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diff --git a/doc/context/sources/general/manuals/math/math-framing.tex b/doc/context/sources/general/manuals/math/math-framing.tex new file mode 100644 index 000000000..b93d57f49 --- /dev/null +++ b/doc/context/sources/general/manuals/math/math-framing.tex @@ -0,0 +1,232 @@ +\environment math-layout + +\startcomponent math-framing + +\startchapter[title=Framing] + +The \type {\framed} macro is one of the core constructors in \CONTEXT\ and it's +used all over the place. This macro is unlikely to change its behaviour and as it +has evolved over years it comes with quite some options and some can interfere +with the expectations one has. In general using this macro works out well but you +need to keep an eye on using struts and alignment. + +\startbuffer +\framed{$e=mc^2$} +\stopbuffer + +\typebuffer + +The outcome of this is: + +\startlinecorrection \getbuffer \stoplinecorrection + +There is a bit of offset (that you can set) but also struts are added as can be +seen when we visualize them: + +\startlinecorrection \showstruts \getbuffer \stoplinecorrection + +These struts can be disabled: + +\startbuffer +\framed[strut=no]{$e=mc^2$} +\stopbuffer + +\typebuffer + +Now the result is more tight. + +\startlinecorrection \showstruts \getbuffer \stoplinecorrection + +These struts are the way to get a consistent look and feel and are used +frequently in \CONTEXT. We mention these struts because they get in the way when +we frame a display formula. Let's first look at what happens when we +just package a formula in a box: + +\startbuffer +\vbox\bgroup + \startformula + e = mc^2 + \stopformula +\egroup +\stopbuffer + +\typebuffer + +We get: + +\startlinecorrection \start \showmakeup \getbuffer \stop \stoplinecorrection + +Now there are a few properties of displaymath that one needs to keep in mind when +messing around with them this way. First of all display math is meant to be used +as part of the page stream. This means that spacing above and below is adapted to +what comes before and after. It also means that, because formulas can be numbered, +we have some settings that relate to horizontal placement. + +The default vertical spacing is easy to get rid of: + +\startbuffer +\vbox\bgroup + \startformula[packed] + e = mc^2 + \stopformula +\egroup +\stopbuffer + +\typebuffer + +This gives: + +\startlinecorrection \start \showmakeup \getbuffer \stop \stoplinecorrection + +Another handy keyword is \type {tight}: + +\startbuffer +\vbox\bgroup + \startformula[tight] + e = mc^2 + \stopformula +\egroup +\stopbuffer + +\typebuffer + +This gives: + +\startlinecorrection \start \showmakeup \getbuffer \stop \stoplinecorrection + +We can combine these two: + +\startbuffer +\vbox\bgroup + \startformula[packed,tight] + e = mc^2 + \stopformula +\egroup +\stopbuffer + +\typebuffer + +This gives: + +\startlinecorrection \start \showmakeup \getbuffer \stop \stoplinecorrection + +Just in case you wonder why we need to go through these troubles: keep in mind +that we are wrapping something (math) that normally goes in a vertical list with +text above and below. + +The \type {packed} and \type {tight} options can help when we want to wrap +a formula in a frame: + +\startbuffer +\framed + [strut=no] + { + \startformula[packed,tight] + e = mc^2 + \stopformula + } +\stopbuffer + +\typebuffer + +which renders as: + +\startlinecorrection \getbuffer \stoplinecorrection + +There is a dedicated math framed instance that is tuned to give better results +and automatically switches to math mode: + +\startbuffer +\mframed { + e = mc^2 +} +\stopbuffer + +\typebuffer + +becomes: + +\startlinecorrection \getbuffer \stoplinecorrection + +Framing a formula is also supported as a option, where the full power of framed can +be applied to the formula. We will illustrate this in detail on the next pages. For this +we use the following sample: + +\typefile{math-framing-001.tex} + +In \in {figure} [framing-flushleft], \in [framing-middle] \in {and} +[framing-flushright] you see some combinations. You can run this example on your +machine and see the details. + +\startplacefigure[location=page,reference=framing-flushleft,title={Framed formulas flushed left.}] + \startcombination[2*2] + {\typesetfile[math-framing-001.tex][page=01,height=.45\textheight]} {\tttf right + flushleft} + {\typesetfile[math-framing-001.tex][page=02,height=.45\textheight]} {\tttf right + flushleft} + {\typesetfile[math-framing-001.tex][page=07,height=.45\textheight]} {\tttf left + flushleft + tight} + {\typesetfile[math-framing-001.tex][page=08,height=.45\textheight]} {\tttf left + flushleft + tight} + \stopcombination +\stopplacefigure + +\startplacefigure[location=page,reference=framing-middle,title={Framed formulas centered.}] + \startcombination[2*2] + {\typesetfile[math-framing-001.tex][page=03,height=.45\textheight]} {\tttf right + middle} + {\typesetfile[math-framing-001.tex][page=04,height=.45\textheight]} {\tttf right + middle} + {\typesetfile[math-framing-001.tex][page=09,height=.45\textheight]} {\tttf left + middle + tight} + {\typesetfile[math-framing-001.tex][page=10,height=.45\textheight]} {\tttf left + middle + tight} + \stopcombination +\stopplacefigure + +\startplacefigure[location=page,reference=framing-flushright,title={Framed formulas flushed right.}] + \startcombination[2*2] + {\typesetfile[math-framing-001.tex][page=05,height=.45\textheight]} {\tttf right + flushright} + {\typesetfile[math-framing-001.tex][page=06,height=.45\textheight]} {\tttf right + flushright} + {\typesetfile[math-framing-001.tex][page=11,height=.45\textheight]} {\tttf left + flushright + tight} + {\typesetfile[math-framing-001.tex][page=12,height=.45\textheight]} {\tttf left + flushright + tight} + \stopcombination +\stopplacefigure + +With each formula class a framed variants is automatically created: + +\startbuffer +\defineformula + [foo] + +\setupformulaframed + [foo] + [frame=on, + framecolor=red] + +\startfooformula[frame] + e=mc^2 +\stopfooformula +\stopbuffer + +\typebuffer + +This time you get a red frame: + +\getbuffer + +You can also frame the number, as in: + +\startbuffer +\setupformulaframed[framecolor=red,frame=on,offset=1ex] +\setupformula[option=frame,color=blue] +\setupformula[numbercommand={\inframed[framecolor=green]}] + +\startplaceformula + \startformula + 2 + 2 = 2x + \stopformula +\stopplaceformula +\stopbuffer + +\typebuffer + +The boxes get properly aligned: + +\start \showboxes \getbuffer \stop + +\stopchapter + +\stopcomponent |