private void GetBrushesFromPalette(double currentValue, double nextValue, out Brush strokeBrush, out Brush fillBrush)
{
// Set default values.
strokeBrush = BorderBrush;
fillBrush = Background;
Palette fillPalette = EffectiveFillPalette;
Palette strokePalette = EffectiveStrokePalette;
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(currentValue));
if (strokePalette != null && strokePalette.Count > 0)
strokeBrush = new SolidColorBrush(strokePalette.GetColor(nextValue));
}
else
{
// Gradient:
// Define end point for gradient direction.
Point startPoint = new Point(0, 0);
Point endPoint = new Point(1, 0);
Axis xAxis = XAxis;
if (xAxis.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(currentValue, nextValue),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = fillPalette.ColorInterpolationMode
};
}
if (strokePalette != null && strokePalette.Count > 0)
{
strokeBrush = new LinearGradientBrush
{
GradientStops = strokePalette.GetGradient(currentValue, nextValue),
StartPoint = startPoint,
EndPoint = endPoint,
ColorInterpolationMode = strokePalette.ColorInterpolationMode
};
}
}
}
public override double GetValue(double position, double startPosition, double endPosition)
{
if (Min >= Max)
{
throw new ChartException("AxisScale.Min must be less than AxisScale.Max.");
}
if (Reversed)
{
ChartHelper.Swap(ref startPosition, ref endPosition);
}
double v = (position - startPosition) / (endPosition - startPosition);
double value = Min * Math.Pow(Max / Min, v);
return(value);
}
/// <summary>
/// Gets the position on the axis for a specified data value.
/// </summary>
/// <param name="value">The data value.</param>
/// <param name="startPosition">The start position (origin) of the axis.</param>
/// <param name="endPosition">The end position of the axis.</param>
/// <returns>The position of the data value on the axis.</returns>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="value"/> is negative.
/// </exception>
/// <exception cref="ChartException">
/// Invalid scale. <see cref="AxisScale.Min"/> is greater than or equal to
/// <see cref="AxisScale.Max"/>.
/// </exception>
public override double GetPosition(double value, double startPosition, double endPosition)
{
if (Min >= Max)
{
throw new ChartException("Scale.Min must be less than Scale.Max.");
}
if (value < 0.0f)
{
throw new ArgumentOutOfRangeException("value", "Cannot have negative values for data using a logarithmic scale.");
}
if (Reversed)
{
ChartHelper.Swap(ref startPosition, ref endPosition);
}
double logValue = Math.Log10(value);
double logMin = Math.Log10(Min);
double logMax = Math.Log10(Max);
return((float)(startPosition + (logValue - logMin) / (logMax - logMin) * (endPosition - startPosition)));
}
private void Update()
{
if (_isValid)
return;
_sectorGeometry.Clear();
_leaderLineGeometry.Clear();
// Fetch dependency properties. (Accessing dependency properties is expensive.)
double centerX = CenterX;
double centerY = CenterY;
double innerRadius = InnerRadius;
double outerRadius = OuterRadius;
double offset = Offset;
double startAngle = StartAngle;
double endAngle = EndAngle;
// Correct invalid values.
if (innerRadius < 0)
innerRadius = 0;
if (outerRadius < 0)
outerRadius = 0;
if (innerRadius > outerRadius)
innerRadius = outerRadius;
if (startAngle > endAngle)
ChartHelper.Swap(ref startAngle, ref endAngle);
// The sector angle.
double angle = endAngle - startAngle;
// The thickness of the ring.
double width = outerRadius - innerRadius;
// The direction vector pointing from the center to the start of the sector.
double startX, startY;
GetDirection(startAngle, out startX, out startY);
// The direction vector pointing from the center to the end of the sector.
double endX, endY;
GetDirection(endAngle, out endX, out endY);
// The direction vector pointing from the center to the middle of the sector.
double midX, midY;
GetDirection((startAngle + endAngle) / 2, out midX, out midY);
// Exploded pie charts: Translate the center of the pie chart.
centerX += offset * midX;
centerY += offset * midY;
if (angle < 2 * Math.PI)
{
// ---- Draw sector.
