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.

* * @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 $patterns of three {@code ResultPoint} to order */ public static function orderBestPatterns($patterns) { // 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 first $pattern1 pattern * @param second $pattern2 pattern * * @return distance between two points */ public static function distance($pattern1, $pattern2) { return MathUtils::distance($pattern1->x, $pattern1->y, $pattern2->x, $pattern2->y); } //@Override /** * 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 - $bX)); } //@Override final public function getX() { return (float)($this->x); } //@Override final public function getY() { return (float)($this->y); } final public function equals($other) { 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() { $result = ''; $result .= ('('); $result .= ($this->x); $result .= (','); $result .= ($this->y); $result .= (')'); return $result; } }