有没有通用的方法来计算动画的结束并在动画结束时在动画之间进行切换？

Question

操你泰勒。你这个混蛋出去吧。

Answer 1

如果您使用 libGDX 中的 Animation 类，您可以使用这些方法（来自 API）：

• getAnimationDuration：整个动画的持续时间，帧数乘以帧持续时间，单位为秒
• isAnimationFinished(float): 在给定状态时间的情况下，如果不循环播放动画是否会完成 (PlayMode#NORMAL)。

所以您需要知道的是当前的

stateTime

，它的计算方式就像您在伪代码中已经完成的那样：

public void draw(float deltaTime) {
    stateTime += deltaTime;
    
    //...
}

有关如何使用 libGDX 动画的进一步介绍，请参阅本教程。

---

在我的一个项目中，我使用包装类来实现一些附加功能。如果你想使用它，你可以在 GitHub 上找到它，或者使用它的当前版本：

动画导演

import com.badlogic.gdx.graphics.g2d.Animation;
import com.badlogic.gdx.graphics.g2d.Animation.PlayMode;

import net.jfabricationgames.gdx.screens.game.GameScreen;

import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;

public class AnimationDirector<T extends TextureRegion> {
    
    public static boolean isTextureRight(boolean initialAnimationDirectionIsRight, AnimationDirector<TextureRegion> animation) {
        return initialAnimationDirectionIsRight != animation.getKeyFrame().isFlipX();
    }
    
    public static boolean isTextureLeft(boolean initialAnimationDirectionIsRight, AnimationDirector<TextureRegion> animation) {
        return initialAnimationDirectionIsRight == animation.getKeyFrame().isFlipX();
    }
    
    private float stateTime;
    private Animation<T> animation;
    
    private AnimationSpriteConfig spriteConfig;
    
    public AnimationDirector(Animation<T> animation) {
        this.animation = animation;
        initializeSpriteConfigWithoutPosition();
    }
    
    protected void initializeSpriteConfigWithoutPosition() {
        T keyFrame = animation.getKeyFrame(0);
        spriteConfig = new AnimationSpriteConfig().setWidth(keyFrame.getRegionWidth()).setHeight(keyFrame.getRegionHeight());
    }
    
    /**
     * Draw the current key frame of this animation onto the {@link SpriteBatch}.<br>
     * ATTENTION: This method will throw an {@link IllegalStateException} if this AnimationDirector does not contain an AnimationSpriteConfig object.
     */
    public void draw(SpriteBatch batch) {
        if (spriteConfig == null) {
            throw new IllegalStateException("No AnimationSpriteConfig. Please add an AnimationSpriteConfig in order to use the draw method");
        }
        T keyFrame = getKeyFrame();
        float x = spriteConfig.x + ((spriteConfig.width - keyFrame.getRegionWidth()) * GameScreen.WORLD_TO_SCREEN * 0.5f);
        float y = spriteConfig.y + ((spriteConfig.height - keyFrame.getRegionHeight()) * GameScreen.WORLD_TO_SCREEN * 0.5f);
        batch.draw(keyFrame, x, y, spriteConfig.width * 0.5f, spriteConfig.height * 0.5f, keyFrame.getRegionWidth(), keyFrame.getRegionHeight(),
                GameScreen.WORLD_TO_SCREEN, GameScreen.WORLD_TO_SCREEN, 0f);
    }
    
    public void drawInMenu(SpriteBatch batch) {
        if (spriteConfig == null) {
            throw new IllegalStateException("No AnimationSpriteConfig. Please add an AnimationSpriteConfig in order to use the draw method");
        }
        
        T keyFrame = getKeyFrame();
        batch.draw(keyFrame, spriteConfig.x, spriteConfig.y, spriteConfig.width, spriteConfig.height);
    }
    
    /**
     * Get the frame at the current time.
     */
    public T getKeyFrame() {
        return animation.getKeyFrame(stateTime);
    }
    
    public float getStateTime() {
        return stateTime;
    }
    
    public void increaseStateTime(float delta) {
        stateTime += delta;
    }
    
    public void setStateTime(float stateTime) {
        this.stateTime = stateTime;
    }
    
    /**
     * Reset the state time to 0 to restart the animation.
     */
    public void resetStateTime() {
        stateTime = 0;
    }
    
    /**
     * Set the animation state time to the end of the animation.
     */
    public void endAnimation() {
        stateTime = animation.getAnimationDuration();
    }
    
    public void setPlayMode(PlayMode playMode) {
        animation.setPlayMode(playMode);
    }
    
    /**
     * Get the {@link Animation} that this object holds.
     */
    public Animation<T> getAnimation() {
        return animation;
    }
    
    public boolean isAnimationFinished() {
        return animation.isAnimationFinished(stateTime);
    }
    
    public float getAnimationDuration() {
        return animation.getAnimationDuration();
    }
    
    /**
     * Flip all key frames of the animation.
     */
    public void flip(boolean x, boolean y) {
        for (TextureRegion region : animation.getKeyFrames()) {
            region.flip(x, y);
        }
    }
    
    public AnimationSpriteConfig getSpriteConfig() {
        return spriteConfig;
    }
    
    public void setSpriteConfig(AnimationSpriteConfig spriteConfig) {
        this.spriteConfig = spriteConfig;
    }
    
    public AnimationSpriteConfig getSpriteConfigCopy() {
        return new AnimationSpriteConfig(spriteConfig);
    }
}

动画精灵配置

import com.badlogic.gdx.graphics.g2d.Sprite;

public class AnimationSpriteConfig {
    
    public static AnimationSpriteConfig fromSprite(Sprite sprite) {
        AnimationSpriteConfig spriteConfig = new AnimationSpriteConfig();
        spriteConfig.width = sprite.getWidth();
        spriteConfig.height = sprite.getHeight();
        spriteConfig.x = sprite.getX();
        spriteConfig.y = sprite.getY();
        
        return spriteConfig;
    }
    
    public AnimationSpriteConfig() {}
    
    public AnimationSpriteConfig(AnimationSpriteConfig spriteConfig) {
        this.x = spriteConfig.x;
        this.y = spriteConfig.y;
        this.width = spriteConfig.width;
        this.height = spriteConfig.height;
    }
    
    public float x;
    public float y;
    public float width;
    public float height;
    
    public AnimationSpriteConfig setX(float x) {
        this.x = x;
        return this;
    }
    
    public AnimationSpriteConfig setY(float y) {
        this.y = y;
        return this;
    }
    
    public AnimationSpriteConfig setWidth(float width) {
        this.width = width;
        return this;
    }
    
    public AnimationSpriteConfig setHeight(float height) {
        this.height = height;
        return this;
    }
}