protected virtual void OnGetStrokeAndFillForLegendSymbol(double paletteIndex, out Brush stroke, out Brush fill)
{
Axis xAxis = XAxis;
Axis yAxis = YAxis;
// Check coloring parameters.
if (PaletteIndex == PaletteIndex.Index && FillMode == AreaFillMode.GradientVertical ||
PaletteIndex == PaletteIndex.XValue && FillMode == AreaFillMode.GradientVertical)
{
throw new NotSupportedException("Vertical gradients are only supported if the palette is indexed by y values.");
}
// Set default values for stroke and fill brush.
stroke = null;
fill = null;
// Try to find colors in palette.
// We draw from 0 upwards or from a negative value upwards to 0.
double lower = Math.Min(0, paletteIndex);
double higher = Math.Max(0, paletteIndex);
//if (FillMode == AreaFillMode.Solid)
//{
// // Fill legend symbol with single color.
// lower = higher;
//}
// Define gradient direction.
Point startPoint;
Point endPoint;
if (PaletteIndex == PaletteIndex.Index || PaletteIndex == PaletteIndex.XValue ||
FillMode == AreaFillMode.GradientHorizontal || FillMode == AreaFillMode.Solid)
{
startPoint = new Point(0, 0);
endPoint = new Point(1, 0);
if (xAxis != null && xAxis.Scale != null && xAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
else
{
startPoint = new Point(0, 1);
endPoint = new Point(0, 0);
if (yAxis != null && yAxis.Scale != null && yAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
// Get brush for fill and stroke.
if (FillPalette != null && FillPalette.Count > 0)
{
fill = new LinearGradientBrush
{
GradientStops = FillPalette.GetGradient(lower, higher),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = FillPalette.ColorInterpolationMode
};
}
if (StrokePalette != null && StrokePalette.Count > 0)
{
stroke = new LinearGradientBrush
{
GradientStops = StrokePalette.GetGradient(lower, higher),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = StrokePalette.ColorInterpolationMode
};
}
}
private void GetBrushes(double paletteIndex, out Brush strokeBrush, out Brush fillBrush)
{
Axis xAxis = XAxis;
Axis yAxis = YAxis;
strokeBrush = null;
fillBrush = null;
if (FillMode == BarFillMode.Solid)
{
// Solid:
// Get a solid color brush for fill and stroke.
if (FillPalette != null && FillPalette.Count > 0)
{
fillBrush = new SolidColorBrush(FillPalette.GetColor(paletteIndex));
}
if (StrokePalette != null && StrokePalette.Count > 0)
{
strokeBrush = new SolidColorBrush(StrokePalette.GetColor(paletteIndex));
}
}
else
{
// Gradient:
// We draw from 0 upwards or from a negative value upwards to 0.
double lower = Math.Min(0, paletteIndex);
double higher = Math.Max(0, paletteIndex);
// Define end point for gradient direction.
Point startPoint;
Point endPoint;
if (PaletteIndex == PaletteIndex.XValue)
{
// Horizontal
startPoint = new Point(0, 0);
endPoint = new Point(1, 0);
if (xAxis != null && xAxis.Scale != null && xAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
else
{
// Vertical
startPoint = new Point(0, 1);
endPoint = new Point(0, 0);
if (yAxis != null && yAxis.Scale != null && yAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
// Get brush for fill and stroke.
if (FillPalette != null && FillPalette.Count > 0)
{
fillBrush = new LinearGradientBrush
{
GradientStops = FillPalette.GetGradient(lower, higher),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = FillPalette.ColorInterpolationMode
};
}
if (StrokePalette != null && StrokePalette.Count > 0)
{
strokeBrush = new LinearGradientBrush
{
GradientStops = StrokePalette.GetGradient(lower, higher),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = StrokePalette.ColorInterpolationMode
};
}
}
}
protected virtual void OnGetStrokeAndFillForSegment(int index, out Brush stroke, out Brush fill)
{
Axis xAxis = XAxis;
Axis yAxis = YAxis;
// Check coloring parameters.
if (PaletteIndex == PaletteIndex.Index && FillMode == AreaFillMode.GradientVertical ||
PaletteIndex == PaletteIndex.XValue && FillMode == AreaFillMode.GradientVertical)
{
throw new NotSupportedException("Vertical gradients are only supported if the palette is indexed by y values.");
}
// Find palette index.
double paletteIndex = 0;
switch (PaletteIndex)
{
case PaletteIndex.Index:
paletteIndex = index;
break;
case PaletteIndex.XValue:
paletteIndex = Data[index].X;
break;
case PaletteIndex.YValue:
paletteIndex = Data[index].Y;
break;
default:
throw new NotSupportedException("PaletteIndex type is not supported.");
}
// Set default values for stroke and fill brush.
stroke = null;
fill = null;
// Try to find colors in palette.
if (FillMode == AreaFillMode.Solid)
{
// Solid:
// Get a solid color fill for fill and stroke.
if (FillPalette != null && FillPalette.Count > 0)
{
fill = new SolidColorBrush(FillPalette.GetColor(paletteIndex));
}
if (StrokePalette != null && StrokePalette.Count > 0)
{
stroke = new SolidColorBrush(StrokePalette.GetColor(paletteIndex));
}
}
else
{
// Get data values.
