Gd::drawTextWatermark

public function drawTextWatermark(TextWatermark $watermark)
{
	if ($this->resource === null)
	{
		return false;
	}

	$font = $watermark->getFont();

	if (!file_exists($font))
	{
		return false;
	}

	$utfText = $watermark->getUtfText();

	$width = $this->getWidth();
	$height = $this->getHeight();

	if (($textWidth = $watermark->getWidth()) > 0)
	{
		$textBox = imagettfbbox(20, 0, $font, $utfText);
		if (!is_array($textBox))
		{
			return false;
		}

		$scale = $textWidth / ($textBox[2] - $textBox[0]);
		$fontSize = 20 * $scale;

		$position = new Rectangle($textWidth, ($textBox[0] - $textBox[7]) * $scale);
	}
	else
	{
		$fontSize = $watermark->getFontSize($width);

		$textBox = imagettfbbox($fontSize, 0, $font, $utfText);

		$position = new Rectangle(($textBox[2] - $textBox[0]), ($textBox[0] - $textBox[7]));
	}

	$watermark->alignPosition($width, $height, $position);

	$color = $watermark->getColor();
	$textColor = imagecolorallocate($this->resource, $color->getRed(), $color->getGreen(), $color->getBlue());

	if ($watermark->getVerticalAlignment() == Watermark::ALIGN_BOTTOM)
	{
		// Try to take into consideration font's descenders.
		// Coordinates in imagettftext are for font's *baseline*.
		// Let the descenders be 20% of the font size.
		$descender = $fontSize * 0.2;
		$y = $position->getY() + $position->getHeight() - $descender; // baseline
	}
	else
	{
		$y = $position->getY() + $fontSize; // baseline
	}

	$result = imagettftext($this->resource, $fontSize, 0, $position->getX(), $y, $textColor, $font, $utfText);

	return ($result !== false);
}