horizontal direction doesn't +influence the width, height and depth in an orthogonal way. Because there are no +longer top|-|down items we don't need to swap the height and or depth with the +width. This also means that we don't need to keep much track of direction +changes. Technically an hpack doesn't need to know its own direction and we can +set it to any value afterwards if we want because the calculation are not +influenced by it; so that also simplified matters. + +The \type {\bodydir} and \type {\pagedir} already didn't make much sense, and in +\CONTEXT\ we actually intercepted them, so now they are removed. The body +direction is always left|-|to|-|right and the page direction was only consulted +in the backend code which we no longer have. Another side effect of going with +only two directions is that rules no longer need to carry the direction property: +there is no flipping of width with height and depth needed. + +\stopsection + +\startsection[title=Four orientations] + +Instead of the top|-|bottom variants we now have four orientations plus a bunch +of anchoring options. Of course one could use the backend save, restore and +matrix whatsits but a natural feature makes more sense. Let's start with what +happens normally: + +\startbuffer[1] +This is a \LUAMETATEX\ goodie. +\stopbuffer + +\startbuffer[2] +\hbox orientation 2{This is a \LUAMETATEX\ goodie.} +\stopbuffer + +\startbuffer[3] +This is a \hbox orientation 2{\LUAMETATEX} goodie. +\stopbuffer + +\startbuffer[4] +\hbox orientation 2{This is a \hbox orientation 002{\LUAMETATEX} goodie.} +\stopbuffer + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[1]}\quad{\showstruts\strut}\blank + +This line has height and depth. We can rotate this sentence by 180 degrees around +the baseline in which case the depth and height are flipped. + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[2]}\quad{\showstruts\strut}\blank + +or we flip part: + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[3]}\quad{\showstruts\strut}\blank + +or flip nested: + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[4]}\quad{\showstruts\strut}\blank + +but we're talking boxes, so the above examples are defined as: + +\typebuffer[1,2,3,4] + +The \type {orientation} keyword does the magic here. There are four such +orientations with zero being the default. We saw that two rotates over 180 +degrees, so one and three are left for up and down. + +\startbuffer[5] +\hbox orientation 0 {\TEX} and +\hbox orientation 1 {\TEX} and +\hbox orientation 2 {\TEX} and +\hbox orientation 3 {\TEX} +\stopbuffer + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[5]}\quad{\showstruts\strut}\blank + +This is codes as: + +\typebuffer[5] + +The landscape and seascape variants both sit on top of the baseline while the +flipped variant has its depth swapped with the height. Although this would be +enough a bit more control is possible. The number is actually a three byte hex +number: + +\starttyping +0x<X><Y><O> +\stoptyping + +or in \TEX\ syntax + +\starttyping +"<X><Y><O> +\stoptyping + +We saw that the last byte regulates the orientation. The first and second one +deal with anchoring horizontally and vertically. The vertical options of the +horizontal variants anchor on the baseline, lower corner, upper corner or center. + +\startbuffer[6] +\hbox orientation "002 {\TEX} and +\hbox orientation "012 {\TEX} and +\hbox orientation "022 {\TEX} and +\hbox orientation "032 {\TEX} +\stopbuffer + +\typebuffer[6] + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[6]}\quad{\showstruts\strut}\blank + +\startbuffer[7] +\hbox orientation "002 {\TEX} and +\hbox orientation "102 {\TEX} and +\hbox orientation "202 {\TEX} and +\hbox orientation "302 {\TEX} and +\hbox orientation "402 {\TEX} +\stopbuffer + +The horizontal options of the horizontal variants anchor in the center, left, right, +halfway left and halfway right. + +\typebuffer[7] + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[7]}\quad{\showstruts\strut}\blank + +All combinations will be shown on the next pages, so we suffice with telling that +for the vertical variants we can vertically anchor on the baseline, top, bottom +or center, while horizontally we center, hang left or right, halfway left or +right, and in addition align on the (rotated) baseline left or right. + +The orientation has consequences for the dimensions so they are dealt with in the +expected way in constructing lines, paragraphs and pages, but the anchoring is +virtual. As a bonus, we have two extra variants for orientation zero: on top of +baseline or below, with dimensions taken into account. + +\startbuffer[8] +\hbox orientation "000 {\TEX} and +\hbox orientation "004 {\TEX} and +\hbox orientation "005 {\TEX} +\stopbuffer + +\typebuffer[8] + +\blank{\showstruts\strut}\quad\ruledhbox{\inlinebuffer[8]}\quad{\showstruts\strut}\blank + +\definecolor[brcolorh][r=1,t=.5,a=1] +\definecolor[brcolord][b=1,t=.5,a=1] +\definecolor[brcolorm][g=1,t=.5,a=1] + +\starttexdefinition ShowAnchor + \blackrule[width=2pt,height=1pt,depth=1pt,color=darkgray] +\stoptexdefinition + +\starttexdefinition DemoRule#1#2#3 + \ShowAnchor + \ruledhbox { + \hbox orientation "#1#2#3 { + \blackrule[height=6mm,depth=0mm,width=8mm,color=brcolorh]\kern-8mm\relax + \blackrule[height=0mm,depth=3mm,width=8mm,color=brcolord]\kern-8mm\relax + \blackrule[height=2mm,depth=-1mm,width=8mm,color=brcolorm] + } + } + \ShowAnchor +\stoptexdefinition + +\starttexdefinition DemoText#1#2#3 + \ShowAnchor + \ruledhbox{\hbox orientation "#1#2#3 {\red\TEX}} + \ShowAnchor +\stoptexdefinition + +\starttexdefinition DemoSet #1#2 + \startcombination[nx=4,ny=7,width=10cm] + {#200#1}{\ttxx 0x00#1} {#201#1}{\ttxx 0x01#1} {#202#1}{\ttxx 0x02#1} {#203#1}{\ttxx 0x03#1} + {#210#1}{\ttxx 0x10#1} {#211#1}{\ttxx 0x11#1} {#212#1}{\ttxx 0x12#1} {#213#1}{\ttxx 0x13#1} + {#220#1}{\ttxx 0x20#1} {#221#1}{\ttxx 0x21#1} {#222#1}{\ttxx 0x22#1} {#223#1}{\ttxx 0x23#1} + {#230#1}{\ttxx 0x30#1} {#231#1}{\ttxx 0x31#1} {#232#1}{\ttxx 0x32#1} {#233#1}{\ttxx 0x33#1} + {#240#1}{\ttxx 0x40#1} {#241#1}{\ttxx 0x41#1} {#242#1}{\ttxx 0x42#1} {#243#1}{\ttxx 0x43#1} + {#250#1}{\ttxx 0x50#1} {#251#1}{\ttxx 0x51#1} {#252#1}{\ttxx 0x52#1} {#253#1}{\ttxx 0x53#1} + {#260#1}{\ttxx 0x60#1} {#261#1}{\ttxx 0x61#1} {#262#1}{\ttxx 0x62#1} {#263#1}{\ttxx 0x63#1} + \stopcombination +\stoptexdefinition + +\startplacefigure[title={orientation 0}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet0\DemoRule}}\stopplacefigure +\startplacefigure[title={orientation 1}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet1\DemoRule}}\stopplacefigure +\startplacefigure[title={orientation 2}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet2\DemoRule}}\stopplacefigure +\startplacefigure[title={orientation 3}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet3\DemoRule}}\stopplacefigure + +\startplacefigure[title={orientation 0}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet0\DemoText}}\stopplacefigure +\startplacefigure[title={orientation 1}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet1\DemoText}}\stopplacefigure +\startplacefigure[title={orientation 2}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet2\DemoText}}\stopplacefigure +\startplacefigure[title={orientation 3}]\scale[width=\textwidth]{\framed[offset=1cm]{\DemoSet3\DemoText}}\stopplacefigure + +% \page + +The anchoring can look somewhat confusing but you need to keep in mind that it is +normally only used in very controlled circumstances and not in running text. +Wrapped in macros users don't see the details. We're talking boxes here, so or +instance: + +\startbuffer +test\quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "002 \bgroup\strut test\egroup test% +\egroup \quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "002 \bgroup\strut test\egroup test% +\egroup \quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "012 \bgroup\strut test\egroup test% +\egroup \quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "022 \bgroup\strut test\egroup test% +\egroup \quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "032 \bgroup\strut test\egroup test% +\egroup \quad +\hbox orientation 3 \bgroup + \strut test\hbox orientation "042 \bgroup\strut test\egroup test% +\egroup +\quad test +\stopbuffer + +\typebuffer + +gives: + +\startlinecorrection[blank] +\ruledhbox\bgroup \showcolorstruts \showboxes \inlinebuffer \egroup +\stoplinecorrection + +\stopsection + +\startsection[title={Right|-|to|-|left typesetting}] + +Another aspect to keep in mind when we transform is the already mentioned +right|-|to|-|left direction. We show some examples where we do things like this: + +\starttyping +\hbox{\hbox + orientation #1 + {\strut abcd}} +\hbox{\hbox + orientation #1 + to 15mm + {\strut abcd}} +\hbox{\hbox + orientation #1 + direction 1 + {\righttoleft\strut abcd}} +\hbox{\hbox + orientation #1 + direction 1 + to 15mm {\righttoleft\strut abcd}} +\stoptyping + +\starttexdefinition TestH #1 + \dontcomplain + \setbox\scratchbox\hbox{abcd}% + x\ruledhbox{\hbox orientation #1 to \wd\scratchbox {\strut abcd}}x\quad + x\ruledhbox{\hbox orientation #1 to 15mm {\strut abcd}}x\quad + x\ruledhbox{\hbox orientation #1 direction 1 to \wd\scratchbox {\righttoleft\strut abcd}}x\quad + x\ruledhbox{\hbox orientation #1 direction 1 to 15mm {\righttoleft\strut abcd}}x% +\stoptexdefinition + +\starttexdefinition TestV #1 + \dontcomplain + \setbox\scratchbox\hbox{abcd}% + x\ruledvbox{\vbox orientation #1 {\hsize \wd\scratchbox\strut abcd}}x\quad + x\ruledvbox{\vbox orientation #1 {\hsize 15mm\strut abcd}}x\quad + x\ruledvbox{\vbox orientation #1 {\righttoleft\hsize \wd\scratchbox\strut abcd}}x\quad + x\ruledvbox{\vbox orientation #1 {\righttoleft\hsize 15mm\strut abcd}}x% +\stoptexdefinition + +\startplacefigure[title={Horizontal boxes.}] + \startcombination[nx=2,ny=2] + {\TestH 0} {orientation 0} + {\TestH 2} {orientation 2} + {\TestH 1} {orientation 1} + {\TestH 3} {orientation 3} + \stopcombination +\stopplacefigure + +\startplacefigure[title={Vertical boxes.}] + \startcombination[nx=2,ny=2] + {\TestV 0} {orientation 0} + {\TestV 2} {orientation 2} + {\TestV 1} {orientation 1} + {\TestV 3} {orientation 3} + \stopcombination +\stopplacefigure + +\stopsection + +\startsection[title={Vertical typesetting}] + +I'm no expert on vertical typesetting and have no application for it either. But +from what I've seen vertically positioned glyphs are normally used in rather +straightforward situations. Here I will just give some examples of how +transformations can be used to achieve certain effects. It is no big deal to make +macros or use \LUA\ to apply magic to node lists but it is beyond this description +to discuss that. + +Before we fine tune this example we have to discuss another feature. When a \typ +{orientation} keyword is given optionally \type {xoffset} and \type {yoffset} can +be specified. These offsets are {\em not} taken into account when calculating +dimensions. This is different from the offsets (at the \LUA\ end) used in