create log and antilog tables for Finite Field Calculations

diff --git a/qrgenerator.cpp b/qrgenerator.cpp
index f5ff5ae2246d016fbe2fc88c5185f8df26c05f08..29fb91b363a4351af27be265303428be2073b689 100644 (file)
--- a/qrgenerator.cpp
+++ b/qrgenerator.cpp
@@ -113,6 +113,50 @@ int main() {
                std::cout << i;
                k++;
        }
+       std::cout << std::endl;
+
+       /* Table 9: V1 QR code M-level Error Correction:
+        * Total Number of Codewords: 26
+        * Number of error correction codewords: 10
+        * value of p = 2
+        * Number of error correction blocks: 1
+        * Error correction doe per block: (c,k,r)^a = (26,16,4)^b
+        * Thus only one block for data codewords
+               */
+       
+       // Reed-Solomon Error Correction
+       //std::vector<bool> primitive = {1,0,0,0,1,1,1,0,1};
+       unsigned int primitive = 0b100011101;
+       std::cout << "Primitive: " << primitive << std::endl;
+       //unsigned int log_table[255]{}, antilog_table[510]{};
+       std::vector<unsigned int> log_table, antilog_table(510,0);
+
+
+       std::cout << "Log table: ";
+       for (unsigned int i{0}; i < 255; ++i){
+               if (i == 0){
+                       log_table.push_back(1);
+               }
+               else if (log_table[i-1] * 2 > 255){
+                       log_table.push_back((log_table[i-1] * 2) ^ primitive);
+               }
+               else {
+                       log_table.push_back((log_table[i-1] * 2));
+               }
+               std::cout << log_table[i] << " ";
+       }
+       std::cout << std::endl;
+
+       std::cout << "Antilog table: ";
+       for (unsigned int i{0}; i < 255; ++i){
+               antilog_table[log_table[i]] = i;
+               antilog_table[510-log_table[i]-1] = i;
+       }
+       for (unsigned int i{0}; i < 510;++i){
+               std::cout << antilog_table[i] << " ";
+       }
+
+       std::cout << std::endl;
 
        return 0;