Cocos2D v3 CCParallaxNode scrolling can't keep player in focus - objective-c

Question

I am very fresher to game development and I need to develop a game like NinjaJump.
I have created a CCParallaxNode to setup scrolling background and added CCPhysicsNode to setup Physics world. I have created player object as shown below.
// Add a sprite
_sprite = [CCSprite spriteWithImageNamed:#"Icon.png"];
_sprite.position = ccp(self.contentSize.width/2,100);
_sprite.physicsBody = [CCPhysicsBody bodyWithRect:(CGRect){CGPointZero, _sprite.contentSize} cornerRadius:0.0];
_sprite.physicsBody.friction = 0.0f;
_sprite.physicsBody.collisionGroup = #"player";
_sprite.physicsBody.collisionType = #"Player";
//_sprite.physicsBody.collisionMask = 0;
//[self addChild:_sprite];
[foreground addChild:_sprite];
foreground is just a node added into CCScene to easily manage player in-focus.
// code for physics world
_physicsWorld = [CCPhysicsNode node];
_physicsWorld.gravity = ccp(0,-100);
_physicsWorld.debugDraw = YES;
//_physicsWorld.collisionDelegate = self;
[self addChild:_physicsWorld];
_foreground = [CCNode node];
//[self addChild: _foreground];
[_physicsWorld addChild: _foreground];
To make player always visible we have implemented update method as
- (void) update:(CFTimeInterval)currentTime {
// Calculate player y offset
if (_player.position.y > 200.0f) {
//_midgroundNode.position = CGPointMake(0.0f, -((_player.position.y - 200.0f)/4));
_foreground.position = CGPointMake(0.0f, -(_player.position.y - 200.0f));
}
}
I can't understand but the player scrolls off screen anyhow. The code is written in Cocos2d v3.
I have also setup a demo project to show what I implemented: https://www.dropbox.com/s/5s55d00kk80wun4/HumptyJump-Example.zip?dl=0
Any kind of help is appreciated. Thanks in advance.

Answer 1

I could not run your sample code but one thing, I can tell you for sure that there is no need of Physics Engine here.
You just keep your player at a particular height and just move your object right to left.
Apply moving parallax background image and objects to give a feel that your character is moving upwards or downwards.
For reference you can see the games like Swing Drop, made on the same approach as above.

Answer 2

I have implemented 2 fixed views changing their positions while physics body goes down ;).
See the same in action
#interface TestScene () {
CCNode *_background;
CCNode *_foreground;
NSArray *grounds; // Keeps track of each of the 2 views
CCPhysicsNode *_physicsWorld;
}
#implementation TestScene
- (id)init {
self = [super init];
if (!self) return(nil);
// Enable touch handling on scene node
self.userInteractionEnabled = YES;
// Physics world setup
_physicsWorld = [CCPhysicsNode node];
_physicsWorld.gravity = ccp(0,-100);
_physicsWorld.debugDraw = YES;
_physicsWorld.collisionDelegate = self;
[self addChild:_physicsWorld];
// Foreground node in which platforms are there and moves downwards as player goes up
_foreground = [CCNode node];
// Adding background images
CCSprite *default1 = [CCSprite spriteWithImageNamed: #"Default.png"];
[default1 setAnchorPoint: ccp(0, 0)];
CCSprite *default2 = [CCSprite spriteWithImageNamed: #"Default.png"];
[default2 setAnchorPoint: ccp(0, 0)];
[default2 setPosition: ccp(0, default1.contentSize.height)];
[_foreground addChild: default1];
[_foreground addChild: default2];
// Adding into array
grounds = #[default1, default2];
// Adding into physics world
[_physicsWorld addChild: _foreground];
// creating player
_player = [CCSprite spriteWithImageNamed: #"Assets.atlas/Player.png"];
[_player setPosition: ccp(160.0f, 160.0f)];
_player.physicsBody = [CCPhysicsBody bodyWithRect:(CGRect){CGPointZero, _player.contentSize} cornerRadius:0]; // 1
_player.physicsBody.collisionGroup = #"playerGroup"; // 2
_player.physicsBody.collisionType = #"player";
//[_physicsWorld addChild:_player];
[_foreground addChild: _player];
// Multiple platforms can be added into body, they are static entities only
PlatformNode *platform = (PlatformNode *)[PlatformNode node];
[platform createPlatformAtPosition:CGPointMake(110, 50) ofType: PLATFORM_NORMAL];
[_foreground addChild: platform];
return self;
}
- (void) update:(CFTimeInterval)currentTime {
// Take background and physics world down, 163 was Y position of the player
_physicsWorld.position = ccp(_physicsWorld.position.x, 163 - _player.position.y);
// loop the ground
for (CCNode *ground in grounds) {
// Get the world position
CGPoint groundWorldPosition = [_physicsWorld convertToWorldSpace: ground.position];
// Get screen position
CGPoint groundScreenPosition = [self convertToNodeSpace: groundWorldPosition];
NSLog(#"Positioning ground ---> world: (%f, %f) & screen: (%f, %f)", groundWorldPosition.x, groundWorldPosition.y, groundScreenPosition.x, groundScreenPosition.y, nil);
if (groundScreenPosition.y <= -ground.contentSize.height) {
ground.position = ccp(ground.position.x, ground.position.y + 2 * ground.contentSize.height);
break;
}
}
}
-(void) touchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
// Take the player upside
[_player.physicsBody applyImpulse: ccp(0, 215)];
}
#end
This is how I coded the background :).