Not detecting collision between boundary frame and SKNode in SpriteKit - ios

Question

Here is my code in my GameScene. I have a simple sprite which falls down under gravity and bounces of the edges of the screen and a particle emitter. All I need is that I should be able to detect collisions between the SKNode and the physicsbody i.e. the frame.
Code Used
#import "GameScene.h"
#interface GameScene () <SKPhysicsContactDelegate>
#property (strong) UITouch *rightTouch;
#property (strong) UITouch *leftTouch;
#property (strong) SKNode *spinnyNode;
#property (assign, nonatomic) int count;
#end
#implementation GameScene {
}
static const uint32_t birdCategory = 1 << 0;
static const uint32_t worldCategory = 1 << 1;
- (void)didMoveToView:(SKView *)view {
self.backgroundColor = [UIColor colorWithRed:134/255.0 green:50/255.0 blue:148/255.0 alpha:1.0];
self.scaleMode = SKSceneScaleModeAspectFit;
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
self.physicsBody.categoryBitMask = worldCategory;
NSString *burstPath = [[NSBundle mainBundle] pathForResource:#"fire" ofType:#"sks"];
SKEmitterNode *burstNode = [NSKeyedUnarchiver unarchiveObjectWithFile:burstPath];
burstNode.position = CGPointMake(0, 0);
[self addChild:burstNode];
self.spinnyNode = [self childNodeWithName:#"ball"];
self.spinnyNode.physicsBody.angularVelocity = 10.0;
self.spinnyNode.hidden = YES;
self.spinnyNode.physicsBody.categoryBitMask = birdCategory;
self.spinnyNode.physicsBody.contactTestBitMask = 0x0;
// self.spinnyNode = ball;
SKNode *leftPaddle = [self childNodeWithName:#"bottom"];
leftPaddle.physicsBody.angularVelocity = 10.0;
}
- (void)touchDownAtPoint:(CGPoint)pos {
self.count = self.count+1;
CGPoint p = pos;
NSLog(#"/n %f %f %f %f", p.x, p.y, self.frame.size.height, self.frame.size.width);
if (self.count == 1)
{
self.spinnyNode.position = p;
self.spinnyNode.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:40];
self.spinnyNode.physicsBody.velocity=CGVectorMake(203, 10);
self.spinnyNode.hidden = NO;
self.spinnyNode.physicsBody.restitution = 0.8;
self.spinnyNode.physicsBody.linearDamping = 0.0;
self.spinnyNode.physicsBody.angularDamping = 0.3;
self.spinnyNode.physicsBody.friction = 0.1;
self.spinnyNode.physicsBody.angularVelocity = -100.0;
}
}
-(void)didBeginContact:(SKPhysicsContact *)contact
{
NSLog(#"contact detected");
NSString *nameA = contact.bodyA.node.name;
NSString *nameB = contact.bodyB.node.name;
SKPhysicsBody *firstBody;
SKPhysicsBody *secondBody;
if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask)
{
firstBody = contact.bodyA;
secondBody = contact.bodyB;
}
else
{
firstBody = contact.bodyB;
secondBody = contact.bodyA;
}
//Your first body is the block, secondbody is the player.
//Implement relevant code here.
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch *t in touches) {[self touchDownAtPoint:[t locationInNode:self]];
}
}
-(void)update:(CFTimeInterval)currentTime {
// Called before each frame is rendered
}
#end
This is my first time working with SpriteKit. So please be patient and help me out.

Answer 1

If you want to get the callback to didBeginContact when they touch you will need to set the contact bit mask like this:
self.spinnyNode.physicsBody.contactTestBitMask = worldCategory;
currently you are setting it to 0x0 which means not to report any contacts to the delegate. You also need to set the delegate on the scene:
self.physicsWorld.contactDelegate = self;
UPDATE
You also need to put the lines:
self.spinnyNode.physicsBody.contactTestBitMask = worldCategory;
self.spinnyNode.physicsBody.categoryBitMask = birdCategory;
into the touchDownAtPoint method after you create the physicsBody with:
self.spinnyNode.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:40];
otherwise they will be reset when you create the physicsBody.