ChromaticityDotNet.AvaloniaDiagram 1.0.4.12

ChromaticityDotNet.AvaloniaDiagram

Reusable Avalonia controls depending only on Avalonia and ChromaticityDotNet:

• ChromaticityDiagram: xy / CIE 1976 u′v′ plots from Chromaticity.Tools, including observer-specific backgrounds, Planckian locus, CCT / Duv and wavelength rays.
• LchPlot: Colorimeter.Embedded's separate L* axis and C*/h° plane, comparing standard and sample with distinct circle / diamond markers.
• SpectrumPlot: Chromaticity.Tools' spectrum curve with Colorimeter.Embedded's nearest-sample selection, extended to arbitrary wavelength ranges and irregular grids.
• SpectrumNavigator: reusable ◀ / ▶ buttons and a wavelength/value readout associated with a SpectrumPlot, matching Colorimeter.Embedded's cyclic navigation.

All controls are in ChromaticityDotNet.AvaloniaDiagram.Controls. Shared data and geometry are in the main package's ChromaticityDotNet.Diagrams namespace.

using ChromaticityDotNet.AvaloniaDiagram.Controls;
using ChromaticityDotNet.Diagrams;
using static ChromaticityDotNet.Model.DataModel;

var lch = new LchPlot
{
    StandardLab = new CIELAB(50, 30, 20),
    SampleLab = new CIELAB(53, 32, 18)
};
var spectrum = new SpectrumPlot { AxisLabel = "%", MinimumMaximum = 100 };
var navigation = new SpectrumNavigator { Plot = spectrum };
// Place navigation above spectrum; navigation aligns to the right by default.
spectrum.SetData(new[] { 18.0, 20.0, 22.0 }, 400, 10);
spectrum.SelectWavelength(413); // Selects the measured 410 nm point: 20%.

Use ChromaticityDiagram.Space to select xy / u′v′, WavelengthData / SetData for sample/white rays, or LightData / SetLightData for a light-source marker. These are bindable styled properties. Clear(observer) clears old markers.

ShowWavelengthLabels controls the edge wavelength markers and captions; ShowPlanckianLocus controls the blackbody curve and nearest-point / Duv overlay; ShowTemperatureLabels controls reference temperatures and the measured CCT label. Reference temperatures can be displayed independently of the curve. Wavelengths and the curve default to visible; temperatures default to hidden. ShowLegend defaults to true and lists the blackbody curve and current measurement markers inside the plot: xy at the top right, u′v′ at the bottom right. Many entries use additional columns; long names are shortened with an ellipsis. The control keeps its square layout. Click a legend item to temporarily hide or restore its curve / marker. Hidden items stay in the legend in gray and are excluded from data selection. Hiding the blackbody curve also hides its reference temperatures and nearest-point overlay, without changing ShowPlanckianLocus or ShowTemperatureLabels. Sample visibility resets when measurements are replaced; the curve stays hidden until restored. Explicitly assigning ShowPlanckianLocus restores its configured visibility. ToggleLegendItem, IsLegendItemVisible and GetLegendItemArea support host control.

The shared default axes are xy 0–1.0 on both axes, and u′v′ 0–0.8 / 0–0.7, leaving room in these corners. Set AxisMaximumX / AxisMaximumY to expand the view for larger legends; null restores the defaults. Changing the display range does not stretch the background in coordinate space or change sample coordinates.

Left-click or touch a sample, white point, wavelength intersection, boundary or blackbody point to show its name and coordinates, plus wavelength / temperature / Duv where applicable. Drag while pressed to inspect nearby targets. Click empty space or press Escape to dismiss the readout. SelectedTarget and SelectionChanged expose full-precision data to the host. HitTestTarget, PlotPoint, PlotArea and LegendArea are available for host interaction or tests; the legend itself does not select targets. Replacing data clears selection.

For a background with named sample points, use the same xy samples in either space:

var diagram = new ChromaticityDiagram
{
    Space = ChromaticityDiagramSpace.UvPrime,
    ShowWavelengthLabels = false,
    ShowPlanckianLocus = false,
    ShowTemperatureLabels = false
};
diagram.SetSamples(new[]
{
    new ChromaticityDiagramSample("Reference", new ChromaticityCoordinates(0.3127, 0.3290), 0xFF2563EB),
    new ChromaticityDiagramSample("Sample 1", new ChromaticityCoordinates(0.4, 0.2), 0xFFE11D48)
});

ChromaticityDiagramSample keeps its name, full-precision xy coordinates and ARGB marker color. Its legend uses the same color. SetSamples takes an immutable snapshot and replaces wavelength/light measurements. Samples is also bindable; replace the list when changing points. Clear and SetData / SetLightData clear named samples; changing display options preserves them.

