/*
 * This file is part of ELKI:
 * Environment for Developing KDD-Applications Supported by Index-Structures
 *
 * Copyright (C) 2022
 * ELKI Development Team
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package elki.visualization.projections;

import elki.data.NumberVector;
import elki.math.scales.LinearScale;

/**
 * Projection to parallel coordinates that allows reordering and inversion of
 * axes.
 * 
 * Note: when using this projection, pay attention to the two different schemes
 * of dimension numbering: by input dimension and by axis position.
 * 
 * @author Robert Rödler
 * @author Erich Schubert
 * @since 0.5.0
 */
public interface ProjectionParallel extends Projection {
  /**
   * Get inversion flag of axis.
   * 
   * @param axis Axis (reordered) position
   * @return Inversion flag
   */
  boolean isAxisInverted(int axis);

  /**
   * Set inversion flag of axis.
   * 
   * @param axis Axis (reordered) position
   * @param bool Value of inversion flag
   */
  void setAxisInverted(int axis, boolean bool);

  /**
   * Toggle inverted flag of axis.
   * 
   * @param axis Axis (reordered) position
   */
  void toggleAxisInverted(int axis);

  /**
   * Get inversion flag of dimension.
   * 
   * @param truedim Dimension in original numbering
   * @return Inversion flag
   */
  boolean isDimInverted(int truedim);

  /**
   * Set inversion flag of a dimension.
   * 
   * @param truedim Dimension in original numbering
   * @param bool Value of inversion flag
   */
  void setDimInverted(int truedim, boolean bool);

  /**
   * Toggle inverted flag of dimension.
   * 
   * @param truedim Dimension in original numbering
   */
  void toggleDimInverted(int truedim);

  /**
   * Get scale for the given axis
   * 
   * @param axis Axis (reordered) position
   * @return Axis scale
   */
  LinearScale getAxisScale(int axis);

  /**
   * Test whether the current axis is visible
   * 
   * @param axis Axis (reordered) position
   * @return Visibility of axis
   */
  boolean isAxisVisible(int axis);

  /**
   * Set the visibility of the axis.
   * 
   * @param axis Axis number
   * @param vis Visibility status
   */
  void setAxisVisible(int axis, boolean vis);

  /**
   * Toggle visibility of the axis.
   * 
   * @param axis Axis number
   */
  void toggleAxisVisible(int axis);

  /**
   * Get the number of visible dimension.
   * 
   * @return Number of visible dimensions
   */
  int getVisibleDimensions();

  /**
   * Exchange axes A and B
   * @param a First axis
   * @param b Second axis
   */
  void swapAxes(int a, int b);

  /**
   * shift a dimension to another position
   * 
   * @param axis axis to shift
   * @param rn new position
   */
  void moveAxis(int axis, int rn);

  /**
   * Get the dimension for the given axis number
   * 
   * @param axis Axis number
   * @return Dimension
   */
  int getDimForAxis(int axis);

  /**
   * Get the dimension for the given visible axis
   * 
   * @param axis Axis number (visible axes only)
   * @return Dimension
   */
  int getDimForVisibleAxis(int axis);

  /**
   * Fast project a vector from data to render space
   * 
   * @param v Input vector
   * @return Vector with reordering, inversions and scales applied.
   */
  double[] fastProjectDataToRenderSpace(double[] v);

  /**
   * Fast project a vector from data to render space
   * 
   * @param v Input vector
   * @return Vector with reordering, inversions and scales applied.
   */
  double[] fastProjectDataToRenderSpace(NumberVector v);

  /**
   * Project the value of a single axis to its display value
   * 
   * @param value Input value
   * @param axis Axis to use for scaling and inversion
   * @return Transformed value
   */
  double fastProjectDataToRenderSpace(double value, int axis);

  /**
   * Project a display value back to the original data space
   * 
   * @param value transformed value
   * @param axis Axis to use for scaling and inversion
   * @return Original value
   */
  double fastProjectRenderToDataSpace(double value, int axis);

  /**
   * Find the axis assigned to the given dimension.
   * 
   * @param truedim Dimension
   * @return Axis number
   */
  int getAxisForDim(int truedim);
}