RGBA.cs

using System;
using System.Collections.Generic;
using SkiaSharp;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Graphs.Functions.Colors
{
    public class RGBA : FunctionMultiVariate
    {
        public RGBA(ScriptNode R, ScriptNode G, ScriptNode B, ScriptNode A, int Start, int Length, Expression Expression)
            : base(new ScriptNode[] { R, G, B, A }, FunctionMultiVariate.argumentTypes4Scalar, Start, Length, Expression)
        {
        }
 
        public override string[] DefaultArgumentNames
        {
            get
            {
                return new string[] { "R", "G", "B", "A" };
            }
        }
 
        public override string FunctionName
        {
            get
            {
                return "RGBA";
            }
        }
 
        public override IElement Evaluate(IElement[] Arguments, Variables Variables)
        {
            int R = (int)(Expression.ToDouble(Arguments[0].AssociatedObjectValue) + 0.5);
            int G = (int)(Expression.ToDouble(Arguments[1].AssociatedObjectValue) + 0.5);
            int B = (int)(Expression.ToDouble(Arguments[2].AssociatedObjectValue) + 0.5);
            int A = (int)(Expression.ToDouble(Arguments[3].AssociatedObjectValue) + 0.5);
 
            if (R < 0)
                R = 0;
            else if (R > 255)
                R = 255;
 
            if (G < 0)
                G = 0;
            else if (G > 255)
                G = 255;
 
            if (B < 0)
                B = 0;
            else if (B > 255)
                B = 255;
 
            if (A < 0)
                A = 0;
            else if (A > 255)
                A = 255;
 
            return new ObjectValue(new SKColor((byte)R, (byte)G, (byte)B, (byte)A));
        }
    }
}