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Diffstat (limited to 'doc/context/sources/general/manuals/luametatex/luametatex-math.tex')
| -rw-r--r-- | doc/context/sources/general/manuals/luametatex/luametatex-math.tex | 181 |
1 files changed, 159 insertions, 22 deletions
diff --git a/doc/context/sources/general/manuals/luametatex/luametatex-math.tex b/doc/context/sources/general/manuals/luametatex/luametatex-math.tex index 9a9fb9eb1..b114dbba3 100644 --- a/doc/context/sources/general/manuals/luametatex/luametatex-math.tex +++ b/doc/context/sources/general/manuals/luametatex/luametatex-math.tex @@ -848,6 +848,12 @@ feature. These additional commands are not all that valuable on their own, but they come in handy as arguments to the math parameter settings that will be added shortly. +Because internally the eight styles are represented as numbers some of the new +primnitives that relate to them also work with numbers and often you can use them +mixed. The \prm {tomathstyle} prefix converts a symbolic style into a number so +\typ {\number \tomathstyle \crampedscriptstyle} gives~\number \tomathstyle +\crampedscriptstyle. + In Eijkhouts \quotation {\TEX\ by Topic} the rules for handling styles in scripts are described as follows: @@ -1004,19 +1010,18 @@ undefined will get presets, quite likely zero): \DB primitive name \BC description \NC \NR \TB \NC \prm {Umathconnectoroverlapmin} \NC \NC \NR -\NC \prm {Umathsubscriptsuperscriptshiftdown} \NC \NC \NR -\NC \prm {Umathfractiondelsize} \NC \NC \NR +\NC \prm {Umathsubsupshiftdown} \NC \NC \NR \NC \prm {Umathfractiondelsize} \NC \NC \NR \NC \prm {Umathnolimitsupfactor} \NC a multiplier for the way limits are shifted up and down \NC \NR \NC \prm {Umathnolimitsubfactor} \NC a multiplier for the way limits are shifted up and down \NC \NR -\NC \prm {Umathaccentbasedepth} \NC the complement of \prm {UmathAccentBaseHeight} \NC \NR -\NC \prm {Umathflattenedaccentbasedepth} \NC the complement of \prm {UmathFlattenedAccentBaseHeight} \NC \NR +\NC \prm {Umathaccentbasedepth} \NC the complement of \prm {Umathaccentbaseheight} \NC \NR +\NC \prm {Umathflattenedaccentbasedepth} \NC the complement of \prm {Umathflattenedaccentbaseheight} \NC \NR \NC \prm {Umathspacebeforescript} \NC \NC \NR \NC \prm {Umathraisepercent} \NC the percentage that the vertical position is scaled \NC \NR -\NC \prm {Umathprimeshiftup} \NC the prime variant of \prm {SuperscriptShiftUp} \NC \NR -\NC \prm {Umathprimeshiftupcramped} \NC the prime variant of \prm {SuperscriptShiftUpCramped} \NC \NR -\NC \prm {Umathprimespaceafter} \NC the prescript variant of \prm {UmathSpaceAfterScript} \NC \NR -\NC \prm {Umathprimebaselinedropmax} \NC the prime variant of \prm {SuperscriptBaselineDropMax} \NC \NR +\NC \prm {Umathprimeshiftup} \NC the prime variant of \prm {Umathsupshiftup} \NC \NR +\NC \prm {Umathprimeshiftupcramped} \NC the prime variant of \prm {Umathsupshiftup} \NC \NR +\NC \prm {Umathprimespaceafter} \NC the prescript variant of \prm {Umathspaceafterscript} \NC \NR +\NC \prm {Umathprimebaselinedropmax} \NC the prime variant of \prm {Umathsupshiftdrop} \NC \NR \NC \prm {Umathprimewidthpercent} \NC the percentage of width that gets added \NC \NR \NC \prm {Umathskeweddelimitertolerance} \NC \NC \NR \NC \prm {Umathaccenttopshiftup} \NC the amount that a top accent is shifted up \NC \NR @@ -1038,7 +1043,7 @@ defaults and tweak them in the goodie files: \DB font parameter \BC primitive name \BC default \NC \NR \TB \NC MinConnectorOverlap \NC \prm {Umathconnectoroverlapmin} \NC 0 \NC \NR -\NC SubscriptShiftDownWithSuperscript \NC \prm {Umathsubscriptsuperscriptshiftdown} \NC inherited \NC \NR +\NC SubscriptShiftDownWithSuperscript \NC \prm {Umathsubsupshiftdown} \NC inherited \NC \NR \NC FractionDelimiterSize \NC \prm {Umathfractiondelsize} \NC undefined \NC \NR \NC FractionDelimiterDisplayStyleSize \NC \prm {Umathfractiondelsize} \NC undefined \NC \NR \NC NoLimitSubFactor \NC \prm {Umathnolimitsupfactor} \NC 0 \NC \NR @@ -1276,6 +1281,16 @@ As this mostly refers to \LUATEX\ there is more to tell about how \LUAMETATEX\ deals with it. However, it is enough to know that much more behavior is configurable. +You can let the engine ignore parameter with \prm {setmathignore}, like: + +\starttyping +\setmathignore \Umathspacebeforescript 1 +\setmathignore \Umathspaceafterscript 1 +\stoptyping + +Be aware of the fact that a global setting can get unnoticed by users because +there is no warning that some parameter is ignored. + \stopsubsection \stopsection @@ -1565,6 +1580,23 @@ keywords: To what extend the options kick in depends on the class as well where and how the atom is used. +The original \TEX\ engines has three atom modifiers: \prm {displaylimits}, \prm +{limits}, and \prm {nolimits}. These look back to the last atom and set a limit +related signal. Just to be consistent we have some more of that: \prm +{Umathadapttoleft}, \prm {Umathadapttoright}, \prm {Umathuseaxis}, \prm +{Umathnoaxis}, \prm {Umathphantom}, \prm {Umathvoid}, \prm {Umathsource}, \prm +{Umathopenupheight}, \prm {Umathopenupdepth}, \prm {Umathlimits}, \prm +{Umathnolimits}. The last two are equivalent to the lowercase ones with the +similar names. Al these modifiers are cheap primitives and one can wonder if they +are needed but that also now also applies to the original three. We could stick +to one modifier that takes an integer but let's not diverge too much from the +original concept. + +The \prm {nonscript} primitive injects a glue node that signals that the next +glue is to be ignored when we are in script or scriptscript mode. The \prm +{noatomruling} does the same but this time the signal is that no inter|-|atom +rules need to be applied. + \stopsubsection \startsubsection[title={Checking a state with \prm {ifmathparameter}}] @@ -1701,6 +1733,10 @@ In typeset form this looks like: \getbuffer +Normally fences need to be matched, that is: when a left fence is seen, there has +to be a right fence. When you set \prm {mathcheckfencesmode} to non|-|zero the +scanner silently recovers from this. + \stopsubsection \startsubsection[title={Accent handling with \prm {Umathaccent}},reference=mathacc] @@ -1963,6 +1999,10 @@ For Latin Modern the result looks as follows: \stoptabulate \stop +For good old times we also have \prm {skewed} and \prm {skewedwithdelims} +although it is unlikely that one will notice as it only makes sense in the +updated approach. + The \type {\over} and related primitives have the form: \starttyping @@ -2040,7 +2080,7 @@ keeping the spacing compatible. \stopsubsection -\startsubsection[title={Delimiters: \type{\Uleft}, \prm {Umiddle} and \prm {Uright}}] +\startsubsection[title={Delimiters: \prm {Uleft}, \prm {Umiddle} and \prm {Uright}}] \topicindex {math+delimiters} @@ -2273,11 +2313,13 @@ $} \typebuffer -The question is: are these double super and subscript triggers the way to go? -Anyway, you need to have them either being active (which in \CONTEXT\ then boils -down to them being other characters), or say \type {\supmarkmode = 1} to disable -the normal multiple \type {^} treatment (a value larger than 1 will also disable -that in text mode). +The problem with the circumflex is that it is also used for escaping character +input. Normally that only happens in a format file so you can safely disable +that. Alternatives are using active characters that adapt. In \CONTEXT\ we make +them regular (other) characters in text mode and set \prm {supmarkmode} to~1 to +disable the normal multiple \type {^} treatment (a value larger than 1 will also +disable that in text mode). In math mode we make them active and behave as +expected. \blank \getbuffer \blank @@ -2450,6 +2492,15 @@ and get: \inlinebuffer. \stopsubsection +\startsubsection[title={Default math codes}] + +The probably not that useful primitive (but who knows) \prm {setdefaultmathcodes} +initializes the mathcodes of digits to family zero and the lowercase and +uppercase letters to family one, just as standard \TEX\ does. Don't do this in in +\CONTEXT. + +\stopsubsection + \stopsection \startsection[title={Modes}] @@ -2630,7 +2681,7 @@ experimenting. \stopsubsection -\startsubsection[title={Some spacing control with \prm {mathsurroundmode} and \prm {mathspacingmode}}] +\startsubsection[title={Some