A flexible charting library for .NET

//============================================================================
//ZedGraph Class Library - A Flexible Line Graph/Bar Graph Library in C#
//Copyright (C) 2004  John Champion
//
//This library is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public
//License as published by the Free Software Foundation; either
//version 2.1 of the License, or (at your option) any later version.
//
//This library 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
//Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public
//License along with this library; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//=============================================================================

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.Serialization;
using System.Security.Permissions;

namespace ZedGraph
{
	/// <summary>
	/// A class representing all the characteristics of the Line
	/// segments that make up a curve on the graph.
	/// </summary>
	/// 
	/// <author> John Champion </author>
	/// <version> $Revision: 3.22 $ $Date: 2006/03/09 06:13:13 $ </version>
	[Serializable]
	public class Line : ICloneable, ISerializable
	{
	#region Fields
		/// <summary>
		/// Private field that stores the pen width for this
		/// <see cref="Line"/>.  Use the public
		/// property <see cref="Width"/> to access this value.
		/// </summary>
		private float width;
		/// <summary>
		/// Private field that stores the <see cref="DashStyle"/> for this
		/// <see cref="Line"/>.  Use the public
		/// property <see cref="Style"/> to access this value.
		/// </summary>
		private DashStyle style;
		/// <summary>
		/// Private field that stores the visibility of this
		/// <see cref="Line"/>.  Use the public
		/// property <see cref="IsVisible"/> to access this value.
		/// </summary>
		private bool isVisible;
		/// <summary>
		/// Private field that stores the smoothing flag for this
		/// <see cref="Line"/>.  Use the public
		/// property <see cref="IsSmooth"/> to access this value.
		/// </summary>
		private bool isSmooth;
		/// <summary>
		/// Private field that stores the smoothing tension
		/// for this <see cref="Line"/>.  Use the public property
		/// <see cref="SmoothTension"/> to access this value.
		/// </summary>
		/// <value>A floating point value indicating the level of smoothing.
		/// 0.0F for no smoothing, 1.0F for lots of smoothing, >1.0 for odd
		/// smoothing.</value>
		/// <seealso cref="IsSmooth"/>
		/// <seealso cref="Default.IsSmooth"/>
		/// <seealso cref="Default.SmoothTension"/>
		private float smoothTension;
		/// <summary>
		/// Private field that stores the color of this
		/// <see cref="Line"/>.  Use the public
		/// property <see cref="Color"/> to access this value.  If this value is
		/// false, the line will not be shown (but the <see cref="Symbol"/> may
		/// still be shown).
		/// </summary>
		private Color color;
		/// <summary>
		/// Private field that stores the <see cref="ZedGraph.StepType"/> for this
		/// <see cref="CurveItem"/>.  Use the public
		/// property <see cref="StepType"/> to access this value.
		/// </summary>
		private StepType	stepType;
		/// <summary>
		/// Private field that stores the <see cref="ZedGraph.Fill"/> data for this
		/// <see cref="Line"/>.  Use the public property <see cref="Fill"/> to
		/// access this value.
		/// </summary>
		private Fill		fill;

	#endregion
	
	#region Defaults
		/// <summary>
		/// A simple struct that defines the
		/// default property values for the <see cref="Line"/> class.
		/// </summary>
		public struct Default
		{
			// Default Line properties
			/// <summary>
			/// The default color for curves (line segments connecting the points).
			/// This is the default value for the <see cref="Line.Color"/> property.
			/// </summary>
			public static Color Color = Color.Red;
			/// <summary>
			/// The default color for filling in the area under the curve
			/// (<see cref="ZedGraph.Fill.Color"/> property).
			/// </summary>
			public static Color FillColor = Color.Red;
			/// <summary>
			/// The default custom brush for filling in the area under the curve
			/// (<see cref="ZedGraph.Fill.Brush"/> property).
			/// </summary>
			public static Brush FillBrush = null;
			/// <summary>
			/// The default fill mode for the curve (<see cref="ZedGraph.Fill.Type"/> property).
			/// </summary>
			public static FillType FillType = FillType.None;
			/// <summary>
			/// The default mode for displaying line segments (<see cref="Line.IsVisible"/>
			/// property).  True to show the line segments, false to hide them.
			/// </summary>
			public static bool IsVisible = true;
			/// <summary>
			/// The default width for line segments (<see cref="Line.Width"/> property).
            /// Units are points (1/72 inch).
            /// </summary>
			public static float Width = 1;
			/// <summary>
			/// The default value for the <see cref="Line.IsSmooth"/>
			/// property.
			/// </summary>
			public static bool IsSmooth = false;
			/// <summary>
			/// The default value for the <see cref="Line.SmoothTension"/> property.
			/// </summary>
			public static float SmoothTension = 0.5F;
			/// <summary>
			/// The default drawing style for line segments (<see cref="Line.Style"/> property).
			/// This is defined with the <see cref="DashStyle"/> enumeration.
			/// </summary>
			public static DashStyle Style = DashStyle.Solid;
			/// <summary>
			/// Default value for the curve type property
			/// (<see cref="Line.StepType"/>).  This determines if the curve
			/// will be drawn by directly connecting the points from the
			/// <see cref="CurveItem.Points"/> data collection,
			/// or if the curve will be a "stair-step" in which the points are
			/// connected by a series of horizontal and vertical lines that
			/// represent discrete, staticant values.  Note that the values can
			/// be forward oriented <code>ForwardStep</code> (<see cref="StepType"/>) or
			/// rearward oriented <code>RearwardStep</code>.
			/// That is, the points are defined at the beginning or end
			/// of the staticant value for which they apply, respectively.
			/// </summary>
			/// <value><see cref="StepType"/> enum value</value>
			public static StepType StepType = StepType.NonStep;
		}
	#endregion

