* Fix frac lline
For frac-line, use an SVG line in an extra tall span.
I still need to think of a way to adust `vertical-separator`.
* Fix spaces in katex.less
* regenerate screenshots
* update HorizontalBraces and StrikeThrough screenshots
* Change frac-line from border to full span
Change `frac-line` and `vertical-separator`. Instead of using span borders, fill entire span using a `box-shadow`.
This change will enable more dependable engagement of the `min-height` CSS.
* Fix indentation
* Fix indent again
* Change box shadow to inline SVG
* Fix lint error
* regenerate screenshots after switching to SVG for fraction bars
* Add \smash, laps, spaces, and phantoms
1. Support `\smash`, including the optional argument from AMS.
2. Change `\llap` and `\rlap` so that they render in text style. Repeat: This *changes* KaTeX behavior.
3. Add `\mathllap` and `\mathrlap`. These will act as they do in `mathtools` and as in previous KaTeX versions of `\llap` and `\rlap`.
4. Add `\mathclap` and `\clap`.
5. Add `\hphantom` and \vphantom`.
6. Add `\thinspace`, `\medspace`, `\thickspace`
7. Add `\hspace`.
This work will resolve issue #270 and parts of #50 and #164.
A. Perlis has written a [concise description](https://www.math.lsu.edu/~aperlis/publications/mathclap/perlis_mathclap_24Jun2003.pdf) of items 1 thru 5. Except for `\smash`'s optional argument. It's described in the [AMS User's Guide](http://texdoc.net/texmf-dist/doc/latex/amsmath/amsldoc.pdf).
Item 6 also comes from the AMS User's Guide.
* Fix test spec
* Exploit makeVList for smash
* update smash and phantom screenshots for chrome
* Pick up review comments
* Change test from \llap to \mathlap
\llap is fundamentally a text-mode function. We should not expect it to work correctly when given math-mode arguments. So test \mathllap instead.
* Correct \llap macro
A correction. The previous macro returned an error if given an argument with math-mode content, such as x^2.
The corrected macro will not return an error. It will instead return well rendered math, but letters are in `\mathrm` font.
* update \llap, \rlap, \clap macros to use \textrm
* update Lap screenshots
The combination of jspngopt and pako should eliminate possible causes for
different PNG encodings, although the core reason for #325 remains unknown.
Pako has poorer compression rates than native libz, but optimization can
counter that effect, and actually reduce the size of the screenshots.
The screenshots for LimitControls and UnsupportedCmds on Firefox used to
exhibit subpixel rendering before, for reasons unknown. The regenerated
versions don't exhibit this. See #324 for a discussion.
A fraction is surrounded by a box of width \nulldelimiterspace on either side.
That size is 1.2pt and does not scale with the style or font size.
Furthermore, a \frac creates a brace-enclosed group which results in a
\mathord, not a \mathinner.
Summary:
Using \phantom with non-phantom math in Perseus doesn't render to be the
same size because \phantom uses MathJax and the non-phantom math uses KaTeX.
Implementing \phantom in KaTeX should solve this alignment issue.
Test Plan:
[x] write (and run) unit tests
[x] create (and run) screenshotter tests
Reviewers: emily
Reviewed By: emily
Differential Revision: https://phabricator.khanacademy.org/D16720
