30 lines
725 B
JavaScript
30 lines
725 B
JavaScript
/**
|
|
* Copyright (c) 2015-present, Facebook, Inc.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*
|
|
* @providesModule setNormalizedColorAlpha
|
|
* @flow
|
|
*/
|
|
/* eslint no-bitwise: 0 */
|
|
'use strict';
|
|
|
|
/**
|
|
* number should be a color processed by `normalizeColor`
|
|
* alpha should be number between 0 and 1
|
|
*/
|
|
function setNormalizedColorAlpha(input: number, alpha: number): number {
|
|
if (alpha < 0) {
|
|
alpha = 0;
|
|
} else if (alpha > 1) {
|
|
alpha = 1;
|
|
}
|
|
|
|
alpha = Math.round(alpha * 255);
|
|
// magic bitshift guarantees we return an unsigned int
|
|
return ((input & 0xffffff00) | alpha) >>> 0;
|
|
}
|
|
|
|
module.exports = setNormalizedColorAlpha;
|