AnimationWorld AnimationWorld uses Graphics to create animations. - - PDF document

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Animation

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AnimationWorld

AnimationWorld uses Graphics to create animations. Essentially, animations are a set of frames with pictures where we flip through pictures one by one.

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AnimationWorld

There are 2 main parts to AnimationWorld:

• Sprites - A sprite is an object that moves in an animation

(Sprites are like actresses and actors. We will create a library of Sprites which will “act” in the animation.)

• Animations - An animation can be thought of as a script

for the Sprites. It includes information such as which Sprites are in the animation, when these Sprites move, etc.

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AnimationWorld

• An animation is created by showing a sequence of

frames

• The frames are numbered starting from 1
• After the first frame, all other frames are created by

updating each Sprite and then painting the Sprite on a new frame

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Creating New Sprites

public class Pulsar extends Sprite { // instance variables ... // constructors ... // instance methods // Describes how to draw the Sprite in a particular frame public void drawState(Graphics g) {...} // 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() {...} }

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Creating New Animations

public class PulsarAnimation extends Animation { // constructor public PulsarAnimation() { this.addSprite( // add Sprite here ); this.addSprite( // add Sprite here ); this.setFps(12); } }

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Pulsar Class

public class Pulsar extends Sprite { // instance variables // constructor

radius (x,y) color maxRadius minRadius

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Drawing the Pulsar

public class Pulsar extends Sprite { ... public void drawState(Graphics g) { } }

x y (0,0) Applet window

(x,y)

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Updating the Pulsar

public class Pulsar extends Sprite { ... public void updateState() { } }

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Resetting the Pulsar

public class Pulsar extends Sprite { ... public void resetState() { } }

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PulsarAnimation Class

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); } }

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BouncingBall Class

public class BouncingBall extends Sprite { // instance variables // constructor

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Drawing the BouncingBall

public class BouncingBall extends Sprite { ... public void drawState(Graphics g) { }

x y (0,0) Applet window

(x,y)

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Resetting the BouncingBall

public class BouncingBall extends Sprite { ... public void resetState() { }

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Updating the BouncingBall

public class BouncingBall extends Sprite { ... public void updateState() { } }

x y (0,0) x y (0,0)

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BouncingBallAnimation Class

public class BouncingBallAnimation extends Animation { // 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); } }