添加项目文件。

zxing.core/xx/pdf417/decoder/ec/ModulusGF.cs

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+/*
+ * Copyright 2012 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.
+ */
+
+using System;
+
+namespace ZXing.PDF417.Internal.EC
+{
+   /// <summary>
+   /// <p>A field based on powers of a generator integer, modulo some modulus.</p>
+   /// @see com.google.zxing.common.reedsolomon.GenericGF
+   /// </summary>
+   /// <author>Sean Owen</author>
+   internal sealed class ModulusGF
+   {
+      public static ModulusGF PDF417_GF = new ModulusGF(PDF417Common.NUMBER_OF_CODEWORDS, 3);
+
+      private readonly int[] expTable;
+      private readonly int[] logTable;
+      public ModulusPoly Zero { get; private set; }
+      public ModulusPoly One { get; private set; }
+      private readonly int modulus;
+
+      public ModulusGF(int modulus, int generator)
+      {
+         this.modulus = modulus;
+         expTable = new int[modulus];
+         logTable = new int[modulus];
+         int x = 1;
+         for (int i = 0; i < modulus; i++)
+         {
+            expTable[i] = x;
+            x = (x * generator) % modulus;
+         }
+         for (int i = 0; i < modulus - 1; i++)
+         {
+            logTable[expTable[i]] = i;
+         }
+         // logTable[0] == 0 but this should never be used
+         Zero = new ModulusPoly(this, new int[] {0});
+         One = new ModulusPoly(this, new int[] {1});
+      }
+
+      internal ModulusPoly buildMonomial(int degree, int coefficient)
+      {
+         if (degree < 0)
+         {
+            throw new ArgumentException();
+         }
+         if (coefficient == 0)
+         {
+            return Zero;
+         }
+         int[] coefficients = new int[degree + 1];
+         coefficients[0] = coefficient;
+         return new ModulusPoly(this, coefficients);
+      }
+
+      internal int add(int a, int b)
+      {
+         return (a + b)%modulus;
+      }
+
+      internal int subtract(int a, int b)
+      {
+         return (modulus + a - b)%modulus;
+      }
+
+      internal int exp(int a)
+      {
+         return expTable[a];
+      }
+
+      internal int log(int a)
+      {
+         if (a == 0)
+         {
+            throw new ArgumentException();
+         }
+         return logTable[a];
+      }
+
+      internal int inverse(int a)
+      {
+         if (a == 0)
+         {
+            throw new ArithmeticException();
+         }
+         return expTable[modulus - logTable[a] - 1];
+      }
+
+      internal int multiply(int a, int b)
+      {
+         if (a == 0 || b == 0)
+         {
+            return 0;
+         }
+         return expTable[(logTable[a] + logTable[b]) % (modulus - 1)];
+      }
+
+      internal int Size
+      {
+         get
+         {
+            return modulus;
+         }
+      }
+   }
+}