price-scale-conversions.ts

import { log10 } from '../helpers/mathex';

import { PriceRangeImpl } from './price-range-impl';

const enum Constants {
	LogicalOffset = 4,
	CoordOffset = 0.0001,
}

export function fromPercent(value: number, baseValue: number): number {
	if (baseValue < 0) {
		value = -value;
	}

	return (value / 100) * baseValue + baseValue;
}

export function toPercent(value: number, baseValue: number): number {
	const result = 100 * (value - baseValue) / baseValue;
	return (baseValue < 0 ? -result : result);
}

export function toPercentRange(priceRange: PriceRangeImpl, baseValue: number): PriceRangeImpl {
	const minPercent = toPercent(priceRange.minValue(), baseValue);
	const maxPercent = toPercent(priceRange.maxValue(), baseValue);
	return new PriceRangeImpl(minPercent, maxPercent);
}

export function fromIndexedTo100(value: number, baseValue: number): number {
	value -= 100;
	if (baseValue < 0) {
		value = -value;
	}

	return (value / 100) * baseValue + baseValue;
}

export function toIndexedTo100(value: number, baseValue: number): number {
	const result = 100 * (value - baseValue) / baseValue + 100;
	return (baseValue < 0 ? -result : result);
}

export function toIndexedTo100Range(priceRange: PriceRangeImpl, baseValue: number): PriceRangeImpl {
	const minPercent = toIndexedTo100(priceRange.minValue(), baseValue);
	const maxPercent = toIndexedTo100(priceRange.maxValue(), baseValue);
	return new PriceRangeImpl(minPercent, maxPercent);
}

export function toLog(price: number): number {
	const m = Math.abs(price);
	if (m < 1e-8) {
		return 0;
	}

	const res = log10(m + Constants.CoordOffset) + Constants.LogicalOffset;
	return ((price < 0) ? -res : res);
}

export function fromLog(logical: number): number {
	const m = Math.abs(logical);
	if (m < 1e-8) {
		return 0;
	}

	const res = Math.pow(10, m - Constants.LogicalOffset) - Constants.CoordOffset;
	return (logical < 0) ? -res : res;
}

export function convertPriceRangeToLog(priceRange: PriceRangeImpl | null): PriceRangeImpl | null {
	if (priceRange === null) {
		return null;
	}

	const min = toLog(priceRange.minValue());
	const max = toLog(priceRange.maxValue());

	return new PriceRangeImpl(min, max);
}

export function canConvertPriceRangeFromLog(priceRange: PriceRangeImpl | null): boolean {
	if (priceRange === null) {
		return false;
	}

	const min = fromLog(priceRange.minValue());
	const max = fromLog(priceRange.maxValue());

	return isFinite(min) && isFinite(max);
}

export function convertPriceRangeFromLog(priceRange: PriceRangeImpl | null): PriceRangeImpl | null {
	if (priceRange === null) {
		return null;
	}

	const min = fromLog(priceRange.minValue());
	const max = fromLog(priceRange.maxValue());

	return new PriceRangeImpl(min, max);
}