java - LibGDX + Box2D : Object Positioning

Question

我正在尝试使用 LibGDX 和 Box2D 编写一些突破性游戏。但有一点我不明白。必须有两 block 砖 block 只与边缘接触。但在模拟器上我只看到两 block 嵌套的砖 block 。

这是 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:乘以代码。

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) 的文档指出参数是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-