Update 1 - Progress so far - IrrlichtDotNet - .Net library for irrlicht that works under Linux

For original article, please go to this article.

After I made the declaration of starting this project on irrlicht forums, roxaz from the forums expressed interest in the project and immediately forked it on github. We bounced around ideas and while I won't yet merge all of his modifications into my repo, I did like many of this ideas and implemented them after tweaking them to fit in with my code. The ideas that I implemented from his repo are:

1. folder reorganization
2. a python script that refreshes the CS project file with all the SWIG generated cs files
3. make.sh file to automate many initial steps

I also spent some time getting myself more familiar with SWIG typemaps and was able to map irr::core::stringc to System.String for almost all instances. These originally got translated to a SWIG generated generic wrapper which wasn't any useful unless you created a companion helper class in C++ to handle the translation both ways between irr::core::stringc and char *, which gets mapped correctly to System.String. Once all occurrences of irr::core::stringc are mapped to System.String, helper class won't be necessary any more. I will also attempt to deploy more typemaps to handle other such mappings in IrrlichtDotNet project.

Linux compatible .Net bindings for irrLicht using SWIG

Ever since I tried IrrLicht, an Open Source 3d Graphics library, I fell in love with it. It is a C++ library and my C++ isn't as good as I'd like it to be and I am more comfortable with C# under .Net.

Since IrrLicht is open source, I figured, someone might have written an .Net binding for it, and I was correct. A few such bindings do exist, although, they are truly only .Net bindings for IrrLicht for Windows platform only.
I also attempted to use MonoGame, which is known to work under Linux, but without any success.

A few days ago, while researching an unrelated subject, I stumbled across SWIG. SWIG stands for Simple Wrapper and Interface Generator. It is used when you want write wrappers to your C/C++ code for other languages. It also happens to support C#. So I decided to give it SWIG a swing and initial results were more than promising.

I decided to test it but exposing the Main method of my C++ test code written to try IrrLicht and called it from a .Net application. It worked!
I decided to take a shot at generating a wrapper for IrrLicht itself. So far, using the bindings that I was able to create with SWIG, I have been able to create simple 3d scenes in C# code.

I've created a project on GitHub to create a Linux compatible .Net binding for IrrLicht using SWIG. The repo is at https://github.com/jimmy00784/IrrlichtDotNet.

Initially, much of the focus will be on creating a Linux centric binding. However, since SWIG is cross platform, if the community is interested in the effort, it could become more cross platform than that.

Implementing ASP.NET MVC like NameValueCollection translation to method parameters

If you've programmed with ASP.NET MVC, you know about a neat feature where the form post data or the query string, which is string data, is automagically converted to strongly typed objects when it is passed to its Controller Action.

For instance, consider the following code:

public class HomeController : Controller

{

     public ActionResult ProductQuery(string Name, int Code)

     {

     ...

     }

}

The web request to http://<server<:port>></AppRoot>/Home/ProductQuery?Name=123&Code=456 will be properly handled and Name will be treated as a string while Code will be treated as an integer value.

Also consider the following code:

// UserRegFormData.cs

public class UserRegFormData

{

     public string Name{get;set;}

     public DateTime Dob{get;set;}

}

// HomeController.cs

public ActionResult Register(UserRegFormData urfd)

{

...

}

You could now setup an html form with action=/Home/Register, method=post, a text field with name="urfd.Name" and another one with name="urfd.Dob". When this form is submitted with data in the two text fields, ASP.NET MVC will automatically create the strongly typed UserRegFormData object with correct values for its properties. This wasn't the case before ASP.NET MVC. You would receive all the values as strings and you were responsible for doing the conversions in your ASP.NET server side code.

Well I've been thinking about how this could be done without using ASP.NET MVC.

Why reinvent the wheel, you might ask. The answer is two fold. Firstly, there might be situations where ASP.NET MVC might just not be a suitable solution, a non web application, perhaps. This type of routing and smart parameter translation would also be useful in scenarios where input contains both the parameters as well as the operation the perform on them. Secondly, I have been facinated by this very approach ever since I discovered it in ASP.NET MVC. When I recently came across Managed Extensibility Framework (MEF) as it is packaged with .Net 4, I wondered if it could be used to create an MVC framework from scratch. It would be a good learning opportunity and I wanted to cease it.

While I made some progress with routing URLs to methods in controller objects, I got faced with the issue of handling the input. The input data would not translate itself to strongly typed objects. Few searches on the Internet revealed that there was nothing readily available for this and I really didn't want to dig through the ASP.NET MVC code to see how it was implemented there.

I did an Internet search on how to convert string objects to other object types. This StackOverflow article provided the solution:

http://stackoverflow.com/questions/2922855/how-to-convert-string-to-any-type

Another search on how to assign property values using reflection yeilded this post on DotNetSpider:

http://www.dotnetspider.com/resources/19232-Set-Property-value-dynamically-using-Reflection.aspx

I found how to create strongly typed arrays from this article on Byte.com:

http://bytes.com/topic/c-sharp/answers/228995-creating-typed-arrays-using-reflection

I had most of what I needed to get started.

I have uploaded the initial code to my github repository. The code is still crude and it has not yet undergone a refactoring exercise. https://github.com/jimmy00784/MEFExample/tree/master/StringToArgumentsTest.