spacing control with \prm {mathsurroundmode}, \prm {mathspacingmode} and \prm {mathgluemode}}] See \in {section} [spacing:surround] for more about inline spacing. The \prm {mathsurroundmode} parameter just permits the glue variant to kick in and indeed @@ -2640,12 +2691,17 @@ The \prm {mathspacingmode} parameter is for tracing: normally zero inter atom glue is not injected but when this parameter is set to non|-|zero even zero spacing will show up. This permits us to check the applied inter atom spacing. -% \mathcheckfencesmode -% \mathpenaltiesmode -% \mathscriptboxmode -% \mathrulesmode - % \supmarkmode -% \mathgluemode +The \prm {mathgluemode} bitset controls if glue can stretch and|/|or shrink. It +is used in some of the upgraded \CONTEXT\ high level math alignment command so +probably more qualifies as a feature specific for that usage. + +\starttabulate[|c|l|] +\DB value \BC meaning \NC \NR +\TB +\NC 0x01 \NC obey stretch component \NC \NR +\NC 0x02 \NC obey shrink component \NC \NR +\LL +\stoptabulate \stopsection @@ -2677,6 +2733,26 @@ effect and use a 20\percent\ scaling: \getbuffer +\startsubsection[title={Scaling with \prm {scaledmathstyle}}] + +Because styles put a style switching node in the stream we have a +scaling primitive that uses such a style node to signal dynamic +scaling. Thisis still somewhat experimental. + +\startbuffer +$ + {\scaledmathstyle 500 x + x}\quad + {\scaledmathstyle 1000 x + x}\quad + {\scaledmathstyle 1500 x + x} +$ +\stopbuffer + +\typebuffer + +You get differently sized math but of course you then probably also need to +handle spacing differently, although for small deviations from 1000 is should +come out acceptable. + \stopsubsection \startsubsection[title={Spreading math with \prm {maththreshold}}] @@ -2688,6 +2764,67 @@ calculations. The \prm {maththreshold} primitive is a regular glue parameter. \stopsubsection +\startsubsection[title={\prm {everymathatom} and \prm {lastatomclass}}] + +Just for completeness we have \prm {everymathatom} as companion for \prm {everyhbox} +and friends and it is probably just as useful. The next example shows how it works: + +\startbuffer +\everymathatom + {\begingroup + \scratchcounter\lastatomclass + \everymathatom{}% + \mathghost{\hbox to 0pt yoffset -1ex{\smallinfofont \setstrut\strut \the\scratchcounter\hss}}% + \endgroup} + +$ a = \mathatom class 4 {b} + \mathatom class 5 {c} $ +\stopbuffer + +\typebuffer + +We get a formula with open- and close atom spacing applied to~$b$ and~$c$: + +{\getbuffer} + +This example shows bit of all: we want the number to be invisible to the math +machinery so we ghost it. So, we need to make sure we don't get recursion due to +nested injection and expansion of \prm {everymathatom} and of course we need to +store the number. The \prm {lastatomclass} state variable is only meaningful +inside an explicit atom wrapper like \prm {mathatom} and \prm {mathatom}. + +\stopsubsection + +\startsubsection[title={\prm {postinlinepenalty} and \prm {preinlinepenalty}}] + +In horizontal lists math is embedded in a begin and end math node. These nodes +also carry information about the surrounding space, and the in \LUAMETATEX\ +optional glue. We also store a penalty so that we can let that play a role in the +decisions to be made; these two internal integer registers control this. Just +like the mentioned spacing they are not visible as nodes in the list. + +\stopsubsection + +\startsubsection[title={\prm {mathforwardpenalties} and \prm {mathbackwardpenalties}}] + +These penalties are experimental and deltas added to the regular penalties +between atoms. Here is an example, as with other primitives that take more +arguments the first number indicates how much follows. + +\startbuffer +$ a + b + c + d + e + f + g + h = x $\par +\mathforwardpenalties 3 300 200 100 +\mathbackwardpenalties 3 250 150 50 +$ a + b + c + d + e + f + g + h = x $\par +\stopbuffer + +\typebuffer + +You'll notice that we apply more severe penalties at the edges: + +{\showmakeup[penalty]\multiply\glyphscale\plustwo \getbuffer} + +\stopsubsection + \stopsection \stopchapter |