在libGDX中绘制线条动画

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.math.MathUtils;

public class LineAnimationExample extends ApplicationAdapter {
    private OrthographicCamera camera;
    private ShapeRenderer shapeRenderer;
    private float lineLength;
    private float angle;

    @Override
    public void create() {
        camera = new OrthographicCamera();
        camera.setToOrtho(false, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
        shapeRenderer = new ShapeRenderer();
        lineLength = 100;
        angle = 0;
    }

    @Override
    public void render() {
        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        camera.update();
        shapeRenderer.setProjectionMatrix(camera.combined);

        shapeRenderer.begin(ShapeRenderer.ShapeType.Line);
        shapeRenderer.setColor(1, 1, 1, 1);

        float x1 = Gdx.graphics.getWidth() / 2;
        float y1 = Gdx.graphics.getHeight() / 2;
        float x2 = x1 + MathUtils.cosDeg(angle) * lineLength;
        float y2 = y1 + MathUtils.sinDeg(angle) * lineLength;

        shapeRenderer.line(x1, y1, x2, y2);

        shapeRenderer.end();

        angle += 1;
    }

    @Override
    public void dispose() {
        shapeRenderer.dispose();
    }
}