RawInputDigitizerContact.cs

using System.Collections.Generic;
using System.Linq;

namespace Linearstar.Windows.RawInput;

public class RawInputDigitizerContact
{
    public static readonly HidUsageAndPage UsageX = new(0x01, 0x30);
    public static readonly HidUsageAndPage UsageY = new(0x01, 0x31);
    public static readonly HidUsageAndPage UsagePressure = new(0x0D, 0x30);
    public static readonly HidUsageAndPage UsageInRange = new(0x0D, 0x32);
    public static readonly HidUsageAndPage UsageInvert = new(0x0D, 0x3c);
    public static readonly HidUsageAndPage UsageTipSwitch = new(0x0D, 0x42);
    public static readonly HidUsageAndPage UsageBarrel = new(0x0D, 0x44);
    public static readonly HidUsageAndPage UsageEraser = new(0x0D, 0x45);
    public static readonly HidUsageAndPage UsageConfidence = new(0x0D, 0x47);
    public static readonly HidUsageAndPage UsageWidth = new(0x0D, 0x48);
    public static readonly HidUsageAndPage UsageHeight = new(0x0D, 0x49);
    public static readonly HidUsageAndPage UsageIdentifier = new(0x0D, 0x51);

    public RawInputDigitizerContactKind Kind { get; }
    public int X { get; }
    public int Y { get; }
    public int MinX { get; }
    public int MinY { get; }
    public int MaxX { get; }
    public int MaxY { get; }
    public int? Pressure { get; }
    public int? MaxPressure { get; }
    public bool? IsInverted { get; }
    public bool? IsButtonDown { get; }
    public int? Width { get; }
    public int? Height { get; }
    public int? Identifier { get; }

    public RawInputDigitizerContact(IEnumerable<HidButtonState> buttonStates, IEnumerable<HidValueState> valueStates)
    {
        var buttons = buttonStates.ToDictionary(x => x.Button.UsageAndPage, x => x.IsActive);
        var values = valueStates.ToDictionary(x => x.Value.UsageAndPage);

        X = values[UsageX].CurrentValue;
        Y = values[UsageY].CurrentValue;
        MinX = values[UsageX].Value.MinValue;
        MinY = values[UsageY].Value.MinValue;
        MaxX = values[UsageX].Value.MaxValue;
        MaxY = values[UsageY].Value.MaxValue;

        if (values.TryGetValue(UsagePressure, out var pressure))
        {
            Pressure = pressure.CurrentValue;
            MaxPressure = pressure.Value.MaxValue;
        }

        IsInverted = buttons.TryGetValue(UsageInvert, out var invert) ? invert : (bool?)null;
        IsButtonDown = buttons.TryGetValue(UsageBarrel, out var barrel) ? barrel : (bool?)null;

        var isTipDown = buttons[UsageTipSwitch];

        if (buttons.TryGetValue(UsageEraser, out var eraser) && eraser)
            Kind = RawInputDigitizerContactKind.Eraser;
        else
            Kind = isTipDown
                ? buttons.TryGetValue(UsageConfidence, out var confidence) && confidence
                    ? RawInputDigitizerContactKind.Finger
                    : RawInputDigitizerContactKind.Pen
                : buttons.TryGetValue(UsageInRange, out var inRange) && inRange
                    ? RawInputDigitizerContactKind.Hover
                    : RawInputDigitizerContactKind.None;

        Width = values.TryGetValue(UsageWidth, out var width) ? width.CurrentValue : (int?)null;
        Height = values.TryGetValue(UsageHeight, out var height) ? height.CurrentValue : (int?)null;
        Identifier = values.TryGetValue(UsageIdentifier, out var identifier) ? identifier.CurrentValue : (int?)null;
    }

    public override string ToString() =>
        "{" + string.Join(", ", new[]
        {
            $"X: {X}/{MaxX}",
            $"Y: {Y}/{MaxY}",
            $"Kind: {Kind}",
            Pressure.HasValue ? $"Pressure: {Pressure}/{MaxPressure}" : null,
            IsInverted.HasValue ? $"Inverted: {IsInverted}" : null,
            IsButtonDown.HasValue ? $"Button: {IsButtonDown}" : null,
            Width.HasValue ? $"Width: {Width}" : null,
            Height.HasValue ? $"Height: {Height}" : null,
            Identifier.HasValue ? $"Identifier: {Identifier}" : null,
        }.Where(i => i != null)) + "}";
}