zxing-cpp 0.5.1

/*
* Copyright 2016 Nu-book Inc.
* Copyright 2016 ZXing authors
*/
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include "BitMatrix.h"

#include <array>
#include <stdexcept>

namespace ZXing::QRCode {

/**
* <p>Encapsulates data masks for the data bits in a QR  and micro QR code, per ISO 18004:2006 6.8.</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>
*/

inline bool GetDataMaskBit(int maskIndex, int x, int y, bool isMicro = false)
{
	if (isMicro) {
		if (maskIndex < 0 || maskIndex >= 4)
			throw std::invalid_argument("QRCode maskIndex out of range");
		maskIndex = std::array{1, 4, 6, 7}[maskIndex]; // map from MQR to QR indices
	}

	switch (maskIndex) {
	case 0: return (y + x) % 2 == 0;
	case 1: return y % 2 == 0;
	case 2: return x % 3 == 0;
	case 3: return (y + x) % 3 == 0;
	case 4: return ((y / 2) + (x / 3)) % 2 == 0;
	case 5: return (y * x) % 6 == 0;
	case 6: return ((y * x) % 6) < 3;
	case 7: return (y + x + ((y * x) % 3)) % 2 == 0;
	}

	throw std::invalid_argument("QRCode maskIndex out of range");
}

inline bool GetMaskedBit(const BitMatrix& bits, int x, int y, int maskIndex, bool isMicro = false)
{
	return GetDataMaskBit(maskIndex, x, y, isMicro) != bits.get(x, y);
}

} // namespace ZXing::QRCode