/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/img/CImage.h>

namespace mrpt::img
{
/** This class encapsulates a MRPT Image and allows the sampling of individual
 * pixels with sub-pixel accuracy and with a change of coordinates (eg, meters).
 *  Only work with graylevels (for convenience), so if a color image is passed
 * it'll be passed first to grayscale.
 *
 * \sa CImage
 * \ingroup mrpt_img_grp
 */
class CMappedImage
{
 protected:
  CImage::Ptr m_img;
  double m_x0, m_x1, m_y0, m_y1;
  /** width * pixel_size = (x1-x0) */
  double m_pixel_size;
  TInterpolationMethod m_method;

 public:
  /** Constructor: Must pass an image (as a smart pointer) and the coordinates
   * of the border
   * \param img The image. A copy of the smart pointer is kept internally to
   * this object.
   * \param x0 Coordinate X of the left side (default: 0)
   * \param x1 Coordinate X of the right side (or -1 to IMAGE_WIDTH-1)
   * \param y0 Coordinate Y of the top side (default: 0)
   * \param y1 Coordinate Y of the bottom side (or -1 to IMAGE_HEIGHT-1)
   * \param method The interpolation method: It can be imNEAREST, imBILINEAR
   * or imBICUBIC.
   */
  CMappedImage(
      CImage::Ptr img,
      double x0 = 0,
      double x1 = -1,
      double y0 = 0,
      double y1 = -1,
      TInterpolationMethod method = IMG_INTERP_LINEAR);

  /** Changes the coordinates of the image (see constructor for the meaning)
   */
  void changeCoordinates(double x0, double x1, double y0, double y1);

  /** Returns the interpolated pixel at the coordinates (x,y), in the range
   * [0,255] (grayscale)
   *  If the point is out of the image, 0 is returned.
   */
  double getPixel(double x, double y) const;

};  // End of class
}  // namespace mrpt::img
