protected function module(int $x, int $y, int $M_TYPE):string{
		if(!$this->options->drawLightModules && !$this->matrix->check($x, $y)){
			return '';
		}
		// modify the output of circular modules to return hearts instead
		// you can then use the respective option values to modify the behaviour
		if($this->options->drawCircularModules && $this->matrix->checkTypeNotIn($x, $y, $this->options->keepAsSquare)){
			return sprintf('M%1$s %2$s m0.5,0.96 l-0.412,-0.412 a0.3 0.3 0 0 1 0.412,-0.435 a0.3 0.3 0 0 1 0.412,0.435Z', $x, $y);
		}
		return sprintf('M%1$s %2$s h1 v1 h-1Z', $x, $y);
	}

class QRSvgWithLogoAndCustomShapes extends QRMarkupSVG{
	/**
	 * @inheritDoc
	 */
	protected function paths():string{
		// make sure connect paths is enabled
		$this->options->connectPaths = true;
		// empty the default value to remove the fill* attributes from the <path> elements
		$this->options->markupDark = '';
		$this->options->markupLight = '';
		$size = (int)ceil($this->moduleCount * $this->options->svgLogoScale);
		// we're calling QRMatrix::setLogoSpace() manually, so QROptions::$addLogoSpace has no effect here
		$this->matrix->setLogoSpace($size, $size);
		// generate the path element(s) - in this case it's just one element as we've "disabled" several options
		$svg = parent::paths();
		// now we're lazy modifying the generated path to add the custom shapes for the finder patterns
		$svg = str_replace('"/>', $this->getFinderPatterns().'"/>', $svg);
		// and add the custom logo
		$svg .= $this->getLogo();
		return $svg;
	}
	/**
	 * returns a path segment for a single module
	 *
	 * @see https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/d
	 */
	protected function module(int $x, int $y, int $M_TYPE):string{
		if(
			!$this->matrix->check($x, $y)
			// we're skipping the finder patterns here
			|| $this->matrix->checkType($x, $y, QRMatrix::M_FINDER)
			|| $this->matrix->checkType($x, $y, QRMatrix::M_FINDER_DOT)
		){
			return '';
		}
		// return a heart shape (or any custom shape for that matter)
		return sprintf('M%1$s %2$s m0.5,0.96 l-0.412,-0.412 a0.3 0.3 0 0 1 0.412,-0.435 a0.3 0.3 0 0 1 0.412,0.435Z', $x, $y);
	}
	/**
	 * returns a custom path for the 3 finder patterns
	 */
	protected function getFinderPatterns():string{
		$qz = $this->options->addQuietzone ? $this->options->quietzoneSize : 0;
		// the positions for the finder patterns (top left corner)
		// $this->moduleCount includes 2* the quiet zone size already so we need to take this into account
		$pos = [
			[0 + $qz, 0 + $qz],
			[0 + $qz, $this->moduleCount - $qz - 7],
			[$this->moduleCount - $qz - 7, 0 + $qz],
		];
		// the custom path for one finder pattern - the first move (M) is parametrized, the rest are relative coordinates
		$path = 'M%1$s,%2$s m2,0 h3 q2,0 2,2 v3 q0,2 -2,2 h-3 q-2,0 -2,-2 v-3 q0,-2 2,-2z m0,1 q-1,0 -1,1 v3 q0,1 1,1 h3 q1,0 1,-1 v-3 q0,-1 -1,-1z m0,2.5 a1.5,1.5 0 1 0 3,0 a1.5,1.5 0 1 0 -3,0Z';
		$finder = [];
		foreach($pos as $coord){
			[$ix, $iy] = $coord;
			$finder[] = sprintf($path, $ix, $iy);
		}
		return implode('', $finder);
	}
	/**
	 * returns a <g> element that contains the SVG logo and positions it properly within the QR Code
	 *
	 * @see https://developer.mozilla.org/en-US/docs/Web/SVG/Element/g
	 * @see https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/transform
	 */
	protected function getLogo():string{
		// @todo: customize the <g> element to your liking (css class, style...)
		return sprintf(
			'%5$s<g transform="translate(%1$s %1$s) scale(%2$s)" class="%3$s">%5$s	%4$s%5$s</g>',
			($this->moduleCount - ($this->moduleCount * $this->options->svgLogoScale)) / 2,
			$this->options->svgLogoScale,
			$this->options->svgLogoCssClass,
			file_get_contents($this->options->svgLogo),
			$this->options->eol
		);
	}
}

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 7 7">
 <path d="M2 0h3a2 2 0 0 1 2 2v3a2 2 0 0 1-2 2H2a2 2 0 0 1-2-2V2a2 2 0 0 1 2-2Zm0 1a1 1 0 0 0-1 1v3a1 1 0 0 0 1 1h3a1 1 0 0 0 1-1V2a1 1 0 0 0-1-1Zm1 1h1a1 1 0 0 1 1 1v1a1 1 0 0 1-1 1H3a1 1 0 0 1-1-1V3a1 1 0 0 1 1-1Z"/>
</svg>

$r = $this->options->circleRadius;
return sprintf(
	'M%1$s %2$s a%3$s %3$s 0 1 0 %4$s 0 a%3$s %3$s 0 1 0 -%4$s 0Z',
	($x + 0.5 - $r),
	($y + 0.5),
	$r,
	($r * 2)
);