/*
 * Copyright © 2021 Mark Raynsford <code@io7m.com> https://www.io7m.com
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

package com.io7m.jcamera;

import com.io7m.jequality.annotations.EqualityReference;
import com.io7m.junreachable.UnreachableCodeException;

/**
 * Implementations of various scaling functions.
 */

@EqualityReference
public final class JCameraScalingFunctions
{
  private static final JCameraScalingFunctionType SCALE_IDENTITY;
  private static final JCameraScalingFunctionType SCALE_SQUARE_ROOT;

  static {
    SCALE_IDENTITY = new JCameraScalingFunctionType()
    {
      @Override
      public double evaluate(
        final double x)
      {
        return x;
      }
    };

    SCALE_SQUARE_ROOT = new JCameraScalingFunctionType()
    {
      @Override
      public double evaluate(
        final double x)
      {
        return Math.sqrt(x);
      }
    };
  }

  private JCameraScalingFunctions()
  {
    throw new UnreachableCodeException();
  }

  /**
   * @return A function that returns the given value.
   */

  public static JCameraScalingFunctionType scaleIdentity()
  {
    return SCALE_IDENTITY;
  }

  /**
   * @return A function that returns the square root of the given value.
   */

  public static JCameraScalingFunctionType scaleSquareRoot()
  {
    return SCALE_SQUARE_ROOT;
  }
}
