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Not complicated code

Although the code in Listing 8 is long and tedious, it isn't particularly complicated. It consists mainly of calls tothe accessor methods of the two sprite objects involved in the collision to modify their property values in some way.

Turn a green sprite into a blue sprite

For example, near the top of Listing 8 , there is a call to the setImage method of the green sprite to change it to a blue sprite.

Kill the green sprite

This is followed by a call to the setLife method to set the life of the (now blue) sprite object to 0, but only if the dieOnCollision variable belonging to the object is true. Later on, all sprite objects with a life property value of 0 will be removed from the population.

And so forth

I could continue down the page describing the calls to various other accessor methods, but that shouldn't be necessary. The embedded comments should sufficefor the explanation.

Play a sound

Finally near the end of the code in Listing 8 , there is a call to the play method belonging to Sound object referred to as blaster .

Each time there is a collision between the red sprite and a green sprite, the sound loaded earlier from the file named "blaster.wav" is played.

The end of the for loop

Listing 8 signals the end of the for loop, but does not signal the end of the update method. There is one more task to complete before the update method terminates.

Remove dead objects from the ArrayList object

The code in Listing 9 uses an Iterator to remove all objects having a life property value that is less than or equal to zero from the ArrayList object.

Listing 9 . Remove dead objects from the ArrayList object.
//Remove dead objects from the ArrayList objectIterator<Sprite01>iter = sprites.iterator(); while(iter.hasNext()){Sprite01 theSprite = iter.next(); if(theSprite.getLife()<= 0){ iter.remove();}//end if }//end while loop}//end update

Explanation of an Iterator

The explanation of an Iterator is beyond the scope of this module. However, if you Google the keywords baldwin java iterator , you will find several tutorials that I have published on this and related topics.

Listing 9 signals the end of the update method.

The render method

The render method is shown in Listing 10 . There is nothing new in this code.

Listing 10 . The render method.
public void render(GameContainer gc, Graphics g) throws SlickException{//set the drawing mode to honor transparent pixels g.setDrawMode(g.MODE_NORMAL);//Draw the background to erase the previous picture. background.draw(0,0);//Draw every sprite in the ArrayList object. for(int cnt = 0;cnt<sprites.size();cnt++){ sprites.get(cnt).draw();}//end for loop//Display the remaining number of sprites. g.drawString("Sprites remaining: " + (sprites.size()),100f,10f); //Signal when all sprites have been eaten.if(sprites.size() == 1){ g.drawString("Burp!",100f,25f);}//end if }//end render}//end class Slick0210 //======================================================//

The end of the class

Questions & Answers

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.
what is biological synthesis of nanoparticles
Sanket Reply
Got questions? Join the online conversation and get instant answers!
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Source:  OpenStax, Anatomy of a game engine. OpenStax CNX. Feb 07, 2013 Download for free at https://legacy.cnx.org/content/col11489/1.13
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