Difference between Transparent and TransparentBlack

caotrong · October 30, 2017, 1:09pm

MonoGame/MonoGame/blob/develop/MonoGame.Framework/Color.cs#L432


/// <summary>

/// Compares whether current instance is equal to specified object.

/// </summary>

/// <param name="obj">The <see cref="Color"/> to compare.</param>

/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>

public override bool Equals(object obj)

{

    return ((obj is Color) && this.Equals((Color)obj));

}



#region Color Bank

/// <summary>

/// TransparentBlack color (R:0,G:0,B:0,A:0).

/// </summary>

[Obsolete("Use Color.Transparent instead. In future versions this method can be removed.")]

public static Color TransparentBlack

{

    get;

    private set;

}

/// TransparentBlack color (R:0,G:0,B:0,A:0).
/// Transparent color (R:0,G:0,B:0,A:0).

It has no difference. I think it should be: TransparentBlack color (R:0,G:0,B:0,A:0) and Transparent color (R:255,G:255,B:255,A:0).

kosmonautgames · October 30, 2017, 1:59pm

No it’s ok like that I think. Some colors have been defined wrongfully (for example I think light gray is darker than gray), but this is just an overdefinition.
In one case you just want a transparent color and rgb don’t matter so they just chose default - 0 and in the other case black with no alpha is expected.

willmotil · October 31, 2017, 3:38am

Transparent denotes the alpha channel is has a value of zero. Rgb 0,0,0 is black 255,255,255 is white thus 255,255,255,0 would be transparent white 0,0,0,255 opaque black and 0,0,0,0 transparent black.
These values are of importance when blending colors under Non Premultiplyed alpha. Earlier versions of xna defaulted to that.