DropShadowBitmapEffect.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Core / CSharp / System / Windows / Media / Effects / DropShadowBitmapEffect.cs / 1407647 / DropShadowBitmapEffect.cs
                        

                        
                            //------------------------------------------------------------------------------ 
//  Microsoft Avalon
//  Copyright (c) Microsoft Corporation, 2005
//
//  File:       BitmapEffectDropShadow.cs 
//-----------------------------------------------------------------------------
 
#region Using directives 

using System; 
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Security; 
using SecurityHelper=MS.Internal.SecurityHelper;
 
#endregion 

namespace System.Windows.Media.Effects 
{
    /// 
    /// The class definition for DropShadowBitmapEffect
    ///  
    public partial class DropShadowBitmapEffect
    { 
 
        /// 
        /// Constructor 
        /// 
        public DropShadowBitmapEffect()
        {
 
        }
 
        ///  
        /// Creates the unmanaged effect handle
        ///  
        /// 
        /// Critical - returns a security critical type SafeHandle.
        /// Safe     - Always returns null.
        ///  
        [SecuritySafeCritical]
        [Obsolete(MS.Internal.Media.VisualTreeUtils.BitmapEffectObsoleteMessage)] 
        unsafe protected override SafeHandle CreateUnmanagedEffect() 
        {
            return null; 
        }

        /// 
        /// /// Update (propagetes) properties to the unmanaged effect 
        /// 
        ///  
        /// This method demands permission because effects should not be run 
        /// in partial trust.
        /// 
        /// SecurityCritical - because SetValue has a link demand
        /// SecutiryTreatAsSafe - because it demans UIWindow permission
        /// 
        [SecurityCritical, SecurityTreatAsSafe] 
        [Obsolete(MS.Internal.Media.VisualTreeUtils.BitmapEffectObsoleteMessage)]
        protected override void UpdateUnmanagedPropertyState(SafeHandle unmanagedEffect) 
        { 
            SecurityHelper.DemandUIWindowPermission();
        } 

        /// 
        /// An ImageEffect can be used to emulate a DropShadowBitmapEffect with certain restrictions. This
        /// method returns true when it is possible to emulate the DropShadowBitmapEffect using an ImageEffect. 
        /// 
        internal override bool CanBeEmulatedUsingEffectPipeline() 
        { 
            return (Noise == 0.0);
        } 

        /// 
        /// Returns a ImageEffect that emulates this DropShadowBitmapEffect.
        ///  
        internal override Effect GetEmulatingEffect()
        { 
            if (_imageEffectEmulation != null && _imageEffectEmulation.IsFrozen) 
            {
                return _imageEffectEmulation; 
            }

            if (_imageEffectEmulation == null)
            { 
                _imageEffectEmulation = new DropShadowEffect();
            } 
 
            Color color = Color;
            if (_imageEffectEmulation.Color != color) 
            {
                _imageEffectEmulation.Color = color;
            }
            // The limits on ShadowDepth preserve existing behavior. 
            // A scale transform can scale the shadow depth to exceed 50.0,
            // and this behavior is also handled correctly in the unmanaged layer. 
            double shadowDepth = ShadowDepth; 
            if (_imageEffectEmulation.ShadowDepth != shadowDepth)
            { 
                if (shadowDepth >= 50.0)
                {
                    _imageEffectEmulation.ShadowDepth = 50.0;
                } 
                else if (shadowDepth < 0.0)
                { 
                    _imageEffectEmulation.ShadowDepth = 0.0; 
                }
                else 
                {
                    _imageEffectEmulation.ShadowDepth = shadowDepth;
                }
            } 

            double direction = Direction; 
            if (_imageEffectEmulation.Direction != direction) 
            {
                _imageEffectEmulation.Direction = direction; 
            }

            double opacity = Opacity;
            if (_imageEffectEmulation.Opacity != opacity) 
            {
                if (opacity >= 1.0) 
                { 
                    _imageEffectEmulation.Opacity = 1.0;
                } 
                else if (opacity <= 0.0)
                {
                    _imageEffectEmulation.Opacity = 0.0;
                } 
                else
                { 
                    _imageEffectEmulation.Opacity = opacity; 
                }
            } 

            double softness = Softness;
            if (_imageEffectEmulation.BlurRadius / _MAX_EMULATED_BLUR_RADIUS != softness)
            { 
                if (softness >= 1.0)
                { 
                    _imageEffectEmulation.BlurRadius = _MAX_EMULATED_BLUR_RADIUS; 
                }
                else if (softness <= 0.0) 
                {
                    _imageEffectEmulation.BlurRadius = 0.0;
                }
                else 
                {
                    _imageEffectEmulation.BlurRadius = _MAX_EMULATED_BLUR_RADIUS * softness; 
                } 
            }
 
            _imageEffectEmulation.RenderingBias = RenderingBias.Performance;

            if (this.IsFrozen)
            { 
                _imageEffectEmulation.Freeze();
            } 
 
            return _imageEffectEmulation;
        } 

        DropShadowEffect _imageEffectEmulation;

        private const double _MAX_EMULATED_BLUR_RADIUS = 25.0; 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK