LibGDX + Box2D：对象定位

Question

我试图用LibGDX和Box2D编写一些突破性游戏。但有一点我不明白。必须有两块砖只与边缘接触。但是在模拟器上我只看到两个嵌套的砖块。

这里是createBox方法的代码：

private void createBox(float posX, float posY, float boxW, float boxH) {
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyDef.BodyType.StaticBody;
    bodyDef.position.set(posX, posY);

    Body body = world.createBody(bodyDef);

    PolygonShape shape = new PolygonShape();
    shape.setAsBox(boxW, boxH);

    FixtureDef fixtureDef = new FixtureDef();
    fixtureDef.shape = shape;
    fixtureDef.density = 1f;

    Fixture fixture = body.createFixture(fixtureDef);

    shape.dispose();
}

编辑：那个相乘的代码。

createBox(CONS_HOLDER.BRICKS_LEFT_MARGIN + (i * CONS_HOLDER.BRICK_WIDTH * 2 ),
                        CONS_HOLDER.BRICK_TOP_SCREEN_MARGIN + (j * CONS_HOLDER.BRICK_HEIGHT * 2 ) + CONS_HOLDER.BRICKS_TOP_MARGIN,
                        CONS_HOLDER.BRICK_WIDTH / 2,
                        CONS_HOLDER.BRICK_HEIGHT / 2);

Answer 1

setAsBox(float, float)的文档指出参数为half-width和half-height。您应该将盒子的尺寸分成两半，以获得正确的尺寸。

private void createBox(float posX, float posY, float boxW, float boxH) {
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyDef.BodyType.StaticBody;
    bodyDef.position.set(posX, posY);

    Body body = world.createBody(bodyDef);

    PolygonShape shape = new PolygonShape();
    shape.setAsBox(boxW / 2.f, boxH / 2.f);

    FixtureDef fixtureDef = new FixtureDef();
    fixtureDef.shape = shape;
    fixtureDef.density = 1f;

    Fixture fixture = body.createFixture(fixtureDef);

    shape.dispose();
}

文档：https://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/physics/box2d/PolygonShape.html#setAsBox-float-float-