	#region Properties
		/// <summary>
		/// The color of the <see cref="Line"/>
		/// </summary>
		/// <seealso cref="Default.Color"/>
		public Color Color
		{
			get { return color; }
			set { color = value; }
		}
		/// <summary>
		/// The style of the <see cref="Line"/>, defined as a <see cref="DashStyle"/> enum.
		/// This allows the line to be solid, dashed, or dotted.
		/// </summary>
		/// <seealso cref="Default.Style"/>
		public DashStyle Style
		{
			get { return style; }
			set { style = value;}
		}
		/// <summary>
        /// The pen width used to draw the <see cref="Line"/>, in points (1/72 inch)
        /// </summary>
		/// <seealso cref="Default.Width"/>
		public float Width
		{
			get { return width; }
			set { width = value; }
		}
		/// <summary>
		/// Gets or sets a property that shows or hides the <see cref="Line"/>.
		/// </summary>
		/// <value>true to show the line, false to hide it</value>
		/// <seealso cref="Default.IsVisible"/>
		public bool IsVisible
		{
			get { return isVisible; }
			set { isVisible = value; }
		}
		/// <summary>
		/// Gets or sets a property that determines if this <see cref="Line"/>
		/// will be drawn smooth.  The "smoothness" is controlled by
		/// the <see cref="SmoothTension"/> property.
		/// </summary>
		/// <value>true to smooth the line, false to just connect the dots
		/// with linear segments</value>
		/// <seealso cref="SmoothTension"/>
		/// <seealso cref="Default.IsSmooth"/>
		/// <seealso cref="Default.SmoothTension"/>
		public bool IsSmooth
		{
			get { return isSmooth; }
			set { isSmooth = value; }
		}
		/// <summary>
		/// Gets or sets a property that determines the smoothing tension
		/// for this <see cref="Line"/>.  This property is only used if
		/// <see cref="IsSmooth"/> is true.  A tension value 0.0 will just
		/// draw ordinary line segments like an unsmoothed line.  A tension
		/// value of 1.0 will be smooth.  Values greater than 1.0 will generally
		/// give odd results.
		/// </summary>
		/// <value>A floating point value indicating the level of smoothing.
		/// 0.0F for no smoothing, 1.0F for lots of smoothing, >1.0 for odd
		/// smoothing.</value>
		/// <seealso cref="IsSmooth"/>
		/// <seealso cref="Default.IsSmooth"/>
		/// <seealso cref="Default.SmoothTension"/>
		public float SmoothTension
		{
			get { return smoothTension; }
			set { smoothTension = value; }
		}
		/// <summary>
		/// Determines if the <see cref="CurveItem"/> will be drawn by directly connecting the
		/// points from the <see cref="CurveItem.Points"/> data collection,
		/// or if the curve will be a "stair-step" in which the points are
		/// connected by a series of horizontal and vertical lines that
		/// represent discrete, constant values.  Note that the values can
		/// be forward oriented <c>ForwardStep</c> (<see cref="ZedGraph.StepType"/>) or
		/// rearward oriented <c>RearwardStep</c>.
		/// That is, the points are defined at the beginning or end
		/// of the constant value for which they apply, respectively.
		/// The <see cref="StepType"/> property is ignored for lines
		/// that have <see cref="IsSmooth"/> set to true.
		/// </summary>
		/// <value><see cref="ZedGraph.StepType"/> enum value</value>
		/// <seealso cref="Default.StepType"/>
		public StepType StepType
		{
			get { return stepType; }
			set { stepType = value;}
		}

