是否可以动态更改Box2d b2Body的形状?我想这样做以达到以下目的。
一世)。以一定比例增加圆形的半径
ii)。更改 Sprite 的边框的尺寸以匹配变化的动画帧。
最佳答案
float radius;
radius = 1;
创建主体:
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(300/PTM_RATIO, 150/PTM_RATIO);
body = world->CreateBody(&bodyDef);
b2CircleShape circleShape;
circleShape.m_radius = radius;
b2FixtureDef fixtureDef;
fixtureDef.shape = &circleShape;
fixtureDef.density = 1;
fixtureDef.friction = 0.3f;
body ->CreateFixture(&fixtureDef);
在您的触摸方式中:
- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if (body != NULL) {
b2Fixture *fixtureA = body->GetFixtureList();
body->DestroyFixture(fixtureA);
b2CircleShape circleShape;
circleShape.m_radius = radius + 0.3;
b2FixtureDef fixtureDef;
fixtureDef.shape = &circleShape;
fixtureDef.density = 1;
fixtureDef.friction = 0.3f;
body->CreateFixture(&fixtureDef);
radius = radius + 0.3;
}
每次触摸都会使主体变大0.3。