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reValuate/node_modules/pngjs/lib/paeth-predictor.js

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2021-04-02 02:24:13 +03:00
"use strict";
module.exports = function paethPredictor(left, above, upLeft) {
let paeth = left + above - upLeft;
let pLeft = Math.abs(paeth - left);
let pAbove = Math.abs(paeth - above);
let pUpLeft = Math.abs(paeth - upLeft);
if (pLeft <= pAbove && pLeft <= pUpLeft) {
return left;
}
if (pAbove <= pUpLeft) {
return above;
}
return upLeft;
};