Esempio n. 1
0
        /// <summary>
        /// Draws the line plot on a GDI+ surface against the provided x and y axes.
        /// </summary>
        /// <param name="g">The GDI+ surface on which to draw.</param>
        /// <param name="xAxis">The X-Axis to draw against.</param>
        /// <param name="yAxis">The Y-Axis to draw against.</param>
        /// <param name="drawShadow">If true draw the shadow for the line. If false, draw line.</param>
        public void DrawLineOrShadow(Graphics g, PhysicalAxis xAxis, PhysicalAxis yAxis, bool drawShadow)
        {
            Pen shadowPen = null;

            if (drawShadow)
            {
                shadowPen       = (Pen)this.Pen.Clone();
                shadowPen.Color = this.ShadowColor;
            }

            SequenceAdapter data =
                new SequenceAdapter(this.DataSource, this.DataMember, this.OrdinateData, this.AbscissaData);

            ITransform2D t = Transform2D.GetTransformer(xAxis, yAxis);

            int numberPoints = data.Count;

            if (data.Count == 0)
            {
                return;
            }

            // clipping is now handled assigning a clip region in the
            // graphic object before this call
            if (numberPoints == 1)
            {
                PointF physical = t.Transform(data[0]);

                if (drawShadow)
                {
                    g.DrawLine(shadowPen,
                               physical.X - 0.5f + this.ShadowOffset.X,
                               physical.Y + this.ShadowOffset.Y,
                               physical.X + 0.5f + this.ShadowOffset.X,
                               physical.Y + this.ShadowOffset.Y);
                }
                else
                {
                    g.DrawLine(Pen, physical.X - 0.5f, physical.Y, physical.X + 0.5f, physical.Y);
                }
            }
            else
            {
                // prepare for clipping
                double leftCutoff  = xAxis.PhysicalToWorld(xAxis.PhysicalMin, false);
                double rightCutoff = xAxis.PhysicalToWorld(xAxis.PhysicalMax, false);
                if (leftCutoff > rightCutoff)
                {
                    Utils.Swap(ref leftCutoff, ref rightCutoff);
                }
                if (drawShadow)
                {
                    // correct cut-offs
                    double shadowCorrection =
                        xAxis.PhysicalToWorld(ShadowOffset, false) - xAxis.PhysicalToWorld(new Point(0, 0), false);
                    leftCutoff  -= shadowCorrection;
                    rightCutoff -= shadowCorrection;
                }

                for (int i = 1; i < numberPoints; ++i)
                {
                    // check to see if any values null. If so, then continue.
                    double dx1 = data[i - 1].X;
                    double dx2 = data[i].X;
                    double dy1 = data[i - 1].Y;
                    double dy2 = data[i].Y;
                    if (Double.IsNaN(dx1) || Double.IsNaN(dy1) ||
                        Double.IsNaN(dx2) || Double.IsNaN(dy2))
                    {
                        continue;
                    }

                    // do horizontal clipping here, to speed up
                    if ((dx1 < leftCutoff && dx2 < leftCutoff) ||
                        (rightCutoff < dx1 && rightCutoff < dx2))
                    {
                        continue;
                    }

                    // else draw line.
                    PointF p1 = t.Transform(data[i - 1]);
                    PointF p2 = t.Transform(data[i]);

                    // when very far zoomed in, points can fall ontop of each other,
                    // and g.DrawLine throws an overflow exception
                    if (p1.Equals(p2))
                    {
                        continue;
                    }

                    if (drawShadow)
                    {
                        g.DrawLine(shadowPen,
                                   p1.X + ShadowOffset.X,
                                   p1.Y + ShadowOffset.Y,
                                   p2.X + ShadowOffset.X,
                                   p2.Y + ShadowOffset.Y);
                    }
                    else
                    {
                        // Ensure that we do not go outside of the graphics capabilities
                        if ((Math.Abs(p1.X) + Math.Abs(p2.X)) < 0x4000007F && (Math.Abs(p1.Y) + Math.Abs(p2.Y)) < 0x4000007F)
                        {
                            g.DrawLine(Pen, p1.X, p1.Y, p2.X, p2.Y);
                        }
                    }
                }
            }
        }