Proposal: Add HsvColor Struct and HsvColor Property to ColorPicker

Proposal: Add HsvColor Struct and HsvColor Property to ColorPicker

Summary

1. Add a new HsvColor struct to WinUI. The struct should support the properties below. The design is based on the Windows Community Toolkit implementation.

// The hue channel 0..359
public double H { get; }

// The saturation channel 0..1 (a percentage)
public double S { get; }

//  The value channel 0..1 (a percentage)
public double V { get; }

// The alpha channel 0..1 (a percentage)
public double A { get; }

1. Add an HsvColor property to the ColorPicker itself
2. Switch the ColorSpectrum HsvColor property to use the HsvColor struct instead of Vector4

Rationale

The color picker internally works in HSV. If applications require high color precision they cannot be converting to/from RGB and HSV repeatedly or the values will drift.

It also makes sense to expose the HSV color to clean-up internal ColorPicker code that shares the value between components.

Scope

Capability	Priority
Add a new HsvColor struct	Must
Expose the internal HsvColor in the ColorPicker	Must
Expose conversion methods from RGB <-> HSV	Must
Rework internal ColorPicker/ColorSpectrum code to use HsvColor instead of Vector4	Should

[chingucoding]

Oh I see, that would also work. Maybe that would be a must then, after all we are already adding a separate API here for the ColorPicker and introducing just the HSV struct without any conversion helpers seems a bit lacking.

[chingucoding]

The proposal does not require it, but I think it would make sense to provide it. Maybe it should be required, having to implement the conversion yourself doesn’t sound like a great experience.