DataPoint data = Data[index];
DataPoint dataBase = new DataPoint(data.X, 0, null); // The base is currently always y = 0.
DataPoint previousData = (index > 0) ? Data[index - 1] : data;
DataPoint previousDataBase = new DataPoint(previousData.X, 0, null); // The base is currently always y = 0.
DataPoint nextData = (index < Data.Count - 1) ? Data[index + 1] : data;
DataPoint nextDataBase = new DataPoint(nextData.X, 0, null); // The base is currently always y = 0.
// Gradient:
double fillStart;
double fillEnd;
double strokeStart;
double strokeEnd;
// Define palette index values.
ChartInterpolation interpolation = EffectiveInterpolation;
if (PaletteIndex == PaletteIndex.Index)
{
// Index-based
if (interpolation == ChartInterpolation.CenteredSteps)
{
fillStart = strokeStart = Math.Max(index - 0.5, 0);
fillEnd = strokeEnd = Math.Min(index + 0.5, Data.Count - 1);
}
else if (interpolation == ChartInterpolation.LeftSteps)
{
fillStart = strokeStart = Math.Max(index - 1, 0);
fillEnd = strokeEnd = index;
}
else
{
fillStart = strokeStart = index;
fillEnd = strokeEnd = index + 1;
}
}
else if (PaletteIndex == PaletteIndex.XValue)
{
// x value based
if (interpolation == ChartInterpolation.CenteredSteps)
{
fillStart = strokeStart = (previousData.X + data.X) / 2;
fillEnd = strokeEnd = (data.X + nextData.X) / 2;
}
else if (interpolation == ChartInterpolation.LeftSteps)
{
fillStart = strokeStart = previousData.X;
fillEnd = strokeEnd = data.X;
}
else
{
fillStart = strokeStart = data.X;
fillEnd = strokeEnd = nextData.X;
}
}
else
{
// y value based
if (FillMode == AreaFillMode.GradientHorizontal)
{
if (interpolation == ChartInterpolation.CenteredSteps)
{
fillStart = strokeStart = (previousData.Y + data.Y) / 2;
fillEnd = strokeEnd = (data.Y + nextData.Y) / 2;
}
else if (interpolation == ChartInterpolation.LeftSteps)
{
fillStart = strokeStart = previousData.Y;
fillEnd = strokeEnd = data.Y;
}
else
{
fillStart = strokeStart = data.Y;
fillEnd = strokeEnd = nextData.Y;
}
}
else
{
fillStart = Math.Min(0, Math.Min(data.Y, dataBase.Y));
fillEnd = Math.Max(0, Math.Max(data.Y, dataBase.Y));
if (interpolation == ChartInterpolation.Linear)
{
fillStart = Math.Min(fillStart, Math.Min(nextData.Y, nextDataBase.Y));
fillEnd = Math.Max(fillEnd, Math.Max(nextData.Y, nextDataBase.Y));
}
// This is the only case where the stroke has a different start and end value than the fill.
// (Because the fill starts at y=0, but the line starts at the data point.)
strokeStart = data.Y;
strokeEnd = nextData.Y;
if (strokeStart > strokeEnd)
{
ChartHelper.Swap(ref strokeStart, ref strokeEnd);
}
}
}
// Define gradient direction.
Point startPoint;
Point endPoint;
if (PaletteIndex == PaletteIndex.Index || PaletteIndex == PaletteIndex.XValue || FillMode == AreaFillMode.GradientHorizontal)
{
startPoint = new Point(0, 0);
endPoint = new Point(1, 0);
if (xAxis != null && xAxis.Scale != null && xAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
else
{
startPoint = new Point(0, 1);
endPoint = new Point(0, 0);
if (yAxis != null && yAxis.Scale != null && yAxis.Scale.Reversed)
{
ChartHelper.Swap(ref startPoint, ref endPoint);
}
}
// Get brush for fill and stroke.
if (FillPalette != null && FillPalette.Count > 0)
{
fill = new LinearGradientBrush
{
GradientStops = FillPalette.GetGradient(fillStart, fillEnd),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = FillPalette.ColorInterpolationMode
};
}
if (StrokePalette != null && StrokePalette.Count > 0)
{
stroke = new LinearGradientBrush
{
GradientStops = StrokePalette.GetGradient(strokeStart, strokeEnd),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = StrokePalette.ColorInterpolationMode
};
}
}
}
