如何在LibGDX中检测对象之间的冲突

Question

这是我第一次发布关于堆栈溢出的帖子，所以如果我违反了发布等方面的任何规则，我会提前道歉。我一直在开发一款小行星式射击游戏，我不知道如何在岩石和激光之间进行碰撞检测
源代码可以在这里找到。我不得不对LevelScreen的更新方法进行一些更改，因为原始代码依赖于使用BlueJ IDE。我在这篇文章中找到了一个修复方法，并使宇宙飞船和岩石之间的碰撞发生了作用。

LevelScreen类

package com.mygdx.game;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
import java.util.ArrayList;
public class LevelScreen extends BaseScreen {
private Spaceship spaceship;
private boolean gameOver;
private boolean rocksNeedRemoved;
private Rock toRemove;
private ArrayList<Rock> rocks;
private ArrayList<Laser> lasers;
public void initialize() {
gameOver = false;
toRemove = null;
rocksNeedRemoved = false;
BaseActor space = new BaseActor(0, 0, mainStage);
space.loadTexture("space.png");
space.setSize(800, 600);
BaseActor.setWorldBounds(space);
spaceship = new Spaceship(400, 300, mainStage);
rocks = new ArrayList<Rock>();
lasers = new ArrayList<Laser>();
rocks.add(new Rock(600, 500, mainStage));
rocks.add(new Rock(600, 300, mainStage));
rocks.add(new Rock(600, 100, mainStage));
rocks.add(new Rock(400, 100, mainStage));
rocks.add(new Rock(200, 100, mainStage));
rocks.add(new Rock(200, 300, mainStage));
rocks.add(new Rock(200, 500, mainStage));
rocks.add(new Rock(400, 500, mainStage));
lasers.add(new Laser(400, 500, mainStage));

}
public void update(float dt) {

//Code from book(Throws class not found error)
/*
for (BaseActor rockActor : BaseActor.getList(mainStage, 
"Rock")) {
if (rockActor.overlaps(spaceship)) {
if (spaceship.shieldPower <= 0) {
Explosion boom = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(spaceship);
spaceship.remove();
spaceship.setPosition(-1000, -1000);
BaseActor messageLose = new BaseActor(0, 0, 
uiStage);
messageLose.loadTexture("message- 
lose.png");
messageLose.centerAtPosition(400, 300);
messageLose.setOpacity(0);
messageLose.addAction(Actions.fadeIn(1));
gameOver = true;
}
else {
spaceship.shieldPower -= 34;
Explosion boom = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(rockActor);
rockActor.remove();
}
}
for (BaseActor laserActor : 
BaseActor.getList(mainStage, "Laser")) {
if (laserActor.overlaps(rockActor)) {
}
Explosion boom = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(rockActor);
laserActor.remove();
rockActor.remove();
}
}
if (!gameOver && BaseActor.count(mainStage, "Rock") == 
0) {
BaseActor messageWin = new BaseActor(0, 0, 
uiStage);
messageWin.loadTexture("message-win.png");
messageWin.centerAtPosition(400, 300);
messageWin.setOpacity(0);
messageWin.addAction(Actions.fadeIn(1));
gameOver = true;
}
}
*/


// loop I used to get collision working between rocks 
and spaceship
for (Rock each : rocks)
if (spaceship.overlaps(each) && !each.crashed && 
spaceship.shieldPower <= 0) {
Explosion boom = new Explosion(0, 0, 
mainStage);
Explosion boom2 = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(spaceship);
boom2.centerAtActor(each);
spaceship.remove();
spaceship.setPosition(-1000, -1000);
each.crashed = true;
each.clearActions();
each.addAction(Actions.fadeOut(1));
each.addAction(Actions.after(Actions.removeActor()));
rocksNeedRemoved = true;
toRemove = each;
} else if (spaceship.overlaps(each) && 
!each.crashed) {
Explosion boom = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(each);
spaceship.shieldPower -= 34;
each.crashed = true;
each.clearActions();
each.addAction(Actions.fadeOut(1));
each.addAction(Actions.after(Actions.removeActor()));
rocksNeedRemoved = true;
toRemove = each;
}
//check for collision between rocks and lasers (Not 
working correctly)
for (int i = rocks.size() - 1; i >= 0; i--) {
Rock rock = rocks.get(i);
for (int j = lasers.size() - 1; j >= 0; j--) {
Laser laser = lasers.get(j);
if(rock.getBounds().overlaps(laser.getBounds())) {
Explosion boom = new Explosion(0, 0, 
mainStage);
boom.centerAtActor(rock);
rock.crashed = true;
rock.clearActions();
rock.addAction(Actions.fadeOut(1));
rock.addAction(Actions.after(Actions.removeActor()));
rocksNeedRemoved = true;
toRemove = rock;
}
}
}
}



