BlobVariation.cs

using System;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
 
namespace Waher.Script.Fractals.IFS.Variations.Flame
{
    public class BlobVariation : FlameVariationMultipleParameters
    {
        private readonly double high;
        private readonly double low;
        private readonly double waves;
 
        public BlobVariation(ScriptNode high, ScriptNode low, ScriptNode waves, int Start, int Length, Expression Expression)
            : base(new ScriptNode[] { high, low, waves }, new ArgumentType[] { ArgumentType.Scalar,
                ArgumentType.Scalar, ArgumentType.Scalar }, Start, Length, Expression)
        {
            this.high = 0;
            this.low = 0;
            this.waves = 0;
        }
 
        private BlobVariation(double High, double Low, double Waves, ScriptNode high, ScriptNode low, ScriptNode waves,
            int Start, int Length, Expression Expression)
            : base(new ScriptNode[] { high, low, waves }, new ArgumentType[] { ArgumentType.Scalar,
                ArgumentType.Scalar, ArgumentType.Scalar }, Start, Length, Expression)
        {
            this.high = High;
            this.low = Low;
            this.waves = Waves;
        }
 
        public override string[] DefaultArgumentNames
        {
            get
            {
                return new string[] { "high", "low", "waves" };
            }
        }
 
        public override IElement Evaluate(IElement[] Arguments, Variables Variables)
        {
            double High = Expression.ToDouble(Arguments[0].AssociatedObjectValue);
            double Low = Expression.ToDouble(Arguments[1].AssociatedObjectValue);
            double Waves = Expression.ToDouble(Arguments[2].AssociatedObjectValue);
 
            return new BlobVariation(High, Low, Waves, this.Arguments[0], this.Arguments[1], this.Arguments[2],
                this.Start, this.Length, this.Expression);
        }
 
        public override void Operate(ref double x, ref double y)
        {
            double r = Math.Sqrt(x * x + y * y);
            double a = Math.Atan2(x, y);
            r *= this.low + (this.high - this.low) * 0.5 * (Math.Sin(this.waves * a) + 1);
            x = r * Math.Cos(a);
            y = r * Math.Sin(a);
        }
 
        public override string FunctionName => nameof(BlobVariation);
    }
}