		/// <summary>
		/// Gets or sets the <see cref="ZedGraph.Fill"/> data for this
		/// <see cref="Line"/>.
		/// </summary>
		public Fill	Fill
		{
			get { return fill; }
			set { fill = value; }
		}

	#endregion
	
	#region Constructors
		/// <summary>
		/// Default constructor that sets all <see cref="Line"/> properties to default
		/// values as defined in the <see cref="Default"/> class.
		/// </summary>
		public Line() : this( Color.Empty )
		{
		}

		/// <summary>
		/// Constructor that sets the color property to the specified value, and sets
		/// the remaining <see cref="Line"/> properties to default
		/// values as defined in the <see cref="Default"/> class.
		/// </summary>
		/// <param name="color">The color to assign to this new Line object</param>
		public Line( Color color )
		{
			this.width = Default.Width;
			this.style = Default.Style;
			this.isVisible = Default.IsVisible;
			this.color = color.IsEmpty ? Default.Color : color;
			this.stepType = Default.StepType;
			this.isSmooth = Default.IsSmooth;
			this.smoothTension = Default.SmoothTension;
			this.fill = new Fill( Default.FillColor, Default.FillBrush, Default.FillType );
		}

		/// <summary>
		/// The Copy Constructor
		/// </summary>
		/// <param name="rhs">The Line object from which to copy</param>
		public Line( Line rhs )
		{
			width = rhs.Width;
			style = rhs.Style;
			isVisible = rhs.IsVisible;
			color = rhs.Color;
			stepType = rhs.StepType;
			isSmooth = rhs.IsSmooth;
			smoothTension = rhs.SmoothTension;
			fill = rhs.Fill.Clone();
		}

		/// <summary>
		/// Implement the <see cref="ICloneable" /> interface in a typesafe manner by just
		/// calling the typed version of <see cref="Clone" />
		/// </summary>
		/// <returns>A deep copy of this object</returns>
		object ICloneable.Clone()
		{
			return this.Clone();
		}

		/// <summary>
		/// Typesafe, deep-copy clone method.
		/// </summary>
		/// <returns>A new, independent copy of this class</returns>
		public Line Clone()
		{
			return new Line( this );
		}

	#endregion

	#region Serialization
		/// <summary>
		/// Current schema value that defines the version of the serialized file
		/// </summary>
		public const int schema = 1;

		/// <summary>
		/// Constructor for deserializing objects
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data
		/// </param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data
		/// </param>
		protected Line( SerializationInfo info, StreamingContext context )
		{
			// The schema value is just a file version parameter.  You can use it to make future versions
			// backwards compatible as new member variables are added to classes
			int sch = info.GetInt32( "schema" );

			width = info.GetSingle( "width" );
			style = (DashStyle) info.GetValue( "style", typeof(DashStyle) );
			isVisible = info.GetBoolean( "isVisible" );
			isSmooth = info.GetBoolean( "isSmooth" );
			smoothTension = info.GetSingle( "smoothTension" );
			color = (Color) info.GetValue( "color", typeof(Color) );
			stepType = (StepType) info.GetValue( "stepType", typeof(StepType) );
			fill = (Fill) info.GetValue( "fill", typeof(Fill) );
		}
		/// <summary>
		/// Populates a <see cref="SerializationInfo"/> instance with the data needed to serialize the target object
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data</param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data</param>
		[SecurityPermissionAttribute(SecurityAction.Demand,SerializationFormatter=true)]
		public virtual void GetObjectData( SerializationInfo info, StreamingContext context )
		{
			info.AddValue( "schema", schema );
			info.AddValue( "width", width );
			info.AddValue( "style", style );
			info.AddValue( "isVisible", isVisible );
			info.AddValue( "isSmooth", isSmooth );
			info.AddValue( "smoothTension", smoothTension );
			info.AddValue( "color", color );
			info.AddValue( "stepType", stepType );
			info.AddValue( "fill", fill );
		}
	#endregion

	#region Rendering Methods
		/// <summary>
		/// Do all rendering associated with this <see cref="Line"/> to the specified
		/// <see cref="Graphics"/> device.  This method is normally only
		/// called by the Draw method of the parent <see cref="LineItem"/> object.
		/// </summary>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
        /// <param name="scaleFactor">
        /// The scaling factor to be used for rendering objects.  This is calculated and
        /// passed down by the parent <see cref="GraphPane"/> object using the
        /// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
        /// font sizes, etc. according to the actual size of the graph.
        /// </param>
        /// <param name="pane">
        /// A reference to the <see cref="ZedGraph.GraphPane"/> object that is the parent or
		/// owner of this object.
		/// </param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		public void Draw( Graphics g, GraphPane pane, CurveItem curve, float scaleFactor )
        {
			// If the line is being shown, draw it
			if ( this.IsVisible )
			{
				if ( curve is StickItem )
					DrawSticks( g, pane, curve, scaleFactor );
				else if ( this.IsSmooth || this.Fill.IsVisible )
                    DrawSmoothFilledCurve( g, pane, curve, scaleFactor );
                else
                    DrawCurve( g, pane, curve, scaleFactor );
            }
		}		