//override default InputProcessor method
public boolean keyDown(int keycode) {
if (keycode == Keys.X)
spaceship.warp();
if (keycode == Keys.SPACE)
spaceship.shoot();
return false;
}
}

太空船级。

package com.mygdx.game;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.math.MathUtils;
public class Spaceship extends BaseActor {
private Thrusters thrusters;
private Shield shield;
public int shieldPower;
public Spaceship(float x, float y, Stage s) {
super(x, y, s);
loadTexture("spaceship.png");
setBoundaryPolygon(8);
setAcceleration(100);
setMaxSpeed(100);
setDeceleration(10);
thrusters = new Thrusters(0, 0, s);
addActor(thrusters);
thrusters.setPosition(-thrusters.getWidth(), 
getHeight() / 2 - thrusters.getHeight() / 2);
shield = new Shield(0, 0, s);
addActor(shield);
shield.centerAtPosition(getWidth() / 2, getHeight() / 
2);
shieldPower = 100;
}
public void act(float dt) {
super.act(dt);
float degreesPerSecond = 160; //rotation speed
if (Gdx.input.isKeyPressed(Keys.LEFT))
rotateBy(degreesPerSecond * dt);
if (Gdx.input.isKeyPressed(Keys.RIGHT))
rotateBy(-degreesPerSecond * dt);
if (Gdx.input.isKeyPressed(Keys.UP)) {
accelerateAtAngle(getRotation());
thrusters.setVisible(true);
}
else {
thrusters.setVisible(false);
}
shield.setOpacity(shieldPower / 100f);
if (shieldPower <= 0)
shield.setVisible(false);
applyPhysics(dt);
wrapAroundWorld();
}
public void warp() {
if(getStage() == null)
return;
Warp warp1 = new Warp(0, 0, this.getStage());
warp1.centerAtActor(this);
setPosition(MathUtils.random(800), 
MathUtils.random(600));
Warp warp2 = new Warp(0, 0, this.getStage());
warp2.centerAtActor(this);
}
public void shoot() {
if (getStage() == null)
return;
Laser laser = new Laser(0, 0, this.getStage());
laser.centerAtActor(this);
laser.setRotation(this.getRotation());
laser.setMotionAngle(this.getRotation());

}
}

激光类。

package com.mygdx.game;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.Action;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
public class Laser extends BaseActor {
Rectangle bounds;
public Laser(float x, float y, Stage s) {
super(x, y, s);
bounds = new Rectangle((int)getX(), (int)getY(), 
(int)getWidth(), (int)getHeight());



loadTexture("laser.png");
addAction(Actions.delay(1));
addAction(Actions.after(Actions.fadeOut(0.5f)));
addAction(Actions.after(Actions.removeActor()));
setSpeed(400);
setMaxSpeed(400);
setDeceleration(0);
}
public void act(float dt) {
super.act(dt);
applyPhysics(dt);
wrapAroundWorld();
}
public Rectangle getBounds() {
return bounds;
}
private void setXY(float pX,float pY) {
setPosition(pX, pY);
bounds.setX((int)pX);
bounds.setY((int)pY);
}
}

