zxing-js/library

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src/core/aztec/encoder/Encoder.ts

Summary

Maintainability
F
3 days
Test Coverage
A
98%
import BitArray from '../../common/BitArray';
import IllegalArgumentException from '../../IllegalArgumentException';
import StringUtils from '../../common/StringUtils';
import BitMatrix from '../../common/BitMatrix';
import AztecCode from './AztecCode';
import ReedSolomonEncoder from '../../common/reedsolomon/ReedSolomonEncoder';
import GenericGF from '../../common/reedsolomon/GenericGF';
import HighLevelEncoder from './HighLevelEncoder';

import { int } from '../../../customTypings';
import Integer from '../../util/Integer';

/*
 * Copyright 2013 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// package com.google.zxing.aztec.encoder;

// import com.google.zxing.common.BitArray;
// import com.google.zxing.common.BitMatrix;
// import com.google.zxing.common.reedsolomon.GenericGF;
// import com.google.zxing.common.reedsolomon.ReedSolomonEncoder;

/**
 * Generates Aztec 2D barcodes.
 *
 * @author Rustam Abdullaev
 */
export default /*public final*/ class Encoder {

  public static /*final*/ DEFAULT_EC_PERCENT: int = 33; // default minimal percentage of error check words
  public static /*final*/ DEFAULT_AZTEC_LAYERS: int = 0;
  private static /*final*/ MAX_NB_BITS: int = 32;
  private static /*final*/ MAX_NB_BITS_COMPACT: int = 4;

  private static /*final*/ WORD_SIZE: Int32Array = Int32Array.from([
    4, 6, 6, 8, 8, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
    12, 12, 12, 12, 12, 12, 12, 12, 12, 12
  ]);

  private constructor() {
  }

  /**
   * Encodes the given binary content as an Aztec symbol
   *
   * @param data input data string
   * @return Aztec symbol matrix with metadata
   */
  public static encodeBytes(data: Uint8Array): AztecCode {
    return Encoder.encode(data, Encoder.DEFAULT_EC_PERCENT, Encoder.DEFAULT_AZTEC_LAYERS);
  }

  /**
   * Encodes the given binary content as an Aztec symbol
   *
   * @param data input data string
   * @param minECCPercent minimal percentage of error check words (According to ISO/IEC 24778:2008,
   *                      a minimum of 23% + 3 words is recommended)
   * @param userSpecifiedLayers if non-zero, a user-specified value for the number of layers
   * @return Aztec symbol matrix with metadata
   */
  public static encode(data: Uint8Array, minECCPercent: int, userSpecifiedLayers: int): AztecCode {
    // High-level encode
    let bits: BitArray = new HighLevelEncoder(data).encode();

    // stuff bits and choose symbol size
    let eccBits: int = Integer.truncDivision((bits.getSize() * minECCPercent), 100) + 11;
    let totalSizeBits: int = bits.getSize() + eccBits;
    let compact: boolean;
    let layers: int;
    let totalBitsInLayer: int;
    let wordSize: int;
    let stuffedBits: BitArray;
    if (userSpecifiedLayers !== Encoder.DEFAULT_AZTEC_LAYERS) {
      compact = userSpecifiedLayers < 0;
      layers = Math.abs(userSpecifiedLayers);
      if (layers > (compact ? Encoder.MAX_NB_BITS_COMPACT : Encoder.MAX_NB_BITS)) {
        throw new IllegalArgumentException(
            StringUtils.format('Illegal value %s for layers', userSpecifiedLayers));
      }
      totalBitsInLayer = Encoder.totalBitsInLayer(layers, compact);
      wordSize = Encoder.WORD_SIZE[layers];
      let usableBitsInLayers: int = totalBitsInLayer - (totalBitsInLayer % wordSize);
      stuffedBits = Encoder.stuffBits(bits, wordSize);
      if (stuffedBits.getSize() + eccBits > usableBitsInLayers) {
        throw new IllegalArgumentException('Data to large for user specified layer');
      }
      if (compact && stuffedBits.getSize() > wordSize * 64) {
        // Compact format only allows 64 data words, though C4 can hold more words than that
        throw new IllegalArgumentException('Data to large for user specified layer');
      }
    } else {
      wordSize = 0;
      stuffedBits = null;
      // We look at the possible table sizes in the order Compact1, Compact2, Compact3,
      // Compact4, Normal4,...  Normal(i) for i < 4 isn't typically used since Compact(i+1)
      // is the same size, but has more data.
      for (let i /*int*/ = 0; ; i++) {
        if (i > Encoder.MAX_NB_BITS) {
          throw new IllegalArgumentException('Data too large for an Aztec code');
        }
        compact = i <= 3;
        layers = compact ? i + 1 : i;
        totalBitsInLayer = Encoder.totalBitsInLayer(layers, compact);
        if (totalSizeBits > totalBitsInLayer) {
          continue;
        }
        // [Re]stuff the bits if this is the first opportunity, or if the
        // wordSize has changed
        if (stuffedBits == null || wordSize !== Encoder.WORD_SIZE[layers]) {
          wordSize = Encoder.WORD_SIZE[layers];
          stuffedBits = Encoder.stuffBits(bits, wordSize);
        }
        let usableBitsInLayers: int = totalBitsInLayer - (totalBitsInLayer % wordSize);
        if (compact && stuffedBits.getSize() > wordSize * 64) {
          // Compact format only allows 64 data words, though C4 can hold more words than that
          continue;
        }
        if (stuffedBits.getSize() + eccBits <= usableBitsInLayers) {
          break;
        }
      }
    }
    let messageBits: BitArray = Encoder.generateCheckWords(stuffedBits, totalBitsInLayer, wordSize);

