在 render() 中随机更改图像而不更改所有其他图像
Change randomly image in render() without changing it for all other images
我跟随 this tutorial 在 LibGDX
中构建了一个简单的游戏。游戏的基本思路是:有水滴落下,玩家应该通过将水桶拖到水滴落下的地方来放置它们。
在原始版本中,所有水滴都是从一个水滴图像创建的,我尝试做的是用不同的水滴(水滴的不同图像)下一场雨,所以我创建了一个 List
- someDrops
不同的 Texture
和 render()
我更换了:
batch.draw(dropImage, raindrop.x, raindrop.y);
与:
int random = MathUtils.random(0, 3;
batch.draw(someDrops.get(random), raindrop.x, raindrop.y);
我得到的是不同水滴的雨,但它们并没有以不同的图像落下,而是落下并同时改变图像。
我该如何设置,以便每次掉落时都带有来自 someDrops
的随机图像,因为它以随机 x,y 位置掉落。
另外我想给每个滴添加不同的点,我应该把它保存在哪里以及选择什么类型的collection?
public class Drop implements ApplicationListener {
private Texture dropImage;
private Texture bucketImage;
private Sound dropSound;
private Music rainMusic;
private SpriteBatch batch;
private OrthographicCamera camera;
private Rectangle bucket;
private Array<Rectangle> raindrops;
private long lastDropTime;
private List<Texture> someDrops;
private Texture drop0;
private Texture drop1;
private Texture drop2;
private Texture drop3;
@Override
public void create() {
// load the images for the droplet and the bucket, 64x64 pixels each
dropImage = new Texture(Gdx.files.internal("droplet.png"));
drop0 = new Texture(Gdx.files.internal("droplet0.png"));
drop1 = new Texture(Gdx.files.internal("droplet1.png"));
drop2 = new Texture(Gdx.files.internal("droplet2.png"));
drop3 = new Texture(Gdx.files.internal("droplet3.png"));
bucketImage = new Texture(Gdx.files.internal("bucket.png"));
someDrops = new ArrayList<Texture>();
someDrops.add(new Texture(drop0));
someDrops.add(new Texture(drop1));
someDrops.add(new Texture(drop2));
someDrops.add(new Texture(drop3));
camera = new OrthographicCamera();
camera.setToOrtho(false, 800, 480);
batch = new SpriteBatch();
// create a Rectangle to logically represent the bucket
bucket = new Rectangle();
bucket.x = 800 / 2 - 64 / 2; // center the bucket horizontally
bucket.y = 20; // bottom left corner of the bucket is 20 pixels above the bottom screen edge
bucket.width = 64;
bucket.height = 64;
//raindrops array and spawn the first raindrop
raindrops = new Array<Rectangle>();
spawnRaindrop();
private void spawnRaindrop() {
Rectangle raindrop = new Rectangle();
raindrop.x = MathUtils.random(0, 800-64);
raindrop.y = 480;
raindrop.width = 64;
raindrop.height = 64;
raindrops.add(raindrop);
lastDropTime = TimeUtils.nanoTime();
}
@Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0.2f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
camera.update();
batch.setProjectionMatrix(camera.combined);
// begin a new batch and draw the bucket and
// all drops
batch.begin();
batch.draw(bucketImage, bucket.x, bucket.y);
for(Rectangle raindrop: raindrops) {
//batch.draw(dropImage, raindrop.x, raindrop.y);
int random = MathUtils.random(0, 4);
batch.draw(someDrops.get(random), raindrop.x, raindrop.y);
}
batch.end();
// check if we need to create a new raindrop
if(TimeUtils.nanoTime() - lastDropTime > 1000000000) spawnRaindrop();
Iterator<Rectangle> iter = raindrops.iterator();
while(iter.hasNext()) {
Rectangle raindrop = iter.next();
raindrop.y -= 200 * Gdx.graphics.getDeltaTime();
if(raindrop.y + 64 < 0) iter.remove();
if(raindrop.overlaps(bucket)) {
dropSound.play();
iter.remove();
}
}
}
在你的 render()
函数中,我相信你调用每一帧,你绘制所有现有的水滴,必要时创建一个新的水滴,并减少水滴的 y 位置。
出现问题是因为每次你想绘制现有的水滴时,你使用
int random = MathUtils.random(0, 4);
这可能会给你一个不同于之前绘制的图像,即当它处于更高的 y 位置时。因此,当它掉落(递减 y)时,每次渲染发生时图像都会不断变化,直到它落入桶中时最终被移除。
要解决此问题,请仅在第一次渲染新水滴时获取随机图像,稍后保存此图像并在水滴的整个生命周期内使用相同的图像绘制它。这个用于保存相应图像的新数组的大小将与雨滴数组保持相同,除非添加了新的雨滴,在这种情况下你会得到一个新的随机图像。
我将添加一些代码来说明这一点,但我从未在 Java 中编程或使用过 libgdx,因此您必须针对编译器错误修复此问题:)
一开始创建raindropTextures
private Array<Texture> raindropTextures; // need an ArrayList here?
