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Listing 10 also signals the end of the Slick0210 class and the end of the program.

Run the program

I encourage you to copy the code from Listing 11 and Listing 12 . Compile the code and execute it,making changes, and observing the results of your changes. Make certain that you can explain why your changes behave as they do.


In this module, you learned how to use the Sprite01 class from an earlier module to write a predator/prey simulation program involvingthousands of sprites, collision detection, and sound effects.

What's next?

In the next module, you will learn how to write a program that simulates the spread of a fatal communicable disease within a population.


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Slick0210: Collision detection and sound
  • File: Slick0210.htm
  • Published: 02/06/13
  • Revised: 10/03/15

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I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.

Complete program listings

Complete listings of the code discussed in this module are provided in Listing 11 and Listing 12 .

Listing 11 . Source code for the program named Slick0210.
/*Slick0210.java Copyright 2013, R.G.BaldwinA baseball coach is attacked by a swarm of fierce green flying insects. Fortunately, a red predator insect comesalong and attacks the green insects just in time to save the coach.There are two scenarios that can be exercised by setting dieOnCollision to true or false. In one scenario,the green insects become harmless blue insects when they collide with the red insect. In the other case, they areconsumed by the red insect upon contact and removed from the population.In both scenarios, contact between a green insect and the red insect causes the red insect to increase in size.If you allow the program to run long enough, the probability is high that all of the green insects willhave collided with the red insect and will either have turned blue or have been consumed.Tested using JDK 1.7 under WinXP *********************************************************/import org.newdawn.slick.AppGameContainer; import org.newdawn.slick.BasicGame;import org.newdawn.slick.GameContainer; import org.newdawn.slick.Graphics;import org.newdawn.slick.Image; import org.newdawn.slick.SlickException;import org.newdawn.slick.Color; import org.newdawn.slick.Sound;import java.util.Random; import java.util.ArrayList;import java.util.Iterator; public class Slick0210 extends BasicGame{//Set the value of this variable to true to cause the// sprites to die on collision and to be removed from // the population.boolean dieOnCollision = true;//Store references to Sprite01 objects here. ArrayList<Sprite01>sprites = new ArrayList<Sprite01>();//Change this value and recompile to change the number // of sprites.int numberSprites = 1000; //Populate these variables with references to Image// objects later. Image redBallImage;Image greenBallImage; Image blueBallImage;//Populate this variable with a reference to a Sound// object later. Sound blaster;//Populate these variables with information about the// background image later. Image background = null;float backgroundWidth; float backgroundHeight;//This object is used to produce values for a variety// of purposes. Random random = new Random();//Frame rate we would like to see and maximum frame// rate we will allow. int targetFPS = 60;//----------------------------------------------------// public Slick0210(){//constructor//Set the title super("Slick0210, baldwin");}//end constructor //----------------------------------------------------//public static void main(String[] args)throws SlickException{ AppGameContainer app = new AppGameContainer(new Slick0210(),414,307,false); app.start();}//end main //----------------------------------------------------//@Override public void init(GameContainer gc)throws SlickException { //Create Image objects that will be used to visually// represent the sprites. redBallImage = new Image("redball.png");greenBallImage = new Image("greenball.png"); blueBallImage = new Image("blueball.png");//Create a Sound object.blaster = new Sound("blaster.wav"); //Create a background image and save information// about it. background = new Image("background.jpg");backgroundWidth = background.getWidth(); backgroundHeight = background.getHeight();//Add a sprite dressed with redBallImage to the// beginning of the ArrayList object. Put it in the // center of the game window. Make the direction of// motion random. Make the speed of motion // (step size)random. Make the size random. Specify// a white (do nothing)color filter. sprites.add(new Sprite01(redBallImage,//image backgroundWidth/2.0f,//initial positionbackgroundHeight/2.0f,//initial position (random.nextFloat()>0.5) ? 1f : -1f,//direction (random.nextFloat()>0.5) ? 1f : -1f,//direction 0.1f+random.nextFloat()*2.0f,//step size0.1f+random.nextFloat()*2.0f,//step size 0.5f+random.nextFloat()*1.5f,//scalenew Color(1.0f,1.0f,1.0f)));//color filter //Populate the ArrayList object with sprites. Dress// them with a greenBallImage. Make the initial // position random. Make the initial direction of// motion random. Make the speed (step size) random. // Make the size (scale) random. Make the color filter// white (do nothing). for(int cnt = 0;cnt<numberSprites;cnt++){ sprites.add(new Sprite01(greenBallImage,//image backgroundWidth*random.nextFloat(),//positionbackgroundHeight*random.nextFloat(),//position (random.nextFloat()>0.5) ? 1f : -1f,//direction (random.nextFloat()>0.5) ? 1f : -1f,//direction 0.1f+random.nextFloat()*2.0f,//step size0.1f+random.nextFloat()*2.0f,//step size random.nextFloat()*1.0f,//scalenew Color(1.0f,1.0f,1.0f)));//color filter }//end for loopgc.setTargetFrameRate(targetFPS);//set frame rate }//end init//----------------------------------------------------// @Overridepublic void update(GameContainer gc, int delta) throws SlickException{//Access to the first sprite in the ArrayList object. Sprite01 redBallSprite = sprites.get(0);//Do the following for every sprite in the ArrayList // objectfor(int cnt = 0;cnt<sprites.size();cnt++){ //Get a reference to the Sprite01 object.Sprite01 thisSprite = sprites.get(cnt);//Ask the sprite to move according to its properties thisSprite.move();//Ask the sprite to bounce off the edge if it is at // an edge.thisSprite.edgeBounce( backgroundWidth,backgroundHeight);//Test for a collision between this sprite and the// sprite that is dressed in the redBallImage. boolean collision =thisSprite.isCollision(redBallSprite); //Process a collision if it has occurred. Exclude// collisions between the redBallSprite and itself. // Also exclude collisions between sprites dressed// in a blueBallImage and the redBallSprite. if((collision == true)&&(! thisSprite.getImage().equals(redBallImage))&&(! thisSprite.getImage().equals(blueBallImage))){ //A collision has occurred, change the color of// this sprite to blue and maybe cause it to // die and be removed from the population.thisSprite.setImage(blueBallImage); if(dieOnCollision){thisSprite.setLife(0); }//end if//Cause the redBallSprite to change direction on// a random basis. redBallSprite.setXDirection((random.nextFloat()>0.5) ? 1f : -1f); redBallSprite.setYDirection((random.nextFloat()>0.5) ? 1f : -1f);//Cause the redBallSprite to change stepsize on a // random basis.redBallSprite.xStep = 0.1f+random.nextFloat()*2.0f;redBallSprite.yStep = 0.1f+random.nextFloat()*2.0f;//Cause the redBallSprite to grow largerredBallSprite.setScale(redBallSprite.getScale() +(redBallSprite.getScale()) * 0.001f); //Play a sound to indicate that a collision has// occurred. blaster.play();}//end if }//end for loop//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 //----------------------------------------------------//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 //======================================================//

Questions & Answers

how can chip be made from sand
Eke Reply
are nano particles real
Missy Reply
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
has a lot of application modern world
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
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
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