		/// <summary>
		/// Render a single <see cref="Line"/> segment to the specified
		/// <see cref="Graphics"/> device.
		/// </summary>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
        /// <param name="pane">
        /// A reference to the <see cref="ZedGraph.GraphPane"/> object that is the parent or
        /// owner of this object.
        /// </param>
        /// <param name="scaleFactor">
        /// The scaling factor to be used for rendering objects.  This is calculated and
        /// passed down by the parent <see cref="GraphPane"/> object using the
        /// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
        /// font sizes, etc. according to the actual size of the graph.
        /// </param>
        /// <param name="x1">The x position of the starting point that defines the
        /// line segment in screen pixel units</param>
		/// <param name="y1">The y position of the starting point that defines the
		/// line segment in screen pixel units</param>
		/// <param name="x2">The x position of the ending point that defines the
		/// line segment in screen pixel units</param>
		/// <param name="y2">The y position of the ending point that defines the
		/// line segment in screen pixel units</param>
        public void DrawSegment( Graphics g, GraphPane pane, float x1, float y1,
                            float x2, float y2, float scaleFactor )
        {
			if ( this.isVisible && !this.Color.IsEmpty )
			{
				Pen pen = new Pen( this.color, pane.ScaledPenWidth(width, scaleFactor) );
				pen.DashStyle = this.Style;
				g.DrawLine( pen, x1, y1, x2, y2 );
			}
		}

		/// <summary>
		/// Render the <see cref="Line"/>'s as vertical sticks (from a <see cref="StickItem" />) to
		/// the specified <see cref="Graphics"/> device.
		/// </summary>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
        /// <param name="pane">
        /// A reference to the <see cref="ZedGraph.GraphPane"/> object that is the parent or
        /// owner of this object.
        /// </param>
		/// <param name="curve">A <see cref="CurveItem"/> representing this
		/// curve.</param>
        /// <param name="scaleFactor">
        /// The scaling factor to be used for rendering objects.  This is calculated and
        /// passed down by the parent <see cref="GraphPane"/> object using the
        /// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
        /// font sizes, etc. according to the actual size of the graph.
        /// </param>
		public void DrawSticks( Graphics g, GraphPane pane, CurveItem curve, float scaleFactor )
		{
			Axis yAxis = curve.GetYAxis( pane );
			float basePix = yAxis.Scale.Transform( 0.0 );
			Pen pen = new Pen( this.color, pane.ScaledPenWidth(width, scaleFactor) );
			pen.DashStyle = this.Style;

			for ( int i=0; i<curve.Points.Count; i++ )
			{
				PointPair pt = curve.Points[i];

				if ( 	pt.X != PointPair.Missing &&
						pt.Y != PointPair.Missing &&
						!System.Double.IsNaN( pt.X ) &&
						!System.Double.IsNaN( pt.Y ) &&
						!System.Double.IsInfinity( pt.X ) &&
						!System.Double.IsInfinity( pt.Y ) &&
						( !pane.XAxis.IsLog || pt.X > 0.0 ) &&
						( !yAxis.IsLog || pt.Y > 0.0 ) )
				{
					float pixY = yAxis.Scale.Transform( curve.IsOverrideOrdinal, i, pt.Y );
					float pixX = pane.XAxis.Scale.Transform( curve.IsOverrideOrdinal, i, pt.X );
					g.DrawLine( pen, pixX, pixY, pixX, basePix );
				}
			}
		}

		/// <summary>
		/// Draw the this <see cref="CurveItem"/> to the specified <see cref="Graphics"/>
		/// device using the specified smoothing property (<see cref="ZedGraph.Line.SmoothTension"/>).
		/// The routine draws the line segments and the area fill (if any, see <see cref="FillType"/>;
		/// the symbols are drawn by the <see cref="Symbol.Draw"/> method.  This method
		/// is normally only called by the Draw method of the
		/// <see cref="CurveItem"/> object.  Note that the <see cref="StepType"/> property
		/// is ignored for smooth lines (e.g., when <see cref="ZedGraph.Line.IsSmooth"/> is true).
		/// </summary>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
        /// <param name="scaleFactor">
        /// The scaling factor to be used for rendering objects.  This is calculated and
        /// passed down by the parent <see cref="GraphPane"/> object using the
        /// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
        /// font sizes, etc. according to the actual size of the graph.
        /// </param>
        /// <param name="pane">
        /// A reference to the <see cref="GraphPane"/> object that is the parent or
		/// owner of this object.
		/// </param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		public void DrawSmoothFilledCurve( Graphics g, GraphPane pane,
                                CurveItem curve, float scaleFactor )
        {
			PointF[]	arrPoints;
			int			count;
			IPointList points = curve.Points;

