Sprite动画Libgdx Java

Question

Trying to have a 2-d, top down sprite that rotates and is animated, i have the main class where it is rendered, and a separate 'assets' class where it is created. The rotation works, however the sprite stays on the same frame. I used the libgdx wiki to try and animate my sprite https://github.com/libgdx/libgdx/wiki/2D-Animation

Here is the code in the assets class:

public class Asset implements ApplicationListener, Screen{

    public static Texture walkSheet;




    private static final int    FRAME_COLS = 4;     
    private static final int    FRAME_ROWS = 2;     

    static Animation           walkAnimation;      
    static TextureRegion[]         walkFrames;     
    static TextureRegion           currentFrame;      
    static SpriteBatch spriteBatch;

    static float stateTime;                


    public static void load(){
        walkSheet = new Texture(Gdx.files.internal(".png"));


        TextureRegion[][] tmp = TextureRegion.split(walkSheet, walkSheet.getWidth()/FRAME_COLS, walkSheet.getHeight()/FRAME_ROWS);              // #10
        walkFrames = new TextureRegion[FRAME_COLS * FRAME_ROWS];
        int index = 0;
        for (int i = 0; i < FRAME_ROWS; i++) {
            for (int j = 0; j < FRAME_COLS; j++) {
                walkFrames[index++] = tmp[i][j];
            }
        }
        walkAnimation = new Animation(0.1f, walkFrames);      // #11
        spriteBatch = new SpriteBatch();                // #12
        stateTime = 0f;
        stateTime += Gdx.graphics.getDeltaTime();
        currentFrame = walkAnimation.getKeyFrame(stateTime, true);
    }

And here is how it is rendered:

game.batch.draw(Asset.currentFrame, x, y, (float)85, (float)85, (float)170, (float)170, (float)1, (float)1, (float)angleDegrees + 270);

What do i need to do to correctly animate the sprite?

Answer 1

The frame will never animate because you are not updating it. In the load() method you did the following:

stateTime += Gdx.graphics.getDeltaTime();
currentFrame = walkAnimation.getKeyFrame(stateTime, true);  

but this will get executed only once when you call the load() method.

As your Asset class implements the Screen interface you must have implemented the abstract method render(float delta) , so you need to update the frame in that method as follows:

 public void render(float delta)
 {
   stateTime += delta;
   currentFrame = walkAnimation.getKeyFrame(stateTime, true);  
   // Then render the frame as follows
   batch.draw(currentFrame, x, y, (float)85, (float)85, (float)170, (float)170, (float)1, (float)1, (float)angleDegrees + 270);
 }

Answer 2

// pass the array of movements to AnimatedActor
// animationFrames = walkSheetArray[moveDirection]; 
// animation = new Animation(1f / 5f, animationFrames);
// myAnimatedActor = new AnimatedActor(animation, rotation)

public class AnimatedActor extends Image {
private float stateTime = 0;
Animation animation;
public AnimatedActor(Animation animation, float rotation) {
super(animation.getKeyFrame(0));
this.animation = animation;
this.rotation = rotation;
}
@Override
public void act(float delta) {
((TextureRegionDrawable) getDrawable()).setRegion(animation.getKeyFrame(stateTime += delta, true));
myAnimatedActor.setRotation(rotation);
super.act(delta);
  }
}

walk frames 8x8