/// <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);
}
}
}
}
}
