[ExecuteInEditMode]
[RequireComponent(typeof(Camera))]
[AddComponentMenu("Image Effects/Screen Transition ImageEffec")]
public class ScreenTransitionImageEffect : MonoBehaviour
{
    public Shader shader;

    [Range(0, 1.0f)]
    public float maskValue;

    public Color maskColor = Color.black;
    public Texture2D maskTexture;
    public float maskInvert;
    public Vector2 xy;
    Material m_Material;
    bool m_maskInvert;

    Material material
    {
        get
        {
            if (m_Material == null)
            {
                m_Material = new Material(shader);
                m_Material.hideFlags = HideFlags.HideAndDontSave;
            }

            return m_Material;
        }
    }

    void Start()
    {
        if (!SystemInfo.supportsImageEffects)
        {
            enabled = false;
            return;
        }


        shader = Shader.Find("Hidden/ScreenTransitionImageEffect");


        if (shader == null || !shader.isSupported)
        {
            enabled = false;
        }

    }

    void OnDisable()
        {
            if (m_Material)
            {
                DestroyImmediate(m_Material);
            }
        }

        void OnRenderImage(RenderTexture source, RenderTexture destination)
        {
            if (!enabled)
            {
                Graphics.Blit(source, destination);
                return;
            }

            material.SetColor("_MaskColor", maskColor);
            material.SetFloat("_MaskValue", maskValue);
            material.SetFloat("_INVERT_MASK", maskInvert);
            material.SetTexture("_MainTex", source);

            material.SetTexture("_MaskTex", maskTexture);
            material.SetVector("_XY", xy);

            Graphics.Blit(source, destination, material);
        }
    }