/**
* @preserve
* Copyright 2015-2018 Igor Bezkrovnyi
* All rights reserved. (MIT Licensed)
*
* common.ts - part of Image Quantization Library
*/
import { PointRGBA } from '../utils/point';
export abstract class AbstractDistanceCalculator {
protected _maxDistance!: number;
protected _whitePoint!: {
r: number;
g: number;
b: number;
a: number;
};
constructor() {
this._setDefaults();
// set default maximal color component deltas (255 - 0 = 255)
this.setWhitePoint(255, 255, 255, 255);
}
setWhitePoint(r: number, g: number, b: number, a: number) {
this._whitePoint = {
r: r > 0 ? 255 / r : 0,
g: g > 0 ? 255 / g : 0,
b: b > 0 ? 255 / b : 0,
a: a > 0 ? 255 / a : 0,
};
this._maxDistance = this.calculateRaw(r, g, b, a, 0, 0, 0, 0);
}
calculateNormalized(colorA: PointRGBA, colorB: PointRGBA) {
return (
this.calculateRaw(
colorA.r,
colorA.g,
colorA.b,
colorA.a,
colorB.r,
colorB.g,
colorB.b,
colorB.a,
) / this._maxDistance
);
}
/**
* Calculate raw distance (non-normalized)
*/
abstract calculateRaw(
r1: number,
g1: number,
b1: number,
a1: number,
r2: number,
g2: number,
b2: number,
a2: number,
): number;
protected abstract _setDefaults(): void;
}
