/// <summary>
/// Gets the width of a unit in the chart
/// </summary>
/// <param name="source">axis orientation</param>
/// <param name="chart">chart model to get the scale at</param>
/// <param name="axis">axis instance</param>
/// <returns></returns>
public static double GetUnitWidth(AxisOrientation source, ChartCore chart, AxisCore axis)
{
double min;
double u = !double.IsNaN(axis.View.BarUnit)
? axis.View.BarUnit
: (!double.IsNaN(axis.View.Unit)
? axis.View.Unit
: 1);
if (source == AxisOrientation.Y)
{
min = axis.BotLimit;
return(ToDrawMargin(min, AxisOrientation.Y, chart, axis) -
ToDrawMargin(min + u, AxisOrientation.Y, chart, axis));
}
min = axis.BotLimit;
return(ToDrawMargin(min + u, AxisOrientation.X, chart, axis) -
ToDrawMargin(min, AxisOrientation.X, chart, axis));
}
/// <summary>
/// Converts from chart values to chart control size.
/// </summary>
/// <param name="value">value to scale</param>
/// <param name="source">axis orientation to scale value at</param>
/// <param name="chart">chart model to scale value at</param>
/// <param name="axis">axis model instance</param>
/// <returns></returns>
public static double ToPlotArea(double value, AxisOrientation source, ChartCore chart, AxisCore axis)
{
var p1 = new CorePoint();
var p2 = new CorePoint();
if (source == AxisOrientation.Y)
{
p1.X = axis.TopLimit;
p1.Y = chart.DrawMargin.Top;
p2.X = axis.BotLimit;
p2.Y = chart.DrawMargin.Top + chart.DrawMargin.Height;
}
else
{
p1.X = axis.TopLimit;
p1.Y = chart.DrawMargin.Width + chart.DrawMargin.Left;
p2.X = axis.BotLimit;
p2.Y = chart.DrawMargin.Left;
}
var deltaX = p2.X - p1.X;
// ReSharper disable once CompareOfFloatsByEqualityOperator
var m = (p2.Y - p1.Y) / (deltaX == 0 ? double.MinValue : deltaX);
return(m * (value - p1.X) + p1.Y);
}
/// <summary>
/// Converts from chart values to chart draw margin size.
/// </summary>
/// <param name="value">value to scale</param>
/// <param name="source">axis orientation</param>
/// <param name="chart">chart model to scale the value at</param>
/// <param name="axis">axis instance to scale the value at</param>
/// <returns></returns>
public static double ToDrawMargin(double value, AxisOrientation source, ChartCore chart, AxisCore axis)
{
var o = source == AxisOrientation.X
? chart.DrawMargin.Left
: chart.DrawMargin.Top;
return(ToPlotArea(value, source, chart, axis) - o);
}
