我想在一个角度上移动一个点 (Vector2)。我有我的角度。但我不擅长数学或 libgdx。为了获得角度,我使用这个:
degrees = (float) ((Math.atan2(touchPoint.x - x,
-(touchPoint.y - y)) * 180.0d / Math.PI) + 240.0f);
现在,我想移动 vector 。但我真的不知道我必须做什么......我看了问题,但只是改变角度,而不是转移。我认为 libgdx 中必须有一个函数。请帮忙。
更新:
public class Games implements ApplicationListener {
SpriteBatch spriteBatch;
Texture texture;
float x = 160;
float y = 5;
Vector2 touch;
Vector2 movement;
Vector2 position;
Vector2 dir;
Vector2 velocity;
float speed;
float deltaTime;
@Override
public void create() {
spriteBatch = new SpriteBatch();
texture = new Texture(Gdx.files.internal("images/1.png"));
touch = new Vector2();
movement = new Vector2();
position = new Vector2();
dir = new Vector2();
velocity = new Vector2();
speed = 5;
deltaTime = Gdx.graphics.getDeltaTime();
}
public void render() {
Gdx.gl.glClear(Gdx.gl10.GL_COLOR_BUFFER_BIT);
deltaTime += 0.5f;
spriteBatch.begin();
begin(deltaTime);
spriteBatch.draw(texture, position.x, position.y);
spriteBatch.end();
}
private void begin(float deltaTime) {
touch.set(Gdx.input.getX(), Gdx.input.getY());
position.set(x, y);
dir.set(touch).sub(position).nor();
velocity.set(dir).scl(speed);
movement.set(velocity).scl(deltaTime);
position.add(movement);
}
最佳答案
如果我没有正确理解您的问题,您是在寻找方向 vector 吗?
如果这是正确的理解,你可以这样做:
// Declared as fields, so they will be reused
Vector2 position = new Vector2();
Vector2 velocity = new Vector2();
Vector2 movement = new Vector2();
Vector2 touch = new Vector2();
Vector2 dir = new Vector2();
// On touch events, set the touch vector, then do this to get the direction vector
dir.set(touch).sub(position).nor();
这将为您提供从位置到触摸点的归一化方向 vector 。
然后您可以将它缩放到您想要移动的速度,然后用它来更新您的位置。
velocity = new Vector2(dir).scl(speed);
在每一帧上,做这样的事情
movement.set(velocity).scl(deltaTime);
position.add(movement);
更新
这是完整类的样子:
class Game extends ApplicationAdapter {
Vector2 position = new Vector2();
Vector2 velocity = new Vector2();
Vector2 movement = new Vector2();
Vector2 touch = new Vector2();
Vector2 dir = new Vector2();
Vector3 temp = new Vector3();
float speed = 100;
OrthographicCamera camera;
SpriteBatch batch;
Texture texture;
Sprite sprite;
@Override
public void create () {
camera = new OrthographicCamera();
camera.setToOrtho(false);
batch = new SpriteBatch();
texture = new Texture(Gdx.files.internal("data/badlogicsmall.jpg"));
sprite = new Sprite(texture);
Gdx.input.setInputProcessor(new InputAdapter() {
@Override
public boolean touchDown (int screenX, int screenY, int pointer, int button) {
camera.unproject(temp.set(screenX, screenY, 0));
touch.set(temp.x, temp.y);
return true;
}
});
}
@Override
public void render () {
Gdx.gl10.glClear(GL10.GL_COLOR_BUFFER_BIT);
update(Gdx.graphics.getDeltaTime());
batch.begin();
sprite.draw(batch);
batch.end();
}
@Override
public void dispose() {
texture.dispose();
batch.dispose();
}
public void update (float deltaTime) {
position.set(sprite.getX(), sprite.getY());
dir.set(touch).sub(position).nor();
velocity.set(dir).scl(speed);
movement.set(velocity).scl(deltaTime);
if (position.dst2(touch) > movement.len2()) {
position.add(movement);
} else {
position.set(touch);
}
sprite.setX(position.x);
sprite.setY(position.y);
}
}
请注意,您可以取消位置 Vector2 并直接使用 x 和 y,但我喜欢使用 Vector2,因为它更简洁。
关于java - 在一个角度上移动一个点( vector )+ Libgdx,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17694076/