/*
    * 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.formats.tiff;
  
  import java.util.stream.IntStream;
  
  import org.apache.commons.imaging.common.Allocator;
  
  /**
   * Provides a simple container for floating-point data. Some TIFF files are used to store floating-point data rather than images. This class is intended to
   * support access to those TIFF files.
   * <p>
   * <strong>Note:</strong> The getData() and getIntData() methods can return direct references to the internal arrays stored in instances of this class. Because
   * these are not safe copies of the data, an application that modified the arrays returned by these methods will change the content of the associated instance.
   * This approach is used for purposes of efficiency when dealing with very large TIFF images.
   * <p>
   * <strong>Data layout:</strong> The elements in the returned array are stored in row-major order. In cases where the data contains multiple samples per raster
   * cell (pixel), the data is organized into blocks of data one sample at a time. The first block contains width*height values for the first sample for each
   * cell, the second block contains width*height values for the second sample for each cell, etc. Thus, the array index for a particular value is computed as
   *
   * <pre>
   * index = y * width + x + iSample * width * height;
   * </pre>
   */
  public final class TiffRasterDataFloat extends AbstractTiffRasterData {
  
      private final float[] data;
  
      /**
       * Constructs an instance allocating memory for the specified dimensions.
       *
       * @param width  a value of 1 or greater
       * @param height a value of 1 or greater
       */
      public TiffRasterDataFloat(final int width, final int height) {
          super(width, height, 1);
          data = Allocator.floatArray(nCells);
      }
  
      /**
       * Constructs an instance allocating memory for the specified dimensions.
       *
       * @param width  a value of 1 or greater
       * @param height a value of 1 or greater
       * @param data   the data to be stored in the raster.
       */
      public TiffRasterDataFloat(final int width, final int height, final float[] data) {
          super(width, height, 1);
          if (data == null || data.length < nCells) {
              throw new IllegalArgumentException("Specified data does not contain sufficient elements");
          }
          this.data = data;
      }
  
      /**
       * Constructs an instance allocating memory for the specified dimensions.
       *
       * @param width           a value of 1 or greater
       * @param height          a value of 1 or greater
       * @param samplesPerPixel a value of 1 or greater
       */
      public TiffRasterDataFloat(final int width, final int height, final int samplesPerPixel) {
          super(width, height, samplesPerPixel);
          data = Allocator.floatArray(nCells);
      }
  
      /**
       * Constructs an instance allocating memory for the specified dimensions.
       *
       * @param width          a value of 1 or greater
       * @param height         a value of 1 or greater
       * @param samplesPerCell the number of samples per pixel
       * @param data           the data to be stored in the raster.
       */
      public TiffRasterDataFloat(final int width, final int height, final int samplesPerCell, final float[] data) {
          super(width, height, samplesPerCell);
          if (data == null || data.length < nCells) {
              throw new IllegalArgumentException("Specified data does not contain sufficient elements");
          }
          this.data = data;
      }
  
      /**
       * Returns a reference to the data array stored in this instance. Note that the array returned is <strong>not</strong> a safe copy and that modifying it
       * directly affects the content of the instance. While this design approach carries some risk in terms of data security, it was chosen for reasons of
      * performance and memory conservation. TIFF images that contain floating-point data are often quite large. Sizes of 100 million raster cells are common.
      * Making a redundant copy of such a large in-memory object might exceed the resources available to a Java application.
      * <p>
      * See the class API documentation above for notes on accessing array elements.
      *
      * @return a direct reference to the data array stored in this instance.
      */
     @Override
     public float[] getData() {
         return data;
     }
 
     /**
      * Gets the raster data type from the instance.
      *
      * @return a value of TiffRasterDataType&#46;FLOAT.
      */
     @Override
     public TiffRasterDataType getDataType() {
         return TiffRasterDataType.FLOAT;
     }
 
     /**
      * Returns an array of integer approximations for the floating-point content stored as an array in this instance.
      * <p>
      * See the class API documentation above for notes on accessing array elements.
      *
      * @return the integer equivalents to the data content stored in this instance.
      */
     @Override
     public int[] getIntData() {
         return IntStream.range(0, nCells).map(i -> (int) data[i]).toArray();
     }
 
