*/ private $bits; /** * @throws InvalidArgumentException if a dimension is smaller than zero */ public function __construct(int $width, int $height = null) { if (null === $height) { $height = $width; } if ($width < 1 || $height < 1) { throw new InvalidArgumentException('Both dimensions must be greater than zero'); } $this->width = $width; $this->height = $height; $this->rowSize = ($width + 31) >> 5; $this->bits = SplFixedArray::fromArray(array_fill(0, $this->rowSize * $height, 0)); } /** * Gets the requested bit, where true means black. */ public function get(int $x, int $y) : bool { $offset = $y * $this->rowSize + ($x >> 5); return 0 !== (BitUtils::unsignedRightShift($this->bits[$offset], ($x & 0x1f)) & 1); } /** * Sets the given bit to true. */ public function set(int $x, int $y) : void { $offset = $y * $this->rowSize + ($x >> 5); $this->bits[$offset] = $this->bits[$offset] | (1 << ($x & 0x1f)); } /** * Flips the given bit. */ public function flip(int $x, int $y) : void { $offset = $y * $this->rowSize + ($x >> 5); $this->bits[$offset] = $this->bits[$offset] ^ (1 << ($x & 0x1f)); } /** * Clears all bits (set to false). */ public function clear() : void { $max = count($this->bits); for ($i = 0; $i < $max; ++$i) { $this->bits[$i] = 0; } } /** * Sets a square region of the bit matrix to true. * * @throws InvalidArgumentException if left or top are negative * @throws InvalidArgumentException if width or height are smaller than 1 * @throws InvalidArgumentException if region does not fit into the matix */ public function setRegion(int $left, int $top, int $width, int $height) : void { if ($top < 0 || $left < 0) { throw new InvalidArgumentException('Left and top must be non-negative'); } if ($height < 1 || $width < 1) { throw new InvalidArgumentException('Width and height must be at least 1'); } $right = $left + $width; $bottom = $top + $height; if ($bottom > $this->height || $right > $this->width) { throw new InvalidArgumentException('The region must fit inside the matrix'); } for ($y = $top; $y < $bottom; ++$y) { $offset = $y * $this->rowSize; for ($x = $left; $x < $right; ++$x) { $index = $offset + ($x >> 5); $this->bits[$index] = $this->bits[$index] | (1 << ($x & 0x1f)); } } } /** * A fast method to retrieve one row of data from the matrix as a BitArray. */ public function getRow(int $y, BitArray $row = null) : BitArray { if (null === $row || $row->getSize() < $this->width) { $row = new BitArray($this->width); } $offset = $y * $this->rowSize; for ($x = 0; $x < $this->rowSize; ++$x) { $row->setBulk($x << 5, $this->bits[$offset + $x]); } return $row; } /** * Sets a row of data from a BitArray. */ public function setRow(int $y, BitArray $row) : void { $bits = $row->getBitArray(); for ($i = 0; $i < $this->rowSize; ++$i) { $this->bits[$y * $this->rowSize + $i] = $bits[$i]; } } /** * This is useful in detecting the enclosing rectangle of a 'pure' barcode. * * @return int[]|null */ public function getEnclosingRectangle() : ?array { $left = $this->width; $top = $this->height; $right = -1; $bottom = -1; for ($y = 0; $y < $this->height; ++$y) { for ($x32 = 0; $x32 < $this->rowSize; ++$x32) { $bits = $this->bits[$y * $this->rowSize + $x32]; if (0 !== $bits) { if ($y < $top) { $top = $y; } if ($y > $bottom) { $bottom = $y; } if ($x32 * 32 < $left) { $bit = 0; while (($bits << (31 - $bit)) === 0) { $bit++; } if (($x32 * 32 + $bit) < $left) { $left = $x32 * 32 + $bit; } } } if ($x32 * 32 + 31 > $right) { $bit = 31; while (0 === BitUtils::unsignedRightShift($bits, $bit)) { --$bit; } if (($x32 * 32 + $bit) > $right) { $right = $x32 * 32 + $bit; } } } } $width = $right - $left; $height = $bottom - $top; if ($width < 0 || $height < 0) { return null; } return [$left, $top, $width, $height]; } /** * Gets the most top left set bit. * * This is useful in detecting a corner of a 'pure' barcode. * * @return int[]|null */ public function getTopLeftOnBit() : ?array { $bitsOffset = 0; while ($bitsOffset < count($this->bits) && 0 === $this->bits[$bitsOffset]) { ++$bitsOffset; } if (count($this->bits) === $bitsOffset) { return null; } $x = intdiv($bitsOffset, $this->rowSize); $y = ($bitsOffset % $this->rowSize) << 5; $bits = $this->bits[$bitsOffset]; $bit = 0; while (0 === ($bits << (31 - $bit))) { ++$bit; } $x += $bit; return [$x, $y]; } /** * Gets the most bottom right set bit. * * This is useful in detecting a corner of a 'pure' barcode. * * @return int[]|null */ public function getBottomRightOnBit() : ?array { $bitsOffset = count($this->bits) - 1; while ($bitsOffset >= 0 && 0 === $this->bits[$bitsOffset]) { --$bitsOffset; } if ($bitsOffset < 0) { return null; } $x = intdiv($bitsOffset, $this->rowSize); $y = ($bitsOffset % $this->rowSize) << 5; $bits = $this->bits[$bitsOffset]; $bit = 0; while (0 === BitUtils::unsignedRightShift($bits, $bit)) { --$bit; } $x += $bit; return [$x, $y]; } /** * Gets the width of the matrix, */ public function getWidth() : int { return $this->width; } /** * Gets the height of the matrix. */ public function getHeight() : int { return $this->height; } }