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-rw-r--r--libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java263
1 files changed, 0 insertions, 263 deletions
diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java
deleted file mode 100644
index 056802287..000000000
--- a/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java
+++ /dev/null
@@ -1,263 +0,0 @@
-/*
- * Copyright 2007 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.
- */
-
-package com.google.zxing.common.reedsolomon;
-
-/**
- * <p>Represents a polynomial whose coefficients are elements of a GF.
- * Instances of this class are immutable.</p>
- *
- * <p>Much credit is due to William Rucklidge since portions of this code are an indirect
- * port of his C++ Reed-Solomon implementation.</p>
- *
- * @author Sean Owen
- */
-final class GenericGFPoly {
-
- private final GenericGF field;
- private final int[] coefficients;
-
- /**
- * @param field the {@link GenericGF} instance representing the field to use
- * to perform computations
- * @param coefficients coefficients as ints representing elements of GF(size), arranged
- * from most significant (highest-power term) coefficient to least significant
- * @throws IllegalArgumentException if argument is null or empty,
- * or if leading coefficient is 0 and this is not a
- * constant polynomial (that is, it is not the monomial "0")
- */
- GenericGFPoly(GenericGF field, int[] coefficients) {
- if (coefficients == null || coefficients.length == 0) {
- throw new IllegalArgumentException();
- }
- this.field = field;
- int coefficientsLength = coefficients.length;
- if (coefficientsLength > 1 && coefficients[0] == 0) {
- // Leading term must be non-zero for anything except the constant polynomial "0"
- int firstNonZero = 1;
- while (firstNonZero < coefficientsLength && coefficients[firstNonZero] == 0) {
- firstNonZero++;
- }
- if (firstNonZero == coefficientsLength) {
- this.coefficients = field.getZero().coefficients;
- } else {
- this.coefficients = new int[coefficientsLength - firstNonZero];
- System.arraycopy(coefficients,
- firstNonZero,
- this.coefficients,
- 0,
- this.coefficients.length);
- }
- } else {
- this.coefficients = coefficients;
- }
- }
-
- int[] getCoefficients() {
- return coefficients;
- }
-
- /**
- * @return degree of this polynomial
- */
- int getDegree() {
- return coefficients.length - 1;
- }
-
- /**
- * @return true iff this polynomial is the monomial "0"
- */
- boolean isZero() {
- return coefficients[0] == 0;
- }
-
- /**
- * @return coefficient of x^degree term in this polynomial
- */
- int getCoefficient(int degree) {
- return coefficients[coefficients.length - 1 - degree];
- }
-
- /**
- * @return evaluation of this polynomial at a given point
- */
- int evaluateAt(int a) {
- if (a == 0) {
- // Just return the x^0 coefficient
- return getCoefficient(0);
- }
- int size = coefficients.length;
- if (a == 1) {
- // Just the sum of the coefficients
- int result = 0;
- for (int i = 0; i < size; i++) {
- result = GenericGF.addOrSubtract(result, coefficients[i]);
- }
- return result;
- }
- int result = coefficients[0];
- for (int i = 1; i < size; i++) {
- result = GenericGF.addOrSubtract(field.multiply(a, result), coefficients[i]);
- }
- return result;
- }
-
- GenericGFPoly addOrSubtract(GenericGFPoly other) {
- if (!field.equals(other.field)) {
- throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field");
- }
- if (isZero()) {
- return other;
- }
- if (other.isZero()) {
- return this;
- }
-
- int[] smallerCoefficients = this.coefficients;
- int[] largerCoefficients = other.coefficients;
- if (smallerCoefficients.length > largerCoefficients.length) {
- int[] temp = smallerCoefficients;
- smallerCoefficients = largerCoefficients;
- largerCoefficients = temp;
- }
