Add SAPC support

[CoreyGinnivan]

https://github.com/Myndex/SAPC/tree/master/JS

[Myndex]

I expect to have an npm package soon. Also just as an FYI we're calling the basic free algorithm "APCA" now... SAPC is the full appearance model...

[Myndex]

APCA npm Package

The APCA npm package is now available: apca-w3

Install:

 npm i apca-w3

Usage:

And the API is trivially simple: send it two colors, it returns a signed INT of the Lc value (lightness contrast).

 Lc = APCAcontrast( sRGBtoY( textColor ), sRGBtoY( backgroundColor ) );

Implementation notes:

Color sent to the required parsing function sRGBtoY() can be a 3 or 6 character hex string #fff or a3b3d4 (hash # is optional but not required), a named CSS color (such as aquamarine), as rgb(99,122,14), or as a number 0x123456 or 15213412. Text color first, background color second — do not swap colors, as use case affects results. light text on a dark background returns a negative value.

For questions and comments please visit the main APCA repo discussion area.

Thank you!

Andy

[Myndex]

Hey @CoreyGinnivan I'm not sure if you are aware but we released Bridge-PCA which is backwards compatible with the old WCAG 2, but using APCA technology — if you pass Bridge-PCA you automatically pass WCAG 2.

Also available as an npm package:

 npm i bridge-pca

Thank you!

Andy