<< Chapter < Page Chapter >> Page >

Why am I emphasizing this so heavily?

Shortly, you will see the changes that I made to the game-math library in preparation for this module. That library makes it possible for you toeasily create and manipulate underlying data objects for column matrices, points, vectors, and lines. Those changes include the ability for points,lines, and vectors to create graphical objects that represent themselves and to display those graphical objects on a specified graphics context upon request.

The left image in Figure 1 shows the manner in which GM2D02.Point objects and GM2D02.Line objects represent themselves on a graphics context.

The right image in Figure 1 shows the manner in which GM2D02.Vector objects represent themselves on a graphics context.

It is very important to understand the difference between the objects that encapsulate the underlying data and the graphic objects that represent thoseobjects for visible human consumption. Later on, we will be doing math using the underlying data objects. However, it is generally not possibleto do math using the graphic objects shown in Figure 1 .

Additional modifications that I made to the library for this module makes it is easyto modify the values encapsulated in one of the underlying data objects. However, once the graphical representation of one of those data objects is drawnon the graphics context, it is fairly difficult to modify, particularly if it overlaps another graphic object that you don't want to modify. Thelibrary does not provide that capability.

All Java parameters are passed to methods by value

Moving to a completely different topic, when you call out the name of a variable as a parameter to be passed to a method in Java, a copy of the contentsof that variable is made and the copy is passed to the method. Code in the method can modify the copy but it cannot modify the contents of the originalvariable. This is typically referred to as passing parameters by value . (Despite what you may have read elsewhere, unlike C and C++, Java parameters are never passed by reference.)

However, Java supports both primitive variables and reference variables. Passing reference variables by value exposes some vulnerabilities in the original version of the library when set methods are added to the library. A complete explanation of this topic is beyond the scope of thismodule. However, I will show you how I modified the code in the library to protect against such vulnerabilities.


I will explain the changes to the library in this module in conjunction with two programs that illustrate the impact of those changes. Bothprograms produce the screen output shown in Figure 1 , but they do so in significantly different ways.

The primary topics to be discussed have to do with:

  • Making it possible for the underlying data objects to represent themselves by drawing graphical objects on a specified 2D graphics contextupon request.
  • Making it possible to call set methods to modify the data encapsulated in the underlying data objects.
  • Protecting the data from corruption due to certain vulnerabilities exposed by adding set methods to the library.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Game 2302 - mathematical applications for game development. OpenStax CNX. Jan 09, 2016 Download for free at https://legacy.cnx.org/content/col11450/1.33
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Game 2302 - mathematical applications for game development' conversation and receive update notifications?