[racket] Interpretation of font information

Hi Nadeem and Matthew,

Thanks for the suggestions. The more I look into fonts - the more
complicated it gets.
I think I will postpone the "render math in Racket" project and try to
render math
formulas via TeX and either pdf or svg (via poppler or rsvg).


2013/11/16 Matthew Butterick <mb at mbtype.com>:
> You've already noticed the essential problem, which is that there is no
> standardized width, height, or alignment for the square-root glyph. (Off the
> top of my head, I can't think of any Unicode glyph that is standardized in
> this way.)
>
> As Nadeem suggested, you can 1) draw it yourself using primitives.
>
> 2) You could also include a math-symbol font in your program and use it for
> all the symbol work. Then you know in advance what the shapes will look like
> and can rely on those measurements.
>
> But I think (1) ends up being more practical, because you soon run into
> situations where your font won't help you — e.g., you want to show the
> square root of an expression with a numerator & denominator. At that point,
> the square-root symbol wants to be two lines high, and merely scaling the
> square-root glyph in the font won't look right.
>
> There are also LaTeX-to-SVG renderers out there, if you want to circumvent
> the problem at a higher level.
>
>
>
>
>
> On Nov 15, 2013, at 2:21 PM, Nadeem Abdul Hamid <nadeem at acm.org> wrote:
>
> Not an answer to your question, but maybe you should try just generating the
> entire symbol programmatically using pict primitives instead of trying to
> get half of it from a font character?
> --- nadeem
>
> On Friday, November 15, 2013, Jens Axel Søgaard wrote:
>>
>> Hi All,
>>
>> I want to render simple mathematical formulas using picts.
>> Consider a simple example, the square root of x:
>>
>>     √x
>>
>> To make this look nice, I want to introduce an overline that draws a bar
>> over x.
>> The bar should begin where the root sign ends. To do this I need to know
>> how high the root sign is. Calculating this has turned out to more
>> complicated
>> than I expected. If I use a font size of say 30, then the root sign will
>> (in
>> some fonts) be higher than 30. If I use (text "√" font) to get a pict then
>> the pict height will be 30 (for most fonts), but the end of the root sign
>> will stick out of the bounding box. It actually makes sense it stick out,
>> since this makes it easy to make roots over tall characters such as h.
>>
>
>
> --
>
> --
> Nadeem Abdul Hamid
> Associate Professor, Computer Science
> Berry College, Mount Berry, GA 30149
> http://cs.berry.edu/~nhamid/
>
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-- 
--
Jens Axel Søgaard