glyphs +because there the vertical offset is taken into account. Here are some examples +of offsets in packaged lists: + +\startbuffer +\hbox + {test 1} +\hbox + orientation 0 + yoffset 15pt + xoffset 150pt + {test} +\vbox + orientation 0 + {\hbox{test}} +\vbox + orientation 0 + yoffset -5pt + xoffset 130pt + {\hbox{test}} +\vbox + orientation 0 + yoffset 2pt + {\hbox{test}} +\stopbuffer + +\typebuffer + +\startlinecorrection[blank] + \start \showboxes \bfd \getbuffer \stop +\stoplinecorrection + +In order to demonstrate some hacking, we first define a font that supports +chinese glyphs: + +\startbuffer +\definefont[NotoCJK][NotoSansCJKtc-Regular*default @ 24pt] +\stopbuffer + +\typebuffer \getbuffer + +We put some text in a horizontal box; it doesn't show up in verbatim but you +get the idea nevertheless: + +\startbuffer +\hbox{\NotoCJK 通用规范汉字表} +\stopbuffer + +\typebuffer + +\startlinecorrection[blank] + \start \showboxes \getbuffer \stop +\stoplinecorrection + +Let's now rotate this line of text: + +\startbuffer[1] +\hbox orientation 1 {\NotoCJK 通用规范汉字表} +\stopbuffer + +\typebuffer[1] + +The result is shown in a while. Because we also need to rotate the glyphs we +deconstruct the box. + +\startbuffer[2] +\hbox orientation 1 \bgroup \NotoCJK % + \vbox {\hbox {通}}% + \vbox {\hbox {用}}% + \vbox {\hbox {规}}% + \vbox {\hbox {test}}% + \vbox {\hbox {范}}% + \vbox {\hbox {汉}}% + \vbox {\hbox {字}}% + \vbox {\hbox {表}}% +\egroup +\stopbuffer + +\typebuffer[2] + +Next we rotate the glyphs. + +\startbuffer[3] +\hbox orientation 1 \bgroup \NotoCJK % + \vbox orientation 3 {\hbox {通}}% + \vbox orientation 3 {\hbox {用}}% + \vbox orientation 3 {\hbox {规}}% + \vbox orientation 0 {\hbox {test}}% + \vbox orientation 3 {\hbox {范}}% + \vbox orientation 3 {\hbox {汉}}% + \vbox orientation 3 {\hbox {字}}% + \vbox orientation 3 {\hbox {表}}% +\egroup +\stopbuffer + +\typebuffer[3] + +This still looks bad so we kick in some offsets and glue: + +\startbuffer[4] +\dontleavehmode\hbox orientation 1 \bgroup \NotoCJK + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {通}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {用}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {规}}\hskip.6ex + \vbox + {\hbox {test}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {范}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {汉}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {字}}\hskip.2ex + \vbox + orientation 0 yoffset -.1ex + {\hbox orientation 3 {表}}\hskip.2ex +\egroup +\stopbuffer + +\typebuffer[4] + +Now we're ready to compare the results + +\startlinecorrection[blank] + \startcombination[9*1] + {\showboxes \getbuffer[1]} {1} + {\showboxes \getbuffer[2]} {2} + {\showboxes \getbuffer[3]} {3} + {\showboxes \getbuffer[4]} {4} + {\quad}{} + {\getbuffer[1]} {1} + {\getbuffer[2]} {2} + {\getbuffer[3]} {3} + {\getbuffer[4]} {4} + \stopcombination +\stoplinecorrection + +This could of course also be done with traditional kerns, raising and|/|or +lowering and messing around with dimensions. It's just that when manipulating +such rather complex constructs a little help (and efficiency) makes a difference, +also at the \LUA\ end. Of course one can argue the result but all is +programmable in the end. + +\stopsection + +\startsection[title={Considerations}] + +Just in case you wonder if using these offsets is better than using normal kerning +and shifting, in practice offsets are not more efficient. Let's compare the +alternatives. We go from most to least efficient. + +\starttyping +\setbox\scratchbox\hpack{} +\boxxoffset\scratchbox\scratchdimen +\boxyoffset\scratchbox\scratchdimen +\stoptyping + +This sets the offsets and by setting them we also