In Part 1 of this article, we started to develop a small racing game using
XNA Game Studio Express 2.0. We learned about the game loop and how it's
implemented by the XNA (by using the Update and Draw methods) framework. We
also created our first track on the screen and four cars started moving on
the screen, but, sadly enough, they left the track and weren't seen again.
What does that mean? It means we should take a closer look at collision
detection. In addition we should design a menu with different options. You
might remember that we want to have a racing game with three computer-driven
cars or a network game with one or more other humans playing against us.
Sounds easy? Well, it's not that hard, but we'll see that a few small changes
in the behavior will lead to a few other problems that have to be solved
(i.e., a game menu means we have to use so-called game s... (more)
The Lightweight Directory Access Protocol (LDAP) is for accessing online
directory services. It runs directly over TCP and can be used to access a
standalone LDAP directory service. Developed in the early 1990s, it defines
how a client should access data on the server. It does not specify how the
data should be stored on the server.
Most often you'll interact with a server specifically built for LDAP, such as
OpenLDAP or iPlanet (now Sun ONE) Directory Server. However, LDAP can become
a front end to any type of datastore. Because of this, most popular directory
services now have... (more)
In Part 1 (PBDJ, Vol. 9, issue 6) I discussed directory services and how they
provide authentication, access control, and finder services for our
application. In Part 2, I explain how the JNDI API lets us easily use LDAP.
The Java Naming and Directory Interface (JNDI) is an application programming
interface (API) that provides naming and directory functionality to Java
applications. It's independent of any specific directory service
implementation, thus a variety of directories - new, emerging, and already
deployed - can be accessed the same way.
Most of the applications we software developers build need to interact
somehow with data from a database. The .NET Framework defined by Microsoft
provides a rich set of objects to manage database interaction; these classes
are collectively referred to as ADO.NET and the latest versions of DataWindow
.NET (which is now version 2.01).
SQL Anywhere (version 10) fits perfectly in this environment, making
development a lot easier; in addition, your applications will look good
without spending a lot of time painting the user interface. In this article
we'll look closer at exactly this... (more)
The Web Services Description Language (WSDL) makes it possible for automated
code-generation tools, like PowerBuilder 9 with its Web services wizard, to
simplify building clients for existing Web services.
In my previous article "Axis" (PBDJ, Vol. 9, issue 8) we discussed the basic
steps involved in implementing a Web service using Axis, EAServer, and
PowerBuilder 8. Now we'll explore the technologies that make it easier to use
Web services that have already been deployed.
What Is WSDL?
WSDL is an XML-based language used to define Web services and describe how to
access them. For... (more)