AnimationWorld AnimationWorld uses Graphics to create animations. - PDF document

AnimationWorld AnimationWorld uses Graphics to create animations. Essentially, animations are a set of frames with Animation pictures where we flip through pictures one by one. V - 1 V - 2 AnimationWorld AnimationWorld • An animation is created by showing a sequence of There are 2 main parts to AnimationWorld: frames • Sprites - A sprite is an object that moves in an animation (Sprites are like actresses and actors. We will create a • The frames are numbered starting from 1 library of Sprites which will “act” in the animation.) • After the first frame, all other frames are created by • Animations - An animation can be thought of as a script updating each Sprite and then painting the Sprite on a for the Sprites. It includes information such as which new frame Sprites are in the animation, when these Sprites move, etc. V - 3 V - 4 Creating New Sprites Creating New Animations public class Pulsar extends Sprite { // instance variables ... public class PulsarAnimation extends Animation { // constructors ... // constructor // instance methods public PulsarAnimation() { this.addSprite( // add Sprite here ); // Describes how to draw the Sprite in a particular frame this.addSprite( // add Sprite here ); public void drawState(Graphics g) {...} this.setFps(12); } // Describes how to update the state of the Sprite // between frames public void updateState() {...} } // Describes how to reset the state of the Sprite back to // its initial state public void resetState() {...} } V - 5 V - 6

Pulsar Class Drawing the Pulsar public class Pulsar extends Sprite { public class Pulsar extends Sprite { ... color // instance variables public void drawState(Graphics g) { (x,y) minRadius } radius maxRadius (0,0) x // constructor (x,y) y Applet window V - 7 V - 8 } Updating the Pulsar Resetting the Pulsar public class Pulsar extends Sprite { public class Pulsar extends Sprite { ... ... public void updateState() { } public void resetState() { } V - 9 V - 10 } } PulsarAnimation Class BouncingBall Class public class BouncingBall extends Sprite { // instance variables public class PulsarAnimation extends Animation { // constructor public PulsarAnimation() { this.addSprite(new Pulsar(200,50,20,40,1,Color.red)); this.addSprite(new Pulsar(300,200,0,200,5,Color.blue)); this.setFps(12); } // constructor } V - 11 V - 12

Drawing the BouncingBall Resetting the BouncingBall public class BouncingBall extends Sprite { public class BouncingBall extends Sprite { ... ... public void drawState(Graphics g) { } (0,0) x public void resetState() { } y (x,y) Applet window V - 13 V - 14 Updating the BouncingBall BouncingBallAnimation Class (0,0) x public class BouncingBall extends Sprite { ... public void updateState() { public class BouncingBallAnimation extends Animation { y // constructor public BouncingBallAnimation() { this.addSprite(new BouncingBall(50,50,30,2,2,Color.magenta)); this.addSprite(new BouncingBall(150,150,25,3,-3,Color.cyan)); this.addSprite(new BouncingBall(250,250,40,1,4,Color.green)); this.setFps(12); } (0,0) x } y } V - 15 V - 16 }