在 create() 中添加这个 -
raindropTextures = new Array<Texture>();
然后在 render()
// if the sizes aren't equal, a new raindrop must have been added!!
if(raindrops.size() != raindropTextures.size()) {
int random = MathUtils.random(0, 4);
raindropTextures.add(someDrops.get(random));
}
for(Rectangle raindrop: raindrops, Texture texture: raindropTextures) {
// make sure the textures and raindrops correspond here; theoritically they should
batch.draw(texture, raindrop.x, raindrop.y);
}
最后 -
Iterator<Rectangle> iter = raindrops.iterator();
Iterator<Texture> iter2 = raindropTextures.iterator();
//later
iter.remove()
iter2.remove()
我跟随 this tutorial 在 LibGDX
中构建了一个简单的游戏。游戏的基本思路是:有水滴落下,玩家应该通过将水桶拖到水滴落下的地方来放置它们。
在原始版本中,所有水滴都是从一个水滴图像创建的,我尝试做的是用不同的水滴(水滴的不同图像)下一场雨,所以我创建了一个 List
- someDrops
不同的 Texture
和 render()
我更换了:
batch.draw(dropImage, raindrop.x, raindrop.y);
与:
int random = MathUtils.random(0, 3;
batch.draw(someDrops.get(random), raindrop.x, raindrop.y);
我得到的是不同水滴的雨,但它们并没有以不同的图像落下,而是落下并同时改变图像。
我该如何设置,以便每次掉落时都带有来自 someDrops
的随机图像,因为它以随机 x,y 位置掉落。
另外我想给每个滴添加不同的点,我应该把它保存在哪里以及选择什么类型的collection?
public class Drop implements ApplicationListener {
private Texture dropImage;
private Texture bucketImage;
private Sound dropSound;
private Music rainMusic;
private SpriteBatch batch;
private OrthographicCamera camera;
private Rectangle bucket;
private Array<Rectangle> raindrops;
private long lastDropTime;
private List<Texture> someDrops;
private Texture drop0;
private Texture drop1;
private Texture drop2;
private Texture drop3;
@Override
public void create() {
// load the images for the droplet and the bucket, 64x64 pixels each
dropImage = new Texture(Gdx.files.internal("droplet.png"));
drop0 = new Texture(Gdx.files.internal("droplet0.png"));
drop1 = new Texture(Gdx.files.internal("droplet1.png"));
drop2 = new Texture(Gdx.files.internal("droplet2.png"));
drop3 = new Texture(Gdx.files.internal("droplet3.png"));
bucketImage = new Texture(Gdx.files.internal("bucket.png"));
someDrops = new ArrayList<Texture>();
someDrops.add(new Texture(drop0));
someDrops.add(new Texture(drop1));
someDrops.add(new Texture(drop2));
someDrops.add(new Texture(drop3));
camera = new OrthographicCamera();
camera.setToOrtho(false, 800, 480);
batch = new SpriteBatch();
// create a Rectangle to logically represent the bucket
bucket = new Rectangle();
bucket.x = 800 / 2 - 64 / 2; // center the bucket horizontally
bucket.y = 20; // bottom left corner of the bucket is 20 pixels above the bottom screen edge
bucket.width = 64;
bucket.height = 64;
//raindrops array and spawn the first raindrop
raindrops = new Array<Rectangle>();
spawnRaindrop();
private void spawnRaindrop() {
Rectangle raindrop = new Rectangle();
raindrop.x = MathUtils.random(0, 800-64);
raindrop.y = 480;
raindrop.width = 64;
raindrop.height = 64;
raindrops.add(raindrop);
lastDropTime = TimeUtils.nanoTime();
}
@Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0.2f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
camera.update();
batch.setProjectionMatrix(camera.combined);
// begin a new batch and draw the bucket and
// all drops
batch.begin();
batch.draw(bucketImage, bucket.x, bucket.y);
for(Rectangle raindrop: raindrops) {
//batch.draw(dropImage, raindrop.x, raindrop.y);
int random = MathUtils.random(0, 4);
batch.draw(someDrops.get(random), raindrop.x, raindrop.y);
}
batch.end();
// check if we need to create a new raindrop
if(TimeUtils.nanoTime() - lastDropTime > 1000000000) spawnRaindrop();
Iterator<Rectangle> iter = raindrops.iterator();
while(iter.hasNext()) {
Rectangle raindrop = iter.next();
raindrop.y -= 200 * Gdx.graphics.getDeltaTime();
if(raindrop.y + 64 < 0) iter.remove();
if(raindrop.overlaps(bucket)) {
dropSound.play();
iter.remove();
}
}
}
在你的 render()
函数中,我相信你调用每一帧,你绘制所有现有的水滴,必要时创建一个新的水滴,并减少水滴的 y 位置。
出现问题是因为每次你想绘制现有的水滴时,你使用
int random = MathUtils.random(0, 4);
这可能会给你一个不同于之前绘制的图像,即当它处于更高的 y 位置时。因此,当它掉落(递减 y)时,每次渲染发生时图像都会不断变化,直到它落入桶中时最终被移除。
要解决此问题,请仅在第一次渲染新水滴时获取随机图像,稍后保存此图像并在水滴的整个生命周期内使用相同的图像绘制它。这个用于保存相应图像的新数组的大小将与雨滴数组保持相同,除非添加了新的雨滴,在这种情况下你会得到一个新的随机图像。
我将添加一些代码来说明这一点,但我从未在 Java 中编程或使用过 libgdx,因此您必须针对编译器错误修复此问题:)
一开始创建raindropTextures
private Array<Texture> raindropTextures; // need an ArrayList here?
在 create() 中添加这个 -
raindropTextures = new Array<Texture>();
然后在 render()
// if the sizes aren't equal, a new raindrop must have been added!!
if(raindrops.size() != raindropTextures.size()) {
int random = MathUtils.random(0, 4);
raindropTextures.add(someDrops.get(random));
}
for(Rectangle raindrop: raindrops, Texture texture: raindropTextures) {
// make sure the textures and raindrops correspond here; theoritically they should
batch.draw(texture, raindrop.x, raindrop.y);
}
最后 -
Iterator<Rectangle> iter = raindrops.iterator();
Iterator<Texture> iter2 = raindropTextures.iterator();
//later
iter.remove()
iter2.remove()