EPS QRCode is mirrored

[Vischerkarpfen]

Hey! I'm working on PHP 7.4 with this library in Symfony. I used this library to create an EPS QRCode with the possibility to choose between squares, circles and diamonds as the shape for the DATA_Modules. Now I have the problem that the whole QRCode is mirrored. :') Any suggestion why and how to fix?

Here is my Custom EPS File in that I'm overriding module():

class QREpsCustomShapes extends QREPS
{
	public function __construct(SettingsContainerInterface $options, QRMatrix $matrix)
	{
		parent::__construct($options, $matrix);
	}

	protected function module(int $x, int $y, int $M_TYPE): string
	{
		if (!$this->drawLightModules && !$this->matrix->isDark($M_TYPE)) {
			return '';
		}

		$scale = $this->options->scale;

		//dump(($M_TYPE & QRMatrix::M_DATA));

		if($this->matrix->checkType($x, $y, QRMatrix::M_FINDER) || $this->matrix->checkType($x, $y, QRMatrix::M_FINDER_DOT))
		{
			switch ($this->options->finderPatternShape) {
				case 'square':
					return $this->drawSquare($x, $y, $scale);
				case 'diamond':
					return $this->drawDiamond($x, $y, $scale);
				case 'circle':
					return $this->drawCircle($x, $y, $scale, $scale);
			}
		}
		else
		{
			$size = $this->options->dataModuleSize;

			switch ($this->options->dataModuleShape) {
				case 'square':
					return $this->drawSquare($x, $y, $scale);
				case 'diamond':
					return $this->drawDiamond($x, $y, $scale);
				case 'circle':
					return $this->drawCircle($x, $y, $scale, $size);
			}
		}

		return parent::module($x, $y, $M_TYPE);
	}

	public function drawSquare(int $x, int $y, int $scale): string
	{
		return sprintf(
			'newpath %.5f %.5f moveto %.5f %.5f lineto %.5f %.5f lineto %.5f %.5f lineto closepath fill',
			$x * $scale, $y * $scale,
			($x + 1) * $scale, $y * $scale,
			($x + 1) * $scale, ($y + 1) * $scale,
			$x * $scale, ($y + 1) * $scale
		);
	}

	public function drawCircle(int $x, int $y, int $scale, int $size): string
	{
		$size = $this->options->dataModuleSize;
		$cx = ($x * $size) + ($size / 2);
		$cy = ($y * $size) + ($size / 2);
		$radius = $size / 2;

		return sprintf('newpath %f %f %f 0 360 arc fill', $cx, $cy, $radius);
	}

	public function drawDiamond(int $x, int $y, int $scale): string
	{
		return sprintf(
			'newpath %.5f %.5f moveto %.5f %.5f lineto %.5f %.5f lineto %.5f %.5f lineto closepath fill',
			($x + 0.5) * $scale, $y * $scale,
			($x + 1) * $scale, ($y + 0.5) * $scale,
			($x + 0.5) * $scale, ($y + 1) * $scale,
			$x * $scale, ($y + 0.5) * $scale
		);
	}

}

My Custom Options:

class QRCustomOptions extends QROptions
{
	public int $dataModuleSize;
	public string $dataModuleShape;
	public string $finderPatternShape;
}

And my ini.php where I store most of the options values:

return [
		'qrcode_templates' => [
			'Standard' => [
				'version' => Version::AUTO,
				'scale' => 25,
				'drawLightModules' => false,
				'eccLevel' => ECClevel::L,
				'bgColor' => [255, 255, 255],
				'quietzoneSize' => 1,
				'moduleValues' => [
					/** @link https://php-qrcode.readthedocs.io/en/stable/Appendix/Terminology.html */
					// Finder-Pattern (Die Quadrate in den Ecken des QR-Codes)
					QRMatrix::M_FINDER_DARK => [0, 0, 0],    // dark (true)
					QRMatrix::M_FINDER_DOT => [0, 0, 0],    // finder dot, dark (true)
					QRMatrix::M_FINDER => [255, 255, 255], // light (false)

					// Alignment-Pattern (Quadrat unten rechts im QR-Code)
					QRMatrix::M_ALIGNMENT_DARK => [111, 138, 160],
					QRMatrix::M_ALIGNMENT => [255, 255, 255],
					// Timing-Pattern (Eine vertikale und eine horizontale Linie im QR-Code nahe der Finder-Patterns)
					QRMatrix::M_TIMING_DARK => [111, 138, 160],
					QRMatrix::M_TIMING => [255, 255, 255],
					// Format-Pattern (Umrandung nahe der Finder-Patterns)
					QRMatrix::M_FORMAT_DARK => [111, 138, 160],
					QRMatrix::M_FORMAT => [255, 255, 255],
					// Version-Pattern (Über den Finder-Patterns links unten und rechts oben im QR-Code)
					QRMatrix::M_VERSION_DARK => [111, 138, 160],
					QRMatrix::M_VERSION => [255, 255, 255],
					// Data-Modul (Die vielen kleinen Quadrate im QR-Code)
					QRMatrix::M_DATA_DARK => [111, 138, 160],
					QRMatrix::M_DATA => [255, 255, 255],
					// Dark-Modul (Kleines Quadrat, das immer neben dem Finder-Pattern unten links ist)
					QRMatrix::M_DARKMODULE => [111, 138, 160],

