✨ init from https://github.com/codemasher/php-qrcode-decoder/commit/5798a53268f14eb1d7d70098d23db0a81b25f98b

src/Decoder/BitMatrix.php

@@ -0,0 +1,204 @@
+<?php
+/**
+ * Class BitMatrix
+ *
+ * @created      17.01.2021
+ * @author       ZXing Authors
+ * @author       Smiley <smiley@chillerlan.net>
+ * @copyright    2021 Smiley
+ * @license      Apache-2.0
+ */
+
+namespace chillerlan\QRCode\Decoder;
+
+use chillerlan\QRCode\Common\{MaskPattern, Version};
+use InvalidArgumentException;
+use function chillerlan\QRCode\Common\uRShift;
+use function array_fill, count;
+
+final class BitMatrix{
+
+	private int   $dimension;
+	private int   $rowSize;
+	private array $bits;
+
+	public function __construct(int $dimension){
+		$this->dimension = $dimension;
+		$this->rowSize   = ((int)(($this->dimension + 0x1f) / 0x20));
+		$this->bits      = array_fill(0, $this->rowSize * $this->dimension, 0);
+	}
+
+	/**
+	 * <p>Sets the given bit to true.</p>
+	 *
+	 * @param int $x ;  The horizontal component (i.e. which column)
+	 * @param int $y ;  The vertical component (i.e. which row)
+	 */
+	public function set(int $x, int $y):void{
+		$offset = (int)($y * $this->rowSize + ($x / 0x20));
+
+		$this->bits[$offset] ??= 0;
+		$this->bits[$offset] |= ($this->bits[$offset] |= 1 << ($x & 0x1f));
+	}
+
+	/**
+	 * <p>Flips the given bit. 1 << (0xf9 & 0x1f)</p>
+	 *
+	 * @param int $x ;  The horizontal component (i.e. which column)
+	 * @param int $y ;  The vertical component (i.e. which row)
+	 */
+	public function flip(int $x, int $y):void{
+		$offset = $y * $this->rowSize + (int)($x / 0x20);
+
+		$this->bits[$offset] = ($this->bits[$offset] ^ (1 << ($x & 0x1f)));
+	}
+
+	/**
+	 * <p>Sets a square region of the bit matrix to true.</p>
+	 *
+	 * @param int $left   ;  The horizontal position to begin at (inclusive)
+	 * @param int $top    ;  The vertical position to begin at (inclusive)
+	 * @param int $width  ;  The width of the region
+	 * @param int $height ;  The height of the region
+	 *
+	 * @throws \InvalidArgumentException
+	 */
+	public function setRegion(int $left, int $top, int $width, int $height):void{
+
+		if($top < 0 || $left < 0){
+			throw new InvalidArgumentException('Left and top must be nonnegative');
+		}
+
+		if($height < 1 || $width < 1){
+			throw new InvalidArgumentException('Height and width must be at least 1');
+		}
+
+		$right  = $left + $width;
+		$bottom = $top + $height;
+
+		if($bottom > $this->dimension || $right > $this->dimension){
+			throw new InvalidArgumentException('The region must fit inside the matrix');
+		}
+
+		for($y = $top; $y < $bottom; $y++){
+			$yOffset = $y * $this->rowSize;
+
+			for($x = $left; $x < $right; $x++){
+				$xOffset              = $yOffset + (int)($x / 0x20);
+				$this->bits[$xOffset] = ($this->bits[$xOffset] |= 1 << ($x & 0x1f));
+			}
+		}
+	}
+
+	/**
+	 * @return int The dimension (width/height) of the matrix
+	 */
+	public function getDimension():int{
+		return $this->dimension;
+	}
+
+	/**
+	 * <p>Gets the requested bit, where true means black.</p>
+	 *
+	 * @param int $x The horizontal component (i.e. which column)
+	 * @param int $y The vertical component (i.e. which row)
+	 *
+	 * @return bool value of given bit in matrix
+	 */
+	public function get(int $x, int $y):bool{
+		$offset = (int)($y * $this->rowSize + ($x / 0x20));
+
+		$this->bits[$offset] ??= 0;
+
+		return (uRShift($this->bits[$offset], ($x & 0x1f)) & 1) !== 0;
+	}
+
+	/**
+	 * See ISO 18004:2006 Annex E
+	 */
+	public function buildFunctionPattern(Version $version):BitMatrix{
+		$dimension = $version->getDimension();
+		// @todo
+		$bitMatrix = new self($dimension);
+
+		// Top left finder pattern + separator + format
+		$bitMatrix->setRegion(0, 0, 9, 9);
+		// Top right finder pattern + separator + format
+		$bitMatrix->setRegion($dimension - 8, 0, 8, 9);
+		// Bottom left finder pattern + separator + format
+		$bitMatrix->setRegion(0, $dimension - 8, 9, 8);
+
+		// Alignment patterns
+		$apc = $version->getAlignmentPattern();
+		$max = count($apc);
+
+		for($x = 0; $x < $max; $x++){
+			$i = $apc[$x] - 2;
+
+			for($y = 0; $y < $max; $y++){
+				if(($x === 0 && ($y === 0 || $y === $max - 1)) || ($x === $max - 1 && $y === 0)){
+					// No alignment patterns near the three finder paterns
+					continue;
+				}
+
+				$bitMatrix->setRegion($apc[$y] - 2, $i, 5, 5);
+			}
+		}
+
+		// Vertical timing pattern
+		$bitMatrix->setRegion(6, 9, 1, $dimension - 17);
+		// Horizontal timing pattern
+		$bitMatrix->setRegion(9, 6, $dimension - 17, 1);
+
+		if($version->getVersionNumber() > 6){
+			// Version info, top right
+			$bitMatrix->setRegion($dimension - 11, 0, 3, 6);
+			// Version info, bottom left
+			$bitMatrix->setRegion(0, $dimension - 11, 6, 3);
+		}
+
+		return $bitMatrix;
+	}
+
+	/**
+	 * Mirror the bit matrix in order to attempt a second reading.
+	 */
+	public function mirror():void{
+
+		for($x = 0; $x < $this->dimension; $x++){
+			for($y = $x + 1; $y < $this->dimension; $y++){
+				if($this->get($x, $y) !== $this->get($y, $x)){
+					$this->flip($y, $x);
+					$this->flip($x, $y);
+				}
+			}
+		}
+
+	}
+
+	/**
+	 * <p>Encapsulates data masks for the data bits in a QR code, per ISO 18004:2006 6.8. Implementations
+	 * of this class can un-mask a raw BitMatrix. For simplicity, they will unmask the entire BitMatrix,
+	 * including areas used for finder patterns, timing patterns, etc. These areas should be unused
+	 * after the point they are unmasked anyway.</p>
+	 *
+	 * <p>Note that the diagram in section 6.8.1 is misleading since it indicates that i is column position
+	 * and j is row position. In fact, as the text says, i is row position and j is column position.</p>
+	 *
+	 * <p>Implementations of this method reverse the data masking process applied to a QR Code and
+	 * make its bits ready to read.</p>
+	 */
+	public function unmask(int $dimension, MaskPattern $maskPattern):void{
+		$mask = $maskPattern->getMask();
+
+		for($y = 0; $y < $dimension; $y++){
+			for($x = 0; $x < $dimension; $x++){
+				if($mask($x, $y) === 0){
+					$this->flip($x, $y);
+				}
+			}
+		}
+
+	}
+
+}