大家好，
我正在使用 libgdx 开发 Android 游戏。我完全陷入了检测两个物体之间的碰撞的部分。 我有一个通过下面的函数创建的播放器
public Body createPlayer(String file_path, String fixture_name) {
// 0. Create a loader for the file saved from the editor.
BodyEditorLoader loader = new BodyEditorLoader(Gdx.files.internal(file_path));
// 1. Create a BodyDef, as usual.
BodyDef bd = new BodyDef();
bd.type = BodyDef.BodyType.DynamicBody;
// 2. Create a FixtureDef, as usual.
FixtureDef fd = new FixtureDef();
fd.density = 1;
fd.friction = 0.5f;
fd.restitution = 0.3f;
// 3. Create a Body, as usual.
body= world.createBody(bd);
//body.setBullet(true);
// 4. Create the body fixture automatically by using the loader.
loader.attachFixture(body, fixture_name, fd, 1);
body.setUserData(this);
return body;
}
以及我使用与玩家相同的功能创建的敌人，其中我仅更改文件路径和夹具名称。 file_path 指向我使用 box2d 编辑器创建的 .json 文件(站点: http://www.aurelienribon.com/blog/projects/physics-body-editor/ )。 创建 body 后，我用两个类似的功能绘制玩家和敌人(我只发布一个):
private void drawPlayer(){
player_sprite = new Sprite(player_TR);
player_sprite.setSize(player.getWidth(), player.getHeight());
player_sprite.setPosition(player.getX(), player.getY());
player_sprite.setOrigin(0, 0);
player_sprite.draw(sb);
}
如果我开始游戏，所有内容都会绘制在它应该在的地方。显然，如果玩家接触敌人，什么也不会发生。 所以我开始尝试搜索如何使两个物体碰撞，但我不太明白如何使用 ContactListener 和 beginContact。 beginContact 想要输入一个联系人，但是什么是联系人？ 我在网上找到了这段代码，它似乎可以解决我的问题，但我不知道如何使用它:
worldbox.setContactListener(new ContactListener() {
@Override
public void beginContact(Contact contact) {
if(contact.getFixtureA().getBody().getUserData()== "body1" &&
contact.getFixtureB().getBody().getUserData()== "body2")
Colliding = true;
System.out.println("Contact detected");
}
你能帮助我(如果可以通过一些代码)解决我的问题吗？ 提前致谢， 弗朗西斯科
更新我的问题 这是我的渲染方法:
public class GameRenderer{
private GameWorld myWorld;
private ShapeRenderer shapeRenderer;
private SpriteBatch sb;
private Camera camera;
private Constants constant;
private Rectangle viewport;
//dichiaro le variabili per caricare gli asset
private Player player;
private ScrollHandler scroller;
private Bordo frontBordoSX_1, backBordoSX_1, frontBordoSX_2, backBordoSX_2;
private Bordo frontBordoDX_1, backBordoDX_1, frontBordoDX_2, backBordoDX_2;
/*
private Ostacolo ob1_sx, ob2_sx, ob3_sx;
private Ostacolo ob4_dx, ob5_dx, ob6_dx;
*/
private TextureRegion player_TR;
private TextureRegion bordoSX_1, bordoSX_2;
private TextureRegion bordoDX_1, bordoDX_2;
private TextureRegion obstacleSX, obstacleSX_flip;
private TextureRegion obstacleDX, obstacleDX_flip;
private TextureRegion enemyS;
private TextureRegion blackBar;
//box2dpart
private World worldbox;
private Sprite fbDx_1,fbDx_2,fbSx_1,fbSx_2;
private Sprite player_sprite;
private Body player_body, bordo_destro;
private MyContactListener contactListener;
public GameRenderer(GameWorld world) {
myWorld = world;
constant = new Constants();
camera = new OrthographicCamera(constant.getWidth(), constant.getHeight());
shapeRenderer = new ShapeRenderer();
shapeRenderer.setProjectionMatrix(camera.combined);
sb = new SpriteBatch();
sb.setProjectionMatrix(camera.combined);
contactListener = new MyContactListener();
worldbox= new World(new Vector2(0,-10),true);
worldbox.setContactListener(contactListener);
