BoxTestViewController.mm

@implementation Game

@synthesize st;
- (id)initWithWidth:(float)width height:(float)height {
    if (self = [super initWithWidth:width height:height]) {
        // this is where the code of your game will start. 
        // in this sample, we add just a simple quad to see if it works.
		st = [[SPSprite alloc] init];
		st.rotation = SP_D2R(90);
		st.x = 320;
		st.stage.width = 480;
		st.stage.height = 320;
		[self addChild:st];
		[self createPhysicsWorld];		
		for (int i = 0; i != 100; i++) {
			SPQuad *sq = [[[SPQuad alloc] init] autorelease];
			sq.height = 10.0f;
			sq.width = 10.0f;
			sq.x = 480/2.0f;
			sq.y = 20.0f;
			sq.color = 0xff0000;
			[st addChild:sq];
			[self addPhysicalBodyForView:sq];
		}
		
		tickTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/60.0 target:self selector:@selector(tick:) userInfo:nil repeats:YES];
		//[self addEventListener:@selector(onEnterFrame:) atObject:self
		//					   forType:SP_EVENT_TYPE_ENTER_FRAME];
    }
	
    return self;
}

-(void)createPhysicsWorld {	
	
	b2Vec2 gravity;
	gravity.Set(0.0f, -9.81f);
	
	bool doSleep = true;
	
	world = new b2World(gravity, doSleep);	
	world->SetContinuousPhysics(true);
	
	b2BodyDef groundBodyDef;
	groundBodyDef.position.Set(0, 0); // bottom-left corner
	b2Body* groundBody = world->CreateBody(&groundBodyDef);
	
	b2EdgeShape groundBox;
	groundBox.Set(b2Vec2(0,0), b2Vec2(480.0f/PTM_RATIO,0));
	groundBody->CreateFixture(&groundBox, 0);

}

-(void)addPhysicalBodyForView:(SPDisplayObject*)physicalView

{
	
	b2BodyDef bodyDef;
	bodyDef.type = b2_dynamicBody;
	
	CGFloat centerX = physicalView.width/2.0 + physicalView.x;
	CGFloat centerY = physicalView.height/2.0 + physicalView.y;	
	
	CGPoint boxDimensions = CGPointMake(physicalView.width/PTM_RATIO/2.0,physicalView.height/PTM_RATIO/2.0);
	
	bodyDef.position.Set(centerX/PTM_RATIO, (480.0f -centerY)/PTM_RATIO);
	bodyDef.userData = physicalView;
	
	b2Body *body = world->CreateBody(&bodyDef);
	b2PolygonShape dynamicBox;	
	
	dynamicBox.SetAsBox(boxDimensions.x, boxDimensions.y);
	
	b2FixtureDef fixtureDef;
	fixtureDef.shape = &dynamicBox;
	fixtureDef.density = 3.0f;
	fixtureDef.friction = 0.3f;
	fixtureDef.restitution = 0.5f; // 0 is a lead ball, 1 is a super bouncy ball
	body->CreateFixture(&fixtureDef);
	body->SetType(b2_dynamicBody);
	
}

-(void) tick:(NSTimer *)timer

{
	
	//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
	
	//<a href="http://gafferongames.com/game-physics/fix-your-timestep/">http://gafferongames.com/game-physics/fix-your-timestep/</a>
	
	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(1.0f/60.0f, velocityIterations, positionIterations);
	
	//Iterate over the bodies in the physics world
	
	for (b2Body* b = world->GetBodyList(); b; b = b->GetNext())
		
	{
		
		if (b->GetUserData() != NULL)
			
		{
			
			SPDisplayObject *oneView = (SPDisplayObject *)b->GetUserData();
			
			// y Position subtracted because of flipped coordinate system
			
			CGPoint newCenter = CGPointMake(b->GetPosition().x * PTM_RATIO,
											
											self.height - b->GetPosition().y * PTM_RATIO);
			
			//oneView.center = newCenter;
			
			oneView.x = newCenter.x;
			
			oneView.y = newCenter.y;
			
			oneView.rotation = SP_D2R(- b->GetAngle());
			
			//          CGAffineTransform transform = CGAffineTransformMakeRotation(- b-&gt;GetAngle());
			
			//
			
			//          oneView.transform = transform;
			
		}
		
	}
	
}


-(void)dealloc {
	self.st = nil;
	[super dealloc];
}

@end