岩石级

package com.mygdx.game;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.Action;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
import com.badlogic.gdx.math.MathUtils;
import com.mygdx.game.BaseActor;
public class Rock extends BaseActor {

public boolean crashed;
Rectangle bounds;
public Rock(float x, float y, Stage s) {
super(x, y, s);
bounds = new Rectangle((int)getX(), (int)getY(), 
(int)getWidth(), (int)getHeight());

loadTexture("rock.png");
float random = MathUtils.random(30);
addAction(Actions.forever(Actions.rotateBy(30 + random, 
1)));
setSpeed(50 + random);
setMaxSpeed(50 + random);
setDeceleration(0);
setMotionAngle(MathUtils.random(360));
crashed = false;
}
public void act(float dt) {

super.act(dt);
applyPhysics(dt);
wrapAroundWorld();
}

public boolean isCrashed() {
return crashed;
}
public void crashed() {
crashed = true;
clearActions();
addAction(Actions.fadeOut(1));
addAction(Actions.after(Actions.removeActor()));
}
public Rectangle getBounds() {
return bounds;
}
private void setXY(float pX,float pY) {
setPosition(pX, pY);
bounds.setX((int)pX);
bounds.setY((int)pY);
}
}

BaseActor类的边界和重叠方法

public void setBoundaryPolygon(int numSides) {
float w = getWidth();
float h = getHeight();
float[] vertices = new float[2 * numSides];
for(int i = 0; i < numSides; i ++) {
float angle = i * 6.28f / numSides;
//x coordinate
vertices[2 * i] = w / 2 * MathUtils.cos(angle) + w / 2;
//y coordinate
vertices[2 * i + 1] = h / 2 * MathUtils.sin(angle) + h / 2;
}
boundaryPolygon = new Polygon(vertices);
}
public Polygon getBoundaryPolygon() {
boundaryPolygon.setPosition(getX(), getY());
boundaryPolygon.setOrigin(getOriginX(), getOriginY());
boundaryPolygon.setRotation(getRotation());
boundaryPolygon.setScale(getScaleX(), getScaleY());
return boundaryPolygon;
}
public boolean overlaps(BaseActor other) {
Polygon poly1 = this.getBoundaryPolygon();
Polygon poly2 = other.getBoundaryPolygon();
//initial text to improve performance
if(!poly1.getBoundingRectangle().overlaps(poly2.getBoundingRectangle()))
return false;
return Intersector.overlapConvexPolygons(poly1, poly2);
}

所以我想真正的问题是，我该如何检查岩石ArrayList和玩家发射的激光之间的碰撞？在这一点上，我只想完成比赛，即使它没有使用最佳实践。我尝试使用这里描述的方法，没有收到任何错误，但激光和岩石之间也没有碰撞。即使我手动将激光器添加到激光器阵列列表中。我发现的最后一篇帖子让我相信我需要像getAllLasers((这样的东西，但我不100%确定如何做到这一点。学习Box2D或Quadtree会更容易吗？

我意识到这是一个复杂的问题，我想提前感谢你花时间阅读它。我很乐意为你提供更多需要的信息。

Answer 1

这两个实体都已经有了Rectangle边界，这就是您所需要的。您可以使用Rectangle.overlaps()

for(Laser laser: lasers){
for(Rock rock: rocks){
if(laser.getBounds().overlaps(rock.getBounds())){
//collided! 
}
}
}

请确保您正在获取更新的矩形/边界。在Rock和LasergetBounds()方法中添加此额外行：

public Rectangle getBounds() {
bounds.set(getX(),getY(),getWidth(),getHeight());
return bounds;
}

如果你的演员缩放或轮换，你应该相应地更新bounds

Answer 2

我认为问题可能是更新你的演员边界，我找不到你在哪里更新它。我写了类似的游戏，我在每个更新步骤上都更改了演员的Bound，在某些行中效果很好。。。

public void update() {
...
// changing bounds
bounds = new Rectangle(position.x,position.y,
actorWidth,
actorHeight);
}

或者，如果你使用其他方法，检查你的边界是否随时间变化