gui-cs.Terminal.Gui/Terminal.Gui/Drawing/Quant/EuclideanColorDistance.cs

namespace Terminal.Gui;

/// <summary>
/// <para>
/// Calculates the distance between two colors using Euclidean distance in 3D RGB space.
/// This measures the straight-line distance between the two points representing the colors.
///</para>
/// <para>
/// Euclidean distance in RGB space is calculated as:
/// </para>
/// <code>
///     √((R2 - R1)² + (G2 - G1)² + (B2 - B1)²)
/// </code>
/// <remarks>Values vary from 0 to ~441.67 linearly</remarks>
/// 
/// <remarks>This distance metric is commonly used for comparing colors in RGB space, though
/// it doesn't account for perceptual differences in color.</remarks>
/// </summary>
public class EuclideanColorDistance : IColorDistance
{
    /// <inheritdoc/>
    public double CalculateDistance (Color c1, Color c2)
    {
        int rDiff = c1.R - c2.R;
        int gDiff = c1.G - c2.G;
        int bDiff = c1.B - c2.B;
        return Math.Sqrt (rDiff * rDiff + gDiff * gDiff + bDiff * bDiff);
    }
}