public static List<Point> OptimizeForIndexedChart(this IEnumerable<Point> points, Chart chart)
{
var isFirst = true;
var result = new List<Point>();
var ppp = chart.PerformanceConfiguration.PixelsPerPoint;
double? x = null;
var g = new List<Point>();
foreach (var point in points)
{
var chartValue = chart.ToPlotArea(point.X,AxisTags.X);
if (x == null) x = chartValue;
if (chartValue - x < ppp)
{
g.Add(point);
continue;
}
//ToDo: Think about this:
//average seems the best "general" method, but maybe a developer
//should be able to choose the method.
var xx = g.Average(p => p.X);
if (isFirst)
{
xx = g.First().X;
isFirst = false;
}
result.Add(new Point(xx, g.Average(p => p.Y)));
g = new List<Point> {point};
x = chart.ToPlotArea(point.X, AxisTags.X);
}
result.Add(new Point(g.Last().X, g.Average(p => p.Y)));
return result;
}
/// <summary>
/// Scales a graph value to screen according to an axis.
/// </summary>
/// <param name="value"></param>
/// <param name="axis"></param>
/// <param name="chart"></param>
/// <returns></returns>
public static double ToPlotArea(double value, AxisTags axis, Chart chart)
{
//y = m (x - x1) + y1
var p1 = axis == AxisTags.X
? new Point(chart.Max.X, chart.PlotArea.Width + chart.PlotArea.X)
: new Point(chart.Max.Y, chart.PlotArea.Y);
var p2 = axis == AxisTags.X
? new Point(chart.Min.X, chart.PlotArea.X)
: new Point(chart.Min.Y, chart.PlotArea.Y + chart.PlotArea.Height);
var m = (p2.Y - p1.Y) / (p2.X - p1.X);
return m * (value - p1.X) + p1.Y;
}
private void Chart_OnPlot(Chart chart)
{
var sunPoint = chart.ToPlotArea(new Point(4, 35));
var snowPoint = chart.ToPlotArea(new Point(8, -3));
var notePoint = chart.ToPlotArea(new Point(1, 35));
Canvas.SetLeft(_sun, sunPoint.X - 20);
Canvas.SetLeft(_snow, snowPoint.X - 20);
Canvas.SetLeft(_note, notePoint.X);
Canvas.SetTop(_sun, sunPoint.Y - 20);
Canvas.SetTop(_snow, snowPoint.Y - 20);
Canvas.SetTop(_note, notePoint.Y);
}
private void InitializeSeries(Chart chart)
{
#if DEBUG
Trace.WriteLine("Chart was initialized (" + DateTime.Now.ToLongTimeString() + ")");
#endif
chart.SeriesInitialized = true;
foreach (var series in chart.Series)
{
var index = _colorIndexer++;
series.Chart = chart;
series.Stroke = series.Stroke ??
new SolidColorBrush(
Colors[(int) (index - Colors.Count*Math.Truncate(index/(decimal) Colors.Count))]);
series.Fill = series.Fill ??
new SolidColorBrush(
Colors[(int) (index - Colors.Count*Math.Truncate(index/(decimal) Colors.Count))])
{
Opacity = DefaultFillOpacity
};
series.RequiresPlot = true;
series.RequiresAnimation = true;
var observable = series.Values as INotifyCollectionChanged;
if (observable != null)
observable.CollectionChanged += chart.OnDataSeriesChanged;
}
chart.ClearAndPlot();
var anim = new DoubleAnimation
{
From = 0,
To = 1,
Duration = TimeSpan.FromMilliseconds(1000)
};
if (!chart.DisableAnimation) chart.Canvas.BeginAnimation(OpacityProperty, anim);
chart.Series.CollectionChanged += (sender, args) =>
{
chart._seriesChanged.Stop();
chart._seriesChanged.Start();
if (args.OldItems != null)
foreach (var serie in args.OldItems.Cast<Series>())
{
chart.EraseSerieBuffer.Add(serie);
}
var newElements = args.NewItems != null ? args.NewItems.Cast<Series>() : new List<Series>();
chart.RequiresScale = true;
foreach (var serie in chart.Series.Where(x => !newElements.Contains(x)))
{
chart.EraseSerieBuffer.Add(serie);
serie.RequiresPlot = true;
}
if (args.NewItems != null)
foreach (var series in newElements)
{
var index = _colorIndexer++;
series.Chart = chart;
series.Stroke = series.Stroke ??
new SolidColorBrush(
Colors[(int)(index - Colors.Count * Math.Truncate(index / (decimal)Colors.Count))]);
series.Fill = series.Fill ??
new SolidColorBrush(
Colors[(int)(index - Colors.Count * Math.Truncate(index / (decimal)Colors.Count))])
{
Opacity = DefaultFillOpacity
};
series.RequiresPlot = true;
series.RequiresAnimation = true;
var observable = series.Values as INotifyCollectionChanged;
if (observable != null)
observable.CollectionChanged += chart.OnDataSeriesChanged;
#if DEBUG
if (observable == null) Trace.WriteLine("series do not implements INotifyCollectionChanged");
#endif
}
};
}
/// <summary>
/// Scales a graph point to screen.
/// </summary>
/// <param name="value"></param>
/// <param name="chart"></param>
/// <returns></returns>
public static Point ToPlotArea(Point value, Chart chart)
{
return new Point(ToPlotArea(value.X, AxisTags.X, chart), ToPlotArea(value.Y, AxisTags.Y, chart));
}
