* 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.
Summary:
Update the MathJaxFonts `Dockerfile` to enable the use of
`ttfautohint` which hints our fonts better. Also, fix the location that
batik is downloaded from, update some formatting in the `Dockerfile`,
and update the fonts and metrics.
Test Plan:
- Compare a rendered `= - A z 4 \Longrightarrow \Sigma \Biggl(` in
Chrome on Windows at font sizes 10px to 20px before and after this
change.
- See that characters look about the same, or better.
- See that the screenshot tests didn't change in firefox (maybe firefox
runs the same autohinting algorithm that we do?), and don't visually
change in chrome
Reviewers: kevinb, alpert
Reviewed By: kevinb, alpert
Differential Revision: https://phabricator.khanacademy.org/D18977
