[NTG-context] \getscaledglyph for width-only

Hans Hagen pragma at wxs.nl
Fri Aug 19 00:11:14 CEST 2016


On 8/18/2016 6:30 PM, Brian R. Landy wrote:
>
>
> On Thu, 18 Aug 2016, Hans Hagen wrote:
>
>> On 8/18/2016 1:12 AM, Brian R. Landy wrote:
>>>
>>>> On Aug 17, 2016, at 5:45 PM, Hans Hagen <pragma at wxs.nl> wrote:
>>>>
>>>> On 8/17/2016 9:56 PM, Brian R. Landy wrote:
>>>>> Hi, I was wondering if there is a way to call \getscaledglyph to
>>>>> scale a
>>>>> glyph only horizontally, leaving the height untouched?  Or maybe an
>>>>> alternate command?
>>>>>
>>>>> I can sort of accomplish this with (for example)
>>>>> \scale[sx=0.75,sy=1.0]{}{A}, but that encloses the glyph in an \hbox,
>>>>> which can be problematic.  \getscaledglyph doesn't cause me any
>>>>> problems, except that it scales the height too.
>>>>
>>>> \starttext
>>>>
>>>> \definefontfeature[whatever][default][extend=2.5]
>>>>
>>>> \definedfont[Serif*whatever at 12pt]
>>>>
>>>> whatever
>>>>
>>>> \stoptext
>>>>
>>>
>>> Thank you.  One thing that \getscaledglyph does it works agnostic to
>>> the currently selected font.  For example:
>>
>> scaling glyphs in one direction is kind of bad anyway so if you want
>> just one glyph you can do
>>
>> \inframed{\scale[width=3em,height=1ex]{...}}
>>
>> or whatever suits the purpose
>
> Agreed.  Here's a little more background, so it makes some sense why I
> want to scale horizontally, and then I describe my final solution.  I
> have a specific case where I use a minus, a hyphen-minus, and a plus
> close to each other, and it's always bugged me that most fonts don't
> vertically align the hyphen-minus with the other two glyphs. An example is:
>
>   {\normalUchar"2212}100-00+
>
> I was thinking that math fonts did align these symbols, hence my
> question on Monday on how to get the hyphen-minus in math mode (and
> thanks for the quick answer on that) but unfortunately was wrong.  So
> that got me searching for a way to horizontally shrink a minus, so it
> would retain the same height and line thickness as the minus.
> Horizontal-only scaling of a hyphen/dash/minus isn't so bad.
>
> \scaled[] worked perfectly, but it breaks inside a natural table with
> character alignment enabled.  I have a commented example of this below.
> \getscaledglyph works in the table, but the vertical shrink is a
> non-starter.
>
> Here's an example:
>
> \edef\mathminus{\normalUchar"2212}
> \edef\smallminus{\getscaledglyph{0.33}{}{\normalUchar"2212}}
> \starttext
>
> This is my starting point:
>
> \bTABLE[aligncharacter=yes,alignmentcharacter={text->-}]
> \bTR \bTD \mathminus100-00+ \eTD \eTR
> \bTR \bTD           100-00  \eTD \eTR
> \bTR \bTD \mathminus 99-00+ \eTD \eTR
> \bTR \bTD \mathminus 99-00  \eTD \eTR
> \eTABLE
>
> % This table won't typeset:
> %
> % \bTABLE[aligncharacter=yes,alignmentcharacter={text->:}]
> % \bTR \bTD \mathminus100\scaled[sx=0.5,sy=1.0]{\mathminus}00:+ \eTD \eTR
> % \bTR \bTD           100\scaled[sx=0.5,sy=1.0]{\mathminus}00:  \eTD \eTR
> % \bTR \bTD \mathminus 99\scaled[sx=0.5,sy=1.0]{\mathminus}00:+ \eTD \eTR
> % \bTR \bTD \mathminus 99\scaled[sx=0.5,sy=1.0]{\mathminus}00:  \eTD \eTR
> % \eTABLE
>
> \stoptext
>
> But I came up with a solution that works.  Rather than attempt to shrink
> the minus glyph, I define a new glyph that corrects the height of the
> hyphen-minus:
>
> \startluacode
>      local function addsmallminus(tfmdata)
>          local hchar    = tfmdata.characters[0x002D]
>          local mchar    = tfmdata.characters[0x2212]
>          tfmdata.characters[0xFE000]   = {
>              width    = hchar.width,
>              height   = mchar.height,
>              commands = {
>                  { "down", hchar.height-mchar.height },
>                  { "char", 0x002D },
>              }
>          }
>      end
>
>      fonts.constructors.newfeatures("otf").register {
>          name        = "smallminus",
>          description = "small minus",
>          manipulators = {
>              base = addsmallminus,
>              node = addsmallminus,
>          }
>      }
>
> \stopluacode
>
> \definefontfeature[default][default][smallminus=yes]
> \edef\smallminus{\normalUchar"FE000}
>
> \starttext
>
> \bTABLE[aligncharacter=yes,alignmentcharacter={text->\smallminus}]
> \bTR \bTD \mathminus100\smallminus00+ \eTD \eTR
> \bTR \bTD           100\smallminus00  \eTD \eTR
> \bTR \bTD \mathminus 99\smallminus00+ \eTD \eTR
> \bTR \bTD \mathminus 99\smallminus00  \eTD \eTR
> \eTABLE
>
> \stoptext
>
> So this looks good and works with any font.  The only issue is fonts
> that use a different line thickness for the minus and hyphen-minus; this
> top-aligns the glyphs.
>
> Is there a way to make this glyph available in math-mode?  I get a "?"
> when I try:

method 1:

\definefontfeature[math-text]         [math-text]         [smallminus=yes]
\definefontfeature[math-script]       [math-script]       [smallminus=yes]
\definefontfeature[math-scriptscript] [math-scriptscript] [smallminus=yes]

method 2: (no need to adapt features)

          name        = "smallminus",
          description = "small minus",
          default     = true,


> \math{\smallminus}
> \math{\mathchar"FE000}
>
> Thanks for all your help!
>
>
> Brian
> ___________________________________________________________________________________
>
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>
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> ___________________________________________________________________________________


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