     /**
      * Gets the value stored at the specified raster coordinates.
      *
      * @param x integer coordinate in the columnar direction
      * @param y integer coordinate in the row direction
      * @return the value stored at the specified location
      */
     @Override
     public int getIntValue(final int x, final int y) {
         return (int) data[checkCoordinatesAndComputeIndex(x, y, 0)];
     }
 
     /**
      * Gets the value stored at the specified raster coordinates.
      *
      * @param x integer coordinate in the columnar direction
      * @param y integer coordinate in the row direction
      * @param i integer sample index (for data sets giving multiple samples per raster cell).
      * @return the value stored at the specified location
      */
     @Override
     public int getIntValue(final int x, final int y, final int i) {
         return (int) data[checkCoordinatesAndComputeIndex(x, y, 0)];
     }
 
     /**
      * Tabulates simple statistics for the raster and returns an instance containing general metadata.
      *
      * @return a valid instance containing a safe copy of the current simple statistics for the raster.
      */
     @Override
     public TiffRasterStatistics getSimpleStatistics() {
         return new TiffRasterStatistics(this, Float.NaN);
     }
 
     /**
      * Tabulates simple statistics for the raster excluding the specified value and returns an instance containing general metadata.
      *
      * @param valueToExclude exclude samples with this specified value.
      * @return a valid instance.
      */
     @Override
     public TiffRasterStatistics getSimpleStatistics(final float valueToExclude) {
         return new TiffRasterStatistics(this, valueToExclude);
     }
 
     /**
      * Gets the value stored at the specified raster coordinates.
      *
      * @param x integer coordinate in the columnar direction
      * @param y integer coordinate in the row direction
      * @return the value stored at the specified location; potentially a Float&#46;NaN.
      */
     @Override
     public float getValue(final int x, final int y) {
         return data[checkCoordinatesAndComputeIndex(x, y, 0)];
     }
 
     /**
      * Gets the value stored at the specified raster coordinates.
      *
      * @param x integer coordinate in the columnar direction
      * @param y integer coordinate in the row direction
      * @param i integer sample index (for data sets giving multiple samples per raster cell).
      * @return the value stored at the specified location; potentially a Float&#46;NaN.
      */
     @Override
     public float getValue(final int x, final int y, final int i) {
         return data[checkCoordinatesAndComputeIndex(x, y, i)];
     }
 
     /**
      * Sets the value stored at the specified raster coordinates.
      *
      * @param x     integer coordinate in the columnar direction
      * @param y     integer coordinate in the row direction
      * @param value the value to be stored at the specified location
      */
     @Override
     public void setIntValue(final int x, final int y, final int value) {
         data[checkCoordinatesAndComputeIndex(x, y, 0)] = value;
     }
 
     /**
      * Sets the value stored at the specified raster coordinates.
      *
      * @param x     integer coordinate in the columnar direction
      * @param y     integer coordinate in the row direction
      * @param i     integer sample index (for data sets giving multiple samples per raster cell).
      * @param value the value to be stored at the specified location
      */
     @Override
     public void setIntValue(final int x, final int y, final int i, final int value) {
         data[checkCoordinatesAndComputeIndex(x, y, 0)] = value;
     }
 
     /**
      * Sets the value stored at the specified raster coordinates.
      *
      * @param x     integer coordinate in the columnar direction
      * @param y     integer coordinate in the row direction
      * @param value the value to be stored at the specified location; potentially a Float&#46;NaN.
      */
     @Override
     public void setValue(final int x, final int y, final float value) {
         data[checkCoordinatesAndComputeIndex(x, y, 0)] = value;
     }
 
     /**
      * Sets the value stored at the specified raster coordinates.
      *
      * @param x     integer coordinate in the columnar direction
      * @param y     integer coordinate in the row direction
      * @param i     integer sample index (for data sets giving multiple samples per raster cell).
      * @param value the value to be stored at the specified location; potentially a Float&#46;NaN.
      */
     @Override
     public void setValue(final int x, final int y, final int i, final float value) {
         data[checkCoordinatesAndComputeIndex(x, y, i)] = value;
     }
 
 }