所以我看到了一个非常奇怪的问题。
使用展示中的 PlayN peas 演示，我组合了一个简单的应用程序 - 我有一个动态实体掉到一个静态实体上，我无法弄清楚它为什么不弹跳。
在做了一些打印输出后，我发现碰撞正在发生 - y 位置保持不变，但 y 速度只是不断增加
这是我在动态实体中的更新代码
@Override
public void paint(float alpha) {
float x = (body.getPosition().x * alpha) + (previousX * (1f - alpha));
float y = (body.getPosition().y * alpha) + (previousY * (1f - alpha));
float w = (body.getAngle() * alpha) + (previousRotationAngle * (1f - alpha));
if (body.m_type == BodyType.DYNAMIC) {
System.out.println("body x = " + body.getPosition().x + ", y = " + body.getPosition().y);
System.out.println("velocity x = " + body.m_linearVelocity.x + ", y = "
+ body.m_linearVelocity.y);
}
imageLayer.setTranslation(x, y);
imageLayer.setRotation(w);
}
@Override
public void update(float delta) {
previousX = body.getPosition().x;
previousY = body.getPosition().y;
previousRotationAngle = body.getAngle();
}
这是打印输出 - 你可以看到速度不断上升，但 y 位置在 8.46 处保持不变
[java] body x = 17.024979, y = 0.5199691
[java] velocity x = 0.0, y = 1.2983631
[java] body x = 17.024979, y = 0.79601336
[java] velocity x = 0.0, y = 2.562787
[java] body x = 17.024979, y = 0.8908453
[java] velocity x = 0.0, y = 2.8736944
[java] body x = 17.024979, y = 0.99586946
[java] velocity x = 0.0, y = 3.18255
[java] body x = 17.024979, y = 0.99586946
[java] velocity x = 0.0, y = 3.18255
[java] body x = 17.024979, y = 1.1110185
[java] velocity x = 0.0, y = 3.489367
[java] body x = 17.024979, y = 1.2362258
[java] velocity x = 0.0, y = 3.794159
[java] body x = 17.024979, y = 1.2362258
[java] velocity x = 0.0, y = 3.794159
[java] body x = 17.024979, y = 1.3714248
[java] velocity x = 0.0, y = 4.096939
[java] body x = 17.024979, y = 1.5165496
[java] velocity x = 0.0, y = 4.3977213
[java] body x = 17.024979, y = 1.6715348
[java] velocity x = 0.0, y = 4.696518
[java] body x = 17.024979, y = 1.6715348
[java] velocity x = 0.0, y = 4.696518
[java] body x = 17.024979, y = 1.8363149
[java] velocity x = 0.0, y = 4.993343
[java] body x = 17.024979, y = 2.0108259
[java] velocity x = 0.0, y = 5.2882085
[java] body x = 17.024979, y = 2.195003
[java] velocity x = 0.0, y = 5.581128
[java] body x = 17.024979, y = 2.388783
[java] velocity x = 0.0, y = 5.8721147
[java] body x = 17.024979, y = 2.388783
[java] velocity x = 0.0, y = 5.8721147
[java] body x = 17.024979, y = 2.5921018
[java] velocity x = 0.0, y = 6.1611805
[java] body x = 17.024979, y = 2.5921018
[java] velocity x = 0.0, y = 6.1611805
[java] body x = 17.024979, y = 2.804897
[java] velocity x = 0.0, y = 6.4483385
[java] body x = 17.024979, y = 3.0271058
[java] velocity x = 0.0, y = 6.733601
[java] body x = 17.024979, y = 3.0271058
[java] velocity x = 0.0, y = 6.733601
[java] body x = 17.024979, y = 3.2586663
[java] velocity x = 0.0, y = 7.016981
[java] body x = 17.024979, y = 3.4995165
[java] velocity x = 0.0, y = 7.298491
[java] body x = 17.024979, y = 3.4995165
[java] velocity x = 0.0, y = 7.298491
[java] body x = 17.024979, y = 3.7495952
[java] velocity x = 0.0, y = 7.5781426
[java] body x = 17.024979, y = 4.0088415
[java] velocity x = 0.0, y = 7.8559484
[java] body x = 17.024979, y = 4.277195
[java] velocity x = 0.0, y = 8.131921
[java] body x = 17.024979, y = 4.5545955
[java] velocity x = 0.0, y = 8.406072
[java] body x = 17.024979, y = 4.5545955
[java] velocity x = 0.0, y = 8.406072
[java] body x = 17.024979, y = 4.840983
[java] velocity x = 0.0, y = 8.678413
[java] body x = 17.024979, y = 4.840983
[java] velocity x = 0.0, y = 8.678413
[java] body x = 17.024979, y = 5.1362987
[java] velocity x = 0.0, y = 8.948957
[java] body x = 17.024979, y = 5.440483
[java] velocity x = 0.0, y = 9.217716
[java] body x = 17.024979, y = 5.440483
[java] velocity x = 0.0, y = 9.217716
[java] body x = 17.024979, y = 5.753478
[java] velocity x = 0.0, y = 9.484701
[java] body x = 17.024979, y = 6.0752254
[java] velocity x = 0.0, y = 9.749924
[java] body x = 17.024979, y = 6.0752254
[java] velocity x = 0.0, y = 9.749924
[java] body x = 17.024979, y = 6.4056673
[java] velocity x = 0.0, y = 10.013396
[java] body x = 17.024979, y = 6.7447467
[java] velocity x = 0.0, y = 10.275129
[java] body x = 17.024979, y = 7.0924063
[java] velocity x = 0.0, y = 10.535135
[java] body x = 17.024979, y = 7.0924063
[java] velocity x = 0.0, y = 10.535135
[java] body x = 17.024979, y = 7.4485893
[java] velocity x = 0.0, y = 10.793425
[java] body x = 17.024979, y = 7.8132396
[java] velocity x = 0.0, y = 11.05001
[java] body x = 17.024979, y = 7.8132396
[java] velocity x = 0.0, y = 11.05001
[java] body x = 17.024979, y = 8.186301
[java] velocity x = 0.0, y = 11.304901
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 11.55811
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 11.55811
