private Point InverseTransform(Point point)
{
if (XAxis != null)
{
return(XAxis.InverseTransform(point.X, point.Y, YAxis));
}
if (YAxis != null)
{
return(new Point(0, YAxis.InverseTransform(point.Y)));
}
return(new Point());
}
/// <summary>
/// Calculates the actual minimums and maximums.
/// </summary>
protected virtual void CalculateActualMinimumsMaximums()
{
this.actualMinimumX = Math.Max(this.MinimumX, this.XAxis.ActualMinimum);
this.actualMaximumX = Math.Min(this.MaximumX, this.XAxis.ActualMaximum);
this.actualMinimumY = Math.Max(this.MinimumY, this.YAxis.ActualMinimum);
this.actualMaximumY = Math.Min(this.MaximumY, this.YAxis.ActualMaximum);
if (!this.ClipByXAxis)
{
double right = XAxis.InverseTransform(PlotModel.PlotArea.Right);
double left = XAxis.InverseTransform(PlotModel.PlotArea.Left);
this.actualMaximumX = Math.Max(left, right);
this.actualMinimumX = Math.Min(left, right);
}
if (!this.ClipByYAxis)
{
double bottom = YAxis.InverseTransform(PlotModel.PlotArea.Bottom);
double top = YAxis.InverseTransform(PlotModel.PlotArea.Top);
this.actualMaximumY = Math.Max(top, bottom);
this.actualMinimumY = Math.Min(top, bottom);
}
}
/// <summary>
/// Renders the line annotation.
/// </summary>
/// <param name="rc">
/// The render context.
/// </param>
/// <param name="model">
/// The plot model.
/// </param>
public override void Render(IRenderContext rc, PlotModel model)
{
base.Render(rc, model);
bool aliased = false;
double actualMinimumX = Math.Max(this.MinimumX, this.XAxis.ActualMinimum);
double actualMaximumX = Math.Min(this.MaximumX, this.XAxis.ActualMaximum);
double actualMinimumY = Math.Max(this.MinimumY, this.YAxis.ActualMinimum);
double actualMaximumY = Math.Min(this.MaximumY, this.YAxis.ActualMaximum);
if (!this.ClipByXAxis)
{
double right = XAxis.InverseTransform(PlotModel.PlotArea.Right);
double left = XAxis.InverseTransform(PlotModel.PlotArea.Left);
actualMaximumX = Math.Max(left, right);
actualMinimumX = Math.Min(left, right);
}
if (!this.ClipByYAxis)
{
double bottom = YAxis.InverseTransform(PlotModel.PlotArea.Bottom);
double top = YAxis.InverseTransform(PlotModel.PlotArea.Top);
actualMaximumY = Math.Max(top, bottom);
actualMinimumY = Math.Min(top, bottom);
}
// y=f(x)
Func <double, double> fx = null;
// x=f(y)
Func <double, double> fy = null;
switch (this.Type)
{
case LineAnnotationType.Horizontal:
fx = x => this.Y;
break;
case LineAnnotationType.Vertical:
fy = y => this.X;
break;
case LineAnnotationType.EquationY:
fx = this.Equation;
break;
case LineAnnotationType.EquationX:
fy = this.Equation;
break;
default:
fx = x => (this.Slope * x) + this.Intercept;
break;
}
var points = new List <DataPoint>();
bool isCurvedLine = !(this.XAxis is LinearAxis) || !(this.YAxis is LinearAxis) || this.Type == LineAnnotationType.EquationY;
if (!isCurvedLine)
{
// we only need to calculate two points if it is a straight line
if (fx != null)
{
points.Add(new DataPoint(actualMinimumX, fx(actualMinimumX)));
points.Add(new DataPoint(actualMaximumX, fx(actualMaximumX)));
}
else if (fy != null)
{
points.Add(new DataPoint(fy(actualMinimumY), actualMinimumY));
points.Add(new DataPoint(fy(actualMaximumY), actualMaximumY));
}
if (this.Type == LineAnnotationType.Horizontal || this.Type == LineAnnotationType.Vertical)
{
// use aliased line drawing for horizontal and vertical lines
aliased = true;
}
}
else
{
if (fx != null)
{
double x = actualMinimumX;
// todo: the step size should be adaptive
double dx = (actualMaximumX - actualMinimumX) / 100;
while (true)
{
points.Add(new DataPoint(x, fx(x)));
if (x > actualMaximumX)
{
break;
}
x += dx;
}
}
else if (fy != null)
{
double y = actualMinimumY;
// todo: the step size should be adaptive
double dy = (actualMaximumY - actualMinimumY) / 100;
while (true)
{
points.Add(new DataPoint(fy(y), y));
if (y > actualMaximumY)
{
break;
}
y += dy;
}
}
}
// transform to screen coordinates
this.screenPoints = points.Select(p => this.Transform(p)).ToList();
// clip to the area defined by the axes
var clippingRectangle = OxyRect.Create(
this.ClipByXAxis ? this.XAxis.ScreenMin.X : PlotModel.PlotArea.Left,
this.ClipByYAxis ? this.YAxis.ScreenMin.Y : PlotModel.PlotArea.Top,
this.ClipByXAxis ? this.XAxis.ScreenMax.X : PlotModel.PlotArea.Right,
this.ClipByYAxis ? this.YAxis.ScreenMax.Y : PlotModel.PlotArea.Bottom);
const double MinimumSegmentLength = 4;
IList <ScreenPoint> clippedPoints = null;
rc.DrawClippedLine(
this.screenPoints,
clippingRectangle,
MinimumSegmentLength * MinimumSegmentLength,
this.GetSelectableColor(this.Color),
this.StrokeThickness,
this.LineStyle,
this.LineJoin,
aliased,
pts => clippedPoints = pts);
ScreenPoint position;
double angle;
double margin = this.TextMargin;
if (this.TextHorizontalAlignment == HorizontalAlignment.Center)
{
margin = 0;
}
else
{
margin *= this.TextPosition < 0.5 ? 1 : -1;
}
if (clippedPoints != null && GetPointAtRelativeDistance(clippedPoints, this.TextPosition, margin, out position, out angle))
{
if (angle < -90)
{
angle += 180;
}
if (angle > 90)
{
angle -= 180;
}
switch (this.TextOrientation)
{
case AnnotationTextOrientation.Horizontal:
angle = 0;
break;
case AnnotationTextOrientation.Vertical:
angle = -90;
break;
}
// Apply 'padding' to the position
var angleInRadians = angle / 180 * Math.PI;
var f = 1;
if (this.TextHorizontalAlignment == HorizontalAlignment.Right)
{
f = -1;
}
if (this.TextHorizontalAlignment == HorizontalAlignment.Center)
{
f = 0;
}
position.X += f * this.TextPadding * Math.Cos(angleInRadians);
position.Y += f * this.TextPadding * Math.Sin(angleInRadians);
var cs = new CohenSutherlandClipping(clippingRectangle);
if (!string.IsNullOrEmpty(this.Text) && cs.IsInside(position))
{
rc.DrawClippedText(
clippingRectangle,
position,
this.Text,
this.ActualTextColor,
this.ActualFont,
this.ActualFontSize,
this.ActualFontWeight,
angle,
this.TextHorizontalAlignment,
this.TextVerticalAlignment);
}
}
}