/// <summary>
/// Draws the line plot using the Context and Physical Axes provided
/// </summary>
/// <param name="ctx">The Drawing Context with 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(Context ctx, PhysicalAxis xAxis, PhysicalAxis yAxis, bool drawShadow)
{
SequenceAdapter data = new SequenceAdapter(DataSource, DataMember, OrdinateData, AbscissaData);
ITransform2D t = Transform2D.GetTransformer(xAxis, yAxis);
int numberPoints = data.Count;
if (data.Count == 0)
{
return;
}
ctx.Save();
ctx.SetLineWidth(lineWidth);
if (lineDash != null)
{
ctx.SetLineDash(0, lineDash);
}
if (numberPoints == 1)
{
Point physical = t.Transform(data[0]);
if (drawShadow)
{
ctx.SetColor(shadowColor);
ctx.MoveTo(physical.X - 0.5 + ShadowOffset.X, physical.Y + ShadowOffset.Y);
ctx.LineTo(physical.X + 0.5 + ShadowOffset.X, physical.Y + ShadowOffset.Y);
ctx.Stroke();
}
else
{
ctx.SetColor(lineColor);
ctx.MoveTo(physical.X - 0.5, physical.Y);
ctx.LineTo(physical.X + 0.5, physical.Y);
ctx.Stroke();
}
}
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.
Point p1 = t.Transform(data[i - 1]);
Point 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)
{
ctx.SetColor(shadowColor);
ctx.MoveTo(p1.X + ShadowOffset.X, p1.Y + ShadowOffset.Y);
ctx.LineTo(p2.X + ShadowOffset.X, p2.Y + ShadowOffset.Y);
ctx.Stroke();
}
else
{
ctx.SetColor(lineColor);
ctx.MoveTo(p1.X, p1.Y);
ctx.LineTo(p2.X, p2.Y);
ctx.Stroke();
}
}
}
ctx.Restore();
}