Point p0 = new Point(centerX + innerRadius * startX, centerY + innerRadius * startY);
Point p1 = new Point(centerX + outerRadius * startX, centerY + outerRadius * startY);
Point p2 = new Point(centerX + outerRadius * endX, centerY + outerRadius * endY);
Point p3 = new Point(centerX + innerRadius * endX, centerY + innerRadius * endY);
var figure = new PathFigure { StartPoint = p0 };
figure.Segments.Add(new LineSegment { Point = p1 });
figure.Segments.Add(new ArcSegment { Point = p2, Size = new Size(outerRadius, outerRadius), IsLargeArc = angle > Math.PI, SweepDirection = SweepDirection.Clockwise });
figure.Segments.Add(new LineSegment { Point = p3 });
figure.Segments.Add(new ArcSegment { Point = p0, Size = new Size(innerRadius, innerRadius), IsLargeArc = angle > Math.PI, SweepDirection = SweepDirection.Counterclockwise });
_sectorGeometry.Figures.Add(figure);
}
else
{
if (innerRadius > 0)
{
// ----- Draw full ring.
Point p0 = new Point(centerX, centerY - outerRadius);
Point p1 = new Point(centerX, centerY + outerRadius);
Point p2 = new Point(centerX, centerY - innerRadius);
Point p3 = new Point(centerX, centerY + innerRadius);
// Outer circle (= two half-circles).
var figure = new PathFigure { StartPoint = p0 };
figure.Segments.Add(new ArcSegment { Point = p1, Size = new Size(outerRadius, outerRadius), SweepDirection = SweepDirection.Clockwise });
figure.Segments.Add(new ArcSegment { Point = p0, Size = new Size(outerRadius, outerRadius), SweepDirection = SweepDirection.Clockwise });
_sectorGeometry.Figures.Add(figure);
// Inner circle (= two half-circles).
figure = new PathFigure { StartPoint = p2 };
figure.Segments.Add(new ArcSegment { Point = p3, Size = new Size(innerRadius, innerRadius), SweepDirection = SweepDirection.Clockwise });
figure.Segments.Add(new ArcSegment { Point = p2, Size = new Size(innerRadius, innerRadius), SweepDirection = SweepDirection.Clockwise });
_sectorGeometry.Figures.Add(figure);
}
else
{
// ----- Draw full disc.
Point p0 = new Point(centerX, centerY - outerRadius);
Point p1 = new Point(centerX, centerY + outerRadius);
// Outer circle (= two half-circles).
var figure = new PathFigure { StartPoint = p0 };
figure.Segments.Add(new ArcSegment { Point = p1, Size = new Size(outerRadius, outerRadius), SweepDirection = SweepDirection.Clockwise });
figure.Segments.Add(new ArcSegment { Point = p0, Size = new Size(outerRadius, outerRadius), SweepDirection = SweepDirection.Clockwise });
_sectorGeometry.Figures.Add(figure);
}
}
// ----- Draw inner label.
if (InnerLabel != null && angle > InnerLabelClipAngle)
{
_innerLabel.Visibility = Visibility.Visible;
_innerLabel.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
Size size = _innerLabel.DesiredSize;
if (size.Width > 0 && size.Height > 0)
{
double x = centerX + innerRadius * midX + 0.6 * width * midX;
double y = centerY + innerRadius * midY + 0.6 * width * midY;
x -= size.Width / 2;
y -= size.Height / 2;
Canvas.SetLeft(_innerLabel, x);
Canvas.SetTop(_innerLabel, y);
}
}
else
{
_innerLabel.Visibility = Visibility.Collapsed;
}
// ----- Draw outer label.
if (OuterLabel != null && angle > OuterLabelClipAngle)
{
_outerLabel.Visibility = Visibility.Visible;
_outerLabel.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
Size size = _outerLabel.DesiredSize;
if (size.Width > 0 && size.Height > 0)
{
// Draw leader line.
double outerLabelDistance = LeaderLineLength;
double l1 = 0.667 * outerLabelDistance; // Segment normal to circle.
double l2 = 0.333 * outerLabelDistance; // Horizontal segment.
double d = 0.5 * l2; // Distance between line and label.
