mainTrc top-level constant

double const mainTrc

Calculations for APCA contrast. Per APCA landing page: The correct code to use is right here apca-w3 in this satellite repository Referring to: https://github.com/Myndex/apca-w3/blob/master/src/apca-w3.js Variable names and most comments are from the original source.

Implementation

const double mainTrc = 2.4;