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 11.8096485
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.059526
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.059526
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.307755
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.554346
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.554346
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 12.799309
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.042655
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.042655
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.284395
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.52454
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.7631
[java] body x = 17.024979, y = 8.465522
[java] velocity x = 0.0, y = 13.7631
[java] body x = 17.024979, y = 8.465522
这是一张图片 - 花是我测试的动态实体 - 它显然停在砖块上，但我不明白为什么速度只是继续上升
我不知道还有什么其他代码在这里会有所帮助——我的设置与展示中的豌豆演示几乎相同——以至于我从展示演示中删除了一些东西并且无法在那。
我在这里 100% 不知所措，因为这是一个物理问题，它有点阻碍了我的所有进步。豌豆演示完全有效
任何帮助将不胜感激 - 我已经尝试了 4 个小时，现在尝试了我能想到的所有事情，但没有任何效果
编辑添加了主要的世界级（这绝对是丑陋的 - 请不要评判我）
public class LevelWorld implements ContactListener, Paintable, Updatable, Destroyable {
private static final float PHYSICS_UNITS_PER_PIXEL = PhysicsScale.PHYSICS_UNITS_PER_PIXEL
.getScaleFactor();
private final playn.core.GroupLayer worldLayer;
private final Context context;
private final World world;
private final float frameRate;
private final List<playn.core.GroupLayer> groupLayers;
private final List<Entity> entities;
private final Stack<Contact> contacts;
private final Map<Body, PhysicsEntity> bodies;
public LevelWorld(Level level, Context context) {
worldLayer = graphics().createGroupLayer();
worldLayer.setScale(1.F / PHYSICS_UNITS_PER_PIXEL);
this.context = context;
final Integer fps = (Integer) context.get(FPS);
this.frameRate = 1.F / fps.floatValue();
final Vec2 gravity = new Vec2(0.F, 10.0F);
world = new World(gravity, true);
world.setWarmStarting(true);
world.setAutoClearForces(true);
groupLayers = new ArrayList<playn.core.GroupLayer>();
entities = new ArrayList<Entity>();
contacts = new Stack<Contact>();
bodies = new HashMap<Body, PhysicsEntity>();
for (final GroupLayer groupLayer : level) {
final playn.core.GroupLayer gl = graphics().createGroupLayer();
gl.setDepth(groupLayer.getDepth());
gl.setScale(groupLayer.getScaleFactor());
groupLayers.add(gl);
for (final Entity entity : groupLayer.getEntities()) {
if (entity instanceof PhysicsEntity) {
final FixtureDef fixtureDef = new FixtureDef();
final BodyDef bodyDef = new BodyDef();
if (PhysicsType.DYNAMIC.equals(entity.getEntityMetadata().getPhysicsType())) {
bodyDef.type = BodyType.DYNAMIC;
} else if (PhysicsType.STATIC.equals(entity.getEntityMetadata().getPhysicsType())) {
bodyDef.type = BodyType.STATIC;
}
final Body body = world.createBody(bodyDef);
fixtureDef.shape = entity.getEntityMetadata().getShape();
fixtureDef.density = 0.4f;
fixtureDef.friction = 0.1f;
fixtureDef.restitution = 0.5f;
body.setLinearDamping(0.2f);
body.createFixture(fixtureDef);
body.setTransform(new Vec2(entity.getPosition().x, entity.getPosition().y),
entity.getRotationAngle());
((PhysicsEntity) entity).setBody(body);
bodies.put(body, (PhysicsEntity) entity);
}
gl.add(entity.getImageLayer());
}
entities.addAll(groupLayer.getEntities());
worldLayer.add(gl);
}
graphics().rootLayer().add(worldLayer);
world.setContactListener(this); // kinda sketchy
}
@Override
public void beginContact(Contact contact) {
System.out.println("BEGIN CONTACT HAPPENED");
contacts.push(contact);
}
@Override
public void endContact(Contact contact) {
}
@Override
public void preSolve(Contact contact, Manifold oldManifold) {
}
@Override
public void postSolve(Contact contact, ContactImpulse impulse) {
}
@Override
public void destroy() {
worldLayer.destroy();
}
@Override
public void update(float delta) {
// worldLayer.setOrigin(worldLayer.originX() + (delta / 250.F),
// worldLayer.originY());
for (final Entity entity : entities) {
entity.update(delta);
}
world.step(0.033F, 10, 10);
// processContacts();
}
@Override
public void paint(float alpha) {
for (final Entity entity : entities) {
entity.paint(alpha);
}
}
private void processContacts() {
while (!contacts.isEmpty()) {
final Contact contact = contacts.pop();
final PhysicsEntity a = bodies.get(contact.m_fixtureA.m_body);
final PhysicsEntity b = bodies.get(contact.m_fixtureB.m_body);
if (a != null && b != null) {
if (a instanceof PhysicsEntity.IsContactListener) {
((PhysicsEntity.IsContactListener) a).contact(b);
}
if (b instanceof PhysicsEntity.IsContactListener) {
((PhysicsEntity.IsContactListener) b).contact(a);
}
}
}
}
}