ResultPoint.php

<?php
/*
* Copyright 2007 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

namespace Zxing;

use Zxing\Common\Detector\MathUtils;

/**
 * <p>Encapsulates a point of interest in an image containing a barcode. Typically, this
 * would be the location of a finder pattern or the corner of the barcode, for example.</p>
 *
 * @author Sean Owen
 */
class ResultPoint
{
	private float $x;
	private float $y;

	public function __construct($x, $y)
	{
		$this->x = (float)($x);
		$this->y = (float)($y);
	}

	/**
	 * Orders an array of three ResultPoints in an order [A,B,C] such that AB is less than AC
	 * and BC is less than AC, and the angle between BC and BA is less than 180 degrees.
	 *
	 * @param array $patterns of three {@code ResultPoint} to order
	 */
	public static function orderBestPatterns(array $patterns): array
	{
		// Find distances between pattern centers
		$zeroOneDistance = self::distance($patterns[0], $patterns[1]);
		$oneTwoDistance = self::distance($patterns[1], $patterns[2]);
		$zeroTwoDistance = self::distance($patterns[0], $patterns[2]);

		$pointA = '';
		$pointB = '';
		$pointC = '';
		// Assume one closest to other two is B; A and C will just be guesses at first
		if ($oneTwoDistance >= $zeroOneDistance && $oneTwoDistance >= $zeroTwoDistance) {
			$pointB = $patterns[0];
			$pointA = $patterns[1];
			$pointC = $patterns[2];
		} elseif ($zeroTwoDistance >= $oneTwoDistance && $zeroTwoDistance >= $zeroOneDistance) {
			$pointB = $patterns[1];
			$pointA = $patterns[0];
			$pointC = $patterns[2];
		} else {
			$pointB = $patterns[2];
			$pointA = $patterns[0];
			$pointC = $patterns[1];
		}

		// Use cross product to figure out whether A and C are correct or flipped.
		// This asks whether BC x BA has a positive z component, which is the arrangement
		// we want for A, B, C. If it's negative, then we've got it flipped around and
		// should swap A and C.
		if (self::crossProductZ($pointA, $pointB, $pointC) < 0.0) {
			$temp = $pointA;
			$pointA = $pointC;
			$pointC = $temp;
		}

		$patterns[0] = $pointA;
		$patterns[1] = $pointB;
		$patterns[2] = $pointC;

		return $patterns;
	}

	/**
	 * @param ResultPoint $pattern1 first pattern
	 * @param ResultPoint $pattern2 second pattern
	 *
	 * @return float distance between two points
	 */
	public static function distance($pattern1, $pattern2)
	{
		return MathUtils::distance($pattern1->x, $pattern1->y, $pattern2->x, $pattern2->y);
	}

	

	/**
	 * Returns the z component of the cross product between vectors BC and BA.
	 */
	private static function crossProductZ(
		$pointA,
		$pointB,
		$pointC
	) {
		$bX = $pointB->x;
		$bY = $pointB->y;

		return (($pointC->x - $bX) * ($pointA->y - $bY)) - (($pointC->y - $bY) * ($pointA->x - $bX));
	}

	

	final public function getX(): float
	{
		return (float)($this->x);
	}

	

	final public function getY(): float
	{
		return (float)($this->y);
	}

	final public function equals($other): bool
	{
		if ($other instanceof ResultPoint) {
			$otherPoint = $other;

			return $this->x == $otherPoint->x && $this->y == $otherPoint->y;
		}

		return false;
	}

	final public function hashCode()
	{
		return 31 * floatToIntBits($this->x) + floatToIntBits($this->y);
	}

	final public function toString(): string
	{
		$result = '';
		$result .= ('(');
		$result .= ($this->x);
		$result .= (',');
		$result .= ($this->y);
		$result .= (')');

		return $result;
	}
}