using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using UnityEngine.Rendering;
using System;
using UnityEngine.Serialization;

public class EffectMask : Mask {

    [NonSerialized]
    private Material c_MaskMaterial;

    [NonSerialized]
    private Material c_UnmaskMaterial;

    protected override void OnDisable()
    {
        // we call base OnDisable first here
        // as we need to have the IsActive return the
        // correct value when we notify the children
        // that the mask state has changed.
        base.OnDisable();
        if (graphic != null)
        {
            graphic.SetMaterialDirty();
            graphic.canvasRenderer.hasPopInstruction = false;
            graphic.canvasRenderer.popMaterialCount = 0;
        }

        StencilMaterial.Remove(c_MaskMaterial);
        c_MaskMaterial = null;
        StencilMaterial.Remove(c_UnmaskMaterial);
        c_UnmaskMaterial = null;

        MaskUtilities.NotifyStencilStateChanged(this);
    }

    public override Material GetModifiedMaterial(Material baseMaterial)
    {
        if (!MaskEnabled())
            return baseMaterial;

        var maskMaterial = StencilMaterial.Add(baseMaterial, 1, StencilOp.Replace, CompareFunction.Always, showMaskGraphic ? ColorWriteMask.All : 0);
        StencilMaterial.Remove(c_MaskMaterial);
        c_MaskMaterial = maskMaterial;

        return c_MaskMaterial;
    }
}