在游戏中,我试图编码,我必须拥有两具尸体。一个StaticBody和一个DynamicBody。我想将DynamicBody置于StaticBody之上。不知怎的,我得到的是:
视口低,左角是否可能在0,0?为什么DynamicBody不能在StaticBody之上?
Gamescreen.java
package com.joelbrun.jetskirider.screens;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
import com.badlogic.gdx.physics.box2d.BodyDef;
import com.badlogic.gdx.physics.box2d.Box2DDebugRenderer;
import com.badlogic.gdx.physics.box2d.Fixture;
import com.badlogic.gdx.physics.box2d.FixtureDef;
import com.badlogic.gdx.physics.box2d.PolygonShape;
import com.badlogic.gdx.physics.box2d.World;
import com.badlogic.gdx.scenes.scene2d.ui.Label;
import com.badlogic.gdx.utils.Scaling;
import com.badlogic.gdx.utils.viewport.ScalingViewport;
import com.badlogic.gdx.utils.viewport.Viewport;
public class Gamescreen implements Screen {
private static final float TIMESTEP = 1 / 60;
private static final int VELOCITY_ITERATIONS = 8;
private static final int POSITION_ITERATIONS = 3;
public static final int GAMESCREEN_WIDTH = 1920;
public static final int GAMESCREEN_HEIGHT = 720;
public static final int OBSTACLE_TYPES = 5;
private static final int WATER_HEIGHT = 200;
private static final float JETSKI_BOX_X = 200;
private static final float JETSKI_BOX_Y = 100;
private World world;
private Box2DDebugRenderer debugRenderer;
public Texture jetski, wave;
public Sprite background;
public SpriteBatch batch;
public OrthographicCamera camera;
public Label score;
Viewport viewport;
@Override
public void show() {
world = new World(new Vector2(0, -9.81f), true);
debugRenderer = new Box2DDebugRenderer();
Texture[] texture = new Texture[OBSTACLE_TYPES];
//Textures
for (int i=0; i<OBSTACLE_TYPES; i++){
texture[i] = new Texture(Gdx.files.internal("game/obstacles/obstacle" + Integer.toString(i+1)+".png"));
}
background = new Sprite(new Texture("game/background.png"));
jetski = new Texture("game/jetski.png");
wave = new Texture("game/water1.png");
batch = new SpriteBatch();
//Camera & Viewport
camera = new OrthographicCamera();
viewport = new ScalingViewport(Scaling.fillY, GAMESCREEN_WIDTH, GAMESCREEN_HEIGHT, camera);
viewport.apply();
camera.position.set(GAMESCREEN_WIDTH / 2, GAMESCREEN_HEIGHT / 2, 0);
//body definition Water
BodyDef bodyDef = new BodyDef();
bodyDef.type = BodyDef.BodyType.StaticBody;
bodyDef.position.set(0, 0);
Body body = world.createBody(bodyDef);
//shape
PolygonShape box = new PolygonShape();
box.setAsBox(2560, WATER_HEIGHT);
//fixture definition
FixtureDef fixtureDef = new FixtureDef();
fixtureDef.shape = box;
fixtureDef.density = 1000;
fixtureDef.friction = .25f;
fixtureDef.restitution = .1f;
Fixture fixture = body.createFixture(fixtureDef);
box.dispose();
//Jetski
bodyDef.type = BodyDef.BodyType.DynamicBody;
bodyDef.position.set(1280,WATER_HEIGHT + 100);
Body jetskiObject = world.createBody(bodyDef);
PolygonShape jetskiBox = new PolygonShape();
jetskiBox.setAsBox(JETSKI_BOX_X, JETSKI_BOX_Y);
fixtureDef.shape = jetskiBox;
fixtureDef.density = 100;
fixtureDef.friction = 0;
Fixture jetskiFixture = body.createFixture(fixtureDef);
jetskiBox.dispose();
}
@Override
public void render(float delta) {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
debugRenderer.render(world, camera.combined);
batch.setProjectionMatrix(camera.combined);
batch.begin();
batch.end();
camera.update();
world.step(TIMESTEP, VELOCITY_ITERATIONS, POSITION_ITERATIONS);
}
@Override
public void resize(int width, int height) {
int SCREEN_WIDTH = width;
int SCREEN_HEIGHT = height;
viewport.setWorldSize(GAMESCREEN_WIDTH, GAMESCREEN_HEIGHT);
viewport.update(SCREEN_WIDTH, SCREEN_HEIGHT,true);
camera.update();
}
@Override
public void pause() {
}
@Override
public void resume() {
}
@Override
public void hide() {
dispose();
}
@Override
public void dispose() {
batch.dispose();
background.getTexture().dispose();
jetski.dispose();
wave.dispose();
world.dispose();
debugRenderer.dispose();
}
}
答案 0 :(得分:1)
对于Box2D,原点是视口的左下角。
您可以在设置BodyDef时设置身体的位置:
bodyDef.position.set(x, y);
不要忘记,在Box2D中,你身体的位置是身体的中心。因此,当您将PolygonShape设置为如下框时:
polygonShape.setAsBox(width, height);
您的实际包装箱宽度为宽* 2,实际包装箱高度为高度* 2
答案 1 :(得分:0)
您使用的是Box2D错误。你应该将Box2D缩小到一个小世界,因为如果没有这样做,物理交互将是1px = 1m而1920 x 720太大(这将反映为你的身体移动得太慢,因为它们太大了)。 / p>
检查您的代码:
PolygonShape box = new PolygonShape();
box.setAsBox(2560, WATER_HEIGHT); // <- your water object dimensions
和
PolygonShape jetskiBox = new PolygonShape();dimensions
jetskiBox.setAsBox(JETSKI_BOX_X, JETSKI_BOX_Y); // <- your jetsky object
然后,检查setAsBox
方法:
public void setAsBox(float hx, float hy)
参数:
hx - 半宽。
hy - 半高。
(增加重点)
因此,对于你的水,你正在创建一个5120 x 400
的静态体,而对于你的jetski 400 x 200
,这个值太高了。
我会尝试使用official wiki中显示的示例,但请检查this等网站并阅读manual以了解Box2D的工作原理。我可以提取这个:
特别是,Box2D已经过调整,可以在0.1到10米之间移动物体。所以这意味着汤罐和公共汽车之间的物体应该很好。静态物体可能长达50米,没有太多麻烦。
作为2D物理引擎,很有可能使用像素作为单位。不幸的是,这将导致模拟不良和可能奇怪的行为。 Box2D将长度为200像素的物体视为45层建筑的大小。
另一件事,我不知道这是否会影响到某种程度,但我总是首先world.step(...)
然后debugRenderer.render(...)
结束,在你的代码中,你有这个倒置(也许这就是你的jetski没有被移动的原因。)
答案 2 :(得分:0)
您应该尝试使用chainshape而不是多边形来表示staticbody。这样动态的身体将保留在其中而不是“传送”出去。动态主体在创建时不得与静态主体相交。希望它能奏效!