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나는 다음과 같은 방법의 도움으로 만든 Box2D 샘플 앱에 약 10 개의 시체가 있습니다. 하지만 내 Update 메서드에서 나는 몸의 b2FixtureDef를 얻고 싶습니다. 왜냐하면 나는 각 body마다 다른 filter.groupIndex가 필요하기 때문입니다. 나는 모든 b2Body를 통해 반복되지만 다음과 같이 Update 메소드를 사용하지만 실제로 b2Body에서 b2FixtureDef를 가져 오는 방법을 찾지 못합니까?b2body Box2d의 b2Fixture 받기?
-(void) addNewSprite:(NSString *)spriteName AtPosition:(CGPoint)p isDynamic:(BOOL)dynamic
{
//CCNode *parent = [self getChildByTag:kTagParentNode];
PhysicsSprite *sprite = [PhysicsSprite spriteWithFile:spriteName];
[self addChild:sprite];
sprite.position = ccp(p.x, p.y);
sprite.tag = check;
// Define the dynamic body.
//Set up a 1m squared box in the physics world
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(sprite.position.x/PTM_RATIO, sprite.position.y/PTM_RATIO);
bodyDef.userData = sprite;
b2Body *body = world->CreateBody(&bodyDef);
// Define another box shape for our dynamic body.
b2PolygonShape dynamicBox;
dynamicBox.SetAsBox((sprite.contentSize.width/PTM_RATIO/2)*(sprite.scaleX),
(sprite.contentSize.height/PTM_RATIO/2)*(sprite.scaleY));//These are mid points for our 1m box
// Define the dynamic body fixture.
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 1.0f;
fixtureDef.friction = 1.0f;
fixtureDef.userData = sprite;
switch (check)
{
case 1:
fixtureDef.filter.categoryBits = 0x0002;
fixtureDef.filter.maskBits = 0x0004;
break;
case 2:
fixtureDef.filter.categoryBits = 0x0004;
fixtureDef.filter.maskBits = 0x0002;
break;
}
body->CreateFixture(&fixtureDef);
[sprite setPhysicsBody:body];
check++;
}
-(void) update: (ccTime) dt
{
//It is recommended that a fixed time step is used with Box2D for stability
//of the simulation, however, we are using a variable time step here.
//You need to make an informed choice, the following URL is useful
//http://gafferongames.com/game-physics/fix-your-timestep/
int32 velocityIterations = 8;
int32 positionIterations = 1;
// Instruct the world to perform a single step of simulation. It is
// generally best to keep the time step and iterations fixed.
world->Step(dt, velocityIterations, positionIterations);
for(b2Body *b = world->GetBodyList(); b; b=b->GetNext()) {
if (b->GetUserData() != NULL)
{
//b2Fixture fixtureDef = *b->GetFixtureList();
//b2Filter filter = fixtureDef.GetFilterData();
// how to get b2FixtureDef from b
}
}