trigger the transform. Scanning +is fast and so is setting them. One million times expanding this takes (as +reference) 0.73 seconds on my current machine. + +\starttyping +\setbox\scratchbox\hpack + orientation \zerocount + xoffset \scratchdimen + yoffset \scratchdimen + {} +\stoptyping + +This takes a bit more time, 1.11 seconds, because the keywords have to be scanned +which happens on a token by token base. + +\starttyping +\setbox\scratchbox\hpack{} +\scratchheight\ht\scratchbox +\scratchdepth\dp\scratchbox +\setbox\scratchbox\hpack + {\kern\scratchdimen + \raise\scratchdimen\box\scratchbox + \kern\scratchdimen} +\ht\scratchbox\scratchheight +\dp\scratchbox\scratchdepth +\stoptyping + +Now we're up to 1.69 seconds for the million expansions. Not only do we have some +parsing going on, but we also have assignments and extra packing, which means +calculations taking place. + +\starttyping +\setbox\scratchbox\hpack{} +\scratchwidth\wd\scratchbox +\scratchheight\ht\scratchbox +\scratchdepth\dp\scratchbox +\setbox\scratchbox\hpack + {\kern\scratchdimen + \raise\scratchdimen\box\scratchbox} +\wd\scratchbox\scratchwidth +\ht\scratchbox\scratchheight +\dp\scratchbox\scratchdepth +\stoptyping + +This variant is about as fast, as I measured 1.72 seconds. So, compared to the +0.73 seconds for the first variant, is this better? Does it help when we look at +our existing macros and adapt them? + +Normally we don't have an empty box and normally we use \type {\hbox} because we +want the content to be processed. And a million times building a list and +processing content (which means runs over the list) will make the differences +in timing become noise. Add to that garbage collection (in \LUA) and memory +management (in \TEX) and it even becomes unpredictable. Seeing differences of +a factor two in such timings is no exception. + +Another aspect is the parsing. When these commands are wrapped in macros we're +talking expanding tokens which is pretty fast. When it comes from the input file +a conversion to tokens has to happen too. And we will never see millions of such +sequences in a source file. + +The backend also plays a role. Handling a kern or shift is more efficient than +analyzing transforms (and offsets) especially in a \LUA\ variant. But on the +other hand, we don't have an extra wrapping in a box so that actually saves work. + +So, before a \CONTEXT\ user thinks \quotation {Let's update macros and change +policy.}, just consider staying with proven good old \TEX\ approaches. These +features are mostly meant for efficient low level manipulations as discussed in +relation to for instance handling scripts. In the rather large \CONTEXT\ code +base there are really only a few places where it will make code look nicer, but +there I don't expect an impact on performance. + +\stopsection + +\startsection[title={Integration}] + +How these mechanisms are used depends on ones needs and the macro package used. +It makes no sense to cook up generic solutions because integration in a macro +package is too different. But anyhow we'll give an example of some (definitely +non optimized) \LUA\ magic. + +\startbuffer +\startluacode +local glyph_id = node.id("glyph") +local fontdata = fonts.hashes.identifiers -- assumes generic font loader + +local function is_vertical(c) + -- more ranges matter but this will do here + return c >= 0x04E00 and c <= 0x09FFF +end + +function document.go_vertical(boxnumber) + local box = tex.getbox(boxnumber) + local n = box.list + while n do + if n.id == glyph_id and is_vertical(n.char) then + local o = .2 * fontdata[n.font].parameters.xheight + local prev, next = n.prev, n.next + n.next, n.prev = nil, nil + local l = nodes.new("hlist") + l.list = n + local w, h, d = n.width, n.height, n.depth + if prev then + prev.next, l.prev = l, prev + else + box.list = l + end + if next then + l.next, next.prev = next, l + end + l.width, l.height, l.depth = h + d + o, w, 0 + l.orientation = 0x003 + l.xoffset, l.yoffset = o/2, -o/2 + l.hoffset, l.doffset = h, d - o + n = next + else + n = n.next + end + end +end +\stopluacode +\stopbuffer + +\typebuffer \getbuffer + +We will use some other magic that we won't discuss here which relates to handling +scripts. For Hangul one needs to inject breakpoints and if needed also glue +between characters. The script environment does this. We also need to bump the +interline spacing. First we define a regular text helper and an auxiliary box. + +\startbuffer[1] +\unexpanded\def\stripe#1% + {\hbox orientation 0 yoffset .2\exheight{\strut #1}} + +\newbox\MyVerticalBox +\stopbuffer + +\typebuffer[1] + +Next we fill that box with some mix of text (I have no clue what, as I just +copied it from some web page). + +\startbuffer[2a] +\setbox\MyVerticalBox\hbox \bgroup + \NotoCJK + \startscript[hangul]% + \dorecurse{20}{通用规范汉字表 \stripe{test #1} }% + \unskip % remove last space + \stopscript +\egroup +\stopbuffer + +\typebuffer[2a] + +We then apply the \LUA\ magic to the result: + +\startbuffer[3a] +\ctxlua{document.go_vertical(\number\MyVerticalBox)} +\stopbuffer + +\typebuffer[3a] + +and finally assemble the result: + +\startbuffer[4a] +\ruledvbox orientation 1 to \textwidth \bgroup + \setupinterlinespace[40pt] + \hsize .95\textheight + \unhbox\MyVerticalBox + \vfill +\egroup +\stopbuffer + +\typebuffer[4a] + +The result is shown in \in {figure} [fig:verticalmagic-1]. Of course this +approach is not that user friendly but it just serves as example. In \CONTEXT\ we +can follow a different route. First we define a new font feature. It is probably +clear that we need some code elsewhere that does something useful with this +information, but I will nos show this as it is rather \CONTEXT\ dependent. + +\startbuffer[2b] +\definefontfeature + [vertical] + [vertical={% + orientation=3,% + down=.1,% + right=.1,% + ranges={% + cjkcompatibility,% + cjkcompatibilityforms,% + cjkcompatibilityideographs,% + cjkcompatibilityideographssupplement,% + cjkradicalssupplement,% + % cjkstrokes,% + cjksymbolsandpunctuation,% + cjkunifiedideographs,% + cjkunifiedideographsextensiona,% + cjkunifiedideographsextensionb,% + cjkunifiedideographsextensionc,% + cjkunifiedideographsextensiond,% + cjkunifiedideographsextensione,% + cjkunifiedideographsextensionf,% + }% + }] +\stopbuffer + +\typebuffer[2b] + +We apply this feature to a font: + +\startbuffer[3b] +\definefont + [NotoCJKvertical] + [NotoSansCJKtc-Regular*default,vertical @ 24pt] +\stopbuffer + +\typebuffer[3b] + +\startbuffer[4b] +\setbox\MyVerticalBox\hbox\bgroup + \NotoCJKvertical + \startscript[hangul]% + \dorecurse{20}{通用规范汉字表 \stripe{test #1} }% + \unskip + \stopscript +\egroup +\stopbuffer + +\typebuffer[4b] + +\startbuffer[5b] +\ruledvbox orientation 1 to \textwidth \bgroup + \setupinterlinespace[40pt] + \hsize .95\textheight + \unhbox\MyVerticalBox + \vfill +\egroup +\stopbuffer + +\typebuffer[5b] + +The result is shown in \in {figure} [fig:verticalmagic-2]. Again this approach is +not that user friendly but it already is a bit easier. + +\startplacefigure[reference=fig:verticalmagic-1,title={Some vertical magic using manipulations.}] + \getbuffer[1,2a,3a,4a] +\stopplacefigure + +\startplacefigure[reference=fig:verticalmagic-2,title={Some vertical magic using fonts.}] + \getbuffer[1,2b,3b,4b,5b] +\stopplacefigure + +\stopsection + +\stopchapter + +\stopcomponent |