- int[] sumDiff = new int[largerCoefficients.length];
- int lengthDiff = largerCoefficients.length - smallerCoefficients.length;
- // Copy high-order terms only found in higher-degree polynomial's coefficients
- System.arraycopy(largerCoefficients, 0, sumDiff, 0, lengthDiff);
-
- for (int i = lengthDiff; i < largerCoefficients.length; i++) {
- sumDiff[i] = GenericGF.addOrSubtract(smallerCoefficients[i - lengthDiff], largerCoefficients[i]);
- }
-
- return new GenericGFPoly(field, sumDiff);
- }
-
- GenericGFPoly multiply(GenericGFPoly other) {
- if (!field.equals(other.field)) {
- throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field");
- }
- if (isZero() || other.isZero()) {
- return field.getZero();
- }
- int[] aCoefficients = this.coefficients;
- int aLength = aCoefficients.length;
- int[] bCoefficients = other.coefficients;
- int bLength = bCoefficients.length;
- int[] product = new int[aLength + bLength - 1];
- for (int i = 0; i < aLength; i++) {
- int aCoeff = aCoefficients[i];
- for (int j = 0; j < bLength; j++) {
- product[i + j] = GenericGF.addOrSubtract(product[i + j],
- field.multiply(aCoeff, bCoefficients[j]));
- }
- }
- return new GenericGFPoly(field, product);
- }
-
- GenericGFPoly multiply(int scalar) {
- if (scalar == 0) {
- return field.getZero();
- }
- if (scalar == 1) {
- return this;
- }
- int size = coefficients.length;
- int[] product = new int[size];
- for (int i = 0; i < size; i++) {
- product[i] = field.multiply(coefficients[i], scalar);
- }
- return new GenericGFPoly(field, product);
- }
-
- GenericGFPoly multiplyByMonomial(int degree, int coefficient) {
- if (degree < 0) {
- throw new IllegalArgumentException();
- }
- if (coefficient == 0) {
- return field.getZero();
- }
- int size = coefficients.length;
- int[] product = new int[size + degree];
- for (int i = 0; i < size; i++) {
- product[i] = field.multiply(coefficients[i], coefficient);
- }
- return new GenericGFPoly(field, product);
- }
-
- GenericGFPoly[] divide(GenericGFPoly other) {
- if (!field.equals(other.field)) {
- throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field");
- }
- if (other.isZero()) {
- throw new IllegalArgumentException("Divide by 0");
- }
-
- GenericGFPoly quotient = field.getZero();
- GenericGFPoly remainder = this;
-
- int denominatorLeadingTerm = other.getCoefficient(other.getDegree());
- int inverseDenominatorLeadingTerm = field.inverse(denominatorLeadingTerm);
-
- while (remainder.getDegree() >= other.getDegree() && !remainder.isZero()) {
- int degreeDifference = remainder.getDegree() - other.getDegree();
- int scale = field.multiply(remainder.getCoefficient(remainder.getDegree()), inverseDenominatorLeadingTerm);
- GenericGFPoly term = other.multiplyByMonomial(degreeDifference, scale);
- GenericGFPoly iterationQuotient = field.buildMonomial(degreeDifference, scale);
- quotient = quotient.addOrSubtract(iterationQuotient);
- remainder = remainder.addOrSubtract(term);
- }
-
- return new GenericGFPoly[] { quotient, remainder };
- }
-
- public String toString() {
- StringBuffer result = new StringBuffer(8 * getDegree());
- for (int degree = getDegree(); degree >= 0; degree--) {
- int coefficient = getCoefficient(degree);
- if (coefficient != 0) {
- if (coefficient < 0) {
- result.append(" - ");
- coefficient = -coefficient;
- } else {
- if (result.length() > 0) {
- result.append(" + ");
- }
- }
- if (degree == 0 || coefficient != 1) {
- int alphaPower = field.log(coefficient);
- if (alphaPower == 0) {
- result.append('1');
- } else if (alphaPower == 1) {
- result.append('a');
- } else {
- result.append("a^");
- result.append(alphaPower);
- }
- }
- if (degree != 0) {
- if (degree == 1) {
- result.append('x');
- } else {
- result.append("x^");
- result.append(degree);
- }
- }
- }
- }
- return result.toString();
- }
-
-}