					// Separator (Die weißen Quadrate zwischen den Data-Modulen)
					QRMatrix::M_SEPARATOR => [255, 255, 255],

					// Bereich um den QR-Code
					QRMatrix::M_QUIETZONE => [255, 255, 255],

					// Logo Space (Bereich für das Logo)
					QRMatrix::M_LOGO => [255, 255, 255],
				],
				'customParameters' => [
					'dataModuleSize' => 25, // Skalierung data module Größe
					'dataModuleShape' => 'circle', // square, diamond, circle
					'finderPatternShape' => 'square', // square, rounded, diamond, circle
				],
			],
		],
];

I create it in my service that implements an own interface:

class QrCodeGenerator implements QrCodeGeneratorInterface
{
	private array $qrCodeOptions;

	private static array $outputInterfaces = [
		QROutputInterface::EPS => QREpsCustomShapes::class,
        QROutputInterface::GDIMAGE_PNG => QRPngCustomShapes::class,
	];

	public function __construct(array $qrCodeOptions)
	{
		$this->qrCodeOptions = $qrCodeOptions;
	}

	/**
	 * @throws InvalidArgumentException
	 */
	public function generateQrCode(string $data, string $outputFilePathOrFormat, string $qrCodeDefinition = null): string
	{
		if (empty($qrCodeDefinition) || !isset($this->qrCodeOptions['qrcode_templates'][$qrCodeDefinition])) {
			$qrCodeDefinition = array_key_first($this->qrCodeOptions['qrcode_templates']);
		}
		$options = new QRCustomOptions($this->qrCodeOptions['qrcode_templates'][$qrCodeDefinition]);

		$outputFilePath = null;

		if (isset(self::$outputInterfaces[$outputFilePathOrFormat])) {
			$outputFormat = $outputFilePathOrFormat;
		}
		else {
			$outputFormat = strtolower(Path::getExtension($outputFilePathOrFormat));
			$outputFilePath = $outputFilePathOrFormat;
		}

		if (!isset(self::$outputInterfaces[$outputFormat])) {
			throw new InvalidArgumentException(sprintf('Unsupported output format "%s".', $outputFormat));
		}

		$options->dataModuleSize = $this->qrCodeOptions['qrcode_templates'][$qrCodeDefinition]['customParameters']['dataModuleSize'];
		$options->dataModuleShape = $this->qrCodeOptions['qrcode_templates'][$qrCodeDefinition]['customParameters']['dataModuleShape'];
		$options->finderPatternShape = $this->qrCodeOptions['qrcode_templates'][$qrCodeDefinition]['customParameters']['finderPatternShape'];
		$options->outputType = QROutputInterface::CUSTOM;
		$options->outputInterface = self::$outputInterfaces[$outputFormat];
		$options->drawCircularModules = true;

		return (new QRCode($options))->render($data, $outputFilePath);
	}
}

[codemasher]

Hey, I think it has something to do with this: #148

You will need to translate the coordinates:

php-qrcode/src/Output/QREps.php

Lines 164 to 168 in 7e7552b

	$outputX = ($x * $this->scale);
	// Actual size - one block = Topmost y pos.
	$top = ($this->length - $this->scale);
	// Apparently y-axis is inverted (y0 is at bottom and not top) in EPS, so we have to switch the y-axis here
	$outputY = ($top - ($y * $this->scale));

[codemasher]

alternatively, you can just use the rotate method on the matrix in combination with an array_reverse() on the matrix array:

php-qrcode/src/Data/QRMatrix.php

Lines 589 to 596 in 7e7552b

	/**
	* Rotates the matrix by 90 degrees clock wise
	*/
	public function rotate90():static{
	$this->matrix = array_map((fn(int ...$a):array => array_reverse($a)), ...$this->matrix);
	return $this;
	}

the diagonal mirror method only exists on the extended QRMatrix for the reader, but it's simple enough to implement in custom output:

php-qrcode/src/Decoder/BitMatrix.php

Lines 98 to 101 in 7e7552b

	// mirror vertically
	$this->matrix = array_reverse($this->matrix);
	// rotate by 90 degrees clockwise
	return $this->rotate90();

Edit: I might as well move the mirror method to the parent class as it may come in handy here and there. The issue with rotating the matrix with its instance method, and then reversing the array output from QRMatrix::getMatrix() will cause issues when values are retrieved via QRMatrix::get() as the values don't match anymore.

[Vischerkarpfen]

Yea I forgot to translate the coordinates! Just added those three lines. Now all I get is a white, blank image. I guess now there's something wrong with my EPS "code" I return with sprintf.

[codemasher]

On a side note: I see your extended options class has public properties - you might want to change them to protected, so that they are run through the internal magic getter and setter. Otherwise the values could be lost or malformed i.e. if you were to export the options instance to JSON. See also: https://github.com/chillerlan/php-settings-container?tab=readme-ov-file#usage