Why didn't the SpriteKit PhysicContactDelegate work? - ios

Question

I am implementing a simple game for iOS.
I am trying to use Sprite Kit for development.
However, I don't know why the detection of contact did not happen.
Can anyone help me fix this problem?
Here is the code that I cannot get the expected results with:
#import "TesttingScene.h"
#interface TesttingScene()<SKPhysicsContactDelegate>
#property (nonatomic) SKTexture *ballText;
#end
#implementation TesttingScene
-(id)initWithSize:(CGSize)size{
self = [super initWithSize:size];
if (self) {
self.physicsWorld.gravity = CGVectorMake(0, 0);
self.physicsWorld.contactDelegate = self;
SKSpriteNode *hitBoxx = [[SKSpriteNode alloc] initWithColor:[UIColor clearColor] size:CGSizeMake(self.frame.size.width/3, self.frame.size.height/3)];
hitBoxx.anchorPoint = CGPointMake(0, 0);
hitBoxx.position = CGPointMake(self.size.width/2, self.size.height/2);
hitBoxx.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:hitBoxx.frame.size];
hitBoxx.physicsBody.dynamic = YES;
hitBoxx.physicsBody.categoryBitMask = abPlayerHitBoxCategory;
hitBoxx.physicsBody.contactTestBitMask = adsViewCategory;
hitBoxx.physicsBody.collisionBitMask = 0;
hitBoxx.physicsBody.usesPreciseCollisionDetection = YES;
self.ballText = [SKTexture textureWithImageNamed:#"FinalBossSkill1SS"];
}
return self;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
SKTexture *t1 = [SKTexture textureWithRect:CGRectMake(0, 0, 0.5, 1) inTexture:self.ballText];
SKTexture *t2 = [SKTexture textureWithRect:CGRectMake(0.5, 0, 0.5, 1) inTexture:self.ballText];
SKSpriteNode *ball = [SKSpriteNode spriteNodeWithTexture:t1];
ball.position = CGPointMake(self.size.width, self.size.height/2);
ball.name = #"FinalBossSkill1Ball";
ball.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:ball.size];
ball.physicsBody.dynamic = YES;
ball.physicsBody.categoryBitMask = adsViewCategory;
ball.physicsBody.contactTestBitMask = abPlayerAttackBoxCategory | abPlayerHitBoxCategory;
ball.physicsBody.collisionBitMask = 0;
ball.physicsBody.usesPreciseCollisionDetection = YES;
SKAction *moveTo = [SKAction moveToX:-ball.size.width duration:1.0];
SKAction *flash = [SKAction animateWithTextures:#[t1,t2] timePerFrame:0.1];
SKAction *moveBall = [SKAction repeatAction:flash count:moveTo.duration/flash.duration];
SKAction *group = [SKAction group:#[moveTo, moveBall]];
[self addChild:ball];
[ball runAction:[SKAction sequence:#[group, [SKAction removeFromParent]]]];
}
-(void)didBeginContact:(SKPhysicsContact *)contact{
NSLog(#"Contact"); // <~~~~this msg doesn't appear in console when the ball pass the hitboxx.
}

Answer 1

You will need to define bit mask category, right below your imports.
static const uint32_t abPlayerHitBoxCategory = 0x1 << 0;
static const uint32_t adsViewCategory = 0x1 << 1;