fungus/Assets/Fungus/Scripts/Editor/CustomGUI.cs

// This code is part of the Fungus library (http://fungusgames.com) maintained by Chris Gregan (http://twitter.com/gofungus).
// It is released for free under the MIT open source license (https://github.com/snozbot/fungus/blob/master/LICENSE)

using UnityEngine;

namespace Fungus.EditorUtils
{
    /// <summary>
    /// Utility functions for drawing custom UI in the editor.
    /// </summary>
    public static class CustomGUI
    {   
        public static Texture2D CreateBlackTexture()
        {
            Texture2D blackTex = new Texture2D(1,2);
            blackTex.SetPixel(0, 0, Color.gray);
            blackTex.SetPixel(1, 0, Color.black);
            blackTex.Apply();
            blackTex.hideFlags = HideFlags.DontSave;
            return blackTex;
        }

        public static Texture2D CreateColorTexture(Color color)
        {
            Texture2D colorTex = new Texture2D(1,1);
            colorTex.SetPixel(0, 0, color);
            colorTex.Apply();
            colorTex.hideFlags = HideFlags.DontSave;
            return colorTex;
        }
        
        public static void DrawLineSeparator(Texture2D blackTex, float width)
        {
            GUIStyle separatorStyle = new GUIStyle(GUI.skin.box);
            separatorStyle.fixedWidth = width;
            separatorStyle.fixedHeight = 2;
            separatorStyle.margin.top = 10;
            separatorStyle.margin.bottom = 10;
            GUILayout.Box(blackTex,separatorStyle);
        }
    }
}