Point p0 = new Point(centerX + outerRadius * midX, centerY + outerRadius * midY);
Point p1 = new Point(centerX + (outerRadius + l1) * midX, centerY + (outerRadius + l1) * midY);
Point p2 = new Point(p1.X + l2 * Math.Sign(midX), p1.Y);
var line = new PathFigure { StartPoint = p0 };
line.Segments.Add(new LineSegment { Point = p1 });
line.Segments.Add(new LineSegment { Point = p2 });
_leaderLineGeometry.Figures.Add(line);
if (midX >= 0)
{
// Label on the right.
Canvas.SetLeft(_outerLabel, p2.X + d);
Canvas.SetTop(_outerLabel, p2.Y - size.Height / 2);
}
else
{
// Label on the left.
Canvas.SetLeft(_outerLabel, p2.X - d - size.Width);
Canvas.SetTop(_outerLabel, p2.Y - size.Height / 2);
}
}
}
else
{
_outerLabel.Visibility = Visibility.Collapsed;
}
_isValid = true;
}
/// <inheritdoc/>
protected override void OnUpdate()
{
base.OnUpdate();
Debug.Assert(Canvas.Children.Count == 0, "Canvas should be cleared in base class.");
if (Data == null || Data.Count == 0 || DataPointTemplate == null)
{
// A relevant property is not set.
return;
}
// Fetch dependency properties. (Accessing dependency properties is expensive.)
Axis xAxis = XAxis;
Axis yAxis = YAxis;
AxisScale xScale = xAxis.Scale;
AxisScale yScale = yAxis.Scale;
double centerX = CenterX;
double centerY = CenterY;
double hole = Hole;
double outerRadius = Radius;
Thickness padding = Padding;
if (hole < 0 || hole > 1)
throw new ChartException("Pie chart has invalid hole size. The hole size is relative to the outer radius and must be in the range [0, 1].");
if (outerRadius < 0)
throw new ChartException("Pie chart has invalid radius. The radius must be a equal to or greater than 0.");
// Determine available space.
double left = xAxis.GetPosition(xScale.Min);
double right = xAxis.GetPosition(xScale.Max);
if (left > right)
{
// Scale is reversed.
ChartHelper.Swap(ref left, ref right);
}
double top = yAxis.GetPosition(yScale.Max);
double bottom = yAxis.GetPosition(yScale.Min);
if (top > bottom)
{
// Scale is reversed.
ChartHelper.Swap(ref top, ref bottom);
}
// Apply padding.
left += padding.Left;
right -= padding.Right;
top += padding.Top;
bottom -= padding.Bottom;
if (Numeric.IsNaN(centerX))
{
// Center pie chart horizontally.
centerX = (left + right) / 2;
}
else
{
centerX = xAxis.OriginX + centerX * xAxis.Length;
}
if (Numeric.IsNaN(centerY))
{
// Center pie chart vertically.
centerY = (top + bottom) / 2;
}
else
{
centerY = yAxis.OriginY - (1.0 - centerY) * yAxis.Length;
}
if (Numeric.IsNaN(outerRadius))
{
// Fit pie chart into available space.
double radiusLeft = centerX - left;
double radiusRight = right - centerX;
double radiusTop = centerY - top;
double radiusBottom = bottom - centerY;
outerRadius = radiusLeft;
if (outerRadius > radiusRight)
outerRadius = radiusRight;
if (outerRadius > radiusTop)
outerRadius = radiusTop;
if (outerRadius > radiusBottom)
outerRadius = radiusBottom;
}
if (Numeric.IsNaN(hole))
hole = 0;
double innerRadius = hole * outerRadius;
ActualHoleRadius = innerRadius;
// Draw pie chart inside chart panel.
