Bug Vanquisher: WPF

Deep Dive into WPF Graphics-The Lost One

Tue, 22 Jul 2008 16:32:20 GMT

Just a (minor) revival to the forgotten series I was supposed to write.

With service pack 1 for .netfx 3.5, milcore.dll no longer provides the low level rendering primitives for WFP. Instead to preserve compatibility with DWM, all new APIs are provided in wpfgfx.dll, which has some minor inclusions (yet unknown to the world, because WPF team refuses to disclose any information).

This blog post reasons about the decision as:

“The reason is that WPF 3.5 SP1 now uses a new graphics DLL (wpfgfx.dll) and certain changes could not be made to Vista’s existing graphics DLL (milcore.dll) that is also used by DWM.”

Features include things like new Effects framework (H/W accelerated this time, not the weenie S/W rendered loonies), integration with DirectX surfaces [all I can remember right now :)].

Apart from that, all DllImports which used to be like DllImport( “milcore.dll” ) now reference the new wpfgfx.dll.

P.S.: I SO hate this post. I don’t do this sort of news aggregator things! Especially when it is so late.

Application+WPF=Sexy Experience!

Thu, 10 Jan 2008 18:02:30 GMT

I don't talk like that, ever. But the application deserves that.

http://www.frogdesign.com/case-study/lawson-smart-client.html

Yahoo Messenger For Windows Vista

Sat, 08 Dec 2007 10:00:07 GMT

Or is it just that?

If you have netfx 3.0 (or greater) installed on, you do not need Windows Vista to run it. Here is proof:

The other window is irrelevant apart from the fact that it really is Windows XP. The only thing missing from Yahoo Messenger (for WPF) is that it sticks "For Windows Vista" everywhere while it is entirely capable of running on any system having the required runtime.

Tim Sneath : Announcing Family.Show 2.0

Wed, 18 Jul 2007 07:16:38 GMT

Tim Sneath : Announcing Family.Show 2.0

Really cool application.

Get indulged

Wed, 06 Jun 2007 13:25:27 GMT

Get spacetime3d. Get indulged. The wonders of 3D browsing hit desktops for the first time. I wonder if someone can do a similar thing in WPF, now with the InteractiveVisual3D library?

Deep drive into WPF graphics internals Part 1

Mon, 23 Apr 2007 07:02:32 GMT

[I cannot make up my mind how to best start this post. Instead of delaying it for another month, I opted to post it anyway. <warning>Take it with a pound of salt, I may be terribly wrong in this article.</warning>]

A few pictures from MSDN should be the best start. They show the interaction between Win32 provided API, DirectX and WPF.

How WPF leverages Windows Platform
The Visual tree
How WPF draws your application.

These articles are mainly focused on graphics implementation in PresentationFramework, PresentationCore and WindowsBase. The unmanaged part will discuss milcore.dll, dwm.exe, dwmapi.exe, user32.dll's redirection APIs.

To dig into all of this, we need a working application. This code will be used through out this post.using System;
using System.Windows;

namespace WPF
{
     class App : Window
     {
         [STAThread]
        public static void Main( )
        {
            ( new Application( ) ).Run( new App( ) );
        }

         protected override void OnRender( System.Windows.Media.DrawingContext drawingContext )
        {
            System.Diagnostics.StackTrace st = new System.Diagnostics.StackTrace( System.Threading.Thread.CurrentThread , true );
             Console.WriteLine( st.ToString( ) );
            base.OnRender( drawingContext );
         }
     }
}

As the name suggest, OnRender is the only method called to do all the drawing. A debug tip shows that it is really an object of type System.Windows.Media.VisualDrawingContext.

Fire up Reflector and have a look at this class:

As we see VisualDrawingContext does not contain many things. _ownerVisual is any Visual having an associated VisualDrawingContext and CloseCore just calls RenderClose on the contained Visual. DrawingContext is the base class which defines the characteristics of what can be drawn and how. DispatcherObject is of no concern here, but in the going, it is essentially a wrapper around System.Threading.Thread and provides some services which check whether, through VerifyAccess and CheckAccess, the caller is on same thread as UI thread or not.

Furthermore, DrawingContext is abstract, therefore, an instance can never be created. RenderDataDrawingContext has an internal constructor. Same goes for its instance too. A transitive closure with the help of Reflector shows that there is no other way to create an instance publically without going through RenderOpen, which returns an instance of VisualDrawingContext.

You may have noticed by now that I skipped RenderDataDrawingContext's description. Well that's the topic for next post.

Must Read

Wed, 04 Apr 2007 07:00:41 GMT

<warning> Geek stuff. Read this immediately. </warning>

An interesting presentation

Fri, 30 Mar 2007 06:59:49 GMT

WFP3D team has posted a very interesting presentation on their blog. Have a look!