			if ( this.IsVisible && !this.Color.IsEmpty && points != null &&
				BuildPointsArray( pane, curve, out arrPoints, out count ) &&
				count > 2 )
			{
                Pen pen = new Pen(this.Color, pane.ScaledPenWidth( width, scaleFactor ) );
                pen.DashStyle = this.Style;
				float tension = this.isSmooth ? this.smoothTension : 0f;
				
				// Fill the curve if needed
				if ( this.Fill.IsVisible )
				{
					Axis yAxis = curve.GetYAxis( pane );

					GraphicsPath path = new GraphicsPath( FillMode.Winding );
					path.AddCurve( arrPoints, 0, count-2, tension );

					double yMin = yAxis.Min < 0 ? 0.0 : yAxis.Min;
					CloseCurve( pane, curve, arrPoints, count, yMin, path );
				
					RectangleF rect = path.GetBounds();
					Brush brush = this.fill.MakeBrush( rect );
					g.FillPath( brush, path );
					brush.Dispose();

					// restore the zero line if needed (since the fill tends to cover it up)
					yAxis.FixZeroLine( g, pane, scaleFactor, rect.Left, rect.Right );
				}

				// Stroke the curve
				g.DrawCurve( pen, arrPoints, 0, count-2, tension );

				pen.Dispose();
			}
		}

		/// <summary>
		/// Draw the this <see cref="CurveItem"/> to the specified <see cref="Graphics"/>
		/// device.  The format (stair-step or line) of the curve is
		/// defined by the <see cref="StepType"/> property.  The routine
		/// only draws the line segments; the symbols are drawn by the
		/// <see cref="Symbol.Draw"/> method.  This method
		/// is normally only called by the Draw method of the
		/// <see cref="CurveItem"/> object
		/// </summary>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
        /// <param name="scaleFactor">
        /// The scaling factor to be used for rendering objects.  This is calculated and
        /// passed down by the parent <see cref="GraphPane"/> object using the
        /// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
        /// font sizes, etc. according to the actual size of the graph.
        /// </param>
        /// <param name="pane">
        /// A reference to the <see cref="GraphPane"/> object that is the parent or
		/// owner of this object.
		/// </param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		public void DrawCurve( Graphics g, GraphPane pane,
                                CurveItem curve, float scaleFactor)
        {
			float	tmpX, tmpY,
					lastX = float.MaxValue,
					lastY = float.MaxValue;
			double	curX, curY, lowVal;
			bool	lastBad = true;
			IPointList points = curve.Points;
			ValueHandler valueHandler = new ValueHandler( pane, false );
			Axis yAxis = curve.GetYAxis( pane );

			Pen pen = new Pen( this.color, pane.ScaledPenWidth( width, scaleFactor ) );
			pen.DashStyle = this.Style;

			if ( points != null && !this.color.IsEmpty && this.IsVisible )
			{
				// Loop over each point in the curve
				for ( int i=0; i<points.Count; i++ )
				{
					if ( pane.LineType == LineType.Stack )
					{
						if ( !valueHandler.GetValues( curve, i, out curX, out lowVal, out curY ) )
						{
							curX = PointPair.Missing;
							curY = PointPair.Missing;
						}
					}
					else
					{
						curX = points[i].X;
						curY = points[i].Y;
					}
					
					// Any value set to double max is invalid and should be skipped
					// This is used for calculated values that are out of range, divide
					//   by zero, etc.
					// Also, any value <= zero on a log scale is invalid
					if ( 	curX == PointPair.Missing ||
							curY == PointPair.Missing ||
							System.Double.IsNaN( curX ) ||
							System.Double.IsNaN( curY ) ||
							System.Double.IsInfinity( curX ) ||
							System.Double.IsInfinity( curY ) ||
							( pane.XAxis.IsLog && curX <= 0.0 ) ||
							( yAxis.IsLog && curY <= 0.0 ) )
					{
						// If the point is invalid, then make a linebreak only if IsIgnoreMissing is false
						// LastX and LastY are always the last valid point, so this works out
						lastBad = lastBad || !pane.IsIgnoreMissing;
					}
					else
					{
						// Transform the current point from user scale units to
						// screen coordinates
						tmpX = pane.XAxis.Scale.Transform( curve.IsOverrideOrdinal, i, curX );
						tmpY = yAxis.Scale.Transform( curve.IsOverrideOrdinal, i, curY );

						if ( !lastBad )
						{
							try
							{
								// GDI+ plots the data wrong and/or throws an exception for
								// outrageous coordinates, so we do a sanity check here
								if ( lastX > 5000000 || lastX < -5000000 ||
										lastY > 5000000 || lastY < -5000000 ||
										tmpX > 5000000 || tmpX < -5000000 ||
										tmpY > 5000000 || tmpY < -5000000 )
									InterpolatePoint( g, pane, pen, lastX, lastY, tmpX, tmpY );

								if ( this.StepType == StepType.ForwardStep )
								{
									g.DrawLine( pen, lastX, lastY, tmpX, lastY );
									g.DrawLine( pen, tmpX, lastY, tmpX, tmpY );
								}
								else if ( this.StepType == StepType.RearwardStep )
								{
									g.DrawLine( pen, lastX, lastY, lastX, tmpY );
									g.DrawLine( pen, lastX, tmpY, tmpX, tmpY );
								}
								else 		// non-step
									g.DrawLine( pen, lastX, lastY, tmpX, tmpY );

							}
							catch
							{
								InterpolatePoint( g, pane, pen, lastX, lastY, tmpX, tmpY );
							}
						}

						lastX = tmpX;
						lastY = tmpY;
						lastBad = false;
					}
				}
			}
		}

		/// <summary>
		/// This method just handles the case where one or more of the coordinates are outrageous,
		/// or GDI+ threw an exception.  This method attempts to correct the outrageous coordinates by
		/// interpolating them to a point (along the original line) that lies at the edge of the AxisRect
		/// so that GDI+ will handle it properly.  GDI+ will throw an exception, or just plot the data
		/// incorrectly if the coordinates are too large (empirically, this appears to be when the
		/// coordinate value is greater than 5,000,000 or less than -5,000,000).  Although you typically
		/// would not see coordinates like this, if you repeatedly zoom in on a ZedGraphControl, eventually
		/// all your points will be way outside the bounds of the plot.
		/// </summary>
		private void InterpolatePoint( Graphics g, GraphPane pane, Pen pen, float lastX, float lastY,
						float tmpX, float tmpY )
		{
			try
			{
				// try to interpolate values
				bool lastIn = pane.AxisRect.Contains( lastX, lastY );
				bool curIn = pane.AxisRect.Contains( tmpX, tmpY );

				// If both points are outside the AxisRect, make a new point that is on the LastX/Y
				// side of the AxisRect, and fall through to the code that handles lastIn == true
				if ( !lastIn )
				{
					float newX, newY;

					if ( Math.Abs( lastX ) > Math.Abs( lastY ) )
					{
						newX = lastX < 0 ? pane.AxisRect.Left : pane.AxisRect.Right;
						newY = lastY + (tmpY - lastY) * (newX - lastX) / (tmpX - lastX);
					}
					else
					{
						newY = lastY < 0 ? pane.AxisRect.Top : pane.AxisRect.Bottom;
						newX = lastX + (tmpX - lastX) * (newY - lastY) / (tmpY - lastY);
					}

					lastX = newX;
					lastY = newY;
				}

				if ( !curIn )
				{
					float newX, newY;

					if ( Math.Abs( tmpX ) > Math.Abs( tmpY ) )
					{
						newX = tmpX < 0 ? pane.AxisRect.Left : pane.AxisRect.Right;
						newY = tmpY + ( lastY - tmpY ) * ( newX - tmpX ) / ( lastX - tmpX );
					}
					else
					{
						newY = tmpY < 0 ? pane.AxisRect.Top : pane.AxisRect.Bottom;
						newX = tmpX + ( lastX - tmpX ) * ( newY - tmpY ) / ( lastY - tmpY );
					}

					tmpX = newX;
					tmpY = newY;
				}

				if ( this.StepType == StepType.ForwardStep )
				{
					g.DrawLine( pen, lastX, lastY, tmpX, lastY );
					g.DrawLine( pen, tmpX, lastY, tmpX, tmpY );
				}
				else if ( this.StepType == StepType.RearwardStep )
				{
					g.DrawLine( pen, lastX, lastY, lastX, tmpY );
					g.DrawLine( pen, lastX, tmpY, tmpX, tmpY );
				}
				else 		// non-step
					g.DrawLine( pen, lastX, lastY, tmpX, tmpY );