DrawPieChart(Canvas, centerX, centerY, innerRadius, outerRadius, BrushSelector, false);
// Update legend symbols inside legends.
// Use a fixed innerRadius
innerRadius = (Hole > 0) ? 2 : 0;
foreach (var legendSymbol in _legendSymbols)
DrawPieChart(legendSymbol, 8, 8, innerRadius, 8, BrushSelector, true);
}
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 override Size ArrangeOverride(Size finalSize)
{
// Ensure that all axes are up to date.
foreach (Axis axis in _monitoredAxes)
axis.Update();
UIElementCollection children = Children;
for (int i = 0; i < children.Count; ++i)
{
UIElement child = children[i];
if (child == null)
continue;
// Get the child or one of its descendants that needs to be positioned.
DependencyObject elementThatRequiresArrange = GetElementThatRequiresArrange(child);
if (elementThatRequiresArrange == null)
{
// This child ignores the attached properties (X1, Y1, X2, Y2).
Rect childBounds = new Rect(new Point(), finalSize);
// Arrange element,
child.Arrange(childBounds);
// Clip to chart area.
if (GetClipToChartArea(child))
ClipElementToChartArea(child, childBounds);
}
else
{
// Determine alignment.
HorizontalAlignment horizontalAlignment = HorizontalAlignment.Left;
VerticalAlignment verticalAlignment = VerticalAlignment.Top;
if (elementThatRequiresArrange is FrameworkElement)
{
FrameworkElement frameworkElement = (FrameworkElement)elementThatRequiresArrange;
horizontalAlignment = frameworkElement.HorizontalAlignment;
verticalAlignment = frameworkElement.VerticalAlignment;
}
// Get associated axes.
Axis xAxis = GetXAxis(elementThatRequiresArrange);
Axis yAxis = GetYAxis(elementThatRequiresArrange);
// Check whether we have to position the element relative to a point (X1, Y1)
// or inside a region (X1, Y1) - (X2, Y2).
// Convert positions given in data values to pixel positions.
double x1 = xAxis.GetPosition(GetX1(elementThatRequiresArrange));
double y1 = yAxis.GetPosition(GetY1(elementThatRequiresArrange));
double x2 = xAxis.GetPosition(GetX2(elementThatRequiresArrange));
double y2 = yAxis.GetPosition(GetY2(elementThatRequiresArrange));
bool isX1Valid = Numeric.IsFinite(x1);
bool isY1Valid = Numeric.IsFinite(y1);
bool isX2Valid = Numeric.IsFinite(x2);
bool isY2Valid = Numeric.IsFinite(y2);
double availableWidth = Double.PositiveInfinity;
double availableHeight = Double.PositiveInfinity;
if (!isX1Valid && !isX2Valid)
{
// No coordinates set. Use 0 and 'left' alignment.
x1 = 0;
x2 = Double.NaN;
horizontalAlignment = HorizontalAlignment.Left;
}
else if (!isX1Valid)
{
// Only X2 set. Use X2 as position.
x1 = x2;
x2 = Double.NaN;
}
else if (isX2Valid)
{
// X1 and X2 are set.
int result = Numeric.Compare(x1, x2);
if (result < 0)
{
// X1 < X2: Horizontal region.
availableWidth = x2 - x1;
}
else if (result == 0)
{
// X1 == X2: Use only X1.
x2 = Double.NaN;
}
else
{
// X2 > X1: Horizontal region, but swapped.
