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The variable declarations near the center of Listing 6 are new to this module.

The overridden LoadContent method

An abbreviated listing of the LoadContent method is shown in Listing 7 .

Listing 7 . Abbreviated overridden LoadContent method.

protected override void Update(GameTime gameTime) { spriteBatch = new SpriteBatch(GraphicsDevice);Font1 = Content.Load<SpriteFont>("Kootenay"); IsMouseVisible = true;//make mouse visible//code deleted for brevity //Position the on-screen text.FontPos = new Vector2(windowWidth / 2, 50); //Position the mouse pointer in the center of the// game window. Mouse.SetPosition(windowWidth / 2,windowHeight /2);}//end LoadContent

The font family

To begin with, note that this program displays text on the screen using the font family named Kootenay (see Figure 3 for a reference to this font-family name).

Make the mouse pointer visible

By default, the mouse pointer is not visible when it is in the game window. The code in Listing 7 sets the inherited variable named IsMouseVisible to true, which causes the mouse pointer to be visible.

Position the on-screen text

The code in Listing 7 causes the text to be centered horizontally, 50 pixels down from the top of the game window as shown in Figure 1 .

Set the initial position of the mouse pointer

The code in Listing 7 causes the initial position of the mouse pointer to be centered in the game window. (I will have more to say aboutthis later.)

End of the LoadContent method

Listing 7 also signals the end of the overridden LoadContent method.

The overridden Update method

An abbreviated listing of the overridden Update method begins in Listing 8 .

Listing 8 . Beginning of an abbreviated overridden Update method.

protected override void Update(GameTime gameTime) { //code deleted for brevity//Check to see if any spiders have made it to the // bottom edge.for(int cnt = 0;cnt<spiders.Count;cnt++) { if(spiders[cnt].Edge == 3) //One or more made it to the bottom edge.spiderCount += 1; }//end for loop

The code in in Listing 8 counts the number of spiders that make it to the bottom and collide with the bottom edge of the game window.

Moving the ladybug objects using the keyboard

The code required to service the keyboard is long, tedious, and repetitive, but is not complicated. That code is shown in Listing 9 .

Listing 9 . Service the keyboard.

//The following code is used to move one or the // other of two ladybugs using the arrow keys.// Press only the arrow keys to move one of the // ladybugs. Press the A plus the arrow keys// to move the other ladybug. //The ladybugs cannot be moved outside the game// window using the keyboard. //While an arrow key is pressed, the ladybug moves//five pixels per call to the Update method. //Get the state of the keyboard.KeyboardState keyboardState = Keyboard.GetState(); //Execute moves on one ladybug with arrow keys plus// the A or a key. if(keyboardState.IsKeyDown(Keys.Left)&&(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[0].Position.X>0)) { ladybugs[0].Position = new Vector2( ladybugs[0].Position.X - 5, ladybugs[0].Position.Y); }//end ifif(keyboardState.IsKeyDown(Keys.Right)&&(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[0].Position.X<(windowWidth - ladybugs[1].Image.Width))) { ladybugs[0].Position = new Vector2( ladybugs[0].Position.X + 5, ladybugs[0].Position.Y); }//end ifif(keyboardState.IsKeyDown(Keys.Up)&&(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[0].Position.Y>0)) { ladybugs[0].Position = new Vector2( ladybugs[0].Position.X, ladybugs[0].Position.Y - 5); }//end ifif(keyboardState.IsKeyDown(Keys.Down)&&(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[0].Position.Y<(windowHeight - ladybugs[1].Image.Height))) { ladybugs[0].Position = new Vector2( ladybugs[0].Position.X, ladybugs[0].Position.Y + 5); }//end if//Execute moves on the other ladybug with arrow // keys pressed but the A key not pressed.if(keyboardState.IsKeyDown(Keys.Left)&&!(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[1].Position.X>0)) { ladybugs[1].Position = new Vector2( ladybugs[1].Position.X - 5, ladybugs[1].Position.Y); }//end ifif(keyboardState.IsKeyDown(Keys.Right)&&!(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[1].Position.X<(windowWidth - ladybugs[1].Image.Width))) { ladybugs[1].Position = new Vector2( ladybugs[1].Position.X + 5, ladybugs[1].Position.Y); }//end ifif(keyboardState.IsKeyDown(Keys.Up)&&!(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[1].Position.Y>0)) { ladybugs[1].Position = new Vector2( ladybugs[1].Position.X, ladybugs[1].Position.Y - 5); }//end ifif(keyboardState.IsKeyDown(Keys.Down)&&!(keyboardState.IsKeyDown(Keys.A))&&(ladybugs[1].Position.Y<(windowHeight - ladybugs[1].Image.Height))) { ladybugs[1].Position = new Vector2( ladybugs[1].Position.X, ladybugs[1].Position.Y + 5); }//end if

Questions & Answers

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
Daniel
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
Maciej
characteristics of micro business
Abigail
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
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.
Virgil
is Bucky paper clear?
CYNTHIA
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Xna game studio. OpenStax CNX. Feb 28, 2014 Download for free at https://legacy.cnx.org/content/col11634/1.6
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