piglow
Version:
javascript interface for the piglow
21 lines (20 loc) • 1.35 kB
JavaScript
/**
* gamma correction table
* used to map brightness values to bit values
* borrowed from: https://github.com/benleb/PyGlow and jon@pimoroni
* @type {Array}
*/
var GAMMA_TABLE = [0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10,
10, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24,
25, 26, 26, 27, 27, 28, 29, 29, 30, 31, 31, 32, 33, 33, 34, 35, 36, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 57, 58,
59, 60, 62, 63, 64, 66, 67, 69, 70, 72, 74, 75, 77, 79, 80, 82, 84, 86, 88, 90, 91, 94, 96, 98, 100, 102, 104, 107, 109, 111, 114, 116, 119, 122, 124, 127,
130, 133, 136, 139, 142, 145, 148, 151, 155, 158, 161, 165, 169, 172, 176, 180, 184, 188, 192, 196, 201, 205, 210, 214, 219, 224, 229, 234, 239, 244, 250, 255];
/**
* mapper that uses the gamma correction table
* @param value
* @return integer
*/
module.exports = function (value) {
return GAMMA_TABLE[value];
};