/Win7oob/Projects/TheOliver.Controls.Effects/ShaderEffects/ChromaKeyAlphaEffect.cs

// <copyright file="ChromaKeyAlphaEffect.cs" company="Microsoft Corporation">

// Copyright (c) 2009 Microsoft Corporation All Rights Reserved

// </copyright>

// <author>Michael S. Scherotter</author>

// <email>mischero@microsoft.com</email>

// <date>2009-05-10</date>

// <summary>Color Key Alpha Pixel Effect for Silverlight 3</summary>



namespace TheOliver.Controls.ShaderEffects

{

    using System.ComponentModel;

    using System.Windows;

    using System.Windows.Media;

    using System.Windows.Media.Effects;

    using TheOliver.Controls;



    /// <summary>

    /// Color Key alpha effect for Silverlight 3

    /// </summary>

    [Description("Chroma Key Alpha effect with tolerance")]

    public class ChromaKeyAlphaEffect : ShaderEffect

    {

        #region Fields



        /// <summary>

        /// This property is mapped to the InputColor variable within the pixel shader.

        /// </summary>

        public static readonly DependencyProperty ColorKeyProperty = DependencyProperty.Register("ColorKey", typeof(Color), typeof(ChromaKeyAlphaEffect), new PropertyMetadata(Colors.Green, PixelShaderConstantCallback(0)));



        /// <summary>

        /// This is the tolerance 0=exact 1=full

        /// </summary>

        public static readonly DependencyProperty ToleranceProperty = DependencyProperty.Register("Tolerance", typeof(double), typeof(ChromaKeyAlphaEffect), new PropertyMetadata(0.1, PixelShaderConstantCallback(1)));



        /// <summary>

        /// The explict input for this pixel shader.

        /// </summary>

        public static readonly DependencyProperty InputProperty = ShaderEffect.RegisterPixelShaderSamplerProperty("Input", typeof(ChromaKeyAlphaEffect), 0);



        /// <summary>

        /// A reference to the pixel shader used.

        /// </summary>

        private static PixelShader pixelShader;



        #endregion



        #region Constructors

        /// <summary>

        /// Initializes static members of the ChromaKeyAlphaEffect class.

        /// </summary>

        static ChromaKeyAlphaEffect()

        {

            pixelShader = new PixelShader();



            pixelShader.UriSource = Global.MakePackUri("ShaderSource/ChromaKeyAlpha.fx.ps");

        }



        /// <summary>

        /// Initializes a new instance of the ChromaKeyAlphaEffect class.

        /// </summary>

        public ChromaKeyAlphaEffect()

        {

            this.PixelShader = pixelShader;



            UpdateShaderValue(ColorKeyProperty);

            UpdateShaderValue(ToleranceProperty);

            UpdateShaderValue(InputProperty);

        }



        #endregion



        #region Properties

        /// <summary>

        /// Gets or sets the InputColor variable within the shader.

        /// </summary>

        public Color ColorKey

        {

            get 

            { 

                return (Color)GetValue(ColorKeyProperty); 

            }



            set 

            { 

                SetValue(ColorKeyProperty, value); 

            }

        }



        /// <summary>

        /// Gets or sets the exactness by which the color must match (0=exact, 1=all colors)

        /// </summary>

        public double Tolerance

        {

            get

            {

                return (double)GetValue(ToleranceProperty);

            }



            set

            {

                if (value >= 0.0 && value <= 1.0)

                {

                    SetValue(ToleranceProperty, value);

                }

            }

        }



        /// <summary>

        /// Gets or sets the Input of shader.

        /// </summary>

        [Description("Gets or sets the input of the shader")]

        public Brush Input

        {

            get { return (Brush)GetValue(InputProperty); }

            set { SetValue(InputProperty, value); }

        }

        #endregion

    }

}