//initialize objects and assets
initGameObjects();
initAssets();
}
private void initGameObjects(){
player = myWorld.getPlayer();
scroller = myWorld.getScroller();
frontBordoSX_1 = scroller.getFrontBordoSX_1();
backBordoSX_1 = scroller.getBackBordoSX_1();
frontBordoSX_2 = scroller.getFrontBordoSX_2();
backBordoSX_2 = scroller.getBackBordoSX_2();
frontBordoDX_1 = scroller.getFrontBordoDX_1();
backBordoDX_1 = scroller.getBackBordoDX_1();
frontBordoDX_2 = scroller.getFrontBordoDX_2();
backBordoDX_2 = scroller.getBackBordoDX_2();
/* other objects
ob1_sx = scroller.getOb1_sx();
ob2_sx = scroller.getOb2_sx();
ob3_sx = scroller.getOb3_sx();
ob4_dx = scroller.getOb4_dx();
ob5_dx = scroller.getOb5_dx();
ob6_dx = scroller.getOb6_dx();
*/
}
private void initAssets(){
player_TR = AssetLoader.player;
bordoSX_1 = AssetLoader.bordoSX;
bordoSX_2 = AssetLoader.bordoSX;
bordoDX_1 = AssetLoader.bordoDX;
bordoDX_2 = AssetLoader.bordoDX;
obstacleDX = AssetLoader.obstacleDX;
obstacleSX = AssetLoader.obstacleSX;
obstacleDX_flip = AssetLoader.obstacleDX_flip;
obstacleSX_flip = AssetLoader.obstacleSX_flip;
enemyS = AssetLoader.enemyS;
blackBar = AssetLoader.blackBar;
//box2d part
}
private void drawMargin(){
//bordo SX
/*
sb.draw(bordoSX_1, frontBordoSX_2.getX(), frontBordoSX_2.getY(), frontBordoSX_2.getWidth(),
frontBordoSX_2.getHeight());
sb.draw(bordoSX_2, frontBordoSX_1.getX(), frontBordoSX_1.getY(), frontBordoSX_1.getWidth(),
frontBordoSX_1.getHeight());
*/
fbSx_1 = new Sprite(bordoSX_1);
fbSx_1.setSize(frontBordoSX_1.getWidth(),frontBordoSX_1.getHeight());
fbSx_1.setPosition(frontBordoSX_1.getX(), frontBordoSX_1.getY());
fbSx_1.setOrigin(0, 0);
fbSx_1.draw(sb);
fbSx_2 = new Sprite(bordoSX_2);
fbSx_2.setSize(frontBordoSX_2.getWidth(),frontBordoSX_2.getHeight());
fbSx_2.setPosition(frontBordoSX_2.getX(), frontBordoSX_2.getY());
fbSx_2.setOrigin(0, 0);
fbSx_2.draw(sb);
fbDx_1 = new Sprite(bordoDX_1);
fbDx_1.setSize(frontBordoDX_1.getWidth(),frontBordoDX_1.getHeight());
fbDx_1.setPosition(frontBordoDX_1.getX(), frontBordoDX_1.getY());
fbDx_1.setOrigin(0, 0);
fbDx_1.draw(sb);
fbDx_2 = new Sprite(bordoDX_2);
fbDx_2.setSize(frontBordoDX_2.getWidth(),frontBordoDX_2.getHeight());
fbDx_2.setPosition(frontBordoDX_2.getX(), frontBordoDX_2.getY());
fbDx_2.setOrigin(0, 0);
fbDx_2.draw(sb);
sb.draw(blackBar,-constant.getWidth()/2,-constant.getHeight()/2,
(float) (0.573913)*(constant.getWidth()/6),constant.getHeight());
sb.draw(blackBar,(float)(constant.getWidth()/2-(0.573913)*(constant.getWidth()/6)),-constant.getHeight()/2,
(float)(0.573913)*(constant.getWidth()/6),constant.getHeight());
}
private void drawPlayer(){
player_sprite = new Sprite(player_TR);
player_sprite.setSize(player.getWidth(), player.getHeight());
player_sprite.setPosition(player.getX(), player.getY());
player_sprite.setOrigin(0, 0);
player_sprite.draw(sb);
}
/*
private void drawOstacoli(){
sb.draw(obstacleSX_flip,ob1_sx.getX(),ob1_sx.getY(),ob1_sx.getWidth(),ob1_sx.getHeight());
sb.draw(obstacleSX,ob2_sx.getX(),ob2_sx.getY(),ob2_sx.getWidth(),ob2_sx.getHeight());
sb.draw(obstacleSX_flip,ob3_sx.getX(),ob3_sx.getY(),ob3_sx.getWidth(),ob3_sx.getHeight());
