GAME DESIGN IN LIBGDX

GUIDE – SIMPLE ANIMATION

DESCRIPTION

Here is the simplest way to create an animation from multiple frames stored in a sprite sheet.

SPRITE SHEET

You will have to start with a LibGDX sprite sheet. The two files have to be placed in the assets folder. Make sure you can see these files inside Eclipse.

CODE

//This program will demonstrate how to create an animation using the

//images that are in a sprite sheet. Essentially, it places the

//images of a sprite sheet into an array and then, based on the time

//that has elapsed, displays the corresponding frame of the animation.

//Note: If you wish to use animation inside of a larger program, it

//would be wise to do the animation work inside of another class to

//hide this complexity at the main game level.

public class AnimationDemo1 extends ApplicationAdapter

{

private TextureAtlas spritesheet;

private TextureRegion[] ourImage;

private SpriteBatch batch;

private final int totalFrames = 25;

private float timeSinceStart;

@Override

public void create ()

{

batch = new SpriteBatch();

spritesheet = new TextureAtlas(Gdx.files.internal("nukeData.txt"));

timeSinceStart = 0;

ourImage = new TextureRegion[totalFrames];

for (int i=1; i<=totalFrames; i++) //1 to 25 inclusively

{

String imgName = "prefix_" + i;

ourImage[i-1] = spritesheet.findRegion(imgName);

}

}

@Override

public void render ()

{

//CLEAR THE SCREEN

Gdx.gl.glClearColor(1, 1, 1, 1);

Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

//UPDATE TIME

timeSinceStart = timeSinceStart + Gdx.graphics.getDeltaTime();

//CALCULATE CURRENT FRAME

//We will display 10 frames per second (fps).

//By using 'mod 25', we can let the animation loop on and on.

float fps = 12;

int currentFrame = (int)(timeSinceStart * fps) % 25;

//DRAW THE CURRENT FRAME

batch.begin();

batch.draw(ourImage[currentFrame], 160, 160);

batch.end();

}
}

JAR FILE

Click here.