ChartHelper.Swap(ref x1, ref x2);
availableWidth = x2 - x1;
}
}
if (!isY1Valid && !isY2Valid)
{
// No coordinates set. Use 0 and 'top' alignment.
y1 = 0;
y2 = Double.NaN;
verticalAlignment = VerticalAlignment.Top;
}
else if (!isY1Valid)
{
// Only Y2 set. Use Y2 as position.
y1 = y2;
y2 = Double.NaN;
}
else if (isY2Valid)
{
// Y1 and Y2 are set.
int result = Numeric.Compare(y1, y2);
if (result < 0)
{
// Y1 < Y2: Horizontal region.
availableHeight = y2 - y1;
}
else if (result == 0)
{
// Y1 == Y2: Use only Y1.
y2 = Double.NaN;
}
else
{
// Y2 > Y1: Horizontal region, but swapped.
ChartHelper.Swap(ref y1, ref y2);
availableHeight = y2 - y1;
}
}
// Get size of child.
double elementWidth = child.DesiredSize.Width;
double elementHeight = child.DesiredSize.Height;
if (elementWidth == 0.0 && elementHeight == 0.0 && child is FrameworkElement)
{
// Fix for Silverlight.
FrameworkElement frameworkElement = (FrameworkElement)child;
elementWidth = frameworkElement.ActualWidth;
elementHeight = frameworkElement.ActualHeight;
}
// Compute bounds of the child element.
Rect childBounds = new Rect();
// Position child horizontally.
if (Numeric.IsNaN(x2))
{
// Position child relative to point.
switch (horizontalAlignment)
{
case HorizontalAlignment.Left:
case HorizontalAlignment.Stretch:
childBounds.X = x1;
childBounds.Width = elementWidth;
break;
case HorizontalAlignment.Center:
childBounds.X = x1 - elementWidth / 2.0;
childBounds.Width = elementWidth;
break;
case HorizontalAlignment.Right:
childBounds.X = x1 - elementWidth;
childBounds.Width = elementWidth;
break;
}
}
else
{
// Position child inside horizontal region.
switch (horizontalAlignment)
{
case HorizontalAlignment.Left:
childBounds.X = x1;
childBounds.Width = elementWidth;
break;
case HorizontalAlignment.Center:
childBounds.X = x1 + availableWidth / 2.0 - elementWidth / 2.0;
childBounds.Width = elementWidth;
break;
case HorizontalAlignment.Right:
childBounds.X = x2 - elementWidth;
childBounds.Width = elementWidth;
break;
case HorizontalAlignment.Stretch:
childBounds.X = x1;
childBounds.Width = availableWidth;
break;
}
}
// Position child vertically.
if (Numeric.IsNaN(y2))
{
// Position child relative to point.
switch (verticalAlignment)
{
case VerticalAlignment.Top:
case VerticalAlignment.Stretch:
childBounds.Y = y1;
childBounds.Height = elementHeight;
break;
case VerticalAlignment.Center:
childBounds.Y = y1 - elementHeight / 2.0;
childBounds.Height = elementHeight;
break;
case VerticalAlignment.Bottom:
childBounds.Y = y1 - elementHeight;
childBounds.Height = elementHeight;
break;
}
}
else
{
// Position child inside vertical region.
switch (verticalAlignment)
{
case VerticalAlignment.Top:
childBounds.Y = y1;
childBounds.Height = elementHeight;
break;
case VerticalAlignment.Center:
childBounds.Y = y1 + availableHeight / 2.0 - elementHeight / 2.0;
childBounds.Height = elementHeight;
break;
case VerticalAlignment.Bottom:
childBounds.Y = y2 - elementHeight;
childBounds.Height = elementHeight;
break;
case VerticalAlignment.Stretch:
childBounds.Y = y1;
childBounds.Height = availableHeight;
break;
}
}
// Arrange element.
child.Arrange(childBounds);
// Clip to chart area.
if (elementThatRequiresArrange is UIElement && GetClipToChartArea(elementThatRequiresArrange))
{
UIElement element = (UIElement)elementThatRequiresArrange;
ClipElementToChartArea(element, childBounds);
}
}
}
return finalSize;
}
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
};
}
}
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
};
}
}
}
