package nom.tam.image.compression.tile.mask;
   
   /*
    * #%L
    * nom.tam FITS library
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    * Copyright (C) 1996 - 2024 nom-tam-fits
    * %%
    * This is free and unencumbered software released into the public domain.
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   * Anyone is free to copy, modify, publish, use, compile, sell, or
   * distribute this software, either in source code form or as a compiled
   * binary, for any purpose, commercial or non-commercial, and by any
   * means.
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   * In jurisdictions that recognize copyright laws, the author or authors
   * of this software dedicate any and all copyright interest in the
   * software to the public domain. We make this dedication for the benefit
   * of the public at large and to the detriment of our heirs and
   * successors. We intend this dedication to be an overt act of
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   * software under copyright law.
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   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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  import java.nio.ByteBuffer;
  import java.nio.DoubleBuffer;
  import java.nio.FloatBuffer;
  import java.nio.IntBuffer;
  import java.nio.LongBuffer;
  import java.nio.ShortBuffer;
  
  import nom.tam.fits.compression.algorithm.api.ICompressorControl;
  import nom.tam.image.tile.operation.buffer.TileBuffer;
  import nom.tam.util.type.ElementType;
  
  /**
   * (<i>for internal use</i>) Preserves blank (<code>null</code>) values in
   * compressed images. This class overwrites the pixels specified in the mask
   * with null values. Where the null value can be defined separately.
   * 
   * @see nom.tam.image.compression.hdu.CompressedImageHDU
   */
  public class NullPixelMaskPreserver extends AbstractNullPixelMask {
  
      /**
       * Creates a new instance for preserving the null values in a specific image
       * tile when compressing the tile.
       * 
       * @param tileBuffer
       *            the buffer containing the serialized tile data (still
       *            uncompressed)
       * @param tileIndex
       *            the sequential tile index
       * @param nullValue
       *            the blank value used in integer type images (this is ignored
       *            for floating-point images where NaN is used always)
       * @param compressorControl
       *            the class that performs the compresion of tiles, and which
       *            will be used to compress the null pixel mask also.
       */
      public NullPixelMaskPreserver(TileBuffer tileBuffer, int tileIndex, long nullValue, ICompressorControl compressorControl) {
          super(tileBuffer, tileIndex, nullValue, compressorControl);
      }
  
      /**
       * Creates a compressed mask to store along with the compressed tile image
       * to indicate where the blanking values appear in in the original image.
       */
      public void preserveNull() {
          if (getTileBuffer().getBaseType().is(ElementType.DOUBLE)) {
              preserveNullDoubles();
          } else if (getTileBuffer().getBaseType().is(ElementType.FLOAT)) {
              preserveNullFloats();
          } else if (getTileBuffer().getBaseType().is(ElementType.LONG)) {
              preserveNullLongs();
          } else if (getTileBuffer().getBaseType().is(ElementType.INT)) {
              preserveNullInts();
          } else if (getTileBuffer().getBaseType().is(ElementType.SHORT)) {
              preserveNullShorts();
          } else if (getTileBuffer().getBaseType().is(ElementType.BYTE)) {
              preserveNullBytes();
          }
          if (getMask() != null) {
              ByteBuffer compressed = ByteBuffer.allocate(getTileBuffer().getPixelSize());
              if (!getCompressorControl().compress(getMask(), compressed, getCompressorControl().option())) {
                  throw new IllegalStateException("could not compress the null pixel mask");
              }
              setMask(compressed);
          }
      }
 
     private void preserveNullBytes() {
         ByteBuffer buffer = (ByteBuffer) getTileBuffer().getBuffer();
         byte nullValue = (byte) getNullValue();
         int size = buffer.remaining();
         for (int index = 0; index < size; index++) {
             if (nullValue == buffer.get(index)) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
     private void preserveNullDoubles() {
         DoubleBuffer buffer = (DoubleBuffer) getTileBuffer().getBuffer();
         int size = getTileBuffer().getPixelSize();
         for (int index = 0; index < size; index++) {
             if (Double.isNaN(buffer.get(index))) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
     private void preserveNullFloats() {
         FloatBuffer buffer = (FloatBuffer) getTileBuffer().getBuffer();
         int size = getTileBuffer().getPixelSize();
         for (int index = 0; index < size; index++) {
             if (Float.isNaN(buffer.get(index))) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
     private void preserveNullInts() {
         IntBuffer buffer = (IntBuffer) getTileBuffer().getBuffer();
         int nullValue = (int) getNullValue();
         int size = getTileBuffer().getPixelSize();
         for (int index = 0; index < size; index++) {
             if (nullValue == buffer.get(index)) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
     private void preserveNullLongs() {
         LongBuffer buffer = (LongBuffer) getTileBuffer().getBuffer();
         long nullValue = getNullValue();
         int size = getTileBuffer().getPixelSize();
         for (int index = 0; index < size; index++) {
             if (nullValue == buffer.get(index)) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
     private void preserveNullShorts() {
         ShortBuffer buffer = (ShortBuffer) getTileBuffer().getBuffer();
         short nullValue = (short) getNullValue();
         int size = getTileBuffer().getPixelSize();
         for (int index = 0; index < size; index++) {
             if (nullValue == buffer.get(index)) {
                 initializedMask(size).put(index, NULL_INDICATOR);
             }
         }
     }
 
 }