OpenType features samples: liga, ccmp, rlig (optimizeLegibility)

This is the same as OpenType features samples: liga, ccmp, rlig, but with the additional CSS setting text-rendering: optimizeLegibility; (and with less pics).

liga

The OpenType feature liga should be enabled by default, see OpenType Layout tag registry, Tag: 'liga'. The font Lato, which is embedded in the following sample, uses liga in an «fi» ligature.

Embedded font Expected display†
Default find «find», liga enabled (expected default), Firefox 10 on OS X
liga enabled find «find», liga enabled (expected default), Firefox 10 on OS X
liga disabled find «find», liga disabled, Firefox 10 on OS X

ccmp

The OpenType feature ccmp should be enabled by default, see OpenType Layout tag registry, Tag: “ccmp”. The font Charis SIL, which is embedded in the following sample, uses ccmp for the tone letters.

Embedded font Expected display†
Default ɔ˧˩˧ tone letters, ccmp enabled (expected default), Firefox 10 on OS X
ccmp enabled ɔ˧˩˧ tone letters, ccmp enabled (expected default), Firefox 10 on OS X
ccmp disabled ɔ˧˩˧ tone letters, ccmp disabled, Firefox 10 on OS X

rlig

The OpenType feature rlig should be enabled by default, see OpenType Layout tag registry, Tag: “rlig”. The font UnifrakturMaguntia, which is embedded in the following sample, uses rlig for forcing ligatures (in order to comply with the implementation notes of the Unicode Standard 6.0.0, p. 528).

Embedded font Expected display†
Default ſit‍zen «ſit‍zen», rlig enabled (expected default), Firefox 10 on OS X
rlig enabled ſit‍zen «ſit‍zen», rlig enabled (expected default), Firefox 10 on OS X
rlig disabled ſit‍zen «ſit‍zen», rlig disabled, Firefox 10 on OS X

Notes

† The pictures for the expected display are screenshots from Firefox 10.