			}

			catch { }
		}

		/// <summary>
		/// Build an array of <see cref="PointF"/> values (pixel coordinates) that represents
		/// the current curve.  Note that this drawing routine ignores <see cref="PointPair.Missing"/>
		/// values, but it does not "break" the line to indicate values are missing.
		/// </summary>
		/// <param name="pane">A reference to the <see cref="GraphPane"/> object that is the parent or
		/// owner of this object.</param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		/// <param name="arrPoints">An array of <see cref="PointF"/> values in pixel
		/// coordinates representing the current curve.</param>
		/// <param name="count">The number of points contained in the "arrPoints"
		/// parameter.</param>
		/// <returns>true for a successful points array build, false for data problems</returns>
		public bool BuildPointsArray( GraphPane pane, CurveItem curve,
			out PointF[] arrPoints, out int count )
		{
			arrPoints = null;
			count = 0;
			IPointList points = curve.Points;

			if ( this.IsVisible && !this.Color.IsEmpty && points != null )
			{
				int		index = 0;
				float	curX, curY,
						lastX = 0,
						lastY = 0;
				double	x, y, lowVal;
				ValueHandler valueHandler = new ValueHandler( pane, false );

				// Step type plots get twice as many points.  Always add three points so there is
				// room to close out the curve for area fills.
				arrPoints = new PointF[ ( this.stepType == ZedGraph.StepType.NonStep ? 1 : 2 ) *
											points.Count + 1 ];

				// Loop over all points in the curve
				for ( int i=0; i<points.Count; i++ )
				{
					// make sure that the current point is valid
					if ( !points[i].IsInvalid )
					{
						// Get the user scale values for the current point
						// use the valueHandler only for stacked types
						if ( pane.LineType == LineType.Stack )
						{
							valueHandler.GetValues( curve, i, out x, out lowVal, out y );
						}
						// otherwise, just access the values directly.  Avoiding the valueHandler for
						// non-stacked types is an optimization to minimize overhead in case there are
						// a large number of points.
						else
						{
							x = points[i].X;
							y = points[i].Y;
						}
						
						// Transform the user scale values to pixel locations
						curX = pane.XAxis.Scale.Transform( curve.IsOverrideOrdinal, i, x );
						Axis yAxis = curve.GetYAxis( pane );
						curY = yAxis.Scale.Transform( curve.IsOverrideOrdinal, i, y );

						if ( curX < -1000000 || curY < -1000000 || curX > 1000000 || curY > 1000000 )
							continue;
						
						// Add the pixel value pair into the points array
						// Two points are added for step type curves
						// ignore step-type setting for smooth curves
						if ( this.isSmooth || index == 0 || this.StepType == StepType.NonStep )
						{
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}
						else if ( this.StepType == StepType.ForwardStep )
						{
							arrPoints[index].X = curX;
							arrPoints[index].Y = lastY;
							index++;
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}
						else if ( this.StepType == StepType.RearwardStep )
						{
							arrPoints[index].X = lastX;
							arrPoints[index].Y = curY;
							index++;
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}

						lastX = curX;
						lastY = curY;
						index++;
						
					}

				}

				// Make sure there is at least one valid point
				if ( index == 0 )
					return false;
					
				// Add an extra point at the end, since the smoothing algorithm requires it
				arrPoints[index] = arrPoints[index-1];
				index++;
				
				count = index;
				return true;
			}
			else
			{
				return false;
			}
		}

		/// <summary>
		/// Build an array of <see cref="PointF"/> values (pixel coordinates) that represents
		/// the low values for the current curve.
		/// </summary>
		/// <remarks>Note that this drawing routine ignores <see cref="PointPair.Missing"/>
		/// values, but it does not "break" the line to indicate values are missing.
		/// </remarks>
		/// <param name="pane">A reference to the <see cref="GraphPane"/> object that is the parent or
		/// owner of this object.</param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		/// <param name="arrPoints">An array of <see cref="PointF"/> values in pixel
		/// coordinates representing the current curve.</param>
		/// <param name="count">The number of points contained in the "arrPoints"
		/// parameter.</param>
		/// <returns>true for a successful points array build, false for data problems</returns>
		public bool BuildLowPointsArray( GraphPane pane, CurveItem curve,
						out PointF[] arrPoints, out int count )
		{
			arrPoints = null;
			count = 0;
			IPointList points = curve.Points;

			if ( this.IsVisible && !this.Color.IsEmpty && points != null )
			{
				int		index = 0;
				float	curX, curY,
						lastX = 0,
						lastY = 0;
				double	x, y, hiVal;
				ValueHandler valueHandler = new ValueHandler( pane, false );

				// Step type plots get twice as many points.  Always add three points so there is
				// room to close out the curve for area fills.
				arrPoints = new PointF[ ( this.stepType == ZedGraph.StepType.NonStep ? 1 : 2 ) *
					( pane.LineType == LineType.Stack ? 2 : 1 ) *
					points.Count + 1 ];

