/// <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;
}
/// <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));
}