/*
    * 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
   * limitations under the License.
   */
  package org.apache.commons.imaging.mylzw;
  
  import java.io.FilterInputStream;
  import java.io.IOException;
  
  import org.apache.commons.imaging.common.Allocator;
  
  public class BitsToByteInputStream extends FilterInputStream {
      private final int desiredDepth;
  
      public BitsToByteInputStream(final MyBitInputStream is, final int desiredDepth) {
          super(is);
          this.desiredDepth = desiredDepth;
      }
  
      @Override
      public int read() throws IOException {
          return readBits(8);
      }
  
      public int readBits(final int bitCount) throws IOException {
          int i = ((MyBitInputStream) in).readBits(bitCount);
          if (bitCount < desiredDepth) {
              i <<= desiredDepth - bitCount;
          } else if (bitCount > desiredDepth) {
              i >>= bitCount - desiredDepth;
          }
  
          return i;
      }
  
      public int[] readBitsArray(final int sampleBits, final int length) throws IOException {
          final int[] result = Allocator.intArray(length);
          for (int i = 0; i < length; i++) {
              result[i] = readBits(sampleBits);
          }
          return result;
      }
  }