sb.draw(obstacleDX,ob4_dx.getX()+constant.getWidth()/2-ob4_dx.getWidth(),ob4_dx.getY(),ob4_dx.getWidth(),ob4_dx.getHeight());
sb.draw(obstacleDX_flip,ob5_dx.getX()+constant.getWidth()/2-ob5_dx.getWidth(),ob5_dx.getY(),ob5_dx.getWidth(),ob5_dx.getHeight());
sb.draw(obstacleDX,ob6_dx.getX()+constant.getWidth()/2-ob6_dx.getWidth(),ob6_dx.getY(),ob6_dx.getWidth(),ob6_dx.getHeight());
}
*/
public void render(float runTime) {
Box2D.init();
int width = constant.getWidth();
int height = constant.getHeight();
float ratio = constant.getRatio();
//viewport
float aspectRatio = (float) width / (float) height;
float scale = 1f;
Vector2 crop = new Vector2(0f, 0f);
if(aspectRatio > ratio)
{
scale = (float)height/(float)height;
crop.x = (width - width * scale) / 2f;
} else if (aspectRatio < ratio) {
scale = (float)width/(float)width;
crop.y = (height - height*scale)/2f;
}
else
{
scale = (float) width / (float) width;
}
float w = (float) width * scale;
float h = (float) height * scale;
viewport = new Rectangle(crop.x, crop.y, w, h);
// update camera
camera.update();
// clear previous frame
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
shapeRenderer.begin(ShapeRenderer.ShapeType.Filled);
// Draw Background color
shapeRenderer.setColor(255 / 255.0f, 255 / 255.0f, 250 / 255.0f, 1);
shapeRenderer.rect(-constant.getWidth() / 2, -constant.getHeight() / 2, constant.getWidth(),
constant.getHeight());
// End ShapeRenderer
shapeRenderer.end();
// set viewport
Gdx.gl.glViewport((int) viewport.x, (int) viewport.y,
(int) viewport.width, (int) viewport.height);
// Begin SpriteBatch
sb.begin();
// The player needs transparency, so we enable that again.
sb.enableBlending();
// Draw player at its coordinates.
drawPlayer();
//draw right and left side
drawMargin();
// End SpriteBatch
sb.end();
worldbox.step(1 / 60f, 6, 2);
}
}
如果我启动程序，我的视野是我的玩家位于中间和边缘，一个在左边，一个在右边。 (不幸的是，我无法发布我的观点的图像，因为我没有足够的代表)。
一切都很好。我用加速度计移动我的播放器，它工作正常，没有任何问题。唯一的问题是，如果我将玩家移动到边缘附近，两个实体就会重叠而不是碰撞，我不明白为什么。 我还修复了该行:
loader.attachFixture(body, fixture_name, fd, 1);
至 loader.attachFixture(主体，fixture_name，fd，player_width)；
但没有任何改变。
最佳答案
首先，来自here ，对象 Contact 管理两个形状之间的接触，并且来自 here ，当两个灯具开始接触时，监听器 ContactListener 将被调用。
因此，为了使您的代码正常工作，您应该使用以下方法为您的主体设置一个自定义对象:setUserData(Object userData)。通常此方法用于将 Sprite 或 Actor 与物理 body 链接，但出于示例目的，您可以只发送一个简单的 ID(如字符串)。
所以在这部分:
// 3. Create a Body, as usual.
body= world.createBody(bd);
//body.setBullet(true);
您可以向对象添加一个标识符，如下所示:
body.setUserData("player");
识别您的对象，然后，当监听器被触发时，您可以检索此值:
@Override
public void beginContact(Contact contact) {
String userDataA = contact.getFixtureA().getBody().getUserData().toString();
String userDataB = contact.getFixtureB().getBody().getUserData().toString();
if(userDataA.equals("player") && userDataB.equals("otherEntity")){
colliding = true;
//do stuffs when collision has started
} else if(userDataB.equals("player") && userDataA.equals("otherEntity")){
colliding = true;
//do stuffs when collision has started
}
System.out.println("Contact detected");
}
之后，您就可以对这次碰撞做任何您想做的事情。
希望您觉得这很有用!
关于java - 使用物理体编辑器进行 Libgdx Box2d 碰撞检测，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31195980/