    // generate mode message
    let messageSizeInWords: int = stuffedBits.getSize() / wordSize;
    let modeMessage: BitArray = Encoder.generateModeMessage(compact, layers, messageSizeInWords);

    // allocate symbol
    let baseMatrixSize: int = (compact ? 11 : 14) + layers * 4; // not including alignment lines
    let alignmentMap: Int32Array = new Int32Array(baseMatrixSize);
    let matrixSize: int;
    if (compact) {
      // no alignment marks in compact mode, alignmentMap is a no-op
      matrixSize = baseMatrixSize;
      for (let i /*int*/ = 0; i < alignmentMap.length; i++) {
        alignmentMap[i] = i;
      }
    } else {
      matrixSize = baseMatrixSize + 1 + 2 * Integer.truncDivision((Integer.truncDivision(baseMatrixSize, 2) - 1), 15);
      let origCenter: int = Integer.truncDivision(baseMatrixSize, 2);
      let center: int = Integer.truncDivision(matrixSize, 2);
      for (let i /*int*/ = 0; i < origCenter; i++) {
        let newOffset: int = i + Integer.truncDivision(i, 15);
        alignmentMap[origCenter - i - 1] = center - newOffset - 1;
        alignmentMap[origCenter + i] = center + newOffset + 1;
      }
    }
    let matrix: BitMatrix = new BitMatrix(matrixSize);

    // draw data bits
    for (let i /*int*/ = 0, rowOffset = 0; i < layers; i++) {
      let rowSize: int = (layers - i) * 4 + (compact ? 9 : 12);
      for (let j /*int*/ = 0; j < rowSize; j++) {
        let columnOffset: int = j * 2;
        for (let k /*int*/ = 0; k < 2; k++) {
          if (messageBits.get(rowOffset + columnOffset + k)) {
            matrix.set(alignmentMap[i * 2 + k], alignmentMap[i * 2 + j]);
          }
          if (messageBits.get(rowOffset + rowSize * 2 + columnOffset + k)) {
            matrix.set(alignmentMap[i * 2 + j], alignmentMap[baseMatrixSize - 1 - i * 2 - k]);
          }
          if (messageBits.get(rowOffset + rowSize * 4 + columnOffset + k)) {
            matrix.set(alignmentMap[baseMatrixSize - 1 - i * 2 - k], alignmentMap[baseMatrixSize - 1 - i * 2 - j]);
          }
          if (messageBits.get(rowOffset + rowSize * 6 + columnOffset + k)) {
            matrix.set(alignmentMap[baseMatrixSize - 1 - i * 2 - j], alignmentMap[i * 2 + k]);
          }
        }
      }
      rowOffset += rowSize * 8;
    }

    // draw mode message
    Encoder.drawModeMessage(matrix, compact, matrixSize, modeMessage);

    // draw alignment marks
    if (compact) {
      Encoder.drawBullsEye(matrix, Integer.truncDivision(matrixSize, 2), 5);
    } else {
      Encoder.drawBullsEye(matrix, Integer.truncDivision(matrixSize, 2), 7);
      for (let i /*int*/ = 0, j = 0; i < Integer.truncDivision(baseMatrixSize, 2) - 1; i += 15, j += 16) {
        for (let k /*int*/ = Integer.truncDivision(matrixSize, 2) & 1; k < matrixSize; k += 2) {
          matrix.set(Integer.truncDivision(matrixSize, 2) - j, k);
          matrix.set(Integer.truncDivision(matrixSize, 2) + j, k);
          matrix.set(k, Integer.truncDivision(matrixSize, 2) - j);
          matrix.set(k, Integer.truncDivision(matrixSize, 2) + j);
        }
      }
    }

    let aztec: AztecCode = new AztecCode();
    aztec.setCompact(compact);
    aztec.setSize(matrixSize);
    aztec.setLayers(layers);
    aztec.setCodeWords(messageSizeInWords);
    aztec.setMatrix(matrix);
    return aztec;
  }

  private static drawBullsEye(matrix: BitMatrix, center: int, size: int): void {
    for (let i /*int*/ = 0; i < size; i += 2) {
      for (let j /*int*/ = center - i; j <= center + i; j++) {
        matrix.set(j, center - i);
        matrix.set(j, center + i);
        matrix.set(center - i, j);
        matrix.set(center + i, j);
      }
    }
    matrix.set(center - size, center - size);
    matrix.set(center - size + 1, center - size);
    matrix.set(center - size, center - size + 1);
    matrix.set(center + size, center - size);
    matrix.set(center + size, center - size + 1);
    matrix.set(center + size, center + size - 1);
  }

  static generateModeMessage(compact: boolean, layers: int, messageSizeInWords: int): BitArray {
    let modeMessage: BitArray = new BitArray();
    if (compact) {
      modeMessage.appendBits(layers - 1, 2);
      modeMessage.appendBits(messageSizeInWords - 1, 6);
      modeMessage = Encoder.generateCheckWords(modeMessage, 28, 4);
    } else {
      modeMessage.appendBits(layers - 1, 5);
      modeMessage.appendBits(messageSizeInWords - 1, 11);
      modeMessage = Encoder.generateCheckWords(modeMessage, 40, 4);
    }
    return modeMessage;
  }

  private static drawModeMessage(matrix: BitMatrix, compact: boolean, matrixSize: int, modeMessage: BitArray): void {
    let center: int = Integer.truncDivision(matrixSize, 2);
    if (compact) {
      for (let i /*int*/ = 0; i < 7; i++) {
        let offset: int = center - 3 + i;
        if (modeMessage.get(i)) {
          matrix.set(offset, center - 5);
        }
        if (modeMessage.get(i + 7)) {
          matrix.set(center + 5, offset);
        }
        if (modeMessage.get(20 - i)) {
          matrix.set(offset, center + 5);
        }
        if (modeMessage.get(27 - i)) {
          matrix.set(center - 5, offset);
        }
      }
    } else {
      for (let i /*int*/ = 0; i < 10; i++) {
        let offset: int = center - 5 + i + Integer.truncDivision(i, 5);
        if (modeMessage.get(i)) {
          matrix.set(offset, center - 7);
        }
        if (modeMessage.get(i + 10)) {
          matrix.set(center + 7, offset);
        }
        if (modeMessage.get(29 - i)) {
          matrix.set(offset, center + 7);
        }
        if (modeMessage.get(39 - i)) {
          matrix.set(center - 7, offset);
        }
      }
    }
  }

  private static generateCheckWords(bitArray: BitArray, totalBits: int, wordSize: int): BitArray {
    // bitArray is guaranteed to be a multiple of the wordSize, so no padding needed
    let messageSizeInWords: int = bitArray.getSize() / wordSize;
    let rs: ReedSolomonEncoder = new ReedSolomonEncoder(Encoder.getGF(wordSize));
    let totalWords: int = Integer.truncDivision(totalBits, wordSize);
    let messageWords: Int32Array = Encoder.bitsToWords(bitArray, wordSize, totalWords);
    rs.encode(messageWords, totalWords - messageSizeInWords);
    let startPad: int = totalBits % wordSize;
    let messageBits: BitArray = new BitArray();
    messageBits.appendBits(0, startPad);
    for (const messageWord/*: int*/ of Array.from(messageWords)) {
      messageBits.appendBits(messageWord, wordSize);
    }
    return messageBits;
  }

  private static bitsToWords(stuffedBits: BitArray, wordSize: int, totalWords: int): Int32Array {
    let message: Int32Array = new Int32Array(totalWords);
    let i: int;
    let n: int;
    for (i = 0, n = stuffedBits.getSize() / wordSize; i < n; i++) {
      let value: int = 0;
      for (let j /*int*/ = 0; j < wordSize; j++) {
        value |= stuffedBits.get(i * wordSize + j) ? (1 << wordSize - j - 1) : 0;
      }
      message[i] = value;
    }
    return message;
  }

  private static getGF(wordSize: int): GenericGF {
    switch (wordSize) {
      case 4:
        return GenericGF.AZTEC_PARAM;
      case 6:
        return GenericGF.AZTEC_DATA_6;
      case 8:
        return GenericGF.AZTEC_DATA_8;
      case 10:
        return GenericGF.AZTEC_DATA_10;
      case 12:
        return GenericGF.AZTEC_DATA_12;
      default:
        throw new IllegalArgumentException('Unsupported word size ' + wordSize);
    }
  }

  static stuffBits(bits: BitArray, wordSize: int): BitArray {
    let out: BitArray = new BitArray();

    let n: int = bits.getSize();
    let mask: int = (1 << wordSize) - 2;
    for (let i /*int*/ = 0; i < n; i += wordSize) {
      let word: int = 0;
      for (let j /*int*/ = 0; j < wordSize; j++) {
        if (i + j >= n || bits.get(i + j)) {
          word |= 1 << (wordSize - 1 - j);
        }
      }
      if ((word & mask) === mask) {
        out.appendBits(word & mask, wordSize);
        i--;
      } else if ((word & mask) === 0) {
        out.appendBits(word | 1, wordSize);
        i--;
      } else {
        out.appendBits(word, wordSize);
      }
    }
    return out;
  }

  private static totalBitsInLayer(layers: int, compact: boolean): int {
    return ((compact ? 88 : 112) + 16 * layers) * layers;
  }
}