ReedSolomonEncoder.cpp Example File

 #include "ReedSolomonEncoder.h"

 #include <zxing/Exception.h>
 #include <stdio.h>
 #include <string.h>

 namespace zxing {

 ReedSolomonEncoder::ReedSolomonEncoder(Ref<GenericGF> field) :
     field_(field), cachedGenerators_()
 {
     ArrayRef<int> arrayRef(1); //will this work?
     arrayRef[0] = 1;
     Ref< GenericGFPoly > tmpGeneratorRef(new GenericGFPoly(field, arrayRef));
     cachedGenerators_.push_back(tmpGeneratorRef);
 }

 Ref<GenericGFPoly> ReedSolomonEncoder::buildGenerator(int degree)
 {
     if (degree >= cachedGenerators_.size()) {
         Ref<GenericGFPoly> lastGenerator = cachedGenerators_.at(cachedGenerators_.size() - 1);
         for (int d = cachedGenerators_.size(); d <= degree; d++)
         {
             ArrayRef<int> arrayRef(2); //will this work?
             arrayRef[0] = 1;
             arrayRef[1] = field_->exp(d - 1 + field_->getGeneratorBase());
             Ref<GenericGFPoly> tmpGFRef(new GenericGFPoly(field_, arrayRef));
             Ref<GenericGFPoly> nextGenerator = (*lastGenerator).multiply(tmpGFRef);
             cachedGenerators_.push_back(nextGenerator);
             lastGenerator = nextGenerator;
         }
     }
     return cachedGenerators_.at(degree); // ??? wont this through exception?
 }

 void ReedSolomonEncoder::encode(std::vector<byte> &toEncode, int ecBytes)
 {
     if (ecBytes == 0) {
         throw Exception("No error correction bytes");
     }

     int dataBytes = toEncode.size();// - ecBytes;
     toEncode.resize(toEncode.size()+ecBytes);
     if (dataBytes <= 0) {
         throw Exception("No data bytes provided");
     }
     Ref<GenericGFPoly> generator = buildGenerator(ecBytes);
     ArrayRef<int> infoCoefficients(dataBytes);

     //to-do optimize the following loop
     for(int i=0; i< dataBytes; i++)
         infoCoefficients[i] = toEncode[i];

     Ref<GenericGFPoly> info(new GenericGFPoly(field_, infoCoefficients));
     info = info->multiplyByMonomial(ecBytes, 1);
     Ref<GenericGFPoly> remainder = info->divide(generator)[1];
     ArrayRef<int> coefficients = remainder->getCoefficients();
     int numZeroCoefficients = ecBytes - coefficients->size();
     for (int i = 0; i < numZeroCoefficients; i++) {
         toEncode[dataBytes + i] = 0;
     }

         for (size_t i = 0; i < coefficients->size(); i++)
       toEncode[dataBytes + numZeroCoefficients + i] = coefficients[i];
 }

 }