				// Loop backwards over all points in the curve
				// In this case an array of points was already built forward by BuildPointsArray().
				// This time we build backwards to complete a loop around the area between two curves.
				for ( int i=points.Count-1; i>=0; i-- )
				{
					// Make sure the current point is valid
					if ( !points[i].IsInvalid )
					{
						// Get the user scale values for the current point
						valueHandler.GetValues( curve, i, out x, out y, out hiVal );
						
						// Transform the user scale values to pixel locations
						curX = pane.XAxis.Scale.Transform( curve.IsOverrideOrdinal, i, x );
						Axis yAxis = curve.GetYAxis( pane );
						curY = yAxis.Scale.Transform( curve.IsOverrideOrdinal, i, y );

						// Add the pixel value pair into the points array
						// Two points are added for step type curves
						// ignore step-type setting for smooth curves
						if ( this.isSmooth || index == 0 || this.StepType == StepType.NonStep )
						{
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}
						else if ( this.StepType == StepType.ForwardStep )
						{
							arrPoints[index].X = curX;
							arrPoints[index].Y = lastY;
							index++;
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}
						else if ( this.StepType == StepType.RearwardStep )
						{
							arrPoints[index].X = lastX;
							arrPoints[index].Y = curY;
							index++;
							arrPoints[index].X = curX;
							arrPoints[index].Y = curY;
						}

						lastX = curX;
						lastY = curY;
						index++;
						
					}

				}

				// Make sure there is at least one valid point
				if ( index == 0 )
					return false;
					
				// Add an extra point at the end, since the smoothing algorithm requires it
				arrPoints[index] = arrPoints[index-1];
				index++;
				
				count = index;
				return true;
			}
			else
			{
				return false;
			}
		}

		/// <summary>
		/// Close off a <see cref="GraphicsPath"/> that defines a curve
		/// </summary>
		/// <param name="pane">A reference to the <see cref="GraphPane"/> object that is the parent or
		/// owner of this object.</param>
		/// <param name="curve">A <see cref="LineItem"/> representing this
		/// curve.</param>
		/// <param name="arrPoints">An array of <see cref="PointF"/> values in screen pixel
		/// coordinates representing the current curve.</param>
		/// <param name="count">The number of points contained in the "arrPoints"
		/// parameter.</param>
		/// <param name="yMin">The Y axis value location where the X axis crosses.</param>
		/// <param name="path">The <see cref="GraphicsPath"/> class that represents the curve.</param>
		public void CloseCurve( GraphPane pane, CurveItem curve, PointF[] arrPoints,
									int count, double yMin, GraphicsPath path )
		{
			// For non-stacked lines, the fill area is just the area between the curve and the X axis
			if ( pane.LineType != LineType.Stack )
			{
				// Determine the current value for the bottom of the curve (usually the Y value where
				// the X axis crosses)
				float yBase;
				Axis yAxis = curve.GetYAxis( pane );
				yBase = yAxis.Scale.Transform( yMin );

				// Add three points to the path to move from the end of the curve (as defined by
				// arrPoints) to the X axis, from there to the start of the curve at the X axis,
				// and from there back up to the beginning of the curve.
				path.AddLine( arrPoints[count-1].X, arrPoints[count-1].Y, arrPoints[count-1].X, yBase );
				path.AddLine( arrPoints[count-1].X, yBase, arrPoints[0].X, yBase );
				path.AddLine( arrPoints[0].X, yBase, arrPoints[0].X, arrPoints[0].Y );
			}
			// For stacked line types, the fill area is the area between this curve and the curve below it
			else
			{
				PointF[]	arrPoints2;
				int			count2;
				
				float		tension = this.isSmooth ? this.smoothTension : 0f;
				
				// Find the next lower curve in the curveList that is also a LineItem type, and use
				// its smoothing properties for the lower side of the filled area.
				int index = pane.CurveList.IndexOf( curve );
				if ( index > 0 )
				{
					CurveItem tmpCurve;
					for ( int i=index-1; i>=0; i-- )
					{
						tmpCurve = pane.CurveList[i];
						if ( tmpCurve is LineItem )
						{
							tension = ((LineItem)tmpCurve).Line.IsSmooth ? ((LineItem)tmpCurve).Line.SmoothTension : 0f;
							break;
						}
					}
				}
				
				// Build another points array consisting of the low points (which are actually the points for
				// the curve below the current curve)
				BuildLowPointsArray( pane, curve, out arrPoints2, out count2 );
				
				// Add the new points to the GraphicsPath
				path.AddCurve( arrPoints2, 0, count2-2, tension );
			}
			
		}

	#endregion
	}
}