51 lines
1.4 KiB
C
51 lines
1.4 KiB
C
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/*
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* Copyright 2016 Nu-book Inc.
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* Copyright 2016 ZXing authors
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*/
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include "BitMatrix.h"
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#include <array>
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#include <stdexcept>
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namespace ZXing::QRCode {
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/**
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* <p>Encapsulates data masks for the data bits in a QR and micro QR code, per ISO 18004:2006 6.8.</p>
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*
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* <p>Note that the diagram in section 6.8.1 is misleading since it indicates that i is column position
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* and j is row position. In fact, as the text says, i is row position and j is column position.</p>
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*/
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inline bool GetDataMaskBit(int maskIndex, int x, int y, bool isMicro = false)
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{
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if (isMicro) {
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if (maskIndex < 0 || maskIndex >= 4)
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throw std::invalid_argument("QRCode maskIndex out of range");
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maskIndex = std::array{1, 4, 6, 7}[maskIndex]; // map from MQR to QR indices
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}
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switch (maskIndex) {
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case 0: return (y + x) % 2 == 0;
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case 1: return y % 2 == 0;
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case 2: return x % 3 == 0;
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case 3: return (y + x) % 3 == 0;
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case 4: return ((y / 2) + (x / 3)) % 2 == 0;
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case 5: return (y * x) % 6 == 0;
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case 6: return ((y * x) % 6) < 3;
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case 7: return (y + x + ((y * x) % 3)) % 2 == 0;
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}
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throw std::invalid_argument("QRCode maskIndex out of range");
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}
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inline bool GetMaskedBit(const BitMatrix& bits, int x, int y, int maskIndex, bool isMicro = false)
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{
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return GetDataMaskBit(maskIndex, x, y, isMicro) != bits.get(x, y);
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}
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} // namespace ZXing::QRCode
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