From 3ecb2fa8d8f70ba304738622273a20c9429635af Mon Sep 17 00:00:00 2001
From: favoritas37 <ftylitak@gmail.com>
Date: Sun, 14 Jun 2015 20:50:26 +0300
Subject: [PATCH] completed the first implementation of
 zxing::ReedSolomonEncoder

---
 .../common/reedsolomon/ReedSolomonEncoder.cpp | 64 +++++++++++++++++++
 .../common/reedsolomon/ReedSolomonEncoder.h   | 26 ++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.cpp
 create mode 100644 source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.h

diff --git a/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.cpp b/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.cpp
new file mode 100644
index 0000000..d37f4d8
--- /dev/null
+++ b/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.cpp
@@ -0,0 +1,64 @@
+#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<int> &toEncode, int ecBytes)
+{
+    if (ecBytes == 0) {
+        throw new Exception("No error correction bytes");
+    }
+    int dataBytes = toEncode.size() - ecBytes;
+    if (dataBytes <= 0) {
+        throw new Exception("No data bytes provided");
+    }
+    Ref<GenericGFPoly> generator = buildGenerator(ecBytes);
+    ArrayRef<int> infoCoefficients(dataBytes);
+    memcpy(infoCoefficients.operator ->(), toEncode.data(), dataBytes);
+    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;
+    }
+
+    //original kept for future checks
+    //System.arraycopy(coefficients, 0, toEncode, dataBytes + numZeroCoefficients, coefficients.length);
+    toEncode.insert(toEncode.begin() + dataBytes + numZeroCoefficients,
+                    coefficients.array_->values().begin(),
+                    coefficients.array_->values().end());
+}
+
+}
diff --git a/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.h b/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.h
new file mode 100644
index 0000000..968ad34
--- /dev/null
+++ b/source/zxing/zxing/common/reedsolomon/ReedSolomonEncoder.h
@@ -0,0 +1,26 @@
+#ifndef REEDSOLOMONENCODER_H
+#define REEDSOLOMONENCODER_H
+
+#include <zxing/common/reedsolomon/GenericGFPoly.h>
+#include <zxing/common/reedsolomon/GenericGF.h>
+#include <zxing/common/Array.h>
+
+namespace zxing {
+
+class ReedSolomonEncoder
+{
+private:
+    Ref<GenericGF> field_;
+    std::vector< Ref< GenericGFPoly > >cachedGenerators_;
+
+    Ref<GenericGFPoly> buildGenerator(int degree);
+
+public:
+    ReedSolomonEncoder(Ref<GenericGF> field);
+
+    void encode(std::vector<int>& toEncode, int ecBytes);
+};
+
+}
+
+#endif // REEDSOLOMONENCODER_H