source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Transforms/CoordinateTransform.cs @ 13792

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using Microsoft.Research.DynamicDataDisplay.Common;
using System.Diagnostics;
using System.Windows.Media;

namespace Microsoft.Research.DynamicDataDisplay
{
  /// <summary>
  /// A central class in 2d coordinate transformation in DynamicDataDisplay.
  /// Provides methods to transform point from one coordinate system to another.
  /// Should be immutable.
  /// </summary>
  public sealed class CoordinateTransform
  {
    private CoordinateTransform(DataRect visibleRect, Rect screenRect)
    {
      this.visibleRect = visibleRect;
      this.screenRect = screenRect;

      rxToScreen = screenRect.Width / visibleRect.Width;
      ryToScreen = screenRect.Height / visibleRect.Height;
      cxToScreen = visibleRect.XMin * rxToScreen - screenRect.Left;
      cyToScreen = screenRect.Height + screenRect.Top + visibleRect.YMin * ryToScreen;

      rxToData = visibleRect.Width / screenRect.Width;
      ryToData = visibleRect.Height / screenRect.Height;
      cxToData = screenRect.Left * rxToData - visibleRect.XMin;
      cyToData = visibleRect.Height + visibleRect.YMin + screenRect.Top * ryToData;
    }

    #region Coeffs
    double rxToScreen;
    double ryToScreen;
    double cxToScreen;
    double cyToScreen;

    double rxToData;
    double ryToData;
    double cxToData;
    double cyToData;
    #endregion

    #region Creation methods

    /// <summary>
    /// Creates CoordinateTransform fro specified rectangles and with Identity transform.
    /// </summary>
    /// <param name="visibleRect">The visible rect.</param>
    /// <param name="screenRect">The screen rect.</param>
    /// <returns></returns>
    public static CoordinateTransform FromRects(DataRect visibleRect, Rect screenRect)
    {
      CoordinateTransform result = new CoordinateTransform(visibleRect, screenRect);
      return result;
    }

    /// <summary>
    /// Closnes transform with current dataTransform and specified rectangles.
    /// </summary>
    /// <param name="visibleRect">The visible rect.</param>
    /// <param name="screenRect">The screen rect.</param>
    /// <returns></returns>
    public CoordinateTransform WithRects(DataRect visibleRect, Rect screenRect)
    {
      CoordinateTransform copy = new CoordinateTransform(visibleRect, screenRect);
      copy.dataTransform = dataTransform;
      return copy;
    }

    /// <summary>
    /// Creates a new instance of CoordinateTransform with the given data transform.
    /// </summary>
    /// <param name="dataTransform">The data transform.</param>
    /// <returns></returns>
    public CoordinateTransform WithDataTransform(DataTransform dataTransform)
    {
      if (dataTransform == null)
        throw new ArgumentNullException("dataTransform");

      CoordinateTransform copy = new CoordinateTransform(visibleRect, screenRect);
      copy.dataTransform = dataTransform;
      return copy;
    }

    internal CoordinateTransform WithScreenOffset(double x, double y)
    {
      Rect screenCopy = screenRect;
      screenCopy.Offset(x, y);
      CoordinateTransform copy = new CoordinateTransform(visibleRect, screenCopy);
      return copy;
    }

    internal static CoordinateTransform CreateDefault()
    {
      CoordinateTransform transform = new CoordinateTransform(new Rect(0, 0, 1, 1), new Rect(0, 0, 1, 1));

      return transform;
    }

    #endregion

    #region Transform methods

    /// <summary>
    /// Transforms point from data coordinates to screen.
    /// </summary>
    /// <param name="dataPoint">The point in data coordinates.</param>
    /// <returns></returns>
    public Point DataToScreen(Point dataPoint)
    {
      Point viewportPoint = dataTransform.DataToViewport(dataPoint);

      Point screenPoint = new Point(viewportPoint.X * rxToScreen - cxToScreen,
        cyToScreen - viewportPoint.Y * ryToScreen);

      return screenPoint;
    }

    /// <summary>
    /// Transforms point from screen coordinates to data coordinates.
    /// </summary>
    /// <param name="screenPoint">The point in screen coordinates.</param>
    /// <returns></returns>
    public Point ScreenToData(Point screenPoint)
    {
      Point viewportPoint = new Point(screenPoint.X * rxToData - cxToData,
        cyToData - screenPoint.Y * ryToData);

      Point dataPoint = dataTransform.ViewportToData(viewportPoint);

      return dataPoint;
    }

    /// <summary>
    /// Transforms point from viewport coordinates to screen coordinates.
    /// </summary>
    /// <param name="viewportPoint">The point in viewport coordinates.</param>
    /// <returns></returns>
    public Point ViewportToScreen(Point viewportPoint)
    {
      Point screenPoint = new Point(viewportPoint.X * rxToScreen - cxToScreen,
        cyToScreen - viewportPoint.Y * ryToScreen);

      return screenPoint;
    }

    /// <summary>
    /// Transforms point from screen coordinates to viewport coordinates.
    /// </summary>
    /// <param name="screenPoint">The point in screen coordinates.</param>
    /// <returns></returns>
    public Point ScreenToViewport(Point screenPoint)
    {
      Point viewportPoint = new Point(screenPoint.X * rxToData - cxToData,
        cyToData - screenPoint.Y * ryToData);

      return viewportPoint;
    }

    #endregion

    [DebuggerBrowsable(DebuggerBrowsableState.Never)]
    private DataRect visibleRect;
    /// <summary>
    /// Gets the viewport rectangle.
    /// </summary>
    /// <value>The viewport rect.</value>
    public DataRect ViewportRect
    {
      get { return visibleRect; }
    }

    [DebuggerBrowsable(DebuggerBrowsableState.Never)]
    private Rect screenRect;
    /// <summary>
    /// Gets the screen rectangle.
    /// </summary>
    /// <value>The screen rect.</value>
    public Rect ScreenRect
    {
      get { return screenRect; }
    }

    [DebuggerBrowsable(DebuggerBrowsableState.Never)]
    private DataTransform dataTransform = DataTransforms.Identity;
    /// <summary>
    /// Gets the data transform.
    /// </summary>
    /// <value>The data transform.</value>
    public DataTransform DataTransform
    {
      get { return dataTransform; }
    }
  }
}