/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
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package org.apache.lucene.geo;

import org.apache.lucene.util.NumericUtils;


reusable cartesian geometry encoding methods
@lucene.internal
/** * reusable cartesian geometry encoding methods * * @lucene.internal */
public final class XYEncodingUtils { public static final double MIN_VAL_INCL = -Float.MAX_VALUE; public static final double MAX_VAL_INCL = Float.MAX_VALUE; // No instance: private XYEncodingUtils() { }
validates value is a number and finite
/** validates value is a number and finite */
static float checkVal(float x) { if (Float.isFinite(x) == false) { throw new IllegalArgumentException("invalid value " + x + "; must be between " + MIN_VAL_INCL + " and " + MAX_VAL_INCL); } return x; }
Quantizes double (64 bit) values into 32 bits
Params:
  • x – cartesian value
Throws:
Returns:encoded value as a 32-bit int
/** * Quantizes double (64 bit) values into 32 bits * @param x cartesian value * @return encoded value as a 32-bit {@code int} * @throws IllegalArgumentException if value is out of bounds */
public static int encode(float x) { return NumericUtils.floatToSortableInt(checkVal(x)); }
Turns quantized value from encode back into a double.
Params:
  • encoded – encoded value: 32-bit quantized value.
Returns:decoded value value.
/** * Turns quantized value from {@link #encode} back into a double. * @param encoded encoded value: 32-bit quantized value. * @return decoded value value. */
public static float decode(int encoded) { float result = NumericUtils.sortableIntToFloat(encoded); assert result >= MIN_VAL_INCL && result <= MAX_VAL_INCL; return result; }
Turns quantized value from byte array back into a double.
Params:
  • src – byte array containing 4 bytes to decode at offset
  • offset – offset into src to decode from.
Returns:decoded value.
/** * Turns quantized value from byte array back into a double. * @param src byte array containing 4 bytes to decode at {@code offset} * @param offset offset into {@code src} to decode from. * @return decoded value. */
public static float decode(byte[] src, int offset) { return decode(NumericUtils.sortableBytesToInt(src, offset)); } static double[] floatArrayToDoubleArray(float[] f) { double[] d = new double[f.length]; for (int i = 0; i < f.length; i++) { d[i] = f[i]; } return d; } }