noise-utilities/Runtime/NoiseCombinator.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Sirenix.OdinInspector;

namespace KairoEngine.NoiseUtilities
{
    [System.Serializable]
    public class NoiseCombinator
    {
        [PreviewField(256, ObjectFieldAlignment.Center), HideLabel, PropertyOrder(0)]
        public Texture2D texture;
        [PropertyOrder(2), OnCollectionChanged("Before", "After"), OnInspectorInit("After")] public List<NoiseGenerator> generators = new List<NoiseGenerator>();
        [PropertyOrder(3), HideInInspector] public Vector2Int size = new Vector2Int(128, 128);

        public float SamplePoint(float x, float y)
        {
            float value = 0;
            for (int i = 0; i < generators.Count; i++)
            {
                switch (generators[i].blending)
                {
                    case NoiseBlendingModes.Blend:
                        value = BlendSubpixel(value, generators[i].SamplePoint(x, y), 1, 1f - generators[i].opacity);
                        break;
                    case NoiseBlendingModes.Addictive:
                        value += generators[i].SamplePoint(x, y) * generators[i].opacity;
                        break;
                    case NoiseBlendingModes.Subtractive:
                        value -= generators[i].SamplePoint(x, y) * generators[i].opacity;
                        break;
                }
                value = Mathf.Clamp(value, 0, 1f);
                
            }
            return value;
        }

        //[Button("Preview"), PropertyOrder(1)]
        public void GenerateTexture()
        {
            texture = new Texture2D(size.x, size.y);
            for (int x = 0; x < size.x; x++)
            {
                for (int y = 0; y < size.y; y++)
                {
                    float xCoord = (((float)x / size.x));
                    float yCoord = (((float)y / size.y));
                    float sample = SamplePoint(xCoord, yCoord);
                    Color color = new Color(sample, sample, sample);
                    texture.SetPixel(x, y, color);
                }
            }
            texture.Apply();
        }

        static float BlendSubpixel(float top, float bottom, float alphaTop, float alphaBottom){
            return (top * alphaTop) + ( (bottom-1f) * (alphaBottom-alphaTop) );
        }

        public void Before() { }

        public void After() 
        {
            for (int i = 0; i < generators.Count; i++) generators[i].OnChangeDelegate = GenerateTexture;
            GenerateTexture();
        }
    }
}