QRDataMask.cpp Example File

 /*
  *  DataMask.cpp
  *  zxing
  *
  *  Created by Christian Brunschen on 19/05/2008.
  *  Copyright 2008 ZXing authors All rights reserved.
  *
  * 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.
  */

 #include <zxing/qrcode/decoder/DataMask.h>

 #include <zxing/common/IllegalArgumentException.h>

 namespace zxing {
 namespace qrcode {

 using namespace std;

 DataMask::DataMask() {
 }

 DataMask::~DataMask() {
 }

 vector<Ref<DataMask> > DataMask::DATA_MASKS;
 static int N_DATA_MASKS = DataMask::buildDataMasks();

 DataMask &DataMask::forReference(int reference) {
   if (reference < 0 || reference > 7) {
     throw IllegalArgumentException("reference must be between 0 and 7");
   }
   return *DATA_MASKS[reference];
 }

 void DataMask::unmaskBitMatrix(BitMatrix& bits, size_t dimension) {
   for (size_t y = 0; y < dimension; y++) {
     for (size_t x = 0; x < dimension; x++) {
       // TODO: check why the coordinates have to be swapped
       if (isMasked(y, x)) {
         bits.flip(x, y);
       }
     }
   }
 }

 /**
  * 000: mask bits for which (x + y) mod 2 == 0
  */
 class DataMask000 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     //          return ((x + y) & 0x01) == 0;
     return ((x + y) % 2) == 0;
   }
 };

 /**
  * 001: mask bits for which x mod 2 == 0
  */
 class DataMask001 : public DataMask {
 public:
   bool isMasked(size_t x, size_t) {
     //          return (x & 0x01) == 0;
     return (x % 2) == 0;
   }
 };

 /**
  * 010: mask bits for which y mod 3 == 0
  */
 class DataMask010 : public DataMask {
 public:
   bool isMasked(size_t, size_t y) {
     return y % 3 == 0;
   }
 };

 /**
  * 011: mask bits for which (x + y) mod 3 == 0
  */
 class DataMask011 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     return (x + y) % 3 == 0;
   }
 };

 /**
  * 100: mask bits for which (x/2 + y/3) mod 2 == 0
  */
 class DataMask100 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     //          return (((x >> 1) + (y / 3)) & 0x01) == 0;
     return (((x >> 1) + (y / 3)) % 2) == 0;
   }
 };

 /**
  * 101: mask bits for which xy mod 2 + xy mod 3 == 0
  */
 class DataMask101 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     size_t temp = x * y;
     //          return (temp & 0x01) + (temp % 3) == 0;
     return (temp % 2) + (temp % 3) == 0;

   }
 };

 /**
  * 110: mask bits for which (xy mod 2 + xy mod 3) mod 2 == 0
  */
 class DataMask110 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     size_t temp = x * y;
     //          return (((temp & 0x01) + (temp % 3)) & 0x01) == 0;
     return (((temp % 2) + (temp % 3)) % 2) == 0;
   }
 };

 /**
  * 111: mask bits for which ((x+y)mod 2 + xy mod 3) mod 2 == 0
  */
 class DataMask111 : public DataMask {
 public:
   bool isMasked(size_t x, size_t y) {
     //          return ((((x + y) & 0x01) + ((x * y) % 3)) & 0x01) == 0;
     return ((((x + y) % 2) + ((x * y) % 3)) % 2) == 0;
   }
 };

 int DataMask::buildDataMasks() {
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask000()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask001()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask010()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask011()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask100()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask101()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask110()));
   DATA_MASKS.push_back(Ref<DataMask> (new DataMask111()));
   return DATA_MASKS.size();
 }

 }
 }