The four-argument ChromaticityDiagramSample(name, coordinates, argb, markerRadius) constructor customizes the circle radius in device-independent pixels. The existing constructor retains its 5-pixel default. Draw a standard with radius 8 before a sample with radius 4 to keep both colors visible when their coordinates coincide. Axis tick spacing adapts to the available plot size so small side-by-side diagrams retain readable labels. Set ShowLegend, ShowPlanckianLocus, ShowTemperatureLabels and ShowWavelengthLabels to false for a points-only view. Set ShowObserverLabel to false to hide the observer/standard caption and reclaim its top margin. The selected observer, background and sample coordinates are preserved.

SpectrumPlot.Data accepts immutable SpectrumDiagramData. SelectedIndex supports two-way binding; SelectedWavelength and SelectedValue are observable read-only properties. SelectionChanged reports changes. Click, touch or drag inside the plot to select a measured point, or use Left/Right/Home/End while focused. Selection uses the actual sampling grid; it does not interpolate values. Changing data clears selection. Missing/nonfinite values are gaps and are skipped. Y-axis limits include zero and round outward to multiples of 10: a peak of 117 uses 0–120, and a minimum of −13 uses −20. MinimumMaximum remains a configurable floor for the upper limit (default 100 for percentage plots). YAxisMinimum / YAxisMaximum expose the displayed limits; source values are unchanged.

For standard/sample comparison, bind StandardData alongside sample Data. Both curves use a shared wavelength range and Y-axis range, including negative values and peaks from either curve. XAxisMinimum / XAxisMaximum expose the combined wavelength range. CurveColor defaults to dark gray; StandardCurveColor defaults to orange. The thicker standard curve and larger selection ring remain visible when curves or selected points coincide. Selection follows the sample's actual grid, falling back to the standard's grid when Data is null. SelectedValue remains the selected curve's source value; SelectedStandardValue is the standard's measured value at that wavelength, or null for a missing/different-grid point. No comparison values are interpolated. Replacing either curve clears selection; Clear() clears both curves. SpectrumDiagramData.ValueAt(wavelength) exposes the same measured-value lookup. An attached SpectrumNavigator selects the first valid point after either curve changes and labels both values in its comparison readout.

var comparison = new SpectrumPlot
{
    Data = SpectrumDiagramData.FromUniform(new[] { 12.0, 18, 22 }, 400, 10),
    StandardData = SpectrumDiagramData.FromUniform(new[] { 15.0, 20, 25 }, 400, 10),
    CurveColor = Avalonia.Media.Color.Parse("#1778B5")
};

When attached, SpectrumNavigator selects the first valid point on load and when data changes. Its buttons move one actual sample at a time, wrap at either end, and skip gaps. The readout stays in the source units (reflectance % or relative spectral power) and follows pointer/keyboard selections too. Plot is bindable; buttons are disabled without valid data. The plot itself no longer repeats this readout in its upper-left corner. For custom buttons, call spectrum.MoveSelection(-1, wrap: true) for the previous sample or spectrum.MoveSelection(1, wrap: true) for the next sample.

The LCh background uses L*=70 and the library's integrated D65 / 10° white. It is a clipped sRGB screen preview, independent of measurement calculations. The C*/h° plane preserves unrounded a*/b* and scales to include both colors.

DiagramControl.LabelTypeface and Translate let the host provide its own font and label translation. The library has no Chromaticity.Tools resources, global language events or Colorimeter services. Hosts should invalidate controls when their language changes.

ChromaticityDiagram.BackgroundColor defaults to white. Set it to the host surface color for a dark theme; labels, axes, grid, and legend automatically use a readable palette.

diagram.BackgroundColor = Avalonia.Media.Color.Parse("#202020");

Call SpectrumNavigator.RefreshLabels() when the host language changes; it uses its plot's translation and label font.

Targets: net8.0, net10.0; Avalonia 12.1.2 or compatible newer version. Avalonia 12 requires .NET 8 or later and does not provide .NET Standard runtime assemblies. The framework-independent geometry and data remain in the main ChromaticityDotNet package, which supports netstandard2.0. Code